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Comparison of the spatial and temporal variability of macroinvertebrate and periphyton-based metrics in a macrophyte-dominated shallow lake

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Frontiers of Earth Science 2015年第1期9卷 137-151页

作者： Lulu zhang Jingling liu yi LI State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China

The influence of spatial differences, which are caused by different anthropogenic disturbances, and temporal changes, which are caused by natural conditions, on macroinvertebrates with periphyton communities in Baiyangdian Lake was compared. Periphyton and macrobenthos assemblage samples were simultaneously col- lected on four occasions during 2009 and 2010. Based on the physical and chemical attributes in the water and sediment, the 8 sampling sites can be divided into 5 habitat types by using cluster analysis. According to coefficients variation analysis （CV）, three primary conclusions can be drawn ：（1） the metrics of Hilsenhoff Biotic Index （HBI）, Percent Tolerant Taxa （PTT）, Percent dominant taxon （PDT）, and community loss index （CLI）, based on macroinvertebrates, and the metrics of algal density （AD）, the proportion of chlorophyta （CHL）, and the proportion of cyanophyta （CYA）, based on periphytons, were mostly constant throughout our study; （2） in terms of spatial variation, the CV values in the macroinvertebratebased metrics were lower than the CV values in the periphyton-based metrics, and these findings may be caused by the effects of changes in environmental factors; whereas, the CV values in the macroinvertebrate-based metrics were higher than those in the periphyton-based metrics, and these results may be linked to the influences of phenology and life history patterns of the macroinvertebrate individuals; and （3） the CV values for the functionalbased metrics were higher than those for the structuralbased metrics. Therefore, spatial and temporal variation for metrics should be considered when assessing applying the biometrics.

关键词： Baiyangdian Lake biomonitoring coefficient variation structural metrics functional metrics

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Photodegradation of perfluorooctanoic acid by 185 nm vacuum ultraviolet light

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Journal of Environmental Sciences 2007年第4期19卷 387-390页

作者： CHEN Jing zhang Peng-yi liu Jian Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China.

The photodegradation of persistent and bioaccumulative perftuorooctanoic acid （PFOA） in water by 185 nm vacuum ultraviolet （VUV） light was examined to develop an effective technology to deal with PFOA pollution. PFOA degraded very slowly under irradiation of 254 nm UV light. However, 61.7% of initial PFOA was degraded by 185 nm VUV light within 2 h, and defluorination ratio reached 17.1%. Pseudo first-order-kinetics well simulated its degradation and defluorination. Besides, fluoride ion formed in water, 4 shorter-chain perfluorinated carboxylic acids （PFCAs）, that is, perfluoroheptanoic acid, perfluorohexanoic acid, perfluoropentanoic acid, and perfluorobutanoic acid. These were identified as intermediates by LC-MS measurement. These PFCAs consecutively formed and further degraded with irradiation time. According to the mass balance calculation, no other byproducts were formed. It was proposed that PFCAs initially are decarboxylated by 185 nm light, and the radical thus formed reacts with water to form shorter-chain PFCA with one less CF2 unit.

关键词： photodegradafion perfluorooctanoic acid perfluorinated carboxylic acid vacuum ultraviolet

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A MAC PROTOCOL TO SUPPORT HYBRID ANTENNAS IN A WIRELESS LAN

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Journal of Electronics(China) 2007年第3期24卷 309-315页

作者： Zhao Liqiang zhang Hailin liu yi State Key Laboratory of Integrated Services Networks Xidian University Xi＇an 710071 China

Hybrid Distributed Coordination Function (HDCF),a modified medium access control pro-tocol of IEEE 802.11 standard,is proposed in this paper to support both smart adaptive array anten-nas and normal omni-directional antennas simultaneously in one wireless LAN. Omni-directional an-tennas follow the standard Distributed Coordination Function (DCF) and smart antennas follow the Directional DCF (DDCF). The proposed DDCF is based on Hybrid Virtual Carrier Sense (HVCS) mechanism,which includes Omni-directional Request-To-Send/Clear-To-Send (ORTS/OCTS) hand-shake mechanism and directional data transmission. HDCF is compatible with DCF. When a node transmits in a directional beam,the other nodes can multiplex the physical channel. Hence,HDCF supports Space Division Multiple Access (SDMA). Simulation results show that HDCF can support hybrid antennas effectively and provide much higher network throughput and lower delay and jitter than DCF does.

关键词： Wireless LAN Smart adaptive array antennas Medium Access Control (MAC) Space Division Multiple Access (SDMA)

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Particle modulations to turbulence in two-phase round jets

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Acta Mechanica Sinica 2009年第5期25卷 611-617页

作者： Bing Wang Huiqiang zhang yi liu Xiaofen Yan Xilin Wang School of Aerospace, Tsinghua University, 100084 Beijing, China School of Aerospace Tsinghua University 100084 Beijing China

The particle modulations to turbulence in round jets were experimentally studied by means of two-phase velocity measurements with Phase Doppler Anemometer （PDA）. Laden with very large particles, no significant attenuations of turbulence intensities were measured in the farfields, due to small two-phase slip velocities and particle Reynolds number. The gas-phase turbulence is enhanced by particles in the near-fields, but it is significantly attenuated by the small particles in the far-fields. The smaller particles have a more profound effect on the attenuation of turbulence intensities. The enhancements or attenuations of turbulence intensities in the far-fields depends on the energy production, transport and dissipation mechanisms between the two phases, which are determined by the particle prop- erties and two-phase velocity slips. The non-dimensional parameter CTI is introduced to represent the change of turbulence intensity.

关键词： Particle modulations Turbulence intensity Particle sizes Two-phase slip velocity Particle-laden round turbulent jet

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Optimizing local search-based partial MaxSAT solving via initial assignment prediction

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Science China(Information Sciences) 2025年第2期68卷 59-73页

作者： Chanjuan liu Guangyuan liu Chuan LUO Shaowei CAI Zhendong LEI Wenjie zhang yi CHU Guojing zhang School of Computer Science and Technology Dalian University of Technology School of Software Beihang University Institute of Software Chinese Academy of Sciences School of Computer Science Peking University

Partial maximum satisfiability(PMS) is a significant generalization of Boolean satisfiability(SAT) and maximum satisfiability(MaxSAT), by introducing hard clauses and soft clauses. Compared with SAT and MaxSAT, the PMS problem has more real-world applications where both hard and soft constraints are involved. Local search is an effective incomplete method for solving PMS and is useful for important domains where good-quality solutions are desired within reasonable *** local search PMS solvers, the approach for initial assignment generation is crucial because its effectiveness significantly affects practical performance. In this study, we propose a novel initial assignment prediction approach, called InitPMS. When predicting an assignment for PMS, InitPMS considers the specific structure of PMS instances, i.e., distinguishing hard and soft clauses. Our experiments on extensive PMS instances from MaxSAT evaluations(MSEs) 2020 and 2021 show that InitPMS significantly boosts the performance of five state-of-the-art local search PMS solvers, demonstrating its generality. In addition,our results indicate that incorporating InitPMS could improve the performance of one of the best incomplete PMS solvers in MaxSAT Evaluation 2021, indicating that InitPMS might help advance the state of the art in PMS solving.

关键词： MaxSAT local search initial assignment incomplete method assignment prediction

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Study on real working performance and overload safety factor of high arch dam

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Science China(Technological Sciences) 2008年第S2期51卷 48-59页

作者： zhang GuoXin,liu yi & ZHOU QiuJing Department of Structures and Materials,China Institute of Water Resources and Hydropower Research,Beijing 100038,China 1. Department of Structures and Materials China Institute of Water Resources and Hydropower Research Beijing 100038 China

Considering the fact that high arch dams have problems such as complicated stress,high cost,and hazards after being damaged,this paper intends to study the effects of load,material strength,and safety analysis method on dam safety and working performance of arch *** this article,the effects of temperature,self weight exaction way and water loading on structure response are first discussed,and a more reasonable way of considering is then put *** taking into consideration the mechanical property of materials and comparing the effects of different yield criteria on overloading safety of high arch dams,this paper concludes that brittle characteristics of concrete should be fully considered when conducting safety assessment for high arch dams to avoid overestimating the bearing capacity of the *** comparing several typical projects,this paper works out a safety assessment system of multiple safety and relevant engineering analogical analysis methods,which is closer to the actual situation,and thus is able to assess the response of high arch dam structure in a more comprehensive way,elicit the safety coefficients in different situations,and provide a new way of considering the safety assessment of high arch dams.

关键词： high arch dam real working performance safety load strength safety assessment method

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Cu gradient design to attain high efficient solution-processed CuIn（S,Se）2 solar cells

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Journal of Energy Chemistry 2025年第2期101卷 213-222页

作者： Xuejun Xu Rutao Meng Yue liu Han Xu Jianpeng Li yi zhang Institute of Photoelectronic Thin Film Devices and Technology State Key Laboratory of Photovoltaic Materials and Cells and Engineering Research Center of Thin Film Optoelectronics Technology Ministry of Education Nankai University

Solution-processed chalcopyrite solar cells are widely regarded as a promising alternative method in reducing the cost compared with vacuum-based *** is noted that the absorber layer usually needs to be prepared under a high insert pressure（～1.6 atm） to suppress element loss or under a mild pressure but additional surface etching is needed for fabricating high efficient solar ***,a copper gradient structured precursor is proposed to prepare CuIn（S,Se）2（CISSe） film under a mild pressure（1.1 atm）.The designed gradient Cu not only promotes crystal grain growth and tailors the defects,but also avoids the surface etching of the formed CISSe film for the fabrication of high efficient solar ***,Cu gradient design decreases the conduction band offset of heterojunction,boosting the carriers transport across the p-n ***,a 13,35% efficient CISSe solar cell,comparable to the high efficient CISSe solar cell prepared by this method under high pressure or with film surface etching,is *** work provides a facile pathway to fabricate high efficient solution-processed chalcopyrite solar cell,avoiding high selenization pressure and film etching,and shows huge potential for solutionprocessed copper-based solar cells.

关键词： Band alignment Carrier transport CISSe Crystal grain growth Cu gradient Defect passivation

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Functional ternary salt construction enabling an in-situ Li3N/LiF-enriched interface for ultra-stable all-solid-state lithium metal batteries

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Journal of Energy Chemistry 2025年第2期101卷 68-75页

作者： Hong-Yan liu Xin-Yu liu Nan zhang Peng-Fei Wang Zong-Lin liu Jie Shu Ting-Feng yi School of Materials Science and Engineering Northeastern University Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province School of Resources and Materials Northeastern University at Qinhuangdao Faculty of Materials Science and Chemical Engineering and Key Laboratory of Photoelectric Detection Materials and Devices of Zhejiang Province Ningbo University

Poly（ethylene oxide）-based polymer all-solid-state lithium metal batteries（ASSLBs） have received widespread attention due to their low cost,good process ability,and high energy ***,the growth of Li dendrites within polymer solid-state electrolytes damages the reversibility of Li anodes and still impedes their widespread *** efficient strategy is to construct a superior solid electrolyte ***,a stable interface enriched with Li3N and LiF is in-situ formed between Li anode and a terna ry salt *** terna ry salt electrolyte is innovatively designed by introducing lithium bis（trifluoromethane sulfonyl）imide（LiTFSI）,lithium bis（fluorosulfonyl）imide（LiFSI）,and LiNO3to poly（ethylene oxide） *** characterization indicates that LiNO3and LiFSI contribute to forming a Li3N-LiF-enriched interface and meanwhile LiTFSI ensures excellent ***,among various Li compound components,Li3N has high ionic conductivity,which is beneficial for reducing overpotential,while LiF has high interfacial energy which can enhance nucleation energy and suppress the formation of Li *** experimental results show that ASSLBs coupled with LiFePO4cathode display extremely excellent cycle stability approximately 2200 cycles at 2 C,with a final and corresponding discharge specific capacity of 96.7 mA h g-1. Additionally,a schematic illustration of the working mechanism for the Li3N-LiF interface is proposed.

关键词： All-solid-state lithium metal batteries In-situ SEI Lithium dendrite PEO (LiTFSI) Solid electrolyte

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Light-controlled protein imprinted nanospheres with variable recognition specificity

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Chinese Chemical Letters 2025年第2期36卷 173-178页

作者： Mingqi Wang Shixin Fa Jiate Yu Guoxian zhang yi Yan Qing liu Qiuyu zhang Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology School of Chemistry and Chemical Engineering Northwestern Polytechnical University

This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA) and lysozyme(Lyz) under different UV light through a gradient dual crosslinked imprinting strategy(i.e., covalent crosslinking and dynamic reversible crosslinking). The imprinting cavities are initially constructed using irreversible covalent crosslinking to specifically recognize BSA, and then the coumarin residues in the imprinting cavities are crosslinked under 365 nm UV light to further imprint Lyz,because Lyz has smaller size than BSA. Since the photo-crosslinking of coumarin is a reversible reaction,the imprinting cavities of Lyz can be de-crosslinked under 254 nm UV light and restore the imprinting cavities of BSA. Moreover, the N-isopropyl acrylamide(NIPAM) and pyrrolidine residues copolymerized in the polymeric surface of the nanospheres are temperature-and p H-responsive respectively. Therefore, the protein rebinding and release behaviors of the nanospheres are controlled by external temperature and p H. As a result, the materials can selectively separate BSA from real bovine whole blood and Lyz from egg white under different UV light. This study may provide a new strategy for construction of protein imprinted materials with tunable specificity for different proteins.

关键词： Dynamically reversible crosslinking Molecularly imprinting Protein recognition Stimulus-response Variable specificity

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HUST-CRA:A New Atmospheric De-Aliasing Model for Satellite Gravimetry

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Advances in Atmospheric Sciences 2025年第2期42卷 382-396页

作者： Weihang zhang Fan YANG yi WU Hailong liu Tao zhang Zhicai LUO Ehsan FOROOTAN School of Physics Huazhong University of Science and TechnologyWuhan 430074China Geodesy Group Department of Sustainability and PlanningAalborg UniversityAalborg 9000Denmark Laoshan Laboratory Qingdao 266237China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China National Meteorological Information Center China Meteorological Administration(CMA)Beijing 100081China

Atmospheric de-aliasing is one of the most important background models for recovering Earth's temporal gravity field from gravity satellite *** meet the needs of China's gravimetric satellite platform,an independent atmospheric dealiasing model that relies on Chinese meteorological data needs to be *** release of CRA-40,as the firstgeneration Chinese atmospheric reanalysis,provides the *** study proposes a revised modeling method to calibrate CRA-40 and develops a new atmospheric de-aliasing model(HUST-CRA,2002-20).Intensive assessments are made between HUST-CRA and the latest official de-aliasing product of the international gravity satellite *** tidal components of the two products demonstrate high consistency,e.g.,the spatial correlation for the major tide S_1 is *** non-tidal components of the two products are also equivalent:(1)the temporal correlation of low-degree terms is higher than 0.97,except for the term of S22(0.93);(2)the spectral correlation of degree geoid height up to degree/order 100 is as high as 0.99;(3)the confidence interval of the spatial correlation(2002-20)is[0.971,0.995]at a confidence level of 95%;and(4)the difference in KBRR(K-band range rate)residuals is less than 0.08μm s^(-1),the difference in the derived temporal gravity field is less than 0.32 mm in terms of geoid height,and both are apparently beyond the ability of the current gravity satellite *** confirms that CRA-40 is of high quality and that the derived de-aliasing product,HUST-CRA,is accurate enough to be used in both Chinese and international gravity satellite missions.

关键词： CRA-40 atmospheric de-aliasing gravity satellite temporal gravity field

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