Interannual variability of dimethylsulfide in the Yellow Sea

Journal of Oceanology and Limnology - The 22-year (1998–2019) surface seawater dimethylsulfide (DMS) concentrations in the Yellow Sea (YS) were hindcasted based on satellite sea surface...     

Production of Pacific White Shrimp Polycultured with Swimming Crab at Different Densities,and Nutrient Budget in the Enclosure System

This study was to evaluate the effect of stocking densities on the nitrogen and phosphorus budgets for a polyculture of the crab Portunus trituberculatus and the Pacific white shrimp Litopenaeus vannamei.The shrimps(initial weight,0.012 g)were cultured at a density of 45 shrimp m^-2,and juvenile crabs(initial weight,0.024 g)were cultured at five densities of 0,3,6,9,and 12 crabs m^-2.The treatments were grouped as C0S45,C3S45,C6S45,C9S45,and C12S45,respectively.Water quality parameters,growth of shrimp and crabs,and nitrogen and phosphorus budget were measured.The results indicated that the shrimp performances in polyculture treatments C3S45 and C6S45 were superior to those in the crab-free treatment(C0S45).The crab in treatments C3S45 and C6S45 exhibited a significantly higher final mean weight and carapace width/length than those in treatments C9S45 and C12S45.The final size and survival of crabs had a negative correlation with the increasing crab stocking density.The contents of total phos-phorus and total nitrogen and the comprehensive contamination index values were higher in the C9S45 and C12S45 treatments than in the other treatments.The conversion ratios of nitrogen for crab and shrimp growth in treatment C3S45 were significantly higher than those in the crab-free treatment.These findings indicate that polyculturing shrimp with crabs at suitable densities can improve productivity,profitability,nutrient utilization,and the environmental quality.From the 60-day treatments,the optimal culture densi-ties were 3-6 crabs m^-2 and 45 shrimps m^-2.     

土地资源开发专家系统设计--以黄河大柳树水利枢纽灌区为例

本文在黄河大柳树水利枢纽灌区土地资源系统研究的基础上,设计了土地资源开发专家系统（ＬＲＤＥＳ）把计算机智能引入了灌区土地资源系列开发中,文章介绍了ＬＲＤＥＳ的参数设计,功能需求及功能模块之间的关系,对系统性能,系统控制流及系统信息流等作了简要分析。     

The evolutionary status of HD 104237, ε Cha and HD 100546

Using the new data from Hipparcos and the TD-1 UV data, we fix the positions of three objects, HD 104237, HD 100546 and ε Cha in the HR diagram and discuss their theoretical evolutionary status.     

具有凝结加热反馈的对称不稳定的解析研究

本文采用非地转非静力条件下存在对流凝结加热反馈的Boussinesq方程组,借用Emanuel(1982)的Wave-CISK方案来考虑凝结反馈作用,并应用Green函数方法和Fourier方法,求得了任意加热廓线时对称不稳定的流函数的解析表达式及其频散关系。本文还对取某些特定的加热廓线时的情况进行了讨论。      

华南古岩溶型铀矿床矿物学及其矿床成因意义

华南古岩溶铀矿床的矿物学特征为:表生矿物发育,原生成矿矿物少见;矿化脉体几乎没有;矿石中铀主要呈吸附状态,其次呈显微和超显微沥青铀矿存在。与古岩溶有关铀矿床则出现典型低中温热液矿物组合,矿化脉体期次分明,矿石中铀基本呈可见状沥青矿存在,沥青铀矿具有热液成因标型。鉴于该类矿床成矿前主岩溶为冷水成因,而热液成矿流体是与岩溶无关的体系,故属古岩溶热液叠造成矿      

雅鲁藏布江中部流域沙地植被的分类和排序

选用模糊聚类分析方法,利用群落组种的相对盖度作为优势度指标,将该区沙地植被划分为22个群系,群系下又划分出了不同的群丛。同时,采用主分量分析(PCA)模型,对10个常见的群落类型进行了二维排序,比较直观和真实地反映了不同群落类型在土壤砾石化程度和土壤潜在肥力2个环境梯度上的分布情况。     

利用等高线分维一高程曲线确定岩溶台面高程的方法探讨

传统的确定岩溶台面的方法是定性的,因而往往有争议,作为台面高程的峰顶面通常并非平坦地面,这也给客观定量地确定台面高程带来困难。本文基于等高线的分形特征,提出根据等高线的分维－高程曲线确定岩溶台面高程。实例研究初步表明,这是一种简便可行的定量方法。      

燕山地区中生代构造应力场特征

燕山地区现今的构造、地貌景观,是在漫长的地质历史时期,经历了长期、复杂的建造、改造过程而形成的。从沉积建造及构造形变特点来看,自元古宙至古生界,本区构造运动平缓,建造和改造的特点主要反映基底断裂的控制作用。中、新生代构造运动是燕山地区主要造山作用期,基本特征是强烈挤压形成线状褶皱及推覆构造系统。
中生代时期,本区构造形变显示水平应力作用的主导性,新生代时期,则以均衡代偿导致的隆升作用为主。本文侧重中生代构造应力场及变形挠度场的重塑,借以恢复本区中、新生代构造形变形成的力学过程及运动程式。      

东海台风出现次数以及在我省沿海登陆的分析与预测

根据３７年（１９５３～１９８９年）的有关气象资料分析表明,浙北地区当年３月温度,上年４～６月降水量,秋、冬季干湿度和年积温与当年东海热带气旋（指强度达到热带风暴以上的热带气旋以下统称台风）出现次数之间有着密切的相关性。在此基础上进一步分析了前期一些气象要素与登陆台风之间的关系,并由此分别建立预报东海台风出现多寡和台风是否登陆的判别式。从其拟合和试报结果来看,效果令人满意。