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1Periodicity of Holocene climatic variations in the Huguangyan Maar Lake显示文摘There exist five primary periods of 2 930, 1 140, 490, 250 and 220 a in the Holocene climatic variations in the Huguangyan Maar Lake, according to the energy-spectrum and filter analyses of high-resolution time sequences (10-15 a) of the sediment dry density. The peak values of the three temperature-decreasing periods with the 2 930 a cycle occur at about 7 300, 4 250 and 1 200 Cal. aBP. There are 7-8 temperature-decreasing periods with the 1 140 a cycle, and the climate fluctuation range is largest in the early Holocene, and reduces gradually in the middle and late Holocene. The millennial-scale climatic change in the Holocene may adjust the global water cycle and the thermohaline circulation intensity through the harmonic tones of the earth’s precession cycle, which in turn influences the global climate change.LIU Jiaqi LÜ Houyuan JNegendank JMingram LUO Xiangjun WANG Wenyuan CHU Guoqiang 2000Chinese Science Bulletin2000,45,18:33
2Energy Management and Operational Control Methods for Grid Battery Energy Storage Systems显示文摘Energy storage is one of the key means for improving the flexibility,economy and security of power system.It is also important in promoting new energy consumption and the energy Internet.Therefore,energy storage is expected to support distributed power and the micro-grid,promote open sharing and flexible trading of energy production and consumption,and realize multi-functional coordination.In recent years,with the rapid development of the battery energy storage industry,its technology has shown the characteristics and trends for large-scale integration and distributed applications with multi-objective collaboration.As a grid-level application,energy management systems(EMS)of a battery energy storage system(BESS)were deployed in real time at utility control centers as an important component of power grid management.Based on the analysis of the development status of a BESS,this paper introduced application scenarios,such as reduction of power output fluctuations,agreement to the output plan at the renewable energy generation side,power grid frequency adjustment,power flow optimization at the power transmission side,and a distributed and niohile energy storage system at the power distribution side.The studies and application status of a BESS in recent years were reviewed.The energy management,operation control methods,and application scenes of large-scale BESSs were also examined in the study.Xiangjun Li Shangxing Wang 2021CSEE Journal of Power and Energy Systems2021,7,5:14
3The program structure designing and optimizing tests of GRAPES physics显示文摘According to the modularization and standardization of program structure in Global/Regional Assimilation and Prediction System (GRAPES), the plug-compatible and transplantable regional meso-scale and global middle-range physics software package is established. The package's component integrality is comparative with the other advanced models physics. A three-level structure of connecting GRAPES physics and dynamic frame has been constructed. The friendly interface is designed for users to plug in their own physics packages. Phenomenon of grid-point storm rainfall in numerical prediction is analyzed with the numerical tests. The scheme of air vertical velocity calculation is improved. Optimizing tests of physics schemes are performed with the correlative parameters adjusting. The results show that the false grid-point storm rainfall is removed by precipitation scheme improving. Then the score of precipitation forecast is enhanced.XU GuoQiang CHEN DeHui XUE JiShan SUN Jian SHEN XueShun SHEN YuanFang HUANG LiPing WU XiangJun ZHANG HongLiang WANG ShiYu 2008Chinese Science Bulletin2008,53,22:11
4A new-generation sand and dust storm forecasting system GRAPES_CUACE/Dust:Model development,verification and numerical simulation显示文摘Based on the new-generation Global/Regional Assimilation and PrEdiction System(GRAPES) developed by the Numerical Prediction Research Center,China Meteorological Administration and the Chinese Unified Atmospheric Chemistry Environment for Dust Atmospheric Chemistry Module(CUACE/Dust) developed by the Centre for Atmosphere Watch and Services(CAWAS) of the Chinese Academy of Meteorological Sciences(CAMS) ,the China sand and dust storm forecasting system GRAPES /CUACE-Dust model has been established.The latest data of land desertification,optical properties of China sand and dust aerosols,daily soil moisture and snow cover over China main land was introduced in this system.The system showed good performance in mass conservation.The comparisons of real-time prediction outputs with surface observations and aerosol indices derived from TOMS ozone spectrophotometers(TOMS AI) indicate that the model can predict the outbreak,development,transport and depletion processes of sand and dust storms accurately over China and the East Asian region.The system makes real-time quantitative prediction of a series of elements including sand and dust injection from the surface,dry and wet deposition amount,dust concentration and optical depth.We selected 7 major dust storms occurring in April 2006 and analyzed the spatiotemporal distribution patterns of dust emission,dry and wet deposition and atmospheric load in this paper.The results showed that about 225 million tons of dust were emitted into the atmosphere from the deserts over east Asia in that month.The 3 major sand and dust sources were just as the following:The deserts in northern Inner Mongolia and the boundary area around China-Mongolia were the first dust sources with a contribution of 153 million tons accounting for 68%of the total emission.The Taklimakan Desert ranked second and contributed approximately 40 million tons accounting for 17%of the dust emission.The Onqin Daga Sandland emitted about 15 million tons or 7%of the total emission.The contributions from other deserts,sandy lands and abandoned farmlands were about only 8%of the total dust emission.The total deposition over the East Asian region in April 2006 was 136 million tons.The regional distribution of dust deposition showed that the 3 major sources were also the major deposition areas.The deposition amount in the 3 major sources accounted for 78%of the total with about 135 million tons falling back to the source regions.The secondary deposition area was the China mainland downriver,where more than 2 million tons deposited accounting for 16%of the total deposition.The deposition over the region east of 120°E including China off-shore regions,Korean Peninsula,Japan and the West Pacific took only 6%of the total deposition,which was about 850000 tons.The analysis on dry and wet deposition showed that dry deposition dominated in the process,accounting for 94%of the total sand and dust depositions in the period and wet deposition only was around for 6%,since it was generally dry with less rainfall over northern China in April.WANG Hong GONG ShanLing ZHANG HongLiang CHEN Yong SHEN XueShun CHEN DeHui XUE JiShan SHEN YuanFang WU XiangJun JIN ZhiYan 2010Chinese Science Bulletin2010,55,7:10
5A Novel Single Phase Grounding Fault Protection Scheme Without Threshold Setting for Neutral Ineffectively Earthed Power Systems显示文摘The setting values of thresholds for fault feature parameters are critical in all kinds of protection schemes.When the detected feature parameter value exceeds the setting value,the protection will trip.However,the setting value based conventional protection schemes sometimes cannot satisfy the protection requirements of neutral ineffectively earthed power systems(NIEPS)due to wide variations in operating conditions and the complexities of fault cases.In this paper,a novel single phase grounding fault protection scheme without threshold setting is proposed.The fault detection is achieved based on operating states rather than setting values.A fuzzy c-means algorithm is used to divide the operating state of the protected feeder into non-fault states and fault states.The cluster center of each state is then obtained by classifying the historical feature samples of the protected feeder extracted under various operating conditions into their corresponding states in a constructed multi-dimensional fault feature space.The distances between the detected feature samples and the cluster centers of the non-fault and the fault states are calculated.If the distance to the fault state is shorter than that to the non-fault state,a fault is detected.Otherwise,the feeder is considered normal.A PSCAD/EMTDC simulator is used to simulate a 35 kV NIEPS under various operating conditions,non-linear loads,and complex fault cases.Results show that the proposed single phase grounding fault protection scheme without threshold setting can protect the system correctly under all kinds of faults.Xiangjun Zeng Kun Yu Yuanyuan Wang Yao Xu 2016CSEE Journal of Power and Energy Systems2016,2,3:9
6Sini powder ameliorates the inflammatory response in rats with stress-induced non-alcoholic fatty liver disease by inhibiting the nuclear factor kappa-B/pyrin domain-containing protein 3 pathway显示文摘OBJECTIVE: To evaluate the effectiveness of Sini powder for the treatment of non-alcoholic fatty liver disease(NAFLD) in rats and the molecular mechanisms involved.METHODS: A rat model of stress-induced NAFLD was established by a combination of long-term tethering and feeding of a high-fat, high-calorie diet. These rats were then intragastrically administered with either simvastatin, Sini powder, or vehicle for 1 week. The body mass and field test scores for each group were recorded weekly. Serum aspartate aminotransferase and alanine aminotransferase activities, and triglyceride, total cholesterol,and free fatty acid concentrations were measured.Liver tissue histopathology was examined on hematoxylin and eosin-stained paraffin sections and oil red O-stained frozen sections. The hepatic m RNA expression of nuclear factor kappa-B(NF-κB),NOD-, LRR-, and pyrin domain-containing protein 3(NLRP3), apoptosis-associated speck-like protein containing CARD(ASC), and caspase-1 were measured by reverse transcription-polymerase chain reaction(RT-PCR). The hepatic protein concentrations of NF-κB and NLRP3, ASC, caspase-1, interleukin-1β(IL-1β), interleukin-6(IL-6), and the serum concentrations of IL-1β and IL-6 were measured by enzyme-linked immunosorbent assay.RESULTS: Compared with the Blank group, rats in the Compound model group showed significant pathologic manifestations of NAFLD, and the expression of NF-κB, NLRP3, ASC, caspase-1, IL-1βand IL-6 were significantly higher(all P < 0.01). Both simvastatin and Sini powder significantly ameliorated the NAFLD pathology and the abnormal expression of NF-κB, NLRP3, ASC, caspase-1, IL-1β, and IL-6(all P < 0.01).CONCLUSION: Sini powder inhibits the inflamma-tory response in rats with NAFLD, which is mediated by NF-κB/NLRP3, IL-1β, and IL-6, reduces the effects of psychological stress, and improves lipid metabolism. Therefore, Sini powder may be effective for the treatment of stress-related NAFLD through multiple mechanisms.Mu Jie Cheng Fafeng Wang Qingguo Wang Xueqian Zhu Wenxiang Ma Chongyang Yin Xiangjun Ren Beida Lian Yajun Du Xin Zhang Haixia Liu Shuling Zhang Shuang 2020Journal of Traditional Chinese Medicine2020,40,2:9
7Effect of discrete fibre reinforcement on soil tensile strength显示文摘The tensile behaviour of soil plays a significantly important role in various engineering applications.Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure.In order to increase soil tensile strength,discrete fibre reinforcement technique was proposed.An innovative tensile apparatus was developed to determine the tensile strength characteristics of fibre reinforced soil.The effects of fibre content,dry density and water content on the tensile strength were studied.The results indicate that the developed test apparatus was applicable in determining tensile strength of soils.Fibre inclusion can significantly increase soil tensile strength and soil tensile failure ductility.The tensile strength basically increases with increasing fibre content.As the fibre content increases from 0%to 0.2%,the tensile strength increases by65.7%.The tensile strength of fibre reinforced soil increases with increasing dry density and decreases with decreasing water content.For instance,the tensile strength at a dry density of 1.7 Mg/m^3 is 2.8times higher than that at 1.4 Mg/m^3.It decreases by 30%as the water content increases from 14.5%to20.5%.Furthermore,it is observed that the tensile strength of fibre reinforced soil is dominated by fibre pull-out resistance,depending on the interfacial mechanical interaction between fibre surface and soil matrix.Jian Li Chaosheng Tang Deying Wang Xiangjun Pei Bin Shi 2014Journal of Rock Mechanics and Geotechnical Engineering2014,6,2:8
8Sediment delivery ratio and its uncertainties on flood event scale:Quantification for the Lower Yellow River显示文摘Sediment delivery ratio(SDR)for fluvial rivers was formulated with sediment rating curve.The observed data of SDR on flood event scale of the Lower Yellow River(LYR)were adopted to examine the formulation and to calibrate the model parameters.A regression formula of SDR was then established and its 95%prediction interval was accordingly quantified to represent its overall uncertainties.Three types of factors including diversity of the incoming flow conditions,river self-regulation processes,and human activities were ascribed to the uncertainties.The following were shown:(1)With the incoming sediment coefficient(ISC)being a variable,it was not necessary to adopt the incoming flow discharge as the second variable in the formulation of SDR;and(2)ISC=0.003 and therefore SDR=2 might be a threshold for distinguishing the characteristics of sediment transport within the LYR.These findings would highlight sediment transport characteristics on the scale of flood event and contribute to uncertainty based analysis of water volume required for sediment transport and channel maintenance of the LYR.FU XuDong 1,JIANG LiWei 1,WU BaoSheng 1,HU ChunHong 2,WANG GuangQian 1 &FEI XiangJun 1 1State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China 2China Institute of Hydropower and Water Resources Research,Beijing 100044,China 2010Science China(Technological Sciences)2010,53,3:7
9A modified rheological model of natural debris flows显示文摘The two coefficients of the linear dimensionless viscous-dispersive mixture model have been modified according to their rheological properties of different types of viscous debris flows based on the observation and experimental data of debris flows and their slurries in the field, and then a rheological model of hyperconcentrated debris flows has been derived. The modified coefficients are the exponent of A which is modified by the highly-viscous slurry medium, and the maximum density which is modified by the volume concentration of original debris flows with heterogenous grain size.WANG Yuyi FEI Xiangjun CHEN Rui 2000Chinese Science Bulletin2000,45,8:6
10Establishment Method of a Mixture Model and Its Practical Application for Transmission Gears in an Engineering Vehicle显示文摘Highly versatile machines, such as wheel loaders, forklifts, and mining haulers, are subject to many kinds of working conditions, as well as indefinite factors that lead to the complexity of the load. The load probability distribution function (PDF) of transmission gears has many distributions centers; thus, its PDF cannot be well represented by just a single-peak function. For the purpose of representing the distribution characteristics of the complicated phenomenon accurately, this paper proposes a novel method to establish a mixture model. Based on linear regression models and correlation coefficients, the proposed method can be used to automatically select the best-fitting function in the mixture model. Coefficient of determination, the mean square error, and the maximum deviation are chosen and then used as judging criteria to describe the fitting precision between the theoretical distribution and the corresponding histogram of the available load data. The applicability of this modeling method is illustrated by the field testing data of a wheel loader. Meanwhile, the load spectra based on the mixture model are compiled. The comparison results show that the mixture model is more suitable for the description of the load-distribution characteristics. The proposed research improves the flexibility and intelligence of modeling, reduces the statistical error and enhances the fitting accuracy, and the load spectra complied by this method can better reflect the actual load characteristic of the gear component.WANG Jixin WANG Zhenyu YU Xiangjun YAO Mingyao YAO Zongwei ZHANG Erping 2012Chinese Journal of Mechanical Engineering2012,25,5:6
11A soil water and heat transfer model including changes in soil frost and thaw fronts显示文摘Freeze-thaw processes in soils,including changes in frost and thaw fronts(FTFs),are important physical processes.The movement of FTFs affects soil hydrothermal characteristics,as well as energy and water exchanges between the land surface and the atmosphere and hydrothermal processes in the land surface.This paper reduces the issue of soil freezing and thawing to a multiple moving-boundary problem and develops a soil water and heat transfer model which considers the effects of FTF on soil hydrothermal processes.A local adaptive variable-grid method is used to discretize the model.Sensitivity tests based on the hierarchical structure of the Community Land Model(CLM)show that multiple FTFs can be continuously tracked,which overcomes the difficulties of isotherms that cannot simultaneously simulate multiple FTFs in the same soil layer.The local adaptive variable-grid method is stable and offers computational efficiency several times greater than the high-resolution case.The simulated FTF depths,soil temperatures,and soil moisture values fit well with the observed data,which further demonstrates the potential application of this simulation to the land-surface process model.WANG AiWen XIE ZhengHui FENG XiaoBing TIAN XiangJun QIN PeiHua 2014Science China Earth Sciences2014,57,6:5
12Planar Velocity Distribution of Viscous Debris Flow at Jiangjia Ravine,Yunnan,China:A Field Measurement Using Two Radar Velocimeters显示文摘Characteristics of planar velocity distribution of vis-cous debris flow were analyzed using the measured data at Jiangjia Ravine,Yunnan,China. The velocity data were measured through using two radar velocimeters. The cross-sectional mean velocities were calculated and used to examine Kang et al's(2004) relation-ship,which was established for converting the flow velocity at river centerline measured by a radar velocimeter into the mean velocity based on the stop-watch method. The velocity coefficient,K,defined by the ratio of the mean velocity to the maximum ve-locity,ranges from 0.2 to 0.6. Kang et al's(2004) relationship was found being inapplicable to flows with K smaller than 0.43. This paper contributes to show the complexity of the planar velocity distribution of viscous debris flows and the applicability of Kang et al's relationship.FU Xudong WANG Guangqian KANG Zhicheng FEI Xiangjun 2007Wuhan University Journal of Natural Sciences2007,12,4:5
13Determination of Content of Amino Acid in Abalone by Precolumn Derivatization and its Nutritional Value Evaluation显示文摘[Objectives] This study was conducted to optimize the determination conditions of amino acids from abalone. [Methods] The sample was treated by acid hydrolysis method and subjected to 2,4-2 nitro fluorobenzene column derivatization. The amino acid content in abalone was determined by HLPC,and the nutritional value of the amino acids was evaluated with egg protein model put forward by Institute of Nutrition and Food Hygiene,Chinese Academy of Preventive Medicine. [Results] Abalone contains full amino acids. According to the FAO/WHO ideal,it is a high-quality protein source and suitable for supplement of protein source for human body. [Conclusions]The experimental method has simple operation and could achieve a good effect with wide linear range and correlation coefficient over 0. 999 8,and the obtained results are satisfactory.Wen CHEN Xiangjun WANG Yujie WANG Yuzhi HUANG Fanmeng MENG Hui CHEN 2018Agricultural Biotechnology2018,7,3:5
14Research on Large Volume Airgun Source Signal Reception in Hutubi, Xinjiang Using Seismic Network Data显示文摘We used data from the Xinjiang Digital Seismic Network and PSD( Power Spectral Density) method to perform noise level assessment for six stations. We calculated the median of the power spectral density to evaluate the noise level of different stations. After the comparison of the power spectral density of different stations and the airgun signal recognition,we found that noise level of stations with recognizable airgun source signals is lower than that of stations without recognizable signals. The largest difference of the power spectral density is 40 d B,and the smallest is 15 d B. Finally,we found that the failure to recognize the signal of airgun sources at some stations is due to the noise level.Su Jinbo Wang Qiong Wang Haitao Shi Yongjun Chen Xiangjun Feng Lei Chen Hao Zhang Wenxiu 2016Earthquake Research in China2016,30,3:4
15Homogenization treatment of high Nb containing TiAl alloys with as-cast and as-forged microstructures显示文摘包含 TiAl 合金的高 Nb 的微观结构进化上的热处理的效果被学习了。结果显示在当演员组和同样伪造的合金的那 -segregation, 分离和 S 分离能有效地在 T 上面在温度被消除(1350-1400 癯牥吗?XU Zhengfang XU Xiangjun LIN Junpin ZHANG Yong WANG Yanli LIN Zhi CHEN Guoliang 2008Rare Metals2008,27,2:4
16Optimization of the Ultrasonic-assisted Extraction Process for Protocatechuic Acid from Emilia sonchifolia DC by Response Surface Methodology显示文摘[Objectives] This study was conducted to optimize the extraction process of protocatechuic acid from Emilia sonchifolia DC. [Methods] The optimal extraction conditions were determined by single factor,response surface analysis and variance analysis,and the content of protocatechuic acid was determined by HPLC. [Results] The protocatechuic acid standard curve equation was: y = 1 435 x + 8 403,R^2= 0. 999 8,indicating a good linear relationship. The optimal extraction conditions were as follows: a temperature at 80 ℃,an extraction time of 1 h,a material-to-liquid ratio at 1:10 and an ultrasonic power of 600 W,and the content of protocatechuic acid extracted was 1. 93 mg/g. The method showed a RSD of 0. 41%,less than 2%,and the detection limit was 0. 0000047261 g/ml.The experimental sample X1 was the low-level 0. 1 mg/ml standard solution,which showed recovery of protocatechuic acid between 100.8% and 105.2%,with a RSD of 0. 013%;and the sample X2 was the high-level 1. 0 mg/ml standard solution,which exhibited recovery between 100. 6% and 102. 2%,with a RSD of 0.076%. Thus,the recovery was high,and the requirements of the performance index were met. [Conclusions] The detection method is stable and reliable and can produce satisfactory results.Wen CHEN Xiangjun WANG Lingyan LI Zhewen ZHAI Xiaoling HUANG Wubing RAO Chenghan ZOU Tengtong LI 2020Agricultural Biotechnology2020,9,3:3
17Review of Coded Modulation Free Space Optical Communication System显示文摘This paper presents a constructive discussion and inclusive review on advancements in the coded modulation free-space optical(FSO) communication system and corresponding techniques. These techniques mainly include channel model,forward error correction(FEC) and modulation schemes. Firstly,a complete view of FSO system is presented which contains the description,the current research situation along with the advantages over the traditional radio frequency(RF) wireless communication and fiber optical communications. Then,the channel model,FEC,modulation schemes and complete system of coded modulation FSO are analyzed successively. At last,the review work of coded modulation FSO system is summarized and further improvements are prospected.WANG Kaimin LIU Bo ZHANG Lijia ZHANG Qi TIAN Qinghua XIN Xiangjun 2015China Communications2015,12,11:3
18Spectral moment estimates of broadband backscattering acoustic wave in moving medium显示文摘In this paper, the signal and noise of broadband moving medium reverberation are supposed to be colored complex Gaussian processes. When the sample number is large, both the mean and variance of the first power spectral moment estimator by covariance techniques are obtained. The results obtained by D. S. ZRNIC[8], where the noise is assumed to be white,are generalized The transmitted signal is pseudo noise (PN) train and consists of two same subtrains between which the difference is only a time delay. In order to simplify the analysis,the center frequency and frequency bandwidth of both signal and noise are also assumed to be equal. It is shown that the mean of the first power spectral moment estimate is an unbiased estimate and that the variance of this estimate is dependent on (1) the correlation coefficient ρ between two subtrains, (2) the signal-to-noise ratio S/N and (3) △fTL, where △f, T and L are the frequency bandwidth, time duration and total number of pulse elements in a subtrain respectively. Three thousand groups of narrow-band-signal data obtained in field are analyzed.Then the range of ρ is determined. All these results are very useful in desiglling a broadballd acoustic Doppler current profiler (BBADCP).ZHU Weiqing WANG Changhong PAN Feng and ZHANG Xiangjun(Institute of Acoustics, Academia Sinica, Beijing 100080) 1996Chinese Journal of Acoustics1996,15,2:3
19DCWord: A Novel Deep Learning Approach to Deceptive Review Identification by Word Vectors显示文摘Due to the anonymous and free-for-all characteristics of online forums,it is very hard for human beings to differentiate deceptive reviews from truthful reviews.This paper proposes a deep learning approach for text representation called DCWord (Deep Context representation by Word vectors) to deceptive review identification.The basic idea is that since deceptive reviews and truthful reviews are composed by writers without and with real experience on using the online purchased goods or services,there should be different contextual information of words between them.Unlike state-of-the-art techniques in seeking best linguistic features for representation,we use word vectors to characterize contextual information of words in deceptive and truthful reviews automatically.The average-pooling strategy (called DCWord-A) and maxpooling strategy (called DCWord-M) are used to produce review vectors from word vectors.Experimental results on the Spam dataset and the Deception dataset demonstrate that the DCWord-M representation with LR (Logistic Regression) produces the best performances and outperforms state-of-the-art techniques on deceptive review identification.Moreover,the DCWord-M strategy outperforms the DCWord-A strategy in review representation for deceptive review identification.The outcome of this study provides potential implications for online review management and business intelligence of deceptive review identification.Wen Zhang Qiang Wang Xiangjun Li Taketoshi Yoshida Jian Li 2019Journal of Systems Science and Systems Engineering2019,28,6:3
20Knockdown of Oct4 and Nanog expression inhibits the stemness of pancreatic cancer cells显示文摘Yuhua Lu Hui Zhu Haiyan Shan Junjie Lu Xu Chang Xiaohong Li Jingjing Lu Xiangjun Fan Shajun Zhu Yao Wang Qingsong Guo Lei Wang Yan Huang Mingyan Zhu Zhiwei Wang 2013Cancer Letters2013,,:3
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