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| 1 | Patterns of above-and belowground biomass allocation in China's grasslands:Evidence from individual-level observations显示文摘Above-and belowground biomass allocation not only influences growth of individual plants,but also influences vegetation structures and functions,and consequently impacts soil carbon input as well as terrestrial ecosystem carbon cycling.However,due to sampling difficulties,a considerable amount of uncertainty remains about the root:shoot ratio(R/S),a key parameter for models of terrestrial ecosystem carbon cycling.We investigated biomass allocation patterns across a broad spatial scale.We collected data on individual plant biomass and systematically sampled along a transect across the temperate grasslands in Inner Mongolia as well as in the alpine grasslands on the Tibetan Plateau.Our results indicated that the median of R/S for herbaceous species was 0.78 in China's grasslands as a whole.R/S was significantly higher in temperate grasslands than in alpine grasslands(0.84 vs.0.65).The slope of the allometric relationship between above-and belowground biomass was steeper for temperate grasslands than for alpine.Our results did not support the hypothesis that aboveground biomass scales isometrically with belowground biomass.The R/S in China's grasslands was not significantly correlated with mean annual temperature(MAT) or mean annual precipitation(MAP).Moreover,comparisons of our results with previous findings indicated a large difference between R/S data from individual plants and communities.This might be mainly caused by the underestimation of R/S at the individual level as a result of an inevitable loss of fine roots and the overestimation of R/S in community-level surveys due to grazing and difficulties in identifying dead roots.Our findings suggest that root biomass in grasslands tended to have been overestimated in previous reports of R/S. | WANG Liang*,NIU KeChang,YANG YuanHe & ZHOU Peng Department of Ecology,Key Laboratory for Earth Surface Processes of the Ministry of Education,Peking University,Beijing 100871,China. | 2010 | Science China(Life Sciences)2010，53，7： | 54 |
| 2 | Comparison of reduction behavior of Fe_2O_3, ZnO and ZnFe_2O_4 by TPR technique显示文摘Advanced integrated gasification combined cycle (IGCC) power generation systems require the development of high-temperature, regenerable, desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier gas to very low levels. As a sort of effective desufurizer, such as Fe2O3, ZnO and ZnFe2O4, it will endure strong reducing atmosphere in desulfurization process. The reduced degree of desufurizer can have an effect on its desulfurization reactivity. In this paper, Fe2O3, ZnO and ZnFe2O4 were synthesized by precipitation or co-precipitation at constant pH. After aging, washing and drying, the solids were calcined at 800 °C. The reduction behaviors of sample were characterized by temperature-programmed reduction (TPR). It is found that there are two reduction peaks for Fe2O3 in TPR, and whereas no reduction peaks for ZnO are found. The reduction process of ZnFe2O4 prepared by co-precipitation is different from that of Fe2O3. ZnFe2O4 is easier to be reduced than Fe2O3. The activation energy of reduction process for Fe2O3 and ZnFe2O4 is obtained at different reduction periods. | Meisheng Liang Wenkai Kang Kechang Xie | 2009 | Journal of Natural Gas Chemistry2009，18，1： | 27 |
| 3 | Reviews of clean coal conversion technology in China:Situations & challenges显示文摘It is important to develop the advanced coal to chemicals industry(ACCI)against a backdrop of coal-based energy structures,excessive imported oil and natural gas,and strict environmental constraints in China.In this study,the technology and industry of China’s ACCI are reviewed to explain the effect of using coal to replace oil and natural gas,and the corresponding resource and environmental burdens that this will create.Development trends in technology and industry are also proposed to explore future scenarios.The review shows that although excellent progress has been made on an industrial scale,demonstrative level,and in terms of technology and equipment,the lack of strategic understanding,severe external constraints,partly underdeveloped technologies,and weak foundations must be immediately addressed.Therefore,it is necessary to clarify the importance that the ACCI has on the energy revolution and energy system.Based on technological innovation,a variety of external factors should be considered as a whole with emphasis on filling the knowledge gap of theoretical foundations and industry standards to support high-quality development for ACCI. | Kechang Xie | 2021 | Chinese Journal of Chemical Engineering2021，34，7： | 12 |
| 4 | Diurnal characteristics of geoelectric fields and their changes associated with the Alxa Zuoqi M_S5.8 earthquake on 15 April 2015(Inner Mongolia)显示文摘In China, efforts are being made to monitor geoelectric fields through a large network of stations deployed and managed by the China Earthquake Administration. The diurnal variations in the geoelectric field waveforms were similar in the quiet magnetic periods when K<5(generally, K<3 indicates a quiet time). The arrival time points of the maxima in the geoelectric field waveforms exhibited differences in local time related to geographic longitude. The amplitude of diurnal variation was several to 16.6 mV/km and decreased with increasing latitude. Further,the amplitude of diurnal variation, which was related to seasonal changes, was larger in summer and autumn than in spring and winter. The periods of diurnal changes during quiet days were 24, 12, 8, 6, 4 hours and several minutes over large areas. Finally, the observed diurnal variations in geoelectric field prior to the Alxa Zuoqi M_S5.8 earthquake on 15 April 2015 were studied, and pronounced changes in the spectral values of the geoelectric fields were found to be associated with the Alxa Zuoqi earthquake in Inner Mongolia. | Qing Ye Ye Fan Xuebin Du Tengfa Cui Kechang Zhou Ramesh P.Singh | 2018 | Earthquake Science2018，31，1： | 12 |
| 5 | Impact of impregnation pressure on desulfurization performance of Zn-based sorbents supported on semi-coke显示文摘High-pressure impregnation, a new preparation method for sorbents to remove H2S from hot coal gas, is introduced in this paper. Semi-coke (SC) and ZnO is selected as the support and active component of sorbent, respectively. The sorbent preparation process includes high-pressure impregnation, filtration, ovendry and calcination. The aim of this research is to primarily study the effects of the impregnation pressure on physical properties and desulfurization ability of the sorbent. The desulfurization experiment was carried out in a fixed-bed reactor at 500°C and a simulated coal gas used in this work was composed of CO (33 vol%), H2 (39 vol%), H2S (300 ppm in volume), and N2 (balance). Experimental results show that the pore structure of the SC support can be improved effectively and ZnO active component can be uniformly dispersed on the support, with the small particle size of 10-500 nm. Sorbents prepared using high-pressure impregnation have better desulfurization capacity and their active components have higher utilization rate. P20-ZnSC sorbent, obtained by high-pressure impregnation at 20 atm, has the best desulfurization ability with a sulfur capacity of 7.54 g S/100g sorbent and a breakthrough time of 44 h. Its desulfurization precision and efficiency of removing H2S from the middle temperature gases can reach <1 ppm and >99.7%, respectively, before sorbent breakthrough. | Xianrong Zheng Weiren Bao Qingmai Jin Ruiyuan He Liping Chang Kechang Xie | 2012 | Journal of Natural Gas Chemistry2012，21，1： | 10 |
| 6 | Adsorption of Carbon Dioxide on Activated Carbon显示文摘未加工的活性炭 A 和三修改活性炭上的 CO2 的吸附取样 B ,6号元素碳的化学符号,并且在从 303~333 K 和吸附的热力学 的温度的氘的符号用一台真空吸附仪器被调查了以便在工业气体在器官的包含硫的混合物的移动上关于 CO2 的效果获得更多的信息。在对为 CO2 和它的体积的吸附的重要影响在修改的碳样品 B, 6 号元素碳的化学符号,和氘的符号上吸附了的碳样品表演使妊娠的活性组分都在未加工的碳样品 A 上比那大。在另一方面,象表面积,毛孔体积,和碳样品的微毛孔体积那样的物理参数不在 CO2 的吸附的数量上显示出影响。Dubinin-Radushkevich (医生) 方程是为在碳样品 A 和 B 上适合吸附数据的最好的模型,当 Freundlich 方程是为碳样品 6 号元素碳的化学符号和氘的符号上的吸附合适的最好时。用 Clapeyron 方程从吸附等温线导出的碳样品 A, B, 6 号元素碳的化学符号,和氘的符号上的 isosteric 稍微减少了装载的增加的表面。吸附的热躺在 10.5 和 28.4 kJ/mol 之间,与根本有最高的价值的碳样品氘的符号被学习的表面覆盖度。为碳与吸附联系的观察的熵变化取样 A, B,和 6 号元素碳的化学符号(在 7 ml/g 的表面覆盖度上面) 是比为活动吸附的理论价值低的。然而,它比为活动吸附的理论价值高,但是为碳样品氘的符号为局部性的吸附比理论价值降低。给词调音:二氧化碳;吸附;吸附的热; | Bo Guo Liping Chang Kechang Xie | 2006 | Journal of Natural Gas Chemistry2006，15，3： | 9 |
| 7 | Effect of Calcium Oxide Additive on the Performance of Iron Oxide Sorbent for High-Temperature Coal Gas Desulfurization显示文摘The effect of calcium oxide additive in iron oxide sorbent for hot gas desulfurization was investigated by XRD and TPR techniques.XRD characterization showed that CaO was highly dispersed after the calcination of sorbents.Calcium sulfate formed in the desulfurization was decomposed and regenerated to CaO by reacting with CO before the next sulfidation process.Calcium participated in every sulfidation/regeneration cycle and contributed to the enhancement of sulfur capacity.The TPR results showed that the reduction temperature of the sorbent increased with the increase of the content of calcium.Calcium played a role of retarding reduction.Therefore,the addition of calcium oxide additive will benefit the utilization of iron oxide sorbent in strongly reducing atmospheres. | Huiling Fan Kechang Xie Ju Shangguan Fang Shen Chunhu Li | 2007 | Journal of Natural Gas Chemistry2007，16，4： | 7 |
| 8 | comLinking flowering and reproductive allocation in response to nitrogen addition in an alpine meadow显示文摘Aims Plants can change in phenology and biomass allocation in response to environmental change.It has been demonstrated that nitrogen is the most limiting resource for plants in many terrestrial ecosystems.Previous studies have usually focused on either flowering phenology or biomass allocation of plants in response to nitrogen addition;how-ever,attempts to link flowering phenology and biomass allocation are still rare.In this study,we tested the effects of nitrogen addition on both flowering phenology and reproductive allocation in 34 common species.We also examined the potential linkage between flowering time and reproductive allocation in response to nitrogen addition.Methods We conducted a 3-year nitrogen addition experiment in Tibetan alpine meadow.We measured first flowering date and the repro-ductive allocation for 34 common plant species in control,low and high nitrogen added plots,respectively.one-way analysis of variance was used to examine differences of first flowering date and reproductive allocation among treatments.The relationships between the change in species first flowering date and change in reproductive allocation in response to nitrogen addition were examined by calculating Pearson correlation coefficients.Important Findings For most species,both first flowering date and reproductive alloca-tion significantly responded to nitrogen addition.Nitrogen addition significantly delayed the first flowering date and reduced the repro-ductive allocation for all graminoid species,but accelerated flower-ing and increased reproductive allocation for most forb species.We found that changes in first flowering date significantly negatively correlated with the changes in reproductive allocation over spe-cies in response to nitrogen,which indicated a positive relationship between flowering response and plant performance in reproductive allocation.species that advanced their flowering time with nitrogen addition increased their reproductive allocation,whereas those that delayed flowering time tended to decline in reproductive allocation with nitrogen addition.our results suggest that species-specific switch from vegetative growth to reproductive growth could influence species performance. | Zhilong Zhang Kechang Niu Xudong Liu Peng Jia Guozhen Du | 2014 | Journal of Plant Ecology2014，7，3： | 7 |
| 9 | Bench-Scale Testing of Zinc Ferrite Sorbent for Hot Gas Clean-up显示文摘预付联合周期(IGCC ) 发电系统要求的综合气化高温度的、能被产生的脱硫吸着剂的发展,它能够把硫化氢从煤 gasifier 气体移开到很低面式。在这篇论文,一起沉淀准备的锌铁酸盐在高温作为新奇的煤气体脱硫吸着剂被识别。锌铁酸盐的准备和毛孔体积,力量和锌铁酸盐脱硫剂的脱硫效率上的文件夹的效果被学习。而且,锌铁酸盐吸着剂的行为在在 350-400 的温度范围下面的脱硫和新生期间 ??6 号元素碳的化学符号被调查。毛孔卷,机械强度和锌铁酸盐吸着剂的脱硫效率上的文件夹的效果显示到锌铁酸盐 desulfurizer 的 kaolinite 的增加似乎比在试验性的条件下面的另外的文件夹优异。给词调音:锌铁酸盐吸着剂;文件夹;热煤气的大扫除;sulfidation; | Meisheng Liang Hongyan Xu Kechang Xie | 2007 | Journal of Natural Gas Chemistry2007，16，2： | 5 |
| 10 | Model and Method of Debris Flow Risk Zoning Based on Momentum Analysis显示文摘A model of debris flow risk zoning is carried out with momentum analysis of debris flow. This model zones the debris flow inundation fan with density and velocity calculated by numerical simulation. The risk classification standard is determined according to the ultimate bearing capacities of different structures under impacting. And the ultimate bearing capacities are tested by impact failure experiment of destruction. Two structures typical in Chinese mountain towns, reinforced concrete frame construction and brickwork with concrete, are chosen in the experiment. The model makes debris flow risk zoning quantitative and the results comparable widely. The results differ much from that of other methods especially in the identification of medium and low risk zones. | WEI Fangqiang ZHANG Yu HU Kaiheng GAO Kechang | 2006 | Wuhan University Journal of Natural Sciences2006，11，4： | 5 |
| 11 | Speciation and thermal transformation of sulfur forms in high-sulfur coal and its utilization in coal-blending coking process:A review显示文摘The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper reviews the speciation,forms and distribution of sulfur in coal,the sulfur removal from raw coal,the thermal transformation of sulfur during coal pyrolysis,and the sulfur regulation during coal-blending coking of high organic-sulfur coals.It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization,which raises the need of a combination of current or newly adopted characterization methods.Different from the removal of inorganic sulfur from coal,the organic sulfur can only be partly removed by chemical technologies;and the coal structure and property,particularly high-sulfur coking coals which have caking ability,may be altered and affected by the pretreatment processes.Based on the interactions among the sulfur radicals,sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char,regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry.An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested.That is,the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2 S from high organic-sulfur coals is blended with high organic-sulfur coals,and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogencontaining radicals generated from high volatile coals.Wherein,the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend. | Yanfeng Shen Yongfeng Hu Meijun Wang Weiren Bao Liping Chang Kechang Xie | 2021 | Chinese Journal of Chemical Engineering2021，34，7： | 5 |
| 12 | Sensor fault diagnosis of nonlinear processes based on structured kernel principal component analysis显示文摘A new sensor fault diagnosis method based on structured kernel principal component analysis (KPCA) is proposed for nonlinear processes. By performing KPCA on subsets of variables, a set of structured residuals, i.e., scaled powers of KPCA, can be obtained in the same way as partial PCA. The structured residuals are utilized in composing an isolation scheme for sensor fault diagnosis, according to a properly designed incidence matrix. Sensor fault sensitivity and critical sensitivity are defined, based on which an incidence matrix optimization algorithm is proposed to improve the performance of the structured KPCA. The effectiveness of the proposed method is demonstrated on the simulated continuous stirred tank reactor (CSTR) process. | Kechang FU Liankui DAI Tiejun WU Ming ZHU | 2009 | 控制理论与应用(英文版)2009，7，3： | 5 |
| 13 | Selenium speciation in flue desulfurization residues显示文摘Flue gas from coal combustion contains significant amounts of volatile selenium(Se).The capture of Se in the flue gas desulfurization(FGD) scrubber unit has resulted in a generation of metal-laden residues.It is important to determine Se speciation to understand the environmental impact of its disposal.A simple method has been developed for selective inorganic Se(IV),Se(VI) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry(AFS).It has been determined that Se(IV),Se(VI) and organic Se can be accurately determined with detection limits(DL) of 0.05,0.06 and 0.06 μg/L,respectively.The accuracy of the proposed method was evaluated by analyzing the certified reference material,NIST CRM 1632c,and also by analyzing spiked tap-water samples.Analysis indicates that the concentration of Se is high in FGD liquid residues and primarily exists in a reduced state as selenite(Se(IV)).The toxicity of Se(IV) is the strongest of all Se species.Flue gas desulfurization residues pose a serious environmental risk. | Liping Zhong Yan Cao Wenying Li Kechang Xie Wei-Ping Pan | 2011 | Journal of Environmental Sciences2011，23，1： | 4 |
| 14 | Studies on the structure and catalytic performance of Cu-Zn-Al catalyst prepared by liquid-phase preparation technology under different heat treatment atmosphere显示文摘Cu-Zn-Al slurry catalysts were prepared using a complete liquid-phase preparation technology under different heat treatment atmospheres.The catalysts were characterized using X-ray diffraction,X-ray photoelectron spectroscope,and N2 adsorption-desorption.Their application in the single-step synthesis of dimethyl ether from syngas was also investigated.The results indicate that the type of heat treatment atmosphere has an influence on the Cu species and the Cu0/Cu+ ratio on the catalyst surface.Moreover,the final Cu/Zn ratio on the catalyst surface is mainly dependent on the composition and reaction environment of the catalyst and less on the type of heat treatment atmosphere.The prepared catalysts can suppress sintering of active sites at high temperatures,and the type of heat treatment atmosphere mainly affects the capability of the catalyst for methanol synthesis.The catalysts perform best using N2 as the heat treatment atmosphere. | Zhihua Gao Wei Huang Lihua Yin Kechang Xie | 2010 | Journal of Natural Gas Chemistry2010，19，6： | 3 |
| 15 | Approach and potential of replacing oil and natural gas with coal in China显示文摘China’s fossil energy is characterized by an abundance of coal and a relative lack of oil and natural gas.Developing a strategy in which coal can replace oil and natural gas is,therefore,a necessary and practical approach to easing the excessive external dependence on oil and natural gas.Based on the perspective of energy security,this paper proposes a technical framework for defining the substitution of oil and natural gas with coal in China.In this framework,three substitution classifications and 11 industrialized technical routes are reviewed.Then,three scenarios(namely,the cautious scenario,baseline scenario,and positive scenario)are developed to estimate the potential of this strategy for 2020 and 2030.The results indicate that oil and natural gas replaced by coal will reach 67 to 81 Mt and 8.7 to 14.3 Gm^3 in 2020 and reach 93 to 138 Mt and 32.3 to 47.3 Gm^3 in 2030,respectively.By implementing this strategy,China’s external dependence on oil,natural gas,and primary energy is expected to be curbed at approximately 70%,40%,and 20%by 2030,respectively.This paper also demonstrates how coal,as a substitute for oil and natural gas,can contribute to carbon and pollution reduction and economic cost savings.It suggests a new direction for the development of the global coal industry and provides a crucial reference for energy transformation in China and other countries with similar energy situations. | Junjie LI Yajun TIAN Xiaohui YAN Jingdong YANG Yonggang WANG Wenqiang XU Kechang XIE | 2020 | Frontiers in Energy2020，14，2： | 3 |
| 16 | High wall-plug efficiency 808-nm laser diodes with a power up to 30.1 W显示文摘A very highly efficient InGaAlAs/AlGaAs quantum-well structure was designed for 808 nm emission,and laser diode chips 390-μm-wide aperture and 2-mm-long cavity length were fabricated.Special pretreatment and passivation for the chip facets were performed to achieve improved reliability performance.The laser chips were p-side-down mounted on the AlN submount,and then tested at continuous wave(CW)operation with the heat-sink temperature setting to 25℃using a thermoelectric cooler(TEC).As high as 60.5%of the wall-plug efficiency(WPE)was achieved at the injection current of 11 A.The maximum output power of 30.1 W was obtained at 29.5 A when the TEC temperature was set to 12°C.Accelerated life-time test showed that the laser diodes had lifetimes of over 62111 h operating at rated power of 10 W. | Zhanqiang Ren Qingmin Li Bo Li Kechang Song | 2020 | Journal of Semiconductors2020，41，3： | 3 |
| 17 | A DFT theoretical study of CH_4 dissociation on gold-alloyed Ni(111)surface显示文摘A density-functional theory(DFT)method has been conducted to systematically investigate the adsorption of CHx(x=0~4)as well as the dissociation of CHx(x=1~4)on(111)facets of gold-alloyed Ni surface.The results have been compared with those obtained on pure Ni(111)surface.It shows that the adsorption energies of CHx(x=1~3)are lower,and the reaction barriers of CH4 dissociation are higher in the first and the fourth steps on gold-alloyed Ni(111)compared with those on pure Ni(111).In particular,the rate-determining step for CH4 dissociation is considered as the first step of dehydrogenation on gold-alloyed Ni(111),while it is the fourth step of dehydrogenation on pure Ni(111).Furthermore,the activation barrier in rate-determining step is higher by 0.41 eV on gold-alloyed Ni(111)than that on pure Ni(111).From above results,it can be concluded that carbon is not easy to form on gold-alloyed Ni(111)compared with that on pure Ni(111). | Hongyan Liu Ruixia Yan Riguang Zhang Baojun Wang Kechang Xie | 2011 | Journal of Natural Gas Chemistry2011，20，6： | 2 |
| 18 | Design, Synthesis and Herbicidal Activities of Tetrahydroisoindoline-1,3-dione Derivatives Containing Alkoxycarbonyl Substituted 2-Benzoxazolinone显示文摘几不同代替 alkoxycarbonyl 的 2-benzoxazolinone 一半被合并了到 tetrahydroisoindoline-1,3-dione 脚手架提供 25 混合物(1a-1u 和 2a-2d ) 。这些混合物的结构被 1 H 和 13 C NMR, HRMS 和 X 光检查单个水晶的衍射。一些这些混合物(1g, 1h, 1j, 1k ) 对以 375 g AI·ha −1 的率的青麻 theophrasti, Amaranthus retroflexus 和 Echinochloa crus-galli 的展出优秀 herbicidal 活动。在他们之中,混合物 1h 和 1j 分别地与 1.8 和 5.3 g AI·ha −1, 的编辑 50 价值对青麻 theophrasti 显示了最好的出现以后的 herbicidal 效果,它比商业 acifluorfen 的优异(44.3 g AI·ha −1) 。地试用证明复合 1h 展出了类似的 herbicidal 活动到高集中 atrazine,并且发现了比 atrazine 为玉米更安全。这研究的结果因此证明复合 1h 能潜在地为玉米领域被用作出现以后的除草剂。 | Hao Zhang Kechang Liu Ruiquan Liu Qibo Li Yongqiang Li Qingmin Wang Shangzhong Liu | 2015 | Chinese Journal of Chemistry2015，33，7： | 2 |
| 19 | Direct Synthesis of Acetic Acid from CH_(4)and CO_(2)in the Presence of O_(2)over a V_(2)O_(5)-PdCl_(2)/Al_(2)O_(3)Catalyst显示文摘The possibility of synthesizing acetic acid from CH4 and CO2 in the presence of O2 over a V2O5-PdCl2/Al2O3 catalyst has been explored. The result shows that it is feasible in catalyzing a direct conversion of CH4, CO2 and O2 to acetic acid. It is concluded that both CO2 and O2 are involved in the formation of acetic acid. | Wei Huang, Cuihong Zhang, Lihua Yin, Kechang XieKey Laboratory of Coal Science and Technology (Taiyuan University of Technology), Ministry of Education and Shanxi Province Institute of Coal Chemistry and Engineering, Taiyuan University of Technology,No. 79 Yingze West Street, Taiyuan 030024, China | 2004 | Journal of Natural Gas Chemistry2004，13，2： | 2 |
| 20 | Study on the structure and pyrolysis characteristics of Chinese western coals显示文摘 | Junhong Wang Juan Du Liping Chang Kechang Xie | 2009 | Fuel Processing Technology2009，，4： | 2 |
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