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Effect of Seasonality on Distribution of Macroalgae in a Stream System(Xin'an Spring) in Shanxi Province,North China

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Journal of Integrative Plant Biology 2006年第8期48卷 889-896页

作者： Bian-Fang Hu shu-Lian xie School of Life Science and Technology Shanxi University Taiyuan 030006 China

A survey of the seasonal distribution of macroalgae in a stream system in Shanxi Province, north China, was undertaken from July 2004 to April 2005. The relative abundance and percentage cover of macroalgae, and several environmental factors were monitored along a 20-m stretch at each of four sites, at intervals of approximately three months （one sampling per season）. Several stream conditions were relatively constant over the sampling period （pH, maximum width and maximum depth）, whereas others exhibited a distinct seasonal pattern （water temperature and specific conductance）, and some fluctuated with no discernable seasonal pattern （current velocity and dissolved oxygen）. Forty-two species of macroalgae were found, with a predominance of Chlorophyta （26 species, 61.9%）. Rhodophyts and Charophyta represented the smallest proportion （1 species each, 2.38%）. Six macroalgae species were the most widespread, occurring in all four sampling sites. Twelve species were found at only one site each. In terms of seasonality, eight species occurred throughout the year, whereas 16 species were found in only one season each. The macroalgal community at Xin＇an Spring was species rich relative to other streams. Species richness per sampling site was negatively correlated with pH. Principal component analysis revealed that no single variable had much influence on the macroalgal seasonal dynamics. We calculated Sorensen similarity indices to compare our study with other continent-wide surveys of stream macroalgae, but the similarity indices were all very low. This study also shows that macroalgae in different locations have significant reproductive isolation.

关键词： China distribution environmental factors seasonality stream macroalgae.

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十堰市理发及美容场所室内空气质量对从业人员健康的影响

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环境卫生学杂志 2023年第5期13卷 378-385页

作者：吴一鸣王顺恺江建勋谢曙光史廷明汪春红崔秀青武汉大学公共卫生学院武汉430071 湖北省疾病预防控制中心十堰市疾病预防控制中心

目的评估十堰市理发及美容场所室内空气质量(indoor air quality,IAQ)水平,探究其与从业人员健康状况间的关联。方法2019—2021年在十堰市抽取理发及美容场所开展室内空气质量监测,收集从业人员健康信息,采用多元Logistic回归分析室内... 详细信息

目的评估十堰市理发及美容场所室内空气质量(indoor air quality,IAQ)水平,探究其与从业人员健康状况间的关联。方法2019—2021年在十堰市抽取理发及美容场所开展室内空气质量监测,收集从业人员健康信息,采用多元Logistic回归分析室内空气质量与从业人员自报健康症状间的关联。结果共收集5轮次场所室内空气质量和212人次从业人员健康数据。室内空气中氨、甲醛及PM_(2.5)存在超标情况,从业人员眼部、呼吸系统及皮肤症状自报率分别为22.2%、20.2%及16.5%。多元Logistic回归分析结果显示,空气中氨的暴露浓度越高,从业人员出现眼部症状的风险越高,OR(95%CI)值为5.83(1.11,36.98);甲醛、氨及PM_(2.5)暴露浓度越高,出现呼吸系统症状的风险越高,OR(95%CI)值分别为4.73(1.08,23.38)、5.60(1.46,24.77)及4.51(1.15,20.56);甲醛、氨及PM_(2.5)暴露浓度越高,出现皮肤症状的风险越高,OR(95%CI)值分别为6.08(1.03,41.71)、5.82(1.16,36.35)及7.13(1.41,47.59)。此外,室内温度较低、年龄较小和每日工作超8 h也是影响从业人员健康状况的危险因素。结论十堰市理发及美容场所室内空气质量对从业人员存在健康风险,特别应重视超标污染物的潜在危害;此外,场所室内温度和每日工作时长等因素所致潜在健康隐患亦不容忽视。

关键词：理发场所美容场所公共场所室内空气质量自报健康症状从业人员

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Comparative Analysis on Chemical Components and Sensory Quality of Aging Flue-Cured Tobacco from Four Main Tobacco Areas of China

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Agricultural Sciences in China 2011年第8期10卷 1222-1231页

作者： SUN Jing-guo HE Jie-wang WU Feng-guang TU shu-xing YAN Tie-jun SI Hui xie Hao College of Resources and Environment Huazhong Agricultural UniversityWuhan 430070P.R.China Technology Center of China Tobacco Industry Co. Wuhan 430051P.R.China

Complicated changes are happening during the aging process of flue-cured tobacco （FCT） and understanding of the changing components is of great significance in improving the quality,shortening aging time,and enhancing production and economic efficiency in tobacco *** aging samples of FCT from four main producing areas of China,i.e.,Yunnan,Sichuan,Hubei,and Dongbei,were used to study the changing rule of the components such as alkali,acid,and carbohydrate as well as the aroma and their relationship with sensory quality;and based on the correlation among the components and the sensory quality index,multivariable models were established to predict the aging *** results showed that the sensory quality of FCT increased steadily during the aging time,and at the same time,the acidic components （total organic acids,volatile acids） increased gradually,while the alkaline substances （nicotine,volatile alkali）,carbohydrate （total sugars,reducing sugar） and pH values showed a downward *** analysis found that the sensory quality and pH values were negatively correlated （P0.05）,while the sensory quality with total organic acids and aroma were positively *** optimal model for predicting the quality of FCT was y=56.75-0.63x12＋50.09x2-13.27x22,（y：sensory quality;x1：pH;x2：total organic acids）.The average predicating error was 1.04% with maximum predicating error of 2.89% and the accuracy rate of above 97%.

关键词： chemical component flue-cured tobacco aging sensory quality regression model

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Effect of CaO content on residual stress of CAS glass-ceramic

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中国有色金属学会会刊：英文版 2006年第B01期16卷 101-104页

作者： xie Jun CHENG Jin-shu LONG Xin-jiang YANG shu-zhen Key Laboratory of Silicate Materials Science and Engineering Wuhan University of Technology Wuhan 430070 China

The mismatch in thermal expansion coefficient between crystalline phase and glass phase can result in large thermal stresses during thermal processing, as well as the low thermal conductivity, which is the most troublesome in the production of the CaO-Al2O3-SiO2 glass-ceramic. CaO content may influence the residual stress in the system. Therefore X-ray diffraction (XRD) ‘sin2ψ’ method was used to calculate the residual stress in samples containing various contents of CaO. The relationship between CaO content and residual stress in CAS system was investigated. Finally reasons causing such residual stress were analyzed.

关键词： CAS玻璃陶瓷氧化钙含量残余应力晶相玻璃相

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Interfacial microstructure and mechanical properties of stainless steel clad plate prepared by vacuum hot rolling

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Journal of Iron and Steel Research International 2018年第7期25卷 732-738页

作者： Jun Jiang Hua Ding Zong-an Luo guang-ming xie School of Materials and Metallurgy Northeastern University Shenyang 110819 Liaoning China Shenyang Aircraft Corporation Shenyang 110034 Liaoning China State Key Laboratory of Roiling and Automation Northeastern University Shenyang 110819 Liaoning China

A stainless steel clad plate composed of stainless steel and carbon steel was prepared by vacuum hot rolling process, and its microstructure, especially the bonding interface, was evaluated using an optical microscope, a scanning electron micro- scope and a transmission electron microscope （TEM）. The corresponding mechanical properties were also assessed by means of hardness and shear tests. The results showed a bonding interface formed between stainless steel and carbon steel, which was relatively straight in macroscope but serrated in microscope. Decarburization layer and carbon-enriched layer were distinguished at the side of carbon steel and stainless steel near the interface, respectively, which should be related to diffusion of carbon and alloying elements. The carbon-enriched layer could also be identified as a recombination region, whose microstructure was mainly recognized as martensite by TEM. Consequently, the hardness was the highest at this region. Furthermore, the result of shear test at the bonding interface showed that the shear strength was 395 MPa and the fracture mode was dominated as ductile fracture, indicating the bonding interface with good quality.

关键词： Stainless steel clad plate Vacuum hot rolling Interface microstructure Mechanical property

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Fault-tolerant FADS system development for a hypersonic vehicle via neural network algorithms

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Theoretical & Applied Mechanics Letters 2023年第5期13卷 357-366页

作者： Qian Wan Minjie Zhang guang Zuo Tianbo xie LandSpace Technology Corporation Ltd.H1 Zhonghang Intl Plaza 13 Ronghua South RoadBeijing 100176China Department of Aerospace and Mechanical Engineering University of Southern CaliforniaLos AngelesCA 90089-1189USA

Hypersonic vehicles suffer from extreme aerodynamic heating during flights, especially around the area of leading edge due to its small curvature. Therefore, flush air data sensing(FADS) system has been developed to perform accurate measurement of the air data parameters. In the present study, the method to develop the FADS algorithms with fail-operational capability for a sharp-nosed hypersonic vehicle is provided. To be specific, the FADS system implemented with 16 airframe-integrated pressure ports is used as a case study. Numerical simulations of different freestream conditions have been conducted to generate the database for the FADS targeting in 2 ≤ Ma ≤ 5 and 0 km ≤ H ≤ 30 km. Four groups of neural network algorithms have been developed based on four different pressure port configurations, and the accuracy has been validated by 280 groups of simulations. Particularly, the algorithms based on the 16-port configuration show an excellent ability to serve as the main solver of the FADS, where 99. 5% of the angle-of-attack estimations are within the error band ±0. 2°. The accuracy of the algorithms is discussed in terms of port configuration. Furthermore, diagnosis of the system health is present in the paper. A fault-tolerant FADS system architecture has been designed, which is capable of continuously sensing the air data in the case that multi-port failure occurs, with a reduction in the system accuracy.

关键词： FADS System Hypersonic vehicle Neural network Numerical simulation Fault detection Redundancy management

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Non-interference topology scheme in wireless sensor networks

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The Journal of China Universities of Posts and Telecommunications 2007年第2期14卷 7-13页

作者： MA shu-hui JI Hong YUE guang-xin School of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

A novel topology scheme, cell with multiple mobile sinks method （CMMSM）, is proposed in this article for the collection of information and for the environment monitoring in wireless sensor networks. The system consists of many static sensors, scattered in a large scale sensing field and multiple mobile sinks, cruising among the clusters. Conservation of energy and simplification of protocol are important design considerations in this scheme. The noninterference topology scheme largely simplifies the full-distributed communication protocol with the ability of collision avoidance and random routing. The total number of cluster heads in such a topology was analyzed, and then an approximate evaluation of the total energy consumption in one round was carded out. Simulation results show that CMMSM can save considerable energy and obtain higher throughput than low-energy adaptive clustering hierarchy （LEACH） and geographical adaptive fidelity （GAF）.

关键词： sensor networks energy consumption topology design multiple mobile sinks

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A Method of Calculation of the Solar Radio Flux Density for High Spatial Resolution Observations

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Chinese Physics Letters 1999年第3期16卷 223-225页

作者： ZHOU shu-rong HUANG guang-li Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008

In this paper we present a method of calculation of the flux density of radio source for high spatial resolution solar radio observations,i.e.,according to the observed solar antenna temperature,we make a correction for the K factor of antenna power pattern,then we can obtain values of solar radio *** to models of different brightness temperature distributions of the quiet sun and radio sources,we deduced the expression of the K factor of antenna power pattern,and calculated the fluxes of the quiet sun and slowly varying component emission of radio sources at 22 GHz.

关键词： antenna Solar Spatial

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Dynamic Asset Allocation with Loss Aversion in a Jump-diffusion Model

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Acta Mathematicae Applicatae Sinica 2015年第2期31卷 557-566页

作者： Hui MI Xiu-chun BI shu-guang ZHANG School of Mathematical Sciences and Institute of Finance and Statistics Nanjing Normal University Department of Statistics and Finance University of Science and Technology of China

This paper investigates a dynamic asset allocation problem for loss-averse investors in a jumpdiffusion model where there are a riskless asset and N risky assets. Specifically, the prices of risky assets are governed by jump-diffusion processes driven by an m-dimensional Brownian motion and a（N- m）-dimensional Poisson process. After converting the dynamic optimal portfolio problem to a static optimization problem in the terminal wealth, the optimal terminal wealth is first solved. Then the optimal wealth process and investment strategy are derived by using the martingale representation approach. The closed-form solutions for them are finally given in a special example.

关键词： jump-diffusion process loss aversion asset allocation martingale

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Influence of Vanes and Blades on Ingress in Axial Rim Seal for Turbine Stages

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Journal of Thermal Science 2024年第3期33卷 833-846页

作者： REN Ran DU Qiang LIU guang ZENG Yanlian xie Lei Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Beijing100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing100190China

Hot gas ingestion refers to the phenomenon of mainstream hot gas flowing into the space cavity of a turbine *** studies have found that mainstream annulus pressure distribution plays an important role in hot gas ingestion,but due to its complexity,the mechanism of the interaction between mainstream flow and hot gas ingestion remains *** paper adopts the URANS method,and three sealing flow rates are considered,named C_(w)=0,C_(w)=500,and C_(w)=*** time-averaged annulus pressure distribution shows that an increase in the sealing flow decreases the pressure value,and the effects of the sealing flow on the pressure distribution of the leading edge of the blade are much more influential than that of the trailing edge of the *** unsteady pressure time-space distribution in the annulus indicates that a time-space tilted distribution of pressure at the rim exits when the sealing flow *** phenomenon is mainly due to the strong feedback mechanism of the sealing flow to the annulus pressure field.A comparison of the pressure and mean radial velocity distribution of the mainstream shows that the ingestion mainly occurs on the blade side,where the pressure is lower than on the vane *** flow characteristics at the wheel rim are analyzed with a sealing flow rate C_(w)=5000,and under these conditions,both pressure-induced ingestion and ingestion caused by a passage vortex can be *** three-dimensional and inertial effects of the mainstream at the wheel rim lead to the generation of separation vortices on the blade side,and the presence of separation vortices leads to ingestion along the blade *** the same time,pressure on the blade side will cause the fluid to have a radial inward flow tendency,which will promote the formation of separation vortices,leading to more serious ingestion in the high-pressure region on the blade *** blade pressure field can be more significant than the vane trailing pressure field in the rim sea

关键词： separation vortex unsteady rim seal the effect of blade on ingestion

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