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269篇 您的检索式:作者名="Changwen"
    题名 作者 年代 出处 被引量
1Interaction of NPK Fertilizers During Their Transformation in Soils: I. Dynamic Changes of Soil pH显示文摘Dynamic changes of soil pH as influenced by ammonium sulfate (AS), monocalcium phosphate (MCP),potassium chloride (KCl) and their interaction in soils were evaluated in incubation experiments. Applyingthese fertilizers significantly reduced soil pH values in all cases and followed sequences of AS > MCP >KCl, MCP > KCl > AS and KCl > AS > MCP for the paddy, calcareous and red soils, respectively. TheAS-induced reduction of pH in the three soils followed the sequence of red soil > paddy soil > calcareous soil,while in MCP and KCl systems the reduction of pH followed the sequences of calcareous soil > paddy soil >red soil and red soil > calcareous soil > paddy soil, respectively. The interactions of the NPK fertilizers on pHwere significant. MCP plus KCl or MCP plus AS reduced pH values more than the fertilizers applied solelyin the paddy soil, but AS partly counteracted the effect of MCP on pH in the 1 d sample of the calcareoussoil. The effect of MCP on pH was trivial when MCP was applied in combination with KCl or AS in the redsoil. When applied in combination with AS, KCl did not affect soil pH initially, but suppressed the reductionof pH at the later incubation stage, which was related to inhibition of nitrification by KCl in the soils.WANG HUOYAN, ZHOU JIANMIN, CHEN XIAOQIN, LI SHOUTIAN, DU CHANGWEN and DONG CAIXIAInstitute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) 2003Pedosphere2003,13,3:28
2Construction and Properties of Structure-and Size-controlled Micro/Nano-energetic Materials显示文摘The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development of the construction strategies for achieving zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) micro/nanostructures from energetic molecules is introduced. Also, an overview of the unique properties induced by micro/nanostructures and size effects is provided. Special emphasis is focused on the size-dependent properties that are different from those of the conventional micro-sized energetic materials, such as thermal decomposition, sensitivity, combustion and detonation, and compaction behaviors. A conclusion and our view of the future development of micro/nano-energetic materials and devices are given.HUANG Bing CAO Minhua NIE Fude HUANG Hui HU Changwen 2013Defence Technology(防务技术)2013,9,2:20
3Reducing oxidative stress and hepatoprotective effect of water extracts from Pu-erh tea on rats with high-fat diet显示文摘Reducing oxidative stress and hepatoprotective effect of Pu-erh tea water extracts on rats fed with high-fat diet were researched for explaining health care of Pu-erh tea.Fifty SD rats were divided into five groups.The body weight was measured once a day.The malondialdehyde(MDA)and glucose(Glu)levels and the activities of alanine aminotransferase(ALT),aspartate aminotransferase(AST),nitric oxide synthase(NOS),and pyruvate kinase(PK)in serum were determined.Furthermore,the hepatic glycogen level(HGL)and the activities of hepatic total superoxide dismutase(T-SOD),catalase(CAT),and glutathione peroxidase(GSH-Px)were also measured after continuous administration for 12 weeks.The result demonstrated that Pu-erh extract caused the decreases in body weight,fat index,MDA and NOS levels,and the increases in hepatic T-SOD,CAT and GSH-Px activities,indicating that the extract may be due to inhibiting the increases of body weight and fat index,reducing oxidant stress state and inhibiting lipid peroxidation,thus decreasing the activities of ALT and AST,and protecting the liver in rat.Meanwhile,the extracts could increase the production of hepatic glycogen and the activity of PK,and reduce glucose level,protecting the liver from the diseases associated with type II diabetes.Jingjing Su Xueqing Wang Wenjun Song Xiaoli Bai Changwen Li 2016Food Science and Human Wellness2016,5,4:9
4CFAR assessment of covariance matrix estimators for non-Gaussian clutter显示文摘In the non-Gaussian clutter modeled as independent and identically distributed spherically invariant random vectors, three estimators of sample covariance matrix (SCM), normalized sample covariance matrix (NSCM) and the corresponding recursive estimator (NSCM-RE) are analyzed. Based on the uniform theorem, three corresponding adaptive normalized matched filters (ANMF) are evaluated from the standpoint of constant false alarm rate (CFAR) property. The theoretical results demonstrate that the SCM-ANMF is only CFAR to the normalized clutter covariance matrix (NCCM); the NSCM-ANMF is only CFAR to the clutter power level; and the NSCM-RE-ANMF with finite number of iterations is still not CFAR to the NCCM. To ensure CFAR property of ANMF, an adaptive estimator (AE) is devised. Moreover, with AE as the initialization matrix for the iterations, the AE-RE is proposed. With finite number of iterations, the corresponding AE-REANMF guarantees CFAR property to both of the NCCM and the clutter power level. Finally, the performance assessment conducted by Monte Carlo simulation confirms the effectiveness of the proposed detectors.HE You, JIAN Tao, SU Feng, QU ChangWen & PING DianFa Research Institute of Information Fusion, Naval Aeronautical and Astronautical University, Yantai 264001, China 2010Science China(Information Sciences)2010,53,11:8
5Genomic sequencing and analysis of the first imported Middle East Respiratory Syndrome Coronavirus(MERS CoV) in China显示文摘Dear Editors,Middle East Respiratory Syndrome(MERS)has spread to more than 23 countries since the first case of a MERS coronavirus(MERS Co V)infection was confirmed in Sep2012[1].Because MERS Co V has led to mortality as high as 40%,it has become one of the most important emerging pathogens threatening human health.Recently,the outbreak of MERS Co V,which resulted in 172 infections andXIE Qian CAO YuJuan SU Juan WU XianBo WAN ChengSong KE ChangWen ZHAO Wei ZHANG Bao 2015Science China(Life Sciences)2015,58,8:8
6High resolution radar target adaptive detector and performance assessment显示文摘The high resolution radar target detection is addressed in the non-Gaussian clutter. An adaptive detector is derived for range-spread target based on a novel covariance matrix estimator. It is proved that the new detector is constant false alarm rate (CFAR) to both of the clutter covariance matrix structure and power level theoretically for match cases. The simulation results show that the new detector is almost CFAR for mismatch cases, and it outperforms the existing adaptive detector based on the sample covariance matrix. It also shows that the detection performance improves, as the number of pulses, the number of secondary data or the clutter spike increases. In addition, the derived detector is robust to different subsets, estimated clutter group sizes and correlations of clutter. Importantly, the number of iterations for practical application is just one.Tao Jian You He Feng Su Changwen Qu Dianfa Ping 2011Journal of Systems Engineering and Electronics2011,22,2:7
7A preliminary analysis of fishery resource exhaustion in the context of biodiversity decline显示文摘Marine biodiversity in almost all oceans is being threatened at the genetic, species, and ecosystem levels. The marine ecosystem is being degraded and the extinction rate of marine organisms has accelerated. In this paper, the potential causes of fishery resource exhaustion in the East China Sea are analyzed, including the change in the stoichiometric composition of seawater with regard to the concentrations of N and P, toxic effects of marine pollution, marine habitat destruction, increased seawater temperatures caused by climate warming, ocean acidification, pressure from overfishing, and the spread of marine pathogenic bacteria. It is believed that the factors mentioned above have significant impact on the exhaustion of fishery resources in the East China Sea. However, considering the cumulative, synergistic, and superimposed effects as well as the amplification effects resulting from their interactions, the actual risk of ecological extinction of marine organisms might be even more severe than that previously estimated. Hence, ecosystem management and research focused on a single risk factor or influencing factor is not enough to prevent marine ecosystem degradation and fishery resource exhaustion. A comprehensive, systematic, effective, and ecosystem-based management policy is imperative for healthy and sustainable fishery development in the East China Sea.ZHAO ShuJiang Lü BaoQiang LI RuWei ZHU AiYi WU ChangWen 2016Science China Earth Sciences2016,59,2:6
8Analysis of Thermoelastohydrodynamic Performance of Journal Misaligned Engine Main Bearings显示文摘To understand the engine main bearings' working condition is important in order to improve the performance of engine. However, thermal effects and thermal effect deformations of engine main bearings are rarely considered simultaneously in most studies. A typical finite element model is selected and the effect of thermoelastohydrodynamic(TEHD) reaction on engine main bearings is investigated. The calculated method of main bearing's thermal hydrodynamic reaction and journal misalignment effect is finite difference method, and its deformation reaction is calculated by using finite element method. The oil film pressure is solved numerically with Reynolds boundary conditions when various bearing characteristics are calculated. The whole model considers a temperature-pressure-viscosity relationship for the lubricant, surface roughness effect, and also an angular misalignment between the journal and the bearing. Numerical simulations of operation of a typical I6 diesel engine main bearing is conducted and importance of several contributing factors in mixed lubrication is discussed. The performance characteristics of journal misaligned main bearings under elastohydrodynamic(EHD) and TEHD loads of an I6 diesel engine are received, and then the journal center orbit movement, minimum oil film thickness and maximum oil film pressure of main bearings are estimated over a wide range of engine operation. The model is verified through the comparison with other present models. The TEHD performance of engine main bearings with various effects under the influences of journal misalignment is revealed, this is helpful to understand EHD and TEHD effect of misaligned engine main bearings.BI Fengrong SHAO Kang LIU Changwen WANG Xia ZHANG Jian 2015Chinese Journal of Mechanical Engineering2015,28,3:6
9Isolation via enrichment and characterization of ten polymorphic microsatellite loci in the cuttlefish, Sepiella maindroni de Rochebruns显示文摘Ten novel polymorphic microsatellite loci were developed using an enrichment and colony hybridization protocol and characterized for the cuttlefish,Sepiella maindroni.Polymorphism was explored by using 30 individuals from the coastal waters of Zhanjiang,Guangdong province,China,in December 2007.The number of alleles ranged from 5 to 13.The ranges of observed and expected heterozygosity were from 0.578 9 to 1.000 0 and 0.682 8 to 0.925 7,respectively,and the average polymorphic information content (P IC) was 0.778 5.These microsatellite loci will certainly facilitate the detection of the genetic variation and population structure of S.maindroni.WU Changwen CHI Changfeng HE Guangyuan LU Zhenming XU Meiying 2010Acta Oceanologica Sinica2010,29,6:6
10Determinants of Self-employment in China:Evidence from Cross-regional Data显示文摘这份报纸在 2000 年代在中国处于自我雇用率论述并且测试,并且说明地区性的变化的一系列来源经济开发的阶段是主要解释因为自我雇用的变化在过去的十年越过区域评价。在在纸识别的经济开发和自我雇用率的阶段之间的否定关系显示中国进入了快工业化的进程,并且自我雇用在经济生长和雇用正在起一个减少的作用。我们也发现在自我雇用和私营企业之间的替换效果。当两个是中国的私人部门的重要部件时,私营企业正在成为中国的经济生长和雇用的日益重要的来源。而且,我们的调查结果也暗示当工作机会是有限的时,在中国的自我雇用是可能的为工资工作不合格的处于不利地位的人的一种强迫的选择。Kun Li Changwen Zhao 2011China & World Economy2011,19,3:6
11Multi-scale finite element analysis of chloride diffusion in concrete incorporating paste/aggregate ITZs显示文摘In this paper,we propose a concurrent multi-scale finite element(FE) model coupling equations of the degree of freedoms of meso-scale model of ITZs and macroscopic model of bulk pastes.The multi-scale model is subsequently implemented and integrated into ABAQUS resulting in easy application to complex concrete structures.A few benchmark numerical examples are performed to test both the accuracy and efficiency of the developed model in analyzing chloride diffusion in concrete.These examples clearly demonstrate that high diffusivity of ITZs,primarily because of its porous microstructure,tends to accelerate chloride penetration along concentration gradient.The proposed model provides new guidelines for the durability analysis of concrete structures under adverse operating conditions.GUO Li GUO XiaoMing MI ChangWen 2012Science China(Physics,Mechanics & Astronomy)2012,55,9:5
12Comparison of nonhuman primates identified the suitable model for COVID-19显示文摘Identification of a suitable nonhuman primate(NHP)model of COVID-19 remains challenging.Here,we characterized severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in three NHP species:Old World monkeys Macaca mulatta(M.mulatta)and Macaca fascicularis(M.fascicularis)and New World monkey Callithrix jacchus(C.jacchus).Infected M.mulatta and M.fascicularis showed abnormal chest radiographs,an increased body temperature and a decreased body weight.Viral genomes were detected in swab and blood samples from all animals.Viral load was detected in the pulmonary tissues of M.mulatta and M.fascicularis but not C.jacchus.Furthermore,among the three animal species,M.mulatta showed the strongest response to SARS-CoV-2,including increased inflammatory cytokine expression and pathological changes in the pulmonary tissues.Collectively,these data revealed the different susceptibilities of Old World and New World monkeys to SARS-CoV-2 and identified M.mulatta as the most suitable for modeling COVID-19.Shuaiyao Lu Yuan Zhao Wenhai Yu Yun Yang Jiahong Gao Junbin Wang Dexuan Kuang Mengli Yang Jing Yang Chunxia Ma Jingwen Xu Xingli Qian Haiyan Li Siwen Zhao Jingmei Li Haixuan Wang Haiting Long Jingxian Zhou Fangyu Luo Kaiyun Ding Daoju Wu Yong Zhang Yinliang Dong Yuqin Liu Yinqiu Zheng Xiaochen Lin Li Jiao Huanying Zheng Qing Dai Qiangming Sun Yunzhang Hu Changwen Ke Hongqi Liu Xiaozhong Peng 2020Signal Transduction and Targeted Therapy2020,5,1:5
13A Case of New Variant COVID-19 First Emerging in South Africa Detected in Airplane Pilot—Guangdong Province,China,January 6,2021显示文摘On January 6,2021,Guangdong CDC successfully isolated the 501Y.V2 variant of coronavirus disease 2019(COVID-19)virus from a throat swab of a patient.The 501Y.V2 variant was first detected in South Africa,and the patient is a 55-year-old male airline pilot of South African nationality.He entered Guangzhou City,the capital of Guangdong Province,from Singapore on the evening of December 8,2020 and was subject to a COVID-19 test.Fengjuan Chen Bosheng Li Peter Hao Yang Song Wenbo Xu Nankun Liu Chunliang Lei Changwen Ke 2021China CDC weekly2021,3,2:5
14MATHEMATICAL MODEL OF OVERLAND FLOW AND MECHANISM OF SOIL CONSERVATION FOR FORESTED STEEP HILLSLOPE--(II)Mechanism of Soil Conservation Over Steep Hillslope显示文摘MATHEMATICALMODELOFOVERLANDFLOWANDMECHANISMOFSOILCONSERVATIONFORFORESTEDSTEEPHILLSLOPE--(II)MechanismofSoilConservationOverSt...WU Changwen and WANG Lixian ( Science. Nanchang College of Water Resources and Hydro Power, 330029)( Dept of Soil and Water Conservation, Beijing Forestry University, 100083,PRC) 1995International Journal of Sediment Research1995,10,2:4
15H_(3)PMo_(12)O_(40)-catalyzed coupling of diarylmethanols with epoxides/diols/aldehydes toward polyaryl-substituted aldehydes显示文摘A versatile heteropoly acid(H_(3)PMo_(12)O_(40))-catalyzed coupling of diarylmethanols with epoxides was established for the synthesis of polyaryl-substituted aldehydes.Furthermore,the catalytic system was also suitable for the reaction of diarylmethanols and diols/aldehydes.The application of such an earthabundant,readily accessible,and nontoxic catalyst provides a green approach for the construction of polyaryl-substituted aldehydes.Guoping Yang Yufeng Liu Ke Li Wei Liu Bing Yu Changwen Hu 2020Chinese Chemical Letters2020,31,12:4
16Novel passive localization algorithm based on double side matrix-restricted total least squares显示文摘In order to solve the bearings-only passive localization problem in the presence of erroneous observer position, a novel algorithm based on double side matrix-restricted total least squares (DSMRTLS) is proposed. First, the aforementioned passive localization problem is transferred to the DSMRTLS problem by deriving a multiplicative structure for both the observation matrix and the observation vector. Second, the corresponding optimization problem of the DSMRTLS problem without constraint is derived, which can be approximated as the generalized Rayleigh quotient minimization problem. Then, the localization solution which is globally optimal and asymptotically unbiased can be got by generalized eigenvalue decomposition. Simulation results verify the rationality of the approximation and the good performance of the proposed algorithm compared with several typical algorithms.Xu Zheng Qu Changwen Wang Changhai 2013Chinese Journal of Aeronautics2013,26,4:4
17Stepwise prediction and statistical screening:B-cell epitopes on neuraminidase of human avian H_5N_1 virus显示文摘The B-cell epitopes of virus are associated with the antiviral drug and the vaccine screening. As the nucleotide sequences of neuraminidase (NA) of stain GD-01-06 were sequenced, we predicted the α-helix and β-fold structure and the indexes of the flexible regions of secondary structure of NA with methods of the Hydrophilicity plot by Kyte-Doolittle, the Surface probability plot by Emini and the Antigenic index by Jameson-Wolf, and then screened statistically the parameters to predict B-cell epitopes by the Hierarchical cluster and the Bivariate correlation and the quartiles with SPSS 13.0. The impact of variation of amino acids in NA on its epitopes was analyzed. The predictive results were evaluated by Wu’s Antigenic Index and SWISS-MODEL. We found that the most possible epitopes on NA were located within or nearby its N-terminal Nos. 120―137, 81―84, 408―415, 273―282, 429―432, 356―368, 46―55, 146―155, 341―350 and 198―209, which were the dominant regions of NA epitopes. Peptide 120―137 including the glycoprotein domain (NGT126―128) was first chosen as the B-cell epitopes on NA. NA in H5N1 strain isolated after 2003 lacked in No. 53 amino acid (I), resulting in an increase in the surface flexible region of NA in GD-01-06 and an enlargement to their epitope regions (VEP46―48→ VEPISNTNFL46―55). Conclusively, prediction of the B-cell epitopes on the NA based on multiple parameters is useful for researches on the molecular immunology and drug screening and immuno-prophylaxis. A deletion of No. 53 amino acid (I) in NA in strain GD-01-06 might increase its antigenicity.HUANG Ping YU ShouYi KE ChangWen 2008Chinese Science Bulletin2008,53,23:4
18Resveratrol prevents interleukin-1 β-induced dysfunction of pancreatic β-cells显示文摘Objective:Interleukin-1β(IL-1β)plays an important role in the development of type 1 and type 2 diabetes mellitus.Resveratrol,a polyphenol,is known to have a wide range of pharmacological properties in vitro.In this research,we examined the effects of resveratrol on IL-1β-inducedβ-cell dysfunction.Methods:We first evaluated the effect of resveratrol on nitric oxide(NO)formation in RINm5F cells stimulated with IL-1βusing the Griess method.Next,we performed transient transfection and reporter assays to measure the transcriptional activity of peroxisome proliferator-activated receptor-γ(PPAR-γ).We also used Western blotting analysis to assess the effect of resveratrol on inducible nitric oxide synthase(iNOS)expression and nuclear factor-κB(NF-κB)translocation to the nuclei in cells treated with IL-1β.In addition,we assessed the transcriptional activity of NF-κB using an electrophoretic mobility shift assay(EMSA).Finally,we evaluated the effect of resveratrol on IL-1β-induced inhibition of glucose-stimulated insulin secretion in freshly isolated rat pancreatic islets.Results:Resveratrol significantly suppressed IL-1β-induced NO production,a finding that correlated well with reduced levels of iNOS mRNA and protein.The molecular mechanism by which resveratrol inhibited iNOS gene expression appeared to involve increased PPAR-γactivity,which resulted in the inhibition of NF-κB activation.Further analysis showed that resveratrol could prevent IL-1β-induced inhibition of glucose-stimulated insulin secretion in rat islets.Conclusion:In this study,we demonstrated that resveratrol could protect against pancreaticβ-cell dysfunction caused by IL-1β.Fang Chen Xiaohua Zhou Yan Lin Changwen Jing Tao Yang Yong Ji Yujie Sun Xiao Han 2010The Journal of Biomedical Research2010,24,5:3
19Supermolecular layered double hydroxides显示文摘Research progresses in the layered double hydroxides [M2+(1-x)M3+x(OH)2]x+An-x/n.mH2O intercalatedwith metal coordinate ions or oxometalates in the last ten years are reviewed. These layered double hydroxides are mainly intercalated with polyoxometalate (POM) ions, a LiAl-LDH photochemical assembly containing TiO2 and CH3(CH2)12COO- anions, together with Zn(TPPC) (porphy-rin derivate) and macrocyclic ligand-containing porphyrin derivate anions. Emphasis is put on the synthesis methods for intercalation of the anions into the interlayer regions, the characterization techniques and structures for the layeredcompounds and the newest research progress in the fields such as catalysis. The review also forecasts the prospects of the field.Hu Changwen Li Danfeng Guo Yihang Wang Enbo 2001Chinese Science Bulletin2001,46,13:3
20Synthesis of Cyclic Carbonates from Alkenyl and Alkynyl Substrates显示文摘Bo Zou Changwen Hu 2017Chinese Journal of Chemistry2017,35,5:3
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