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Frontiers of environmental Science & Engineering 2021年第6期15卷 457-469页

作者： Xiao Deng Yixuan Chen Yang Yang Liang Peng Luo Si Qingru Zeng college of resources and environment Hunan Agricultural UniversityChangsha 410128China

Global rice production practices have gradually changed from a reliance on transplanting to direct *** how this shift may alter cadmium(Cd)accumulation in rice is poorly *** we conducted field experiments with two rice genotypes cultivars that were planted using three methods:via direct seeding(DS),seedling throwing(ST),and manual transplanting(MT).Rice samples were collected during four growth *** formation and distribution of iron plaque were analyzed using DCB(dithionite-citrate-bicarbonate)extractions and observed under micro-XRF(micro X-ray fluorescence).The results revealed that,in each growth stage,DS rice was more apt to harbor Cd distributed in the plant’s aerial parts,and the Cd concentration of brown rice from DS was 21.8%–43.3%significantly higher than those from ST and MT at maturity stage(p<0.05).During the vegetative stages,the Cd uptake percentage was higher in DS than MT rice,and those plants arising from the DS method were capable of absorbing more Cd earlier in their growth and ***,using DS decreased the amount of iron plaque covering the root surface in every growth stage,especially in the critical period of Cd accumulation,such that the roots’middle areas were distinguished by a near-complete absence of iron plaque,thus weakening its role as an effective barrier to Cd uptake from ***,this study demonstrated that implementing the DS mode of planting will increase Cd’s distribution in the aboveground parts of rice,and heightening the risk of Cd contamination in grain.

关键词： Cadmium Genotypes Growth stages Micro X-ray fluorescence Planting mode

Treated wastewater irrigation effect on soil,crop and environment:Wastewater recycling in the loess area of China

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Journal of environmental Sciences 2007年第9期19卷 1093-1099页

作者： WANG Jun-feng WANG Gen-xu WANYAN Hua college of Resource and environmental Science Lanzhou University Lanzhou 730000 China Institute of Mountain Hazards and environment Chinese Academy of Sciences Chengdu 610041 China college of environmental and Municipal Engineering Lanzhou Jiaotong University Lanzhou 730070 China

A study was carded out at the Loess Plateau in Dongzhi, China, to test the feasibility of using secondary treatment sewage effluent and to determine whether the water quality would then meet the recommended irrigation norm. Seven crops, including celery, wheat, maize, millet, apples, rapeseed and yellow beans, were tested in the study. Physical and chemical properties of the soil, crop yield and quality and leachate at different soil depths were measured. In most cases, the quality of the crops that made use of treated sewage was not distinctively different from those that did not use treated sewage. However, yields for the former were much higher than they were for the latter. Leachates at different soil depths were analyzed and the results did not show alarming levels of constituents. For a period of approximately 14 months, the treated sewage irrigation had no significant effect on the loess soil and no cases of illness resulting from contact with the treated sewage were reported. With treated sewage irrigation, a slight increase in the organic content of the soil was observed.

关键词： irrigation treated sewage crop quality crop yield soil groundwater

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

Quantification of the effects of management factors on maize (Zea mays L.) and cotton(Gossypium hirsutum L.) residues decomposition rate

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Journal of environmental Sciences 2002年第2期14卷 165-172页

作者： JONES Chilima, HUANG Chang yong, WU Ci fang (college of Natural resources and environment, Zhejiang University, Hangzhou 310029, China. college of Natural resources and environment Zhejiang University Hangzhou 310029 China

Efforts to quantify management effects on decomposition rate of added substrates to the soil is important especially where such information is to be used for prediction in mathematical or simulation models. Using data from a short term (60 days) greenhouse simulation study, a procedure for quantifying effects of management on SOM and substrate decomposition is presented. Using microbial growth rate u (q), microbial efficiency in substrate utilization e (q), specific decomposition rates for added plant residues to two contrasting soils, red earth (Ferrasol) and black earth (Acrisol) were estimated. The treatments included straw addition + buried, (T1); straw addition + mineral N (T2); and straw addition + tillage, (T3). Sampling was done every 15 days. Straw decomposition rate was affected by external mineral N sources (Urea 46% N). Addition of an external N source significantly increased decomposition rates. The study could not, however, fully account for the effect of tillage on residues because of the limited effect of the tillage method due to the artificial barrier to mechanical interference supplied by the mesh bags. It is concluded that using few decomposer parameters, decomposition rates and consequently SOM trends in a soil system can be monitored and quantification of the influence of perturbations on decomposition rate of added substrates possible.

关键词： management factors residue decomposition rate maize cotton red soil black soil

Nonlinear magneto-electric response of a giant magnetostrictive/piezoelectric composite cylinder

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Acta Mechanica Sinica 2012年第2期28卷 385-392页

作者： Yuan-Wen Gao Juan-Juan Zhang Key Laboratory of Mechanics on Western Disaster and environment Ministry of Education and College of Civil Engineering and MechanicsLanzhou University730000 LanzhouChina

In this study, we investigate the nonlinear cou- pling magneto-electric （ME） effect of a giant magnetostric- tive/piezoelectric composite cylinder. The nonlinear consti- tutive relations of the ME material are taken into account, and the influences of the nonlinear material properties on the ME effect are investigated for the static and dynamic cases, respectively. The influences of different constraint conditions on the ME effect are discussed. In the dynamic case considering nonlinear material properties, the double frequency ME response （The response frequency is twice the applied magnetic frequency） is obtained and discussed, which can be used to explain the experiment phenomenon in which the input signal with frequency f is converted to the output signal with 2f in ME laminated structures. Some calculations on nonlinear ME effect are conducted. The obtained results indicate that the nonlinear material properties affect not only the magnitude of the ME effect in the static case but also the ME response frequency in the dynamic case

关键词： Nonlinear coupling ME effect Layered com- posite cylinder. Double frequency ME response

Surface energy balance of Bayi Ice Cap in the middle of Qilian Mountains,China

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Journal of Mountain Science 2018年第6期15卷 1229-1240页

作者： QING Wen-wu HAN Chun-tan LIU Jun-feng Key Laboratory of Western China＇s environmental Systems （Ministry of Edueation） College of Earth and Environmental Sciences Lanzhou University Lanzhou 730000 China Northwest Institute of Eeo-environment and resources Chinese Academy of Sciences Lanzhou 730000 China

Energy balance at the glacier surface is important for understanding the impacts of climate change on glaciers. Here, we analyzed the characteristics of the glacier surface energy fluxes along with their contributions to glacier melt on Bayi Ice Cap in Qilian Mountains by using a point-scale energy balance model. The half-hourly meteorological data from an automatic weather station(AWS) located on the glacier was used to drive the energy balance model. The model simulated results could accurately represent the mass-balance observations from the stake near the weather station during summer 2016. Our results showed the net radiation(86%) played an important role in the surface energy balance, and the contribution of the turbulent heat fluxes(14%) to the energy budget was relatively less important. A distinct behavior of energy balance, as compared to other continental glaciers in China(e.g., two adjacent glaciers Laohugou No. 12 Glacier and Qiyi Glacier), is the fact that a sustained period of positive turbulent latent flux exists on Bayi Ice Cap during August, causing faster melt rate in the month of August. Our study also presented the effect of frequent summer snowfall in slowing down surface melt by changing the surface albedo during the beginning of the melting season.

关键词： Surface melting Energy balance Turbulent latent flux Summer snowfall Glacier

Future variation in mountainous discharge in arid northwestern China:A basin case study

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Journal of Mountain Science 2021年第9期18卷 2287-2303页

作者： WU Lei LI Chang-bin XIE Xu-hong LV Jia-nan WEI Jian-mei ZHOU Xuan YANG Lin-shan Key Laboratory of Western China’s environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Northwest Institute of Eco-environment and resources Chinese Academy of SciencesLanzhou 730000China

To better understand the variation in mountainous discharge(MD)in the future,a basin case study was conducted in the upstream Taolai River Basin(UTRB)in arid northwestern *** Blaney-Criddle(B-C)equation,Budyko framework,and water balance method were coupled for MD *** outputs of 10 global climate models(GCMs)are synthesized to confirm the future changes in air temperature and precipitation under 3 selected Representative Concentration Pathway(RCP)*** climate elasticity(CE)method was used to determine the variation in MD,and the influence of climate factors on that was quantitatively *** results reveal that the coupling framework of the three methods is suitable for MD determination in the *** weight-based synthesis of the 10 GCM outputs shows overall increases in temperature(T)and precipitation(P)under the 3 scenarios during most of the time until *** above climate change leads to an increase in *** to CE analysis,the positive effectiveness of precipitation is greater than the negative effectiveness of temperature on MD variation,and the increase in precipitation would induce more MD in the *** analysis reveals that GCM outputs dominate in predicting precipitation,while the RCP scenarios influence temperature ***,under the background of climate change,the risk of extreme floods during wet years might increase,and a water deficit will still occur during normal and dry *** study provides a case example for better understanding MD responses to climate change in the upper reaches of inland river *** are helpful for reasonable water resource development and utilization in the middle and lower reaches of these basins in the *** in the Taolai River Basin,considering the future water demand across the whole basin,the development of watersaving technologies and reasonable industrial structures is crucial for a sustainable future.

关键词： Mountainous discharge Future variation GCM outputs Climate change Taolai River Basin

Biodiversity in Saline and Non-Saline Soils Along the Bohai Sea Coast,China

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Pedosphere 2015年第2期25卷 307-315页

作者： WU Yu-Peng ZHANG Yi BI Yan-Meng SUN Zhen-Jun college of resources and environmental Sciences China Agricultural University college of resources and environment Huazhong Agricultural University

A plethora of information is available on the effects of salinity on plant growth and soil physico-chemical properties,but the effects on soil organisms are often ***,a systematic investigation of how soil biodiversity,including bacteria,nematodes,mites,and earthworms,changes along saline gradients was conducted along the Bohai Sea coast at Laizhou City,Shandong Province,China,with 30 soil samples randomly selected and classified by salinity into two categories:saline and *** revealed a significantly higher abundance of the surveyed organisms in non-saline *** redundancy analysis showed that a negative correlation was observed between electrical conductivity and soil organism abundance in saline soil,but not in non-saline *** organic matter,available nitrogen,and total nitrogen all positively affected organism abundance in both saline and non-saline *** richness and Shannon diversity of nematodes were significantly higher in non-saline soils,but were not significantly different between soil types for other *** of the environmental factors surveyed was obviously related to soil organism ***,our results suggested that soil electrical conductivity only negatively affected soil organisms in saline soil,while soil fertility positively affected soil organisms in both saline and non-saline soils.

关键词： electrical conductivity microbes microbial biomass carbon nematodes organism abundance redundancy analysis richness Shannon diversity

Root tensile strength of terrace hedgerow plants in the karst trough valleys of SW China:Relation with root morphology and fiber content

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International Soil and Water Conservation Research 2022年第4期10卷 677-686页

作者： Yun Chen Han Tang Binghui He Zhehao Yan Xiaohong Liu Jiaojiao Qiang college of resources and environment/Chongqing Key Laboratory of Karst environment Southwest UniversityChina

Root tensile strength is commonly affected by root morphology and fiber content,which combinedly affect the effectiveness of terrace hedgerow on controlling soil erosion in sloping ***,the relationships between these root characteristics are still *** study aimed to compare the root tensile strength,root morphologies,and root fiber contents,and quantify their differences among different plant *** root systems of three terrace hedgerow plant species,i.e.,***,***,and *** *** sampled for detecting root morphologies and fiber contents at different slope positions on a representative hillslope in karst trough *** root specimens were collected to measure root tensile properties for these three plant *** showed that most root morphological parameters were the highest in ***,followed by *** *** plant species presented the same dominant diameter class as<1.0 mm,and root volumes as<1.50 *** with contents closing to 50%was the main fiber type,and increased significantly linearly with the increasing root diameter in both *** and *** highest tensile strength and Young's modulus were found in *** L.,while the best ultimate tensile force and ultimate elongation were displayed in *** diameter showed negative power relationships with tensile strength and Young's modulus,a positive power relationship with ultimate tensile force,and a positive linear relationship with ultimate *** results will deepen the understanding of the terrace hedgerow functions for controlling soil erosion worldwide.

关键词： Soil bioengineering Soil erosion Tensile strength Root diameter Fiber content

Role of interfacial electron transfer reactions on sulfamethoxazole degradation by reduced nontronite activating H_(2)O_(2)

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Journal of environmental Sciences 2023年第2期124卷 688-698页

作者： Hao-Jie Cui Yaqi Ning CongWu Wei Peng Dong Cheng Lichu Yin Weijun Zhou Wenjuan Liao college of resources and environment Hunan Agricultural UniversityChangsha 410128China college of environment Zhejiang University of TechnologyHangzhou 310014China

It has been documented that organic contaminants can be degraded by hydroxyl radicals(•OH)produced by the activation of H2O2 by Fe(II)-bearing ***,the interfacial electron transfer reactions between structural Fe(Ⅱ)and H_(2)O_(2) for•OH generation and its effects on contaminant remediation are *** this study,we first investigated the relation between•OH generation sites and sulfamethoxazole(SMX)degradation by activating H2O2 using nontronite with different reduction ***(5.2–16.9μmol/L)degradation first increased and then decreased with an increase in the reduction extent of nontronite from 22% to 62%,while the•OH production increased *** treatment of edge sites and structural variation results revealed that interfacial electron transfer reactions between Fe(Ⅱ)and H2O2 occur at both the edge and basal *** enhancement on basal plane interfacial electron transfer reactions in a high reduction extent rNAu-2 leads to the enhancement on utilization efficiencies of structural Fe(Ⅱ)and H_(2)O_(2) for•OH ***,the•OH produced at the basal planes is less efficient in oxidizing SMX than that of at edge *** of SMX could be sustainable in the H_(2)O_(2)/rNAu-2 system through chemically *** results of this study show the importance role of•OH generation sites on antibiotic degradation and provide guidance and potential strategies for antibiotic degradation by Fe(Ⅱ)-bearing clay minerals in H2O2-based treatments.

关键词： Reduced nontronite Electron transfer Sulfamethoxazole degradation Reaction sites Hydroxyl radicals