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Pollution characteristics of atmospheric dustfall and heavy metals in a typical inland heavy industry city in china

Journal of Environmental Sciences 2018年第9期30卷 283-291页

作者： Jinhe Wang Xi Zhang Qing Yang Kai Zhang Yue Zheng Guanhua Zhou School of Municipal and Environmental Engineering Shandong Jianzhu University Jinan 250101 China Shanghai key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3) Shanghai 200433 China State key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012 China School of Instrument Science and Opto-Electronics Engineering Beihang University Beijing 100083 China

Through field sampling of atmospheric dustfall in regions of Zhuzhou City, china for a period of one year, the deposition fluxes of atmospheric dustfall and five heavy metals contained inside, including Cr, As, Cd, Hg and Pb, were analyzed. Meanwhile the enrichment factor and index methods were used to analyze the pollution characteristics of heavy metals of atmospheric dustfall in Zhuzhou. The annual deposition flux of atmospheric dustfall in Zhuzhou was 50.79 g/（m^***）, while the annual deposition fluxes of Cr, As, Cd, Hg and Pb were 9.80, 59.69, 140.09, 0.87 and 1074.91 mg/（m^***）, respectively. The pollution level of atmospheric dustfall in Zhuzhou was relatively lower compared with most other cities in china, but the deposition fluxes of As, Cd, Hg and Pb in atmospheric dustfall in Zhuzhou were much higher than that in most cities and regions around the world. Cd is the typical heavy metal element in atmospheric dustfall in Zhuzhou, and both the enrichment factor and pollution index of Cd were the highest. Cd, Hg, Pb and As in atmospheric dustfall were mainly from human activities. According to the single-factor index, Nemerow index and pollution load index analyses, the atmospheric dustfall in Zhuzhou could easily cause severe heavy metal pollution to urban soil, and the most polluting element was Cd, followed by Pb, As and Hg. Only the pollution level of Cr lay in the safety region and mainly originated from natural sources.

关键词： Atmospheric dustfall Heavy metal Deposition flux Factor analysis Zhuzhou city

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Estimating Design Loads with Environmental Contour Approach Using Copulas for an Offshore Jacket Platform

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Journal of Ocean University of china 2020年第5期19卷 1029-1041页

作者： ZHAO Yuliang LIU Dahui DONG Sheng College of Engineering Ocean University of ChinaQingdao 266100China CIMC Offshore Engineering Institute Co. Ltd.Yantai 264670China

Jacket-type offshore platforms are widely used for oil, gas field, and energy development in shallow water. The design of a jacket structure is highly dependent on target environmental variables. This study focuses on a strategy to estimate design loads for offshore jacket structures based on an environmental contour approach. In addition to the popular conditional distribution model, various classes of bivariate copulas are adopted to construct joint distributions of environmental variables. Analytical formulations of environmental contours based on various models are presented and discussed in this study. The design loads are examined by dynamic response analysis of jacket platform. Results suggest that the conditional model is not recommended for use in estimating design loads in sampling locations due to poor fitting results. Independent copula produces conservative design loads and the extreme response obtained using the conditional model are smaller than those determined by copulas. The suitability of a model for contour construction varies with the origin of wave data. This study provides a reference for the design load estimation of jacket structures and offers an alternative procedure to determine the design criteria for offshore structures.

关键词： design loads jacket platform joint probability distribution conditional model copula theory environmental contour method

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THE RELATIONSHIP BETWEEN THE TAIWAN WARM CURRENT AND TSUSHIMA WARM CURRENT

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Journal of Hydrodynamics 2009年第2期21卷 212-218页

作者： ZHENG Pei-nan WU De-xing LIN Xiao-pei Physical Oceanography Laboratory Ocean University of China Qingdao 266100 China Marine Environmental Ensuring of the Headquarters of General Staff Beijing 100081 China

The Taiwan Warm Current （TWC） and the Tsushima Warm Current （TSWC） flow northward over the shelf in the East china Sea （ECS）, which some previous studies regard as a Taiwan-Tsushima Warm Current （TTWC） System. But the roles of the TWC and TSWC in the formation of the TTWC system have not been clarified. This article will show that the TSWC is more important in the TTWC system. Using a three-dimensional baroclinic model, we conducted several numerical experiments to reveal the dynamic relationship between the TWC and TSWC. The results show that the TWC has little effect on the TSWC, while the TSWC has a significant effect on the TWC. A source-sink driven mechanism along isobaths may be used to explain this phenomenon The perennial northward flow through the Tsushima Strait pumps the response over the northern shelf in the ECS that gives rise to the TWC. Although the TSWC is located at the ＂downstream＂ region, it could induce about 0.5 Sv to TWC in annual mean values.

关键词： Taiwan-Tsushima warm current system POM source-sink driven circulation

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Anomalous strain effect in heteroepitaxial SrRuO_(3) films on(111) SrTiO_(3) substrates

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Chinese Physics B 2022年第12期31卷 412-416页

作者： Zhenzhen Wang Weiheng Qi Jiachang Bi Xinyan Li Yu Chen Fang Yang Yanwei Cao Lin Gu Qinghua Zhang Huanhua Wang Jiandi Zhang Jiandong Guo Xiaoran Liu Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201China Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials Department of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Songshan Lake Materials Laboratory Dongguan 523808China

We report comprehensive investigations into the structure of high-quality(111)-oriented SrRuO_(3)films on SrTiO_(3)substrates to elucidate the effect of(111)heteroepitaxial *** found that SrRuO_(3)film with a thickness of~40 nm is compressively strained in plane on the substrate with full ***,the out-of-plane spacing is almost the same as in the bulk,which is at odds with the conventional *** probing a series of half-order Bragg reflections using synchrotron-based x-ray diffraction combined with analyses of the scanning transmission electron microscopy images,we discovered that the heteroepitaxial strain is accommodated via significant suppression of the degree of c+octahedral tilting and the formation of three equivalent domain structures on the(111)SrTiO_(3)*** anomalous effect sheds light on the understanding of an unconventional paradigm of film-substrate coupling for the(111)heteroepitaxial strain.

关键词： perovskite SrRuO_(3) (111)-oriented thin films heteroepitaxial strain octahedral tilt and rotation

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Does bicarbonate affect the nitrate utilization and photosynthesis of Orychophragmus violaceus?

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Acta Geochimica 2018年第6期37卷 875-885页

作者： Ye Lu Yanyou Wu Kaiyan Zhang State key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang550081China University of Chinese Academy of Sciences Beijing100049China

The effect of bicarbonate(HCO_3^-) on the growth and development of plants varies by species. To better understand inorganic carbon and nitrogen assimilation changes of karst-adaptable plants under different HCO_3^- treatments, we conducted experiments on seedlings and in vitro plantlets of Orychophragmus violaceus(Ov).We found that the vital photosynthesis potential(as measured by net photosynthetic rate, actual photochemical efficiency of photosystem-II, photochemical quenching coefficient, and the instantaneous carbon isotope ratio of3-phosphoglycerate) was consistent under different HCO_3^- treatments of Ov. Bicarbonate's lack of effect on carbon assimilation of Ov may be related to carbonic anhydrase in Ov converting HCO_3^- to H2 O and CO2. In this way, Ov could prevent HCO_3^- ion toxicity and high pH from harming its growth and development under HCO_3^- *** study also found that high HCO_3^- concentrations could promote nitrogen assimilation and utilization of Ov through changes in related indexes(foliar nitrogen isotope fractionation ratio, stable nitrogen isotope assimilation ratio, foliar stable nitrogen isotope fractionation, nitrate nitrogen utilization efficiency, and nitrate utilization share)under different HCO_3^- treatments. Bicarbonate has different effects on photosynthesis and on inorganic nitrogen assimilation of Ov, which may be connected tophotosynthesis providing electrons for nitrate/nitrite reduction through the photosynthetic chain.

关键词： Nitrogen assimilation Photosynthetic capacity HCO3^- Orychophragmus violaceus

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Scheme for Robust Long-Distance Continuous Variable Quantum key Distribution

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Chinese Physics Letters 2006年第6期23卷 1372-1374页

作者：张永生郭光灿 Laboratory of Quantum Information University of Science and Technology of China Hefei 230026

It is shown that the configuration of phase coding for quantum key distribution with single photon can also be used for continuous variable quantum key distribution. Therefore the robust long-distance high-speed quant... 详细信息

关键词： ENTANGLED PHOTONS CRYPTOGRAPHY STATES

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Evaluating agricultural water-use efficiency based on water footprint of crop values: a case study in Xinjiang of china

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Journal of Arid Land 2020年第4期12卷 580-593页

作者： HAI Yang LONG Aihua ZHANG Pei DENG Xiaoya LI Junfeng DENG Mingjiang State key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100038China College of Water Conservancy and Architectural Engineering Shihezi UniversityShihezi 832003China Xinjiang Water Conservancy and Hydropower Planning and Design Management Bureau Urumqi 830000China

Efficient agricultural water use is crucial for food safety and water conservation on a global scale. To quantitatively investigate the agricultural water-use efficiency in regions exhibiting the complex agricultural structure, this study developed an indicator named water footprint of crop values(WFV) that is based on the water footprint of crop production. Defined as the water volume used to produce a unit price of crop(m^3/CNY), the new indicator makes it feasible to directly compare the water footprint of different crops from an economic perspective, so as to comprehensively evaluate the water-use efficiency under the complex planting structure. On the basis of WFV, the study further proposed an indicator of structural water-use coefficient(SWUC), which is represented by the ratio of water-use efficiency for a given planting structure to the water efficiency for a reference crop and can quantitatively describe the impact of planting structure on agricultural water efficiency. Then, a case study was implemented in Xinjiang Uygur Autonomous Region of china. The temporal and spatial variations of WFV were assessed for the planting industries in 14 prefectures and cities of Xinjiang between 1991 and 2015. In addition, contribution rate analysis of WFV for different prefectures and cities was conducted to evaluate the variations of WFV caused by different influencing factors: agricultural input, climatic factors, and planting structure. Results from these analyses indicated first that the average WFV of planting industries in Xinjiang significantly decreased from 0.293 m^3/CNY in 1991 to 0.153 m^3/CNY in 2015, corresponding to an average annual change rate of –3.532%. WFV in 13 prefectures and cities(with the exception of Karamay) has declined significantly during the period of 1991–2015, indicating that agricultural water-use efficient has effectively improved. Second, the average SWUC in Xinjiang decreased from 1.17 to 1.08 m^3/CNY in the 1990 s, and then declined

关键词： agricultural input climatic factors contribution rate planting structure structural water-use coefficient water footprint of crop values

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Frequency stability of an RF oscillator with an MEMS-based encapsulated resonator

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Journal of Semiconductors 2015年第7期36卷 103-107页

作者：彭波华骆伟赵继聪袁泉杨晋玲杨富华 Institute of Semiconductors Chinese Academy of Sciences State key Laboratory of Transducer Technology

This paper presents a high-Q RF MEMS oscillator consisting of a micro-disk resonator and low noise feedback circuits. The oscillator has high frequency stability and low phase noise. The two-port resonator was hermetically encapsulated using low-cost Sn-rich Au-Sn solder bonding, which significantly improves the frequency stability. A low noise oscillator circuit was designed with a two-stage amplifying architecture which effectively improves both the frequency stability and phase noise performance. The measured phase noise is -96 dBc/Hz at 1 kHz offset and-128 dBc/Hz at far-from-carrier offsets. Moreover, the medium-term frequency stability and Allan deviation of the oscillator are 4-4 ppm and 10 ppb, respectively. The oscillator is a promising component in future wireless communication application.

关键词： MEMS disk resonator oscillator phase noise frequency stability encapsulation

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Performances and emissions of a petroleum coke oil slurry engine

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Journal of Central South University 2012年第11期19卷 3342-3350页

作者：向立明李兴虎蔡楚江沈志刚 School of Transportation Science and Engineering Beihang University Beijing key Laboratory for Powder Technology research and development(Beihang University)

In order to solve the failure of fuel system when using petroleum coke oil slurry (PCOS) in a R180 diesel engine directly,a petroleum coke oil slurry fuel system (PCOSFS) was developed and installed in R180 engine,which was called PCOS *** order to analyze performances and emissions of the PCOS engine,a comparative experiment between PCOS engine fueled with PCOS and R180 engine fueled with diesel oil was carried *** results show that the PCOS engine can run smoothly,the maximum output power decreases by about 6.2% and 19.0% and the maximum brake thermal efficiency reduces by around 5.85% and 4.13% as compared to R180 engine under the conditions of 1 200 and 1 600 r/*** HC emissions of PCOS engine are lower than those of R180 engine at 1 200 r/min,and are close to those of R180 engine at 1 600 r/*** CO emissions are similar to R180 engine at 1 200 and 1 600 r/*** smoke intensity is close to R180 engine at 1 200 r/min,and is higher than R180 engine at 1 600 r/*** particles emitted from PCOS engine array sparsely,but particles emitted from R180 engine array closely,cohering together.

关键词： diesel oil petroleum coke oil slurry compression ignition engine emissions

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Integrated Optimal Siting and Sizing for VSCHVDC-link-based Offshore Wind Farms and Shunt Capacitors

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Journal of Modern Power Systems and Clean Energy 2021年第2期9卷 274-284页

作者： Yong Li Xuebo Qiao Chun Chen Yi Tan Wenchao Tian Qiuping Xia Yijia Cao Kwang Y.Lee the College of Electrical and Information Engineering Hunan UniversityChangsha 410082China the Zhangjiakou Power Supply Company State Grid Jibei Electric Power Company LimitedZhangjiakou 075000China the Department of Electrical and Computer Engineering Baylor UniversityWacoTexas 76798-7356USA the School of Electrical and Information Engineering Changsha University of Science and TechnologyChangsha 410082China

It is economic and secure to determine the optimal siting and sizing of the offshore wind farms(OWFs)integrated into the AC system through voltage-source converter high-voltage direct current(VSC-HVDC)*** this paper,an integrated planning model for the VSC-HVDC-link-based OWFs and the capacitors is proposed,where a decomposition technique is presented to solve the proposed mixed-integer nonlinear programming(MINLP)problem and obtain the optimal *** model can optimize the siting and sizing of the OWFs to improve the voltage profile and reduce the adverse influence of the reactive power of the *** the proposed planning model,the total investment costs,operation costs and maintenance costs of the OWFs,VSC-HVDC links,and the capacitors can be *** on the modified IEEE 118-bus system show that the proposed integrated planning model can provide more economic scheme than the independent planning scheme,in which the capacitors are planned after the ***,a series of sensitivity analysis on certain equipment costs are studied to obtain the regular pattern for sizing VSC stations.

关键词： Capacitor installed capacity point of common coupling(PCC) offshore wind farm(OWF) voltage-source converter high-voltage direct current(VSC-HVDC)link

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