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| 1 | Quantitative characterization of reservoir space in the Lower Silurian Longmaxi Shale,southern Sichuan,China显示文摘Based on the drilling data of the Upper Ordovician Wufeng Shale and the Lower Silurian Longmaxi Shale in southern Sichuan Basin,the construction of matrix pores and the development condition of fractures in a marine organic-rich shale are quantitatively evaluated through the establishment of the reservoir petrophysical models and porosity mathematical models.Our studies show that there are four major characteristics of the Longmaxi Shale confirmed by the quantitative characterization:(1)the pore volume of per unit mass is the highest in organic matter,followed in clay minerals,finally in brittle minerals;(2)the porosity of the effective shale reservoir is moderate and equal to that of the Barnett Shale,and the main parts of the shale reservoir spaces are interlayer pores of clay minerals and organic pores;(3)the porosity of the organic-rich shale is closely related to TOC and brittle mineral/clay mineral ratio,and mainly increases with TOC and clay mineral content;(4)fractures are developed in this black shale,and are mainly micro ones and medium-large ones.In the Longmaxi Shale,the fracture density increases from top to bottom,reflecting the characteristics with high brittle mineral content,high Young’s modulus,low Poisson's ratio and high brittleness at its bottom. | WANG YuMan DONG DaZhong YANG Hua HE Ling WANG ShiQian HUANG JinLiang PU BoLing WANG ShuFang | 2014 | Science China Earth Sciences2014，57，2： | 36 |
| 2 | Progress in China's Unconventional Oil & Gas Exploration and Development and Theoretical Technologies显示文摘The new century has witnessed a strategic breakthrough in unconventional oil & gas.Hydrocarbon accumulated in micro-/nano-scale pore throat shale systems has become an important domain that could replace current oil & gas resources.Unconventional oil & gas plays an increasingly important role in our energy demand.Tight gas,CBM,heavy oil and asphaltic sand have served as a key domain of exploration & development,with tight oil becoming a 'bright spot' domain and shale gas becoming a 'hotspot' domain.China has made great breakthroughs in unconventional oil & gas resources,such as tight gas,shale gas,tight oil and CBM,and great progress in oil shale,gas hydrate,heavy oil and oil sand.China has an estimated(223-263)×10~8t of unconventional oil resources and(890-1260)×l0^(12)m^3 of gas resources.China has made a breakthrough for progress in unconventional oil & gas study.New progress achieved in fine-grained sedimentary studies related to continental open lacustrine basin large-scale shallow-water delta sand bodies,lacustrine basin central sandy clastic flow sediments and marine-continental fine-grained sediments provide a theoretical basis for the formation and distribution of basin central reservoir bodies.Great breakthroughs have been made in unconventional reservoir geology in respect of research methodology & technology,multi-scale data merging and physical simulation of formation conditions.Overall characterization of unconventional reservoirs via multi-method and multi-scale becomes increasingly popular and facilitates the rapid development of unconventional oil & gas geological theory,method and technology.The formation of innovative,continuous hydrocarbon accumulation theory,the establishment of the framework of the unconventional oil & gas geological theory system,and the determination of the implications,geological feature,formation mechanism,distribution rule and core technology of unconventional oil& gas geological study lays a theoretical foundation for extensive unconventional oil & gas exploration and development.Theories and technologies of unconventional oil & gas exploration and development developed rapidly,including some key evaluation techniques such as 'sweet spot zone' integrated evaluation and a six-property evaluation technique that uses hydrocarbon source,lithology,physical property,brittleness,hydrocarbon potential and stress anisotropy,and some key development &engineering technologies including micro-seismic monitoring,horizontal drilling & completion and 'factory-like' operation pattern, 'man-made reservoir' development,which have facilitated the innovative development of unconventional oil & gas.These breakthroughs define a new understanding in four aspects:①theoretical innovation;② key technologies;③ complete market mechanism and national policy support;and ④ well-developed ground infrastructure,which are significant for prolonging the life cycle of petroleum industry,accelerating the upgrade and development of theories and technologies and altering the global traditional energy structure. | ZOU Caineng YANG Zhi ZHU Rukai ZHANG Guosheng HOU Lianhua WU Songtao TAO Shizhen YUAN Xuanjun DONG Dazhong WANG Yuman WANG Lan HUANG Jinliang WANG Shufang | 2015 | Acta Geologica Sinica(English Edition)2015，89，3： | 27 |
| 3 | Effects of land use, climate, topography and soil properties on regional soil organic carbon and total nitrogen in the Upstream Watershed of Miyun Reservoir, North China显示文摘Soil organic carbon (SOC) and total nitrogen (TN) contents as well as their relationships with site characteristics are of profound importance in assessing current regional, continental and global soil C and N stocks and potentials for C sequestration and N conservation to offset anthropogenic emissions of greenhouse gases. This study investigated contents and distribution of SOC and TN under different land uses, and the quantitative relationships between SOC or TN and site characteristics in the Upstream Watershed of Miyun Reservoir, North China. Overall, both SOC and TN contents in natural secondary forests and grasslands were much higher than in plantations and croplands. Land use alone explained 37.2% and 38.4% of variations in SOC and TN contents, respectively. The optimal models for SOC and TN, achieved by multiple regression analysis combined with principal component analysis (PCA) to remove the multicollinearity among site variables, showed that elevation, slope, soil clay and water contents were the most significant factors controlling SOC and TN contents, jointly explaining 70.3% of SOC and 67.1% of TN contents variability. Only does additional 1.9% and 3% increase in the interpretations of SOC and TN contents variability respectively when land use was added to regressions, probably due to environment factors determine land use. Therefore, environmental variables were more important for SOC and TN variability than land use in the study area, and should be taken into consideration in properly evaluating effects of future land use changes on SOC and TN on a regional scale. | Shufang Wang Xiaoke Wang Zhiyun Ouyang | 2012 | Journal of Environmental Sciences2012，24，3： | 16 |
| 4 | Litter decomposition and C and N dynamics as affected by N additions in a semi-arid temperate steppe, Inner Mongolia of China显示文摘Litter decomposition is the fundamental process in nutrient cycling and soil carbon(C) sequestration in terrestrial ecosystems. The global-wide increase in nitrogen(N) inputs is expected to alter litter decomposition and,ultimately, affect ecosystem C storage and nutrient status. Temperate grassland ecosystems in China are usually N-deficient and particularly sensitive to the changes in exogenous N additions. In this paper, we conducted a 1,200-day in situ experiment in a typical semi-arid temperate steppe in Inner Mongolia to investigate the litter decomposition as well as the dynamics of litter C and N concentrations under three N addition levels(low N with 50 kg N/(hm2?a)(LN), medium N with 100 kg N/(hm2?a)(MN), and high N with 200 kg N/(hm2?a)(HN)) and three N addition forms(ammonium-N-based with 100 kg N/(hm2?a) as ammonium sulfate(AS), nitrate-N-based with 100 kg N/(hm2?a) as sodium nitrate(SN), and mixed-N-based with 100 kg N/(hm2?a) as calcium ammonium nitrate(CAN)) compared to control with no N addition(CK). The results indicated that the litter mass remaining in all N treatments exhibited a similar decomposition pattern: fast decomposition within the initial 120 days, followed by a relatively slow decomposition in the remaining observation period(120–1,200 days). The decomposition pattern in each treatment was fitted well in two split-phase models, namely, a single exponential decay model in phase I(<398 days) and a linear decay function in phase II(≥398 days). The three N addition levels exerted insignificant effects on litter decomposition in the early stages(<398 days, phase I; P>0.05). However, MN and HN treatments inhibited litter mass loss after 398 and 746 days, respectively(P<0.05). AS and SN treatments exerted similar effects on litter mass remaining during the entire decomposition period(P>0.05). The effects of these two N addition forms differed greatly from those of CAN after 746 and 1,053 days, respectively(P<0.05). During the decomposition period, N concentrations in the decomposing litter increased whereas C concentrations decreased, which also led to an exponential decrease in litter C:N ratios in all treatments. No significant effects were induced by N addition levels and forms on litter C and N concentrations(P>0.05). Our results indicated that exogenous N additions could exhibit neutral or inhibitory effects on litter decomposition, and the inhibitory effects of N additions on litter decomposition in the final decay stages are not caused by the changes in the chemical qualities of the litter, such as endogenous N and C concentrations. These results will provide an important data basis for the simulation and prediction of C cycle processes in future N-deposition scenarios. | Qin PENG YuChun QI YunShe DONG YaTing HE ShengSheng XIAO XinChao LIU LiangJie SUN JunQiang JIA ShuFang GUO CongCong CAO | 2014 | Journal of Arid Land2014，6，4： | 16 |
| 5 | Extracting mineral alteration information using WorldView-3 data显示文摘The multispectral commercial satellite-WorldView-3(WV-3) has the highest spatial, spectral and radiation resolutions among the satellites currently and can generate good data in the shortwave infrared(SWIR). The study area is located in the Pobei area of Xinjiang Uygur Autonomous Region, which is rich in mineral resources. The spectral analyses of some typical altered hydroxy-bearing, iron-bearing, and carbonate-bearing minerals could establish several Principal Component Analysis(PCA) models and mineral indices, using the visible and near infrared(VNIR) and the shortwave infrared(SWIR) subsystems of WV-3 data. In addition, the Spectral Angle Method and the spectrum index tool of ENVI software were used to extract the relevant alteration information. The WV-3 data is well suited for identifying hydroxy-bearing alteration with rich SWIR bands which distinguish Al-OH-bearing from MgOH-bearing alteration. Hence, this study provides a basis for the prediction of mineral resources in the Pobei area and sets the foundation for WV-3 data to be used as an important tool in extracting alteration information and prospecting practices. | Yaqin Sun Shufang Tian Baogang Di | 2017 | Geoscience Frontiers2017，8，5： | 13 |
| 6 | Aging Precipitation Behavior and Mechanical Properties of Inconel 617 Superalloy显示文摘Aging precipitation behavior and mechanical properties of Inconel 617 superalloy aged at 760 ℃ for up to 10000 h were investigated. The results showed that the precipitates of the aged alloy are M23C6 and M6C carbides and γ phase. The carbide particles precipitated both at the grain boundaries and within grains, and the γ phase particles were situated at intragranular sites in the process of aging. The carbide particles were discontinuously dispersed at grain boundaries after aging for 3000 h, while after aged for 5000 h the carbide particles are merged. The precipitates inside grains remained stable even after aging for 10000 h. The hardness was increased for the alloy aged for 300 h up to 3000 h, which was resulted primarily from the precipitation of carbides as discrete particles both at the grain boundaries and inside grains. Small quantity γ precipitates were formed inside grains, to some extent, which contributed to an enhanced hardness. However, a decrease of the hardness was observed after aging for 5000 h. A significant drop in toughness of the alloy aged for 300 h was attributed to the reduction of the bonding interface strength when carbides precipitated at grain boundaries. Thereafter, the toughness decreased slowly with the prolonged aging time. The high temperature tensile properties of the aged alloy are rather stable even aged for 300-3000 h. | Yan GUO Bohan WANG Shufang HOU | 2013 | Acta Metallurgica Sinica(English Letters)2013，26，3： | 12 |
| 7 | Effects of alfalfa coverage on runoff,erosion and hydraulic characteristics of overland flow on loess slope plots显示文摘An evaluation of the interactions between vegetation,overland and soil erosion can provide valuable insight for the conservation of soil and water.An experiment was conducted to study water infiltration,runoff generation process,rate of sediment erosion,and hydrodynamic characteristics of overland flow from a sloping hillside with different draw-off discharges from alfalfa and control plots with 20°slope.The effect of alfalfa on runoff and sediment transport reduction was quantitatively analyzed.Alfalfa was discussed for its ability to reduce the overland flow scouring force or change the runoff movement.Compared to the bare-soil plots,alfalfa plots generated a 1.77 times increase in infiltration rate.Furthermore,the down-slope water infiltration rate for the bare soil plots was higher than in the up-slope,while the opposite was found in the alfalfa plots.In addition,alfalfa had a significant effect on runoff and sediment yield.In comparison to the control,the runoff coefficient and sediment transportation rate decreased by 28.3%and 78.4%in the grass slope,respectively.The runoff generated from the alfalfa and bare-soil plots had similar trends with an initial increase and subsequent leveling to a steady-state rate.The transport of sediment reduced with time as a consequence of the depletion of loose surface materials.The maximum sediment concentration was recorded within the first few minutes of each event.The alfalfa plots had subcritical flow while the baresoil plots had supercritical flow,which indicate that the capability of the alfalfa slope for resisting soil erosion and sediment movement was greater than for bare soil plots.Moreover,the flow resistance coefficient and roughness coefficient for the alfalfa plots were both higher than for the bare-soil plots,which indicate that overland flow in alfalfa plots had retarded and was blocked,and the flow energy along the runoff path had gradually dissipated.Finally,the ability to erode and transport sediment had decreased. | Shufang WU Pute WU Hao FENG G.P.Merkley | 2011 | Frontiers of Environmental Science & Engineering2011，5，1： | 11 |
| 8 | The response of annual runoff to the height change of the summertime 0℃ level over Xinjiang显示文摘According to climate features and river runoff conditions,Xinjiang could be divided into three research areas:The Altay-Tacheng region,the Tianshan Mountain region and the northern slope of the Kunlun Mountains.Utilizing daily observations from 12 sounding stations and the annual runoff dataset from 34 hydrographical stations in Xinjiang for the period 1960-2002,the variance of the summertime 0℃ level height and the changing trends of river runoff are analyzed both qualitatively and quantitatively,through trend contrast of curves processed by a 5-point smoothing procedure and linear correlation.The variance of the summertime 0℃ level height in Xinjiang correlates well with that of the annual river runoff,especially since the early 1990s,but it differs from region to region,with both the average height of the 0℃ level and runoff quantity significantly increasing over time in the Altay-Tacheng and Tianshan Mountain regions but decreasing on the northern slope of the Kunlun Mountains.The correlation holds for the whole of Xinjiang as well as the three individual regions,with a 0.01 significance level.This indicates that in recent years,climate change in Xinjiang has affected not only the surface layer but also the upper levels of the atmosphere,and this raising and lowering of the summertime 0℃ level has a direct impact on the warming and wetting process in Xinjiang and the amount of river runoff.Warming due to climate change increases the height of the 0℃ level,but also speeds up,ice-snow melting in mountain regions,which in turn increases river runoff,leading to a season of plentiful water instead of the more normal low flow period. | ZHANG Guangxing SUN Shufang MA Yufen ZHAO Ling | 2010 | Journal of Geographical Sciences2010，20，6： | 10 |
| 9 | Methods for Shale Gas Play Assessment: A Comparison between Silurian Longmaxi Shale and Mississippian Barnett Shale显示文摘Based on field work, organic geochemical analyses and experimental testing, a six-property assessment method for shale gas is proposed. These six properties include organic matter properies, lithofacies, petrophysical properties, gas content, brittleness and local stress field. Due to the features of continuous distribution over a large area and low resource abundance in shale plays, a sweet spot should have these following properties:(a) TOC>2%;(b) brittle minerals content(>40%) and clay minerals(<30%);(c) Ro(>1.1%);(d) porosity(>2%) and permeability(>0.000 1 m D), and(e) effective thickness(30–50 m). Applying these criteria in the Sichuan Basin, the Silurian Longmaxi shale consists of four prospecting sweet spots, including blocks of Changning, Weiyuan, Zhaotong and Fushun-Yongchuan. Although these four blocks have some similarities, different features were usually observed. After comprehensive analyses using the six-property assessment method, the Fushun-Yongan Block ranks the most favorable sweet spot, followed by the Weiyuan Block. For the other two blocks, the Changning Block is better than the Zhaotong Block. By comparing with the Mississippian Barnett shale, characteristics that are crucial for a high-yielding in the Sichuan Basin include a high content of organic matter(TOC>2.5%), a moderate thermal maturity(Ro=0.4%–2%), a high content of brittle minerals(quartz: 30%–45%), a high gas content(>2.5 m3?t-1), and types I and II1 kerogen. | Songqi Pan Caineng Zou Zhi Yang Dazhong Dong Yuman Wang Shufang Wang Songtao Wu Jinliang Huang Qun Liu Dule Wang Ziyuan Wang | 2015 | Journal of Earth Science2015，26，2： | 10 |
| 10 | Recent progress in luminescent materials based on lanthanide complexes intercalated synthetic clays显示文摘Interest in lanthanide complexes in the synthetic clays remains growing considerably during the last decades because of the attractive features of the individuals. Synthetic clays like Laponite~? and Aminoclay show great potentials in building up the luminescent hybrid materials due to their obvious advantages such as high purity, high dispersibility(or solubility) in water to yield translucent gels and clear aqueous solution. Additionally, their strong adsorption capacity for non-polar molecules or complexes is favorable to the formation of water-soluble and aqueous processable luminescent materials. This feature article summarizes the latest developments in the design and preparation of highly luminescent organicinorganic hybrid materials with excellent aqueous process ability based on lanthanide complexes intercalated synthetic clays. | Yige Wang Peng Li Shufang Wang Huanrong Li | 2019 | Journal of Rare Earths2019，37，5： | 10 |
| 11 | Shale Gas Formation and Occurrence in China: An Overview of the Current Status and Future Potential显示文摘Shale gas is one of the most promising unconventional resources both in China and abroad. It is known as a form of self-contained source-reservoir system with large and continuous dimensions. Through years of considerable exploration efforts, China has identified three large shale gas fields in the Fuling, Changning and Weiyuan areas of the Sichuan Basin, and has announced more than 540 billion m^3 of proven shale gas reserves in marine shale systems. The geological theories for shale gas development have progressed rapidly in China as well. For example, the new depositional patterns have been introduced for deciphering the paleogeography and sedimentary systems of the Wufeng shale and Longmaxi shale in the Sichuan Basin. The shale gas storage mechanism has been widely accepted as differing from conventional natural gas in that it is adsorbed on organic matter or a mineral surface or occurs as free gas trapped in pores and fractures of the shale. Significant advances in the techniques of microstructural characterization have provided new insights on how gas molecules are stored in micro- and nano-scale porous shales. Furthermore, newly-developed concepts and practices in the petroleum industry, such as hydraulic fracturing, microseismic monitoring and multiwell horizontal drilling, have made the production of this unevenly distributed but promising unconventional natural gas a reality. China has 10–36 trillion m^3 of promising shale gas among the world's whole predicted technically recoverable reserves of 206.6 trillion m^3. China is on the way to achieving its goal of an annual yield of 30–50 billion m^3 by launching more trials within shale gas projects. | ZOU Caineng YANG Zhi PAN Songqi CHEN Yanyan LIN Senhu HUANG Jinliang WU Songtao DONG Dazhong WANG Shufang LIANG Feng SUN Shasha HUANG Yong WENG Dingwei | 2016 | Acta Geologica Sinica(English Edition)2016，90，4： | 9 |
| 12 | An efficient visible-light photocatalyst for CO2 reduction fabricated by cobalt porphyrin and graphitic carbon nitride via covalent bonding显示文摘Nanoparticle photosensitizers possess technical advantages for photocatalytic reactions due to enhanced light harvesting and efficient charge transport.Here we report synthesis of semiconductor nanoparticles through covalent coupling and assembly of metalloporphyrin with condensed carbon nitride.The resultant nanoparticles consist of light harvesting component from the condensed carbon nitride and photocatalytic sites from the metalloporphyrins.This synergetic particle system effectively initiates efficient charge separation and transport and exhibits excellent photocatalytic activity for CO2 reduction.The CO production rate can reach up to 57μmol/(g·h)with a selectivity of 79%over competing H2 evolution.Controlled experiments demonstrate that the combination of light harvesting with photocatalytic activity via covalent assembly is crucial for the high photocatalytic activity.Due to effective charge separation and transfer,the resultant nanoparticle photocatalysts show exceptional photo stability against photo-corrosion under light irradiation,enabling for long-term utilization.This research opens a new way for the development of stable,effective nanoparticle photocatalysts using naturally abundant porphyrin pigments. | Shufang Tian Sudi Chen Xitong Ren Yaoqing Hu Haiyan Hu Jiajie Sun Feng Bai | 2020 | Nano Research2020，13，10： | 9 |
| 13 | Inheritance of Perpetual Blooming in Rosa chinensis ‘Old Blush'显示文摘Perpetual blooming is one of the most important biological and economical traits in modern rose, while the genetic basis underlining the control of this trait is poorly investigated. With an aim in dissecting the genetic determinism of perpetual blooming, we developed six rose populations(OB, W, F1, F2, BC1 OB and BC1W) derived from a WOB population [interspecific diploid hybridization between Rosa chinensis ‘Old Blush'(OB) and R. wichuriana ‘Basye's Thornless'(W)]. Perpetual blooming is absent both in a F1 population with 296 individuals and a BC1 W population(W as the backcross parent) with 150 individuals. However, the perpetual blooming trait showed a typical 3︰1 segregation in a backcross population BC1 OB with OB as the backcross parent. In this population with 300 individuals, 83 plants had the perpetual blooming phenotype while the other 217 featured non-perpetual blooming, indicating that the perpetual blooming trait is very likely controlled by two recessive genes in R. chinensis(rpb1 and rpb2). These genetic data suggest that the inheritance of rose perpetual blooming may be controlled by a complex mechanism. | LI Shubin ZHOU Ningning ZHOU Qing YAN Huijun JIAN Hongying WANG Qigang CHEN Min QIU Xianqin ZHANG Hao WANG Shufang LI Shufa TANG Kaixue | 2015 | Horticultural Plant Journal2015，1，2： | 9 |
| 14 | Synthesis of bifunctional Pt/MgAPO-5 catalysts and their catalytic performance in the hydrogenation of nitrobenzene to p-aminophenol显示文摘MgAPO-5 molecular sieves have been synthesized using diethylaminoethanol as the templating agent in a wide range of the MgO/Al2O3 ratio.The samples were characterized by XRD,SEM,solid state NMR,FT-IR and NH3-TPD.Using MgAPO-5 as acidic supports,bifunctional Pt/MgAPO-5 catalysts were prepared for hydrogenation of nitrobenzene to p-aminophenol (PAP).The results showed that the MgO/Al2O3 ratios influenced the Mg content and the acidity of MgAPO-5 samples,thereby greatly affecting the catalytic performance of Pt/MgAPO-5 catalysts.The selectivity to PAP over Pt/MgAPO-5 was dependent on the amount of strong acid sites of MgAPO-5.When the MgO/Al2O3 molar ratio was 0.5,the synthesized MgAPO-5 sample exhibited the largest amount of strong acid and a highest PAP yield of 41.1% was achieved over Pt/MgAPO-5 catalyst. | ShuFang Wang YaDan Jin BeiBei He YanJi Wang XinQiang Zhao | 2010 | Science China Chemistry2010，53，7： | 9 |
| 15 | Bottom-up fabrication of graphitic carbon nitride nanosheets modified with porphyrin via covalent bonding for photocatalytic H2 evolution显示文摘In order to broaden the absorption range of graphitic carbon nitride,one of the common methods is to couple the well-known photosensitizer porphyrin with graphitic carbon nitride through van der Waals weak in teractions.To date,to combine porphyrin with graphitic carbon nitridethrough covalent in teractions has not been settled.In this work,through rational molecular design,we successfully in corporated porphyrininto the matrixes of graphitic carbon nitride by covale nt bonding via on expot thermal copolymerization.The resulta nt material not only can wide nthe absorption range but also possess the enlarged specific surface area and construction intramolecular heterojunctions which can contributeto improve electron-holes separation efficiency.The resultant photocatalyst exhibited enhanced H2 production rate(7.6 mmol·g^-1·h^-1)and withthe apparent quantum efficiency(AQE)of 13.3%at 450 nm.At the same time,this method opens a way to fabricate graphitic carb on nitridenano sheets via bottom-up strategy. | Shufang Tian Sudi Chen Xitong Ren Ronghui Cao Haiyan Hu Feng Bai | 2019 | Nano Research2019，12，12： | 8 |
| 16 | Did Ecological Engineering Projects Have a Significant Effect on Large-scale Vegetation Restoration in Beijing-Tianjin Sand Source Region, China? A Remote Sensing Approach显示文摘Aiming for the restoration of degraded ecosystems, many ecological engineering projects have been implemented around the world. This study investigates the ecological engineering project effectiveness on vegetation restoration in the Beijing-Tianjin Sand Source Region(BTSSR) from 2000 to 2010 based on the rain use efficiency(RUE) trend in relation to the land cover. More than half of the BTSSR experienced a vegetation productivity increase from 2000 to 2010, with the increasing intensity being sensitive to the indicators chosen. A clear tendency towards smaller increasing areas was shown when using the net primary productivity(NPP, 51.30%) instead of the accumulated normalized difference vegetation index(59.30%). The short-term variation in the precipitation and intra-seasonal precipitation distribution had a great impact on the remote sensing-based vegetation productivity. However, the residual trends method(RESTREND) effectively eliminated this correlation, while incorporating the variance and skewness of the precipitation distribution increased the models′ ability to explain the vegetation productivity variation. The RUE combined with land cover dynamics was valid for the effectiveness assessment of the ecological engineering projects on vegetation restoration. Particularly, the result based on growing season accumulated normalized difference vegetation index(ΣNDVI) residuals was the most effective, showing that 47.39% of the BTSSR experienced vegetation restoration from 2000 to 2010. The effectiveness of the ecological engineering projects differed for each subarea and was proportional to the strength of ecological engineering. The water erosion region dominated by woodland showed the best restoration, followed by the wind-water erosion crisscross regions, while the wind erosion regions dominated by grassland showed the worst effect. Seriously degraded regions still cover more area in the BTSSR than restored regions. Therefore, more future effort should be put in restoring degraded land. | LI Xiaosong WANG Hongyan ZHOU Shufang SUN Bin GAO Zhihai | 2016 | Chinese Geographical Science2016，26，2： | 8 |
| 17 | Saddlepoint approximation based structural reliability analysis with non-normal random variables显示文摘The saddlepoint approximation (SA) can directly estimate the probability distribution of linear performance function in non-normal variables space. Based on the property of SA, three SA based methods are developed for the structural system reliability analysis. The first method is SA based reliability bounds theory (RBT), in which SA is employed to estimate failure probability and equivalent normal reliability index for each failure mode firstly, and then RBT is employed to obtain the upper and the lower bounds of system failure probability. The second method is SA based Nataf approximation, in which SA is used to estimate the probability density function (PDF) and cumulative distribution function (CDF) for the approximately linearized performance function of each failure mode. After the PDF of each failure mode and the correlation coefficients among approximately linearized performance functions are estimated, Nataf distribution is employed to approximate the joint PDF of multiple structural system performance functions, and then the system failure probability can be estimated directly by numerical simulation using the joint PDF. The third method is SA based line sampling (LS). The standardization transformation is needed to eliminate the dimensions of variables firstly in this case. Then LS method can express the system failure probability as an arithmetic average of a set of failure probabilities of the linear performance functions, and the probabilities of the linear performance functions can be estimated by the SA in the non-normal variables space. By comparing basic concepts, implementations and results of illustrations, the following conclusions can be drawn: (1) The first method can only obtain the bounds of system failure probability and it is only acceptable for the linear limit state function; (2) the second method can give the estimation of system failure probability, and its error mostly results from the approximation of Nataf distribution for the joint PDF of the structural system performance functions and the linearization of the performance functions; (3) the SA based LS method can obtain the estimator of system failure probability, which converges to the actual value along with the increase of sample size. The SA based LS method considers the influence of nonlinearity of limit state function on the failure probability, and it is acceptable for the structural system both with a single failure mode and with multiple failure modes, therefore it has the widest applicability. | SONG ShuFang & LU ZhenZhou School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, China | 2010 | Science China(Technological Sciences)2010，53，2： | 8 |
| 18 | Reliability Sensitivity Algorithm Based on Stratified Importance Sampling Method for Multiple Failure Modes Systems显示文摘Combining the advantages of the stratified sampling and the importance sampling,a stratified importance sampling metho(SISM) is presented to analyze the reliability sensitivity for structure with multiple failure modes.In the presented method,th variable space is divided into several disjoint subspace by n-dimensional coordinate planes at the mean point of the random vec tor,and the importance sampling functions in the subspaces are constructed by keeping the sampling center at the mean poin and augmenting the standard deviation by a factor of λ.The sample size generated from the importance sampling function i each subspace is determined by the contribution of the subspace to the reliability sensitivity,which can be estimated by iterativ simulation in the sampling process.The formulae of the reliability sensitivity estimation,the variance and the coefficient o variation are derived for the presented SISM.Comparing with the Monte Carlo method,the stratified sampling method and th importance sampling method,the presented SISM has wider applicability and higher calculation efficiency,which i demonstrated by numerical examples.Finally,the reliability sensitivity analysis of flap structure is illustrated that the SISM ca be applied to engineering structure. | Zhang Feng Lu Zhenzhou Cui Lijie Song Shufang | 2010 | Chinese Journal of Aeronautics2010，23，6： | 7 |
| 19 | Reliability and Sensitivity Analysis of Transonic Flutter Using Improved Line Sampling Technique显示文摘考虑飞机机翼结构参数的随机性,提供了一种有效的可靠性数字模拟方法—改进线抽样方法,来进行跨声速机翼颤振的概率和灵敏性分析。线抽样方法适用于高维、小失效概率和隐式极限状态方程的可靠性问题的概率和灵敏度分析,而不用引入任何隐式极限状态方程的近似替代函数。考虑机翼结构参数,如固有频率、重心位置参数和质量比等的不确定性,将改进线抽样技术应用于带有操纵面机构的二元机翼颤振问题的不确定性分析。采用基于计算流体动力学(CFD)技术的非定常气动力降阶方法,可得到基于结构模态坐标的非定常气动力模型,耦合结构状态方程和气动状态方程得到气动弹性系统的状态方程,通过求解状态方程中矩阵的特征值得到颤振的临界速度,并建立颤振的安全裕度方程。分别采用Monte Carlo模拟法和改进线抽样法进行随机不确定性分析,改进线抽样方法的计算效率比Monte Carlo模拟法有很大程度的提高。此外,灵敏度分析所得的灵敏度因子能够定量地反映随机参数对颤振临界速度的影响程度,从而为提高颤振临界速度的结构优化设计提供依据。 | Song Shufang Lu Zhenzhou Zhang Weiwei Ye Zhengyin | 2009 | Chinese Journal of Aeronautics2009，22，5： | 7 |
| 20 | Metal-organic frameworks-derived nitrogen-doped carbon supported nanostructured PtNi catalyst for enhanced hydrosilylation of 1-octene显示文摘Here,we successfully developed nano structured PtNi particles supported on n itroge rrdoped carbon(NC),which were obtai ned by carbon izati on of metal-organic frameworks under different temperatures,forming the nano-PtNi/NC-600,nano-PtNi/NC-800,nano-PtNi/NC-900 and nano-PtNi/NC-1000 catalysts.For hydrosilylation of 1-octene,we found that the nano-PtNi/NC-1000 catalyst exhibits higher activity for anti-Markovnikov hydrosilylation of 1-octene than those of nano-PtNi/NC-600,nano-PtNi/NC-800,nano-PtNi/NC-900 catalysts.Experiments have verified that benefiting from obvious charge transfer from nano-PtNi particles to NC support carbonized at 1,000℃,the nano-PtNi/NC-1000 catalyst achieved almost complete conversion and produce exclusive adduct for anti-Markovnikov hydrosilylation of 1-octene.Importantly,the nano-PtNi/NC-1000 catalyst exhibited good reusability for the hydrosilylation reaction.This work provides a new path to optimize electronic structure of catalysts by support modification to enhance electron transfer between metal active species and supports for highly catalytic performance. | Junfeng Wen Yuanjun Chen Shufang Ji Jian Zhang Dingsheng Wang and Yadong Li | 2019 | Nano Research2019，12，10： | 6 |
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