Study on Ecosystem Status and its Evolution in Jiulongjiang River Estuary

随着社会经济的发展和自然环境的变化，我国的河口生态系统面临着日益严重的压力和一系列生态灾害频发的风险，迫切需要对河口生态系统开展评价，从科学的角度分析生态系统过去、现状、成因、发展趋势，以指导生态系统管理工作。因此，研究河口生态系统状态及其演变具有重要的理论和实际应用价值。 目前，我国对河口生态系统状态的研究和评价的开展尚在探索阶段，还未形成制度化的评价机制、指标体系及评价方法，虽然有少量与河口生态系统相关的研究成果，但长时间序列的河口生态系统评价少之又少。本文构建了河口生态系统PSR模型评价指标体系，并以中国特有的五年经济社会发展规划时间为划分评价时间单元，建立了长期的河口生态系统状态演变...According to the development of community economy and the changes of natural environment, the estuarine ecosystem in China are faced with growing pressure and a series of risks of environment disaster. It is necessary to assessment on the estuarine ecosystem, to analyze the past, current status, cause and ecolution trends by scientific angles, in order to guide ecosystem management. Therefore, res...学位：理学硕士院系专业：海洋与环境学院海洋学系_海岸带综合管理学号：2242007115083

日本产业经济特征、转型及启示

本文从作为日本经济异常突出的现象的产业经济出发,探讨一下日本经济中存在的产业问题,及其今后面临的转型,在此基础上希望能得出一些有益的启示,特别是对于与之同处于亚洲地区且在文化和经济发展中有着许多类似特点的亚洲国家包括我们中国经济的一些有益的启示

切削力系数辨识的贝叶斯推断方法

快速标定斜角切削力系数的方法在切削力建模中得到了广泛应用,但该方法忽略了系数辨识过程中的不确定性因素。针对此问题,提出了一种基于贝叶斯推断的切削力系数辨识方法。推导了镶齿面铣刀铣削力解析模型,给出了快速标定斜角切削力系数的线性回归方法。通过马尔科夫链蒙特卡罗方法从切削力系数的后验分布中生成样本,然后基于贝叶斯推断方法评价切削力系数的变化。在给定的实验条件下,分别用线性回归方法和贝叶斯推断方法进行切削力系数辨识,将计算得到的铣削力与实验铣削力值进行对比,结果表明贝叶斯推断方法具有更高的预测精度

福建云霄水头宋代窑址发掘简报

水头窑址位于福建省漳州市云霄县火田镇水头村田头前自然村东300米的碗仔山上(图一),地处一山间小盆地之中,北侧有小溪(窑陂)汇入漳江,东、南、西三面为柴薪充足的丘陵山地,平均海拔35～50米。窑址发现于20世纪50年代末,1985年被公布为云霄县文物保护单位,现保存有数处窑业堆积,地表散见碗、杯、盘、碟、炉等瓷器标本及匣钵、垫饼等

The Species and Toxicities of Nassariidae Collected from the Coast of Southeast China Sea

为了解我国东南沿海地区织纹螺体内的毒素状况,利用生物法对采自我国东南沿海的织纹螺样品毒性进行了测定.实验结果和相关资料表明:织纹螺的毒性与其种类关系密切.光织纹螺(nASSArIuS ruTIlAnS)、正织纹螺(zEuXIS SCAlArIS)和节织纹螺(nASSArIuS HEPATICuS)为有毒织纹螺;纵肋织纹螺(nASSArIuS VArICIfEruS)、习见织纹螺(nASSArIuS dEAlbATuS)和胆形织纹螺(nASSArIuST HErSITES)为无毒织纹螺;方格织纹螺(nASSArIuS ClATHrATuS)、西格织纹螺(nASSArIuS SIQuInJOrEnSIS)、半褶织纹螺(nASSArIuS SEMIPlICATuS)、红带织纹螺(nASSArIuS SuCCInCTuS)、疣织纹螺(nASSArIuS PAPIllOSuS)、花织纹螺(zEuXIS CASTuS)、素面织纹螺(nASSArIuS SufflAyuS)和橡子织纹螺(nASSArIuS glAnS)毒性不明,可能为季节性有毒织纹螺.多种织纹螺的毒性变化规律目前尚不清楚,人们应尽量避免食用织纹螺.To investigate the distribution of toxic Nassarius in the southeast coast in China, we detected snail samples collected from these areas by bioassay.Results indicated that the toxicity of Nassarius was relative to species.Nassarius rutilans, Zeuxis scalaris, and Nassarius hepaticus were toxic gastropods, and Nassarius variciferus, Nassarius dealbatus, and Nassarius thersites were nontoxic gastropods, while the toxicity of Nassarius clathratus, Nassarius siquinjorensis, Nassarius semiplicatus, Nassarius succinctus, Nassarius papillosus, Zeuxis castus, Nassarius sufflayus, and Nassarius glans probably changed with the season.The change regularity of Nassarius's toxicity is still unknown.Therefore the best way to prevent humans from the harmful effects of Nassarius is to stop eating them.人事部留学回国人员科研启动基金资助项

Toward an understanding of the turbidity measurement of fleterocoagulation rate constants of dispersions containing particles of different sizes

Our previous studies have shown that the determination of coagulation rate constants by turbidity measurement becomes impossible for a certain operating wavelength (that is, its blind point) because at this wavelength the change in the turbidity of a dispersion completely loses its response to the coagulation process. Therefore, performing the turbidity measurement in the wavelength range near the blind point should be avoided. In this article, we demonstrate that the turbidity measurement of the rate constant for coagulation of a binary dispersion containing particles of two different sizes (heterocoagulation) presents special difficulties because the blind point shifts with not only particle size but also with the component fraction. Some important aspects of the turbidity measurement for the heterocoagulation rate constant are discussed and experimentally tested. It is emphasized that the T-matrix method can be used to correctly evaluate extinction cross sections of doublets formed during the heterocoagulation process, which is the key data determining the rate constant from the turbidity measurement, and choosing the appropriate operating wavelength and component fraction are important to achieving a more accurate rate constant. Finally, a simple scheme in experimentally determining the sensitivity of the turbidity changes with coagulation over a wavelength range is proposed

Optical Factors Determined by the T-matrix Method in Turbidity Measurement of Absolute Coagulation Rate Constants

Turbidity measurement for the absolute coagulation rate constant of suspensions has been extensively adopted because of its simplicity and easy implementation. A key factor to derive the rate constant from experimental data is how to theoretically evaluate the so-called optical factor involved in calculating the extinction cross section of doublets formed in the aggregation. In a previous paper, we have shown that compared with other theoretical approaches, the T-matrix method provides a robust solution to this problem and is effective in extending the applicability range of the turbidity methodology as well as increasing measurement accuracy. This paper will provide a more comprehensive discussion about the physical insight of using the T-matrix method in turbidity measurement and associated technical details. In particular, the importance of ensuring the correct value for the refractive indices for colloidal particles and the surrounding medium used in the calculation is addressed because the indices generally vary with the wavelength of the incident light. The comparison of calculated results with experiments shows that the T-matrix method can correctly calculate optical factors even for large particles, whereas other existing theories cannot. In addition, the calculated data of the optical factor by the T-matrix method for a range of particle radii and incident light wavelengths are listed

中国式学科评估:问题与出路

今年四月份,教育部学位与研究生教育发展中心(以下简称"教育部学位中心")邀请全国学位授予单位参加全国第四轮一级学科整体水平评估。随之,各个高校展开了一场大规模、高级别的学科评估申报及材料提交总动员。第四轮学科评估自发布起也引发了学界的广泛关注和热烈讨论。高等教育是中国崛起的思想发动机,关涉民族复兴的未来,而学科评估是近年来中国高等教育学科建设成就的集中展示,其意义和影响可谓深远。为了更好推进学科评估科学进行,特别是促进高等教育健康发展,《探索与争鸣》编辑部邀请全国