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Search Results: 1 - 10 of 78231 matches for " Chen Zhanqing "
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Simultaneous Biohydrogen and Bioethanol Production from Anaerobic Fermentation with Immobilized Sludge
Wei Han,Zhanqing Wang,Hong Chen,Xin Yao,Yongfeng Li
Journal of Biomedicine and Biotechnology , 2011, DOI: 10.1155/2011/343791
Abstract: The effects of organic loading rates (OLRs) on fermentative productions of hydrogen and ethanol were investigated in a continuous stirred tank reactor (CSTR) with attached sludge using molasses as substrate. The CSTR reactor with attached sludge was operated under different OLRs, ranging from 8 to 24 kg/m3·d. The H2 and ethanol production rate essentially increased with increasing OLR. The highest H2 production rate (10.74 mmol/h?L) and ethanol production rate (11.72 mmol/h?L) were obtained both operating at OLR = 24 kg/m3·d. Linear regression results show that ethanol production rate () and H2 production rate () were proportionately correlated and can be expressed as =1.5365?5.054 (2=0.9751). The best energy generation rate was 19.08 kJ/h?L, which occurred at OLR = 24 kg/m3·d. In addition, the hydrogen yield was affected by the presence of ethanol and acetic acid in the liquid phase, and the maximum hydrogen production rate occurred while the ratio of ethanol to acetic acid was close to 1.
Diagnosis of hepatic fibrosis in hepatitis B patients by logistic regression modeling based on plasma amino acid ratio and age
ZHANG Zhanqing
Journal of Clinical Hepatology , 2013,
Abstract: ObjectiveTo explore the efficacy of logistic regression modeling based on plasma amino acid profile and patient age, for diagnosing hepatic fibrosis in patients with chronic hepatitis B (CHB). MethodsOne-hundred-and-forty-eight patients (108 males; mean age: 38.1±11.9 years, range: 16-72 years) histologically diagnosed with CHB at our institute between January 2009 and June 2011 were enrolled for study. Pathological staging of fibrosis classified patients as: significant (≥S2), severe (≥S3), or advanced (S4) stages. Plasma molar concentrations of amino acids were determined by high-performance liquid chromatography, and used to establish the top six fractional ratio models according to progressive significance of correlations with pathological stages (by Spearman′s rank correlation coefficient analysis). The abilities of scale models to predict fibrosis were evaluated using the area under the receiver operating characteristic (AUROC) curve. ROC curve analysis allowed for the best cutoff for age to be determined for the pathological stages and calculation of sensitivity, specificity, and accuracy for the corresponding prediction probabilities (PP). ResultsPatient age was postively correlated with pathological stage (rs=0.262, P=0.001). The significant correlation coefficients for the six models were (in descending order): (isoleucine+leucine)/tyrosine (rs=-0.350, P=0.000), leucine/tyrosine (rs=-0.349, P=0.000), (isoleucine+leucine+valine)/tyrosine (rs=-0.345, P=0000), (leucine+valine)/tyrosine (rs=-0.342, P=0.000), (isoleucine+valine)/tyrosine (rs=-0.336, P=0.000), valine/tyrosine (rs=-0311, P=0.000).The logistic regression model based on age and the ratio models of plasma amino acids could not be established. For severe fibrosis, the PP was 0.722 (95% CI: 0.640-0.804), with sensitivity of 0.49, specificity of 0.85, and accuracy of 0.69. For advanced fibrosis, the PP was 0.792 (95% CI: 0.708-0.876), with sensitivity of 0.73, specificity of 0.76, and accuracy of 0.75. ConclusionLogistic regression modeling based on plasma amino acid profile and patient age could have clinical utility for sensitive, specific and accurate diagnosis of severe and advanced fibrosis in CHB patients.
Assessing forest ecosystem health Ⅱ.A case study
森林生态系统健康评估Ⅱ.案例实践

CHEN Gao~,DENG Hongbing,DAI Limin,HAO Zhanqing,WANG Qingli,
陈高

应用生态学报 , 2005,
Abstract: On the bases of samples investment and related data collected by others,and with the method of health distance assessment and the ecosystem health index system of Korean pine and broad-leaved mixed forest established in prior paper,this paper attempted to assess the ecosystem health of Korean pine and broad-leaved mixed forest under various human disturbances.The results showed that the health degree was in the order of 20% intensity selective cutting stand (0.21) <50% intensity selective cutting stand (0.44)
Geographical Range and Local Abundance of Tree Species in China
Haibao Ren, Richard Condit, Bin Chen, Xiangcheng Mi, Min Cao, Wanhui Ye, Zhanqing Hao, Keping Ma
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0076374
Abstract: Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1) whether locally abundant species tend to be geographically widespread; 2) whether species are more abundant towards their range-centers; and 3) how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20–25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km2, and >90% of 651 species had ranges >105 km2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species’ abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges.
NONLINEAR DYNAMIC STUDY ON GAS FLOW IN BROKEN ROCK MASS
破碎岩体中气体渗流的非线性动力学研究

LI Shuncai,CHEN Zhanqing,MIAO Xiexing,MAO Xianbiao,
李顺才
,陈占清,缪协兴,茅献彪

岩石力学与工程学报 , 2007,
Abstract: In fields of coal mining,geotechnical engineering,the flow in broken rock is nonlinear,instable and time-varying for seepage parameters.Under the external disturbance,the gradual variation of the seepage parameter is apt to result in the catastrophe of the dynamic responses of the flow system and induces disasters such as water inrush and gas outburst.The study of the flow stability on the broken rock mass induced by mining is a basic subject of a series of important research topics such as controlling the stability of the surrounding rock,preventing the outburst disaster,exploiting and using the underground resources.The theories of bifurcation and catastrophe in nonlinear science are used to study the dynamic mechanism of instability of gas flow in broken rock.The nonlinear dynamical equations of one-dimensional non-Darcy and unsteady gas flow in broken rock are established.The solution diagram of dimensionless velocity under steady-state is given and the distribution laws along the direction of flow are obtained for the pore pressure and the steady-state flow velocity;namely,along the flow direction,the product of the pore pressure and the flow velocity of the dimensionless steady-states is a constant and the square of the pore pressure descends linearly.With low relaxation iteration,the dynamical responses corresponding to the different flow parameters of seepage system are also given.The results indicate that there is a saddle-node bifurcation in dynamic system of flow in broken rock;and at the bifurcation point,the breaking of edges and corners of rock grains is remarkable;thus an arbitrary weak perturbing at this point may result in a fold catastrophe of flow system and induce some dynamic disasters such as gas outburst,etc..
Systematic variations of cloud top temperature and precipitation rate with aerosols over the global tropics
Feng Niu,Zhanqing Li
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2012,
Abstract: Aerosols may modify cloud properties and precipitation via a variety of mechanisms with varying and contradicting consequences. Using a large ensemble of satellite data acquired by the Moderate Resolution Imaging Spectroradiometer onboard the Earth Observing System's Aqua platform, the CloudSat cloud profiling radar and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite over the tropical oceans, we identified two distinct correlations of clouds and precipitation with aerosol loading. Cloud-top temperatures are significantly negatively correlated with increasing aerosol index (AI) over oceans and aerosol optical depth (AOT) over land for deep mixed-phase clouds with liquid droplets near the warm bases and ice crystals near the cold tops; no significant changes were found for uniformly liquid clouds. Precipitation rates are positively correlated with the AI for mixed-phase clouds, but negatively correlated for liquid clouds. These distinct correlations might be a manifestation of two potential mechanisms: the invigoration effect (which enhances convection and precipitation) and the microphysical effect (which suppresses precipitation). We note that the highly limited information garnered from satellite products cannot unequivocally support the causal relationships between cloud-top temperature/precipitation rate and aerosol loading. But if aerosols are indeed the causes for the observed relationships, they may change the overall distribution of precipitation, leading to a more extreme and unfavorable rainfall pattern of suppressing light rains and fostering heavy rains.
Comparison of Circulating, Hepatocyte Specific Messenger RNA and microRNA as Biomarkers for Chronic Hepatitis B and C
Xiaonan Zhang, Zhanqing Zhang, Fahui Dai, Bisheng Shi, Liang Chen, Xinxin Zhang, Guoqing Zang, Jiming Zhang, Xiaorong Chen, Fangxing Qian, Yunwen Hu, Zhenghong Yuan
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0092112
Abstract: Circulating microRNAs have been widely recognized as a novel category of biomarker in a variety of physiological and pathological conditions. Other reports revealed that fragments of organ specific messenger RNAs are also detectable in serum/plasma and can be utilized as sensitive indicators of liver pathology and cancer. In order to assess the sensitivity and reliability of these two class of RNAs as marker of hepatitis B or C induced chronic liver disease, we collected plasma samples from 156 chronic hepatitis B or C patients (HBV active n = 112, HBV carrier n = 19, hepatitis C n = 25) and 22 healthy donors and quantified their circulating mRNA for albumin, HP (haptoglobin), CYP2E1 (cytochrome P450, family 2, subfamily E) and ApoA2 (Apolipoprotein A2) in conjunction with microRNA-122, a well established marker for acute and chronic liver injury. We found that plasma microRNA-122 level is significantly elevated in patients with active HBV but not in HBV carriers. Furthermore, microRNA-122 is not elevated in HCV patients even though their median serum alanine aminotransferase (sALT) was three fold of the healthy donors. Nevertheless, circulating mRNAs, especially albumin mRNA, showed much more sensitivity in distinguishing active hepatitis B, hepatitis B carrier or HCV patientsfrom healthy control. Correlation and multiple linear regression analysis suggested that circulating mRNAs and miRNAs are much more related to HBsAg titre than to sALT. Immunoprecipitation of HBsAg in HBV patients’ plasma resulted in enrichment of albumin and HP mRNA suggesting that fragments of liver specific transcripts can be encapsidated into HBsAg particles. Taken together, our results suggest that hepatocyte specific transcripts in plasma like albumin mRNA showed greater sensitivity and specificity in differentiating HBV or HCV induced chronic liver disease than microRNA-122. Circulating mRNA fragments merit more attention in the quest of next generation biomarkers for various maladies.
TESTING STUDY ON PERMEABILITY OF NON-DARCY FLOW IN POST-PEAK SANDSTONE
峰后砂岩非Darcy流渗透特性的试验研究

Cheng Yikang,Chen Zhanqing,Miao Xiexing,Mao Xianbiao,
程宜康
,陈占清 缪协兴 茅献彪

岩石力学与工程学报 , 2004,
Abstract: It is of practical importance to investigate the permeability of rock under high stress,especially under post-peak stress with low confining pressure. A patented device,combined with MTS815.02 Rock Mechanics System,makes the measurement of non-Darcy permeability possible. The configuration of test system of permeability measurement of non-Darcy flow in post-failure rock,test principle and plan,and the processing method for test data are presented. The permeability of non-Darcy flow in post-peak rock is carefully measured by using steady seepage method. Sandstone specimens are divided into five groups. Every group consists of ten specimens,which undergo same axial strain before permeability measurement. The permeability of each specimen is obtained by fitting the seepage velocity-pressure gradient curve. The statistical indexes of every group of specimens are calculated. The relation between the indexes and axial strain are established by linear regression. It is shown that the permeability of post-peak rock is remarkably larger than that of pre-peak rock. The permeability of post-peak rock varies parabolically with axial strain. This study provides the method and technique for measuring permeability of non-Darcy flow in post-peak rock,which can be employed in mining,civil and other engineerings.
Approaches for assessing forest ecosystem health
森林生态系统健康评估的一般性途径探讨

CHEN Gao,DENG Hongbing,WANG Qingli,DAI Limin,HAO Zhanqing,
陈高
,邓红兵,王庆礼,代力民,郝占庆

应用生态学报 , 2003,
Abstract: Assessment and indicator system become the key issues in the research on ecosystem health in 21 st century. Assessing forest ecosystem health gradually attach much attention because it is an important component of terrestrial ecosystem. The definition,measurement,evaluation and its management had been discussed broadly,and some theories,assessing methods and frameworks had been proposed,which provides a new concept and a serial research approaches for dealing with the crisis of terrestrial ecosystems,even the environment problems in the world. Now,the common operational models for assessing forest ecosystem health do not exist owing to the manifold limitations. This paper discussed forest ecosystem health problem,and brought forward three preconditions for assessing forest ecosystem health:1) a clear conceptual framework;2) adequate data sets;3) proper research and analysis techniques. The issues of three preconditions were discussed,and the possible approaches for the assessing research on forest ecosystem health,e.g.,long term studies and environment monitoring,space for time substation studies,e.g.,history approaches,economics valuation and others were expariated.
Assessing forest ecosystem health I Model, method, and index system
森林生态系统健康评估I.模式、计算方法和指标体系

CHEN Gao,DAI Limin,JI Lanzhu,DENG Hongbing,HAO Zhanqing,WANG Qingli,
陈高
,代力民,姬兰柱

应用生态学报 , 2004,
Abstract: Ecosystem health assessment is one of the main researches and urgent tasks of ecosystem science in 21st century. An operational definition on ecosystem health and an all-sided, simple, easy operational and standard index system, which are the foundation of assessment on ecosystem health, are necessary in obtaining a simple and applicable assessment theory and method of ecosystem health. Taking the Korean pine and broadleaved mixed forest ecosystem as an example, an originally creative idea on ecosystem health was put forward in this paper based on the idea of mode ecosystem set and the idea of forest ecosystem health, together with its assessment. This creative idea can help understand what ecosystem health is. Finally, a formula was deduced based on a new effective health assessment method--health distance (HD), which is the first time to be brought forward in China. At the same time, aiming at it's characteristics by status understanding and material health questions, a health index system of Korean pine and broadleaved mixed forest ecosystem was put forward in this paper, which is a compound ecosystem based on the compound properties of nature, economy and society. It is concrete enough to measure sub-index, so it is the foundation to assess ecosystem health of Korean pine and broadleaved mixed forest in next researches.
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