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PROBLEMS AND COUNTERMEASURES OF WATER RESOURCES FOR SUSTAINABLE UTILIZATION IN CHINA

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Chinese Geographical Science 2002年第4期12卷 289-293页

作者： DENG Wei,bai jun-hong,yan Min-hua(Changchun Institute of Geography,t he Chinese Academy of Sciences,Changchun 130012,P.R.China) Changchun Institute of Geography the Chinese Academy of Sciences Changchun 130012 P. R. China

According to the theory of sustainable development,the current situation and existent problems of the expl oita-tion of water resources were analyze d in this *** results show that the contradiction between supply an d demand of water resources is continually aggravating,water pollution is incre asingly serious,water environment is worse,the over-extraction area of the underground water is expanding and water crisis stands out gradually,so it is imp erative under the situation to actualize the susta inable exploitation strategies of water *** is necessary for s ustainable utilizing water resources to introduce the mod el of sustainable utilization of water resources-the model of wealth transferring be-tween the generations of water resou rces,establish water-saving socie ty system and water market,form tech nology sys-tems,management systems and evaluation systems for many sorts of water r esources,improve the utilization r atio of water resources,transform waste water in to resources and maintain and restore the water space of water environmen t.

关键词： water resources sustainable utilization countermeasures

Effects of salinity and betaine addition on anaerobic granular sludge properties and microbial community succession patterns in organic saline wastewater

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Journal of Environmental Sciences 2025年第1期147卷 310-321页

作者： Zhifei Zhang Jinquan Wan Gang Ye yan Wang Yuwei bai Zhicheng yan College of Environment and Energy South China University of TechnologyGuangzhou 510006China Shijiazhuang High Tech Industrial Development Zone Water Supply and Drainage Company Shijiazhuang 050000China

In this study,the effects of different salinity gradients and addition of compatible solutes on anaerobic treated effluent water qualities,sludge characteristics and microbial communities were *** increase in salinity resulted in a decrease in particle size of the granular sludge,which was concentrated in the range of 0.5-1.0 *** content of EPS(extracellular polymeric substances)in the granular sludge gradually increased with increasing salinity and the addition of betaine(a typical compatible solute).Meanwhile,the microbial community structure was significantly affected by salinity,with high salinity reducing the diversity of *** higher salinity,Patescibacteria and Proteobacteria gradually became the dominant phylum,with relative abundance increasing to 13.53%and 12.16%at 20 g/L *** and its subordinate Desulfovibrio,which secrete EPS in large quantities,dominated significantly after betaine *** relative abundance reached 13.65%and 7.86%at phylum level and genus *** effect of these changes on the treated effluent was shown as the average chemical oxygen demand(COD)removal rate decreased from 82.10%to 79.71%,78.01%,68.51%and 64.55%when the salinity gradually increased from 2 g/L to 6,10,16 and 20 g/*** the salinity of 20 g/L,average COD removal increased to 71.65%by the addition of 2 mmol/L *** gradient elevated salinity and the exogenous addition of betaine played an important role in achieving stability of the anaerobic system in a highly saline environment,which provided a feasible strategy for anaerobic treatment of organic saline wastewater.

关键词： Organic saline wastewater Anaerobic granular sludge Compatible solute Extracellular polymeric substance Microbial community

Flow behavior and dynamic softening mechanism of Pt−10Ir precious alloy

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中国有色金属学报 2025年第1期35卷 225-242页

作者： Xin-pei ZHANG jun-jie HE Lin PI Quan FU Wen-yan ZHOU jun CHENG Sheng-wen bai Xuan ZHOU Yi LIU Yong MAO Materials Genome Institute School of Materials and EnergyYunnan UniversityKunming 650091China Kunming Precious Materials&Technology Co. Ltd.Yunnan Precious Metals Laboratory Co.Ltd.Sino-Platinum Metals Co.Ltd.Kunming 650106China Kunming Institute of Precious Metals Kunming 650106China State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals Sino-Platinum Metals Co.Ltd.Kunming 650106China Shaanxi Key Laboratory of Biomedical Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The hot deformation behavior of Pt−10Ir alloy was studied under a wide range of deformation *** a low deformation temperature(950−1150℃),the softening mechanism is primarily dynamic *** addition,dynamic recrystallization by progressive lattice rotation near grain boundaries(DRX by LRGBs)and microshear bands assisted dynamic recrystallization(MSBs assisted DRX)coordinate the ***,it is difficult for the dynamic softening to offset the stain hardening due to a limited amount of DRXed *** a high deformation temperature(1250−1350℃),three main DRX mechanisms associated with strain rates occur:DRX by LRGBs,DRX by a homogeneous increase in misorientation(HIM)and geometric DRX(GDRX).With increasing strain,DRX by LRGBs is enhanced gradually under high strain rates;the“pinch-off”effect is enhanced at low strain rates,which was conducive to the formation of a uniform and fine microstructure.

关键词： platinum alloy hot deformation microstructure evolution dynamic recovery dynamic recrystallization

Some Eigenvalue Properties of Third-order Boundary Value Problems with Distributional Potentials

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Acta Mathematicae Applicatae Sinica 2025年第1期41卷 179-199页

作者： Hai-yan ZHANG Ji-jun AO College of Sciences Inner Mongolia University of TechnologyHohhot 010051China

Several eigenvalue properties of the third-order boundary value problems with distributional potentials are ***,we prove that the operators associated with the problems are self-adjoint and the corresponding eigenvalues are ***,the continuity and differential properties of the eigenvalues of the problems are given,especially we find the differential expressions for the boundary conditions,the coefficient functions and the ***,we show a brief application to a kind of transmission boundary value problems of the problems studied here.

关键词： third-order boundary value problems distributional potentials quasi-derivatives eigenvalues

Boron shielding design for neutron and gamma detectors of a pulsed neutron tool

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Nuclear Science and Techniques 2025年第1期36卷 115-126页

作者： Xin-yang Wang jun-yan Chen Qiong Zhang University of Electronic Science and Technology of China Chengdu 611731China

Shielding materials are critical for downhole pulsed neutron tool design because they directly influence the accuracy of formation measurements.A well-designed shield configuration ensures that the response of the tool is maximally representative of the formation without being affected by the tool and borehole *** study investigated the effects of boron-containing materials on neutron and gamma detectors based on a newly designed logging-while-drilling tool that is currently undergoing *** the boron content increased,the ability to absorb thermal neutrons increased *** simulation,it was proven that boron carbide(B_(4)C)can be used as an effective boron shielding material for thermal neutrons,and is therefore employed in this *** shield against thermal neutrons migrating from the mud pipes,the optimal shielding thicknesses for the near-and far-neutron detectors were determined to be 5 and 4 *** a porosity of 25 p.u.,near-neutron sensitivity exhibited a 5.6%***,to shield the capture gamma generated by thermal neutrons once they enter the tool from the mud pipe and formation,internal and external shields for the gamma detector were *** results show that the internal shield requires a boron content of 75%,whereas the external shield has a thickness of 14.2 mm thickness and a boron content of 25%to minimize the tool effect.

关键词： Nuclear well logging Pulsed neutron tool Boron shielding

Adsorption and retention of fracturing fluid and its impact on gas transport in tight sandstone with different clay minerals

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Petroleum Science 2025年第1期22卷 370-383页

作者： Yi-jun Wang Li-jun You Jian yang Yi-Li Kang Ming-jun Chen Jia-Jia bai Jian Tian State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Engineering Technology Research Institute of Southwest Oil & Gas Field Company PetroChina School of Petroleum Engineering Changzhou University State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University

To elucidate the adsorption characteristics and retention mechanisms of fracturing fluids in diverse clay minerals, we conducted on-line nuclear magnetic resonance(NMR) and atomic force microscopy(AFM)experiments. The depth and extent of solid phase damage are determined by the ratio between the size of fine fractions in fracturing fluid residue and the pore-throat size in experiments. Poor physical properties(K 0.5 m D) combined with a scattered distribution of retained fracturing fluid is associated with high gas phase recovery permeability, whereas a continuous sheet-like distribution results in low recovery permeability. The expansive surface area and presence of filamentous illite minerals facilitate the multiple winding and adsorption of fracturing fluids, demonstrating strong hydrogen-bonding, multi-layering and multiple adsorption properties. The geological characteristics of the main gas formations exhibit significant variation, and the severity of damage caused by fracturing fluids occurs in diverse sequences. To address this issue, a differentiated strategy for optimizing fracturing fluids has been proposed.

关键词： Clay minerals Formation damage Fracturing fluid retention distribution Adsorption morphology

Travelling characteristics of road vehicles on single-level rail-cum-road bridge under the dynamic and aerodynamic impact of travelling trains

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Earthquake Engineering and Engineering Vibration 2025年第1期24卷 235-256页

作者： He Jiajun Lu jun Guo Wei Dong Lianjie bai Xue Li Yongle Southwest Municipal Design&Research Institute of China Chengdu 610299China Southwest Jiaotong University Chengdu 610031China

Aerodynamic and dynamic interference from trains is a key issue of concern for the safety of road vehicles travelling on single-level rail-cum road *** on the wind-road vehicle-train-bridge(WRTB)coupled vibration system developed herein,this study examines the dynamic characteristics when road vehicles meet trains in this *** influence of load combination,vehicle type and vehicle location is analyzed.A method to obtain the aerodynamic load of road vehicles encountering the train at an arbitrary wind speed is *** results show that due to the windproof facilities and the large line distance between the railway and highway,the aerodynamic and dynamic influence of trains on road vehicles is slight,and the vibration of road vehicles depends on the road *** the road vehicles discussed,the bus is the easiest to rollover,and the truck-trailer is the easiest to *** with the aerodynamic impact of trains,the crosswind has a more significant influence on road *** first peak/valley value of aerodynamic loads determines the maximum dynamic response,and the quick method is optimized based on this *** cases show that the optimized method can produce conservative results and can be used for relevant research or engineering applications.

关键词： single-level rail-cum-road bridge vehicle-bridge coupled vibration dynamic characteristic aerodynamic impact road vehicle

Full biosynthetic pathway of pyrrolobenzoxazines

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Chinese Chemical Letters 2025年第1期36卷 433-436页

作者： Kunya Wang Bingyu Liu Daojiang yan Jian bai Haibo Yu Youcai Hu State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China

Pyrrolobenzoxazines are a rare terpene-amino acid family of natural products with potent biological ***,we reported the full biosynthetic pathway of paeciloxazine(1),a typical pyrrolobenzoxazine,with significant insecticidal *** on heterologous expression,chemical complement experiment,and in vitro biochemical assays,we demonstrated the sesquiterpene portion of 1 derived from discontinuously oxidations of amorphdiene,in which P450 monooxygenase PaxH catalyzed a cascade of hydroxylation and epoxidation,while two flavin dependent monooxygenases are involved in the transformation of the esterified tryptophan into a pyrrolobenzoxazine ***,a total of 15 compounds were generated through heterologous expression,of which 13,17 and 20 showed potential antiepileptic *** study fully elucidated the biosynthetic pathway of paeciloxazine(1)and showed the diversity and complexity of constructing natural products by organisms.

关键词： Pyrrolobenzoxazines Paeciloxazine Biosynthesis P450 monooxygenase Antiepileptic activity

Characterization of size-resolved aerosol hygroscopicity and liquid water content in Nanjing of the yangtze River Delta

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Journal of Environmental Sciences 2025年第5期151卷 26-41页

作者： Youling Jiang yan Ma jun Zheng Nan Ye Cheng Yuan School of Environmental Science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science&TechnologyNanjing 210044China School of Emergency Management Nanjing University of Information Science&TechnologyNanjing 210044China

Aerosol hygroscopicity and liquid water content(ALWC)have important influences on the environmental and climate effect of *** this study,we measured the hygroscopic growth factors(GF)of particles with dry diameters of 40,80,150,and 200 nm during the wintertime in *** the GF-derived hygroscopicity parameter(κ_(gf))and ALWC increased with particle size,but displayed differing diurnal variations,withκ_(gf)peaking around the midday,while ALWC peaking in the early ***,ammonium and oxygenated organic aerosols(OOA)were found as the chemical components mostly strongly correlated with ALWC.A closure study suggests that during midday photo-oxidation and nighttime high ALWC periods,theκof organic aerosols(κ_(org))was underestimated when using previous ***,we re-constructed parameterizations forκ_(org)and the oxidation level of organics for these periods,which indicates a higher hygroscopicity of photochemically formed OOA than the aqueous OOA,yet both being much higher than the generally assumed OOA ***,in a typical high ALWC episode,concurrently increased ALWC,nitrate,OOA as well as aerosol surface area and mass concentrations were observed under elevated ambient *** strongly indicates a coupled effect that the hygroscopic secondary aerosols,in particular nitratewith strong hygroscopicity,led to large increase in ALWC,which in turn synergistically boosted nitrate and OOA formation by heterogeneous/aqueous *** interaction may represent an important mechanism contributing to enhanced formation of secondary aerosols and rapid growth of fine particulate matter under relatively high RH conditions.

关键词： Aerosol hygroscopicity Aerosol liquid water content Photo-oxidation Aqueous/heterogeneous reactions