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Helium isotope investigation on magnetic reversal boundaries of loess-paleosol sequence at Luochuan, central Chinese Loess Plateau

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Chinese science Bulletin 2007年第17期52卷 2407-2412页

作者： DU XueQing1,6, WANG YongHong2, REN JianGuo3, YE XianRen4 & LU HuaYu5,1 1 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of sciences, Xi’an 710075, china 2 college of Marine Geosciences, Ocean university of china, Qingdao 266003, china 3 National Natural science Foundation of china, Beijing 100085, china 4 Lanzhou Research Center for Petroleum and Natural Gas resources, Institute of Geology and Geophysics, Chinese Academy of sciences, Lanzhou 730000, china 5 Key Laboratory of Coast and Island Development, School of Geographic and Oceanographic sciences, nanjing university, nanjing 210093, china 6 Graduate university of Chinese Academy of sciences, Beijing 100049, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi''an 710075 China

Extraterrestrial particles have higher 3He/4He ratios than those of terrestrial sediments ( > 100 Ra versus < 0.03 Ra, where Ra is the 3He/4He ratio normalized to the atmospheric value of 1.4×10?6). The inter- planet... 详细信息

Extraterrestrial particles have higher 3He/4He ratios than those of terrestrial sediments ( > 100 Ra versus 3 Ra, where Ra is the 3He/4He ratio normalized to the atmospheric value of 1.4×10?6). The inter- planetary dust particles (IDPs), which are very rich in 3He, continuously bombard the Earth and can accumulate in deposits. IDPs sedimentation rate changes can significantly influence 3He concentration in the Earth surface sediments. Since IDPs are not easy to detect in terrestrial deposits, measuring helium isotopes is a helpful approach to examine changes in IDPs. Helium concentration and helium isotopic composition magnetic substances and the quartz particles were examined for helium concen- tration and helium isotopic ratio. Results show that the 3He/4He ratio and the 3He concentrations of the magnetic substances are clearly higher than those of the bulk samples and the quartz particles, and, the 3He/4He ratio of the extracted magnetic substances is also higher than that of the average level of the Earth’s crust. The higher helium content in the magnetic fractions can be explained by an influx of IDPs.

关键词：中国黄土高原古土壤氦同位素行星际尘埃颗粒反方向磁化

Study on the double-logarithmic profile of tidal flow velocity in the near-bed layers

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Acta Oceanologica Sinica 2009年第6期28卷 84-92页

作者： NI Zhihui SONG Zhiyao WU Lichun Southwestern Research Institute of Water Transport Engineering Chongqing Jiaotong UniversityChongqing 400016 China Key Laboratory of Virtual Geographic Environment （Ministry of Education） Nanjing NormMUniversity Nanjing 210097 China State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering Hohai UniversityNanjing 210098 China Chongqing Education college Chongqing 400067 China

Tidal current velocity profile in the near-bed layers has been widely studied. The results showed that velocity profile in the near-bed layer obviously departure from the traditional logarithmic profile, due to the acceleration or deceleration. Although the logarithmic linear profile can reduce the rate of deviation from this, only it is a lower-order approximate solution. In this paper, considering the unsteady and non-linear features of tidal motion, the double logarithmic profile near-bed layers in estuarine and coastal waters is established on the assumption that the turbulent shear stress along the water depth was parabolic distribution, and on the basis of Prandtl＇s mixing length theory and yon Karman＇s self-similar theory. Having been verified the data observed at the West Solent in the south of England, and comparison of the logarithmic linear profile, it found that the double logarithmic profile is more precious than the latter. At last, the discussed results showed that：（1） The parabolic distribution of the tidal shear stresses verified good by the field data and experimental data, can be better reflected the basic features of the tidal shear stress deviating from linear distribution that is downward when to accelerate, upward when to decelerate. （2） The traditional logarithmic velocity profile is the zero-order approximation solution of the double logarithmic profile, the logarithmic linear profile is the first order, and the logarithmic parabolic profile is the second order. （3） Ignoring the conditions of diffusion and convection in the tida movement, the double logarithmic profile can reflect the tidal properties of acceleration or deceleration, so that the calculation of the friction velocity and roughness length are more reasonable. When the acceleration or the deceleration is about zero, the double logarithmic profile becomes the logarithmic profile.

关键词： turbulence shear stress tidal current double logarithmic profile near-bed layers friction velocity roughness length

Validation and Scenario Analysis of a Soil Organic Carbon Model

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agricultural sciences in china 2002年第4期1卷 417-423页

作者： HUANG Yao, LIU Shi-Hang, SHEN Qi-rong, ZONG Liang-gang, JIANG Ding-an and HUANG Hong-guang(college of Resource and environmental sciences , nanjing agricultural university, nanjing 210095 , P,R. china Institute of Atmospheric Physics , Chinese Academy of sciences , Beijing 100029 , P. R . china agricultural Bureau of Yixing City, Yixing 214209 , P.R. china ) college of Resource and environmental sciences Nanjing Agricultural University Nanjing 210095 P.R. China Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 P.R. China college of Resource and environmental sciences Nanjing Agricultural University Nanjing 210095 P.R. China agricultural Bureau of Yixing City Yixing 214209 P. R . China

A model developed by the authors was validated against independent data sets. The data sets were obtained from field experiments of crop residue decomposition and a 7-year soil improvement in Yixing City, Jiangsu Province. Model validation indicated that soil organic carbon dynamics can be simulated from the weather variables of temperature, sunlight and precipitation, soil clay content and bulk density, grain yield of previous crops, qualities and quantities of the added organic matter. Model simulation in general a-greed with the measurements. The comparison between computed and measured resulted in correlation coefficient γ2 values of 0.9291* * * (n= 48) and 0.6431* * (n = 65) for the two experiments, respectively. Model prediction under three scenarios of no additional organic matter input, with an annual incorporation of rice and wheat straw at rates of 6.75t/ha and 9.0t/ha suggested that the soil organic carbon in Wanshi Township of Yixing City would be from an initial value of 7.85g/kg in 1983 to 6.30g/kg, 11.42g/kg and 13g/kg in 2014, respectively. Consequently, total nitrogen content of the soil was predicted to be respectively 0.49g/kg, 0.89g/kg and 1.01g/kg under the three scenarios.

关键词： agricultural soils Organic carbon Simulation model Validation Scenario analysis

Kinetic analysis of waste activated sludge hydrolysis and short-chain fatty acids production at pH 10

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Journal of environmental sciences 2009年第5期21卷 589-594页

作者： FENG Leiyu, YAN Yuanyuan, CHEN Yinguang State key Laboratory of Pollution Control and resources Reuse, School of environmental science and Engineering, Tongji university, Shanghai 200092, china. [a]State key Laboratory of Pollution Control and resources Reuse School of Environmental Science and Engineering Tongji University Shanghai 200092 China

The accumulation of short-chain fatty acids （SCFAs）, a preferred carbon source for enhanced biological phosphorus removal microbes, was significantly improved when waste activated sludge （WAS） was fermented at pH 10. The kinetics of WAS hydrolysis and SCFAs production at pH 10 was investigated. It was observed that during WAS anaerobic fermentation the accumulation of SCFAs was limited by the hydrolysis process, and both the hydrolysis of WAS particulate COD and the accumulation of SCFAs followed first-order kinetics. The hydrolysis and SCFAs accumulation rate constants increased with increasing temperature from 10 to 35℃, which could be described by the Arrhenius equation. The kinetic data further indicated that SCFAs production at pH 10 was a biological process. Compared with the experiment of pH uncontrolled （blank test）, both the rate constants of WAS hydrolysis and SCFAs accumulation at 20℃ were improved significantly when WAS was fermented at pH 10.

关键词： waste activated sludge hydrolysis short-chain fatty acids kinetics alkaline pH

Relationship Between Vegetation Restoration and Soil Microbial Characteristics in Degraded Karst Regions: A Case Study

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Pedosphere 2011年第1期21卷 132-138页

作者： WEI Yuan YU Li-Fei ZHANG Jin-Chi YU Yuan-Chun D. L. DEANGELIS School of resources and environmental Management Guizhou College of Finance and Economics Guiyang 550004 (China) college of Forestry Guizhou University Guiyang 550025 (China) college of Forest and Environment Nanjing Forestry University Nanjing 210037 (China) Department of Biology University of Maimi P. O. Box 249118 Coral Gables FL 33124 (USA)

The mechanism of vegetation restoration on degraded karst regions has been a research focus of soil science and ecology for the last *** an attempt to preferably interpret the soil microbiological characteristic variation associated with vegetation restoration and further to explore the role of soil microbiology in vegetation restoration mechanism of degraded karst regions,we measured microbial biomass C and basal respiration in soils during vegetation restoration in Zhenfeng County of southwestern Guizhou Province,*** community level physiological profiles(CLPP) of the soil microbial community to were estimated determine if vegetation changes were accompanied by changes in functioning of soil microbial *** results showed that soil microbial biomass C and microbial quotient(microbial biomass C/organic C) tended to increase with vegetation restoration,being in the order arboreal community stage > shrubby community stage > herbaceous community stage > bare land *** trend was found in the change of basal respiration(BR).The metabolic quotient(the ratio of basal respiration to microbial biomass,qCO 2) decreased with vegetation restoration,and remained at a constantly low level in the arboreal community *** of the CLPP data indicated that vegetation restoration tended to result in higher average well color development,substrate richness,and functional *** utilization of specific substrate guilds was highest in the arboreal community *** component analysis of the CLPP data further indicated that the arboreal community stage was distinctly different from the other three *** conclusion,vegetation restoration improved soil microbial biomass C,respiration,and utilization of carbon sources,and decreased qCO 2,thus creating better soil conditions,which in turn could promote the restoration of vegetation on degraded karst regions.

关键词： basal respiratory community level physiological profile functional diversity metabolic quotient microbial biomass C

Immobilization of an enzyme from a Fusarium fungus WZ-I for chlorpyrifos degradation

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Journal of environmental sciences 2010年第12期22卷 1930-1935页

作者： Hui Xie,Lusheng Zhu,Tingting Ma,Jun Wang,Jinhua Wang,Jun Su,Bo Shao college of resources and Environment,Shandong agricultural university,Taian 271018,china [a] college of resources Environment Shandong Agricultural University Taian 271018 China

The free enzyme extracted from WZ-I, which was identified as Fusarium LK. ex Fx, could effectively degrade chlorpyrifos, an organophosphate insecticide. The methods of immobilizing this free enzyme and determined its degradation-related characteristics were investigated. The properties of the immobilized enzyme were compared with those of the free enzyme. The optimal immobilization of the enzyme was achieved in a solution of 30 g/L sodium alginate at 4℃ for 4-12 hr. The immobilized enzyme showed the maximal activity at pH 8.0, 45℃. The maximum initial rate and the substrate concentration of the immobilized enzyme were less than that of the free enzyme. The immobilized enzyme, therefore, had a higher capacity to withstand a broader range of temperatures and pH conditions than the free enzyme. With varying pH and temperatures, the immobilized enzyme was more active than the free enzyme in the degradation reaction. In addition, the immobilized enzyme exhibited only a slight loss in its initial activity, even after three repeated uses. The results showed that the immobilized enzyme was more resistant to different environmental conditions, suggesting that it was viable for future practical use.

关键词： organophosphate pesticide immobilized enzyme degradation fungus

Identification of Prorocentrum minimum and Takayama pulchella by fluorescence in situ hybridization through epifluorescence microscopy and flow cytometry

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Acta Oceanologica Sinica 2009年第2期28卷 103-114页

作者： HOU Jianjun LAI Hongyan HUANG Bangqin CHEN Jixin college of Fisheries Huazhong Agricultural University Wuhan 430070 China college of Life sciences Hubei Normal University Huangshi 435002 China State Key Laboratory of Marine environmental science Environmental Science Research Center Xiamen University Xiamen 361005 China Key Laboratory of Freshwater Fish Germplasm resources and Biotechnology Yangtse River Fisheries Research Institute Jinzhou 434000 China State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China

Partial rDNA sequences of Prorocentrum minimum and Takayama pulchella were amplified, cloned and sequenced, and these sequence data were deposited in the GenBank. Eight oligonucleotide probes （DNA probes） were designed based on the sequence analysis. The probes were employed to detect and identify P. minimum and T. pulchella in unialgal and mixed algal samples with a fluorescence in situ hybridization method using flow cytometry. Epifluorescence micrographs showed that these specific probes labeled with fluorescein isothiocyanate entered the algal cells and bound to target sequences, and the fluorescence signal resulting from whole-cell hybridization varied from probe to probe. These DNA probes and the hybridization protocol we developed were specific and effective for P. minimum and T. pulchella, without any specific binding to other algal species. The hybridization efficiency of different probes specific to P. minimum was in the order： PM18S02 PM28S02 〉 PM28S01 〉PM18S01, and that of the probes specific to T. pulcheUa was TP18S02 TP28S01 〉 TP28S02 〉TP18S01. The different hybridization efficiency of the DNA probes could also be shown in the fluorescent signals between the labeled and unlabeled cells demonstrated using flow cytometry. The DNA probes PM18S02, PM28S02, TP18S02 and TP28S01, and the protocol, were also useful for the detection of Mgae in natural samples.

关键词： oligonucleotide DNA probes Prorocentrum minimum Takayama pulcheUa fluorescence in situ hybridization flow cytometry

Effect of leachate inoculum on biopretreatment of municipal solid waste by a combined hydrolytic-aerobic process

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Journal of environmental sciences 2009年第8期21卷 1162-1168页

作者： ZHANG Dongqing, HE Pinjing, SHAO Liming State Key Laboratory of Pollution Control and resources Reuse, Key Laboratory of Yangtze River Water Environment, college of environmental science and Engineering, Tongji university, Shanghai 200092, china. [a]State Key Laboratory of Pollution Control and resources Reuse Key Laboratory of Yangtze River Water Environment College of Environmental Science and Engineering Tongji University Shanghai 200092 China

The biopretreatment of municipal solid waste by a combined hydrolytic-aerobic process has become of great interest for biostabilization or biodrying. The study aimed at investigating the effect of leachate inoculurn on the biopretreatment. During the hydrolytic stage, the inoculum addition at the ratio of leachate to waste （LWR） of 5% and 7% stimulated the start-up of hydrolysis and enhanced the hydrolysis rate by 27.4% and 24.2%, respectively; whereas the inoculation at LWR of 1% had almost no effect on the hydrolysis rate and the inoculation at LWR of 10% reduced the hydrolysis rate by 12.7%. During the subsequent aerobic stage, the inoculations at LWRs greater than 5% decreased organics degradation rate. As a whole, compared with none inoculation, the total degradation rates of organics for inoculating trials at LWRs of 5%, 7% and 10% decreased by 14.5%, 14.3% and 32.7%, respectively. Correspondingly, their net water removal rates were reduced by 4.4%, 5.8% and 19.0%. The inoculation at LWR of 1% could not significantly affect the biopretreatment. The inoculum addition at LWR of 5% and 7% could shorten hydrolytic stage and thus accelerate the whole combined process. Moreover, the inoculations at LWRs greater than 5% were favorable for lignocelluloses degradation.

关键词： biopretreatment hydrolysis-aeration inoculation leachate municipal solid waste

EXPERIMENTAL STUDY AND NUMERICAL SIMULATION OF FLUORIDE IN SAND

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Journal of Hydrodynamics 2006年第6期18卷 748-751页

作者： ZHANG Hong-mei SU Bao-yu School of resources and Safety Engineering China University of Mining and Technology Beijing 100083China college Of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098China

The transport and transformation of fluoride in sand were studied by using soil tank test under the condition of saturated water in this article. Based on the analysis of the laboratory experiments, the rules of fluorine transportation and transformation were simulated in sand by solving the advection-diffusion equation. Through comparison between computed results and observed data , it is shown that the established model and determined parameters could be used to simulate the fluoride transport in sand.

关键词： sand fluoride dynamic test numerical simulation