海南岛作物种质资源考察与评价

1、全面考察了海南岛19个县(市)，设1444个考察点，其地貌类型包括山地、丘陵、盆地、沼泽地及海滩，行程15万公里，考察的作物包括粮食、油料、蔬菜、果树、纤维、茶叶、桑树、橡胶、椰子、腰果、油棕、龙舌兰麻类、胡椒、咖啡、可可、花卉、香料、药材、木棉、珍稀濒危植物、绿肥等21大类资源(包括栽培和野生类型)，取得了系列科学考察成果资料。2、共搜集各类作物种质资源5545份，其中具生命力的活种质4922份；腊叶标本7437份；我国特有种6个；海南特有种122个。3、撰写各类作物考察报告46篇，考察工作报告22篇，资源目录8册；提出各类作物种质资源的保护和开发利用建议22篇；编印《海南岛作物种质资源考察收集目录》，均具有重大学术价值，是珍贵的资料。4、基本摸清了各类作物种质资源在海南岛上的分布、生境概况。每份种质都建立了记录卡归类保存。5、列入濒危级的有40个种，渐危级64个种，稀有级71个种。同时，发掘了一些作物的丰产源、优质源、抗源、早花等400份供开发利用。6、对考察收集起来的种质作了妥善的保存，保存方法有：1156份入国家种质库；3947份入承担单位资源圃保存；3442份就地保存。对珍贵的、特殊的及新发现的种质进行了录像。大大地丰富了我国作物资源库，对栽培作物的起源、演变、进化、分类的研究有重要的理论价值和学术意义。7、拍摄资源彩色照片4170张。

Height-length relation of shells in the Indian backwater oyster Crassostrea madrasensis (Preston) of the Cochin harbour

Height-length relationship in Crassostrea madrasensis (Preston) showed an exponential trend and relation in the form, H=ALᴮ. Deviations of actual values from the mean values consequent to the increase in size were noticed. Height and length approximated in oysters of less than 3.5cm in height resulting in orbicular shape. In oyster of shell height 3.5cm to 8cm, increase in height is faster leading to an oval shape. Above 8cm in height, the oysters become further elongated. Height-length relation is non-linear with an index (B value) of 1.1156. A linear relationship also holds good as the B value is not very much different from unity (H=-2.5424+2.0036L).

Theoretical investigation of CoSi2/Si1-xGex detectors: Influence of a Si tunneling barrier on the electro-optical characteristics

We present a theoretical investigation of the influence of a non-reacted Si layer on the transport and optical properties of CoSi2/Si1-xGex Schottky barrier diodes grown from Co/Si/Si1-xGex systems. The presence of this layer reduces the effect of the lowering of the Schottky barrier height which would be expected in a CoSi2/Si1-xGex. However, due to the small thickness of this Si layer, the charge carriers are able to tunnel through it. This tunneling process allows for a significant lowering of the Schottky barrier height and therefore an extension of the detection regime into the infrared. © 1996 American Institute of Physics.

救救北海湿地

<正>好不容易盼来长假,我们兴冲冲地参加了去腾冲的旅游团。经过十多个小时的 颠簸,终于来到了素有"热海"之美誉的腾冲。 然而长途跋涉后,旅游的第一个项目实在令我们瞪目结舌。只听导游介绍说, 我们第一站要去的地方是北海--云南省唯一一块国家级湿地。 "它好似一块浮在水上的毛毯。我们要去毛毯上踩一踩、跳一跳。

The use of spatial impulse responses to characterise flexible forming processes with mobile tools

A novel test method for the characterisation of flexible forming processes is proposed and applied to four flexible forming processes: Incremental Sheet Forming (ISF), conventional spinning, the English wheel and power hammer. The proposed method is developed in analogy with time-domain control engineering, where a system is characterised by its impulse response. The spatial impulse response is used to characterise the change in workpiece deformation created by a process, but has also been applied with a strain spectrogram, as a novel way to characterise a process and the physical effect it has on the workpiece. Physical and numerical trials to study the effects of process and material parameters on spatial impulse response lead to three main conclusions. Incremental sheet forming is particularly sensitive to process parameters. The English wheel and power hammer are strongly similar and largely insensitive to both process and material parameters. Spinning develops in two stages and is sensitive to most process parameters, but insensitive to prior deformation. Finally, the proposed method could be applied to modelling, classification of existing and novel processes, product-process matching and closed-loop control of flexible forming processes. © 2012 Elsevier B.V.

生活污水对蝌蚪红细胞微核及核异常的诱导

利用青蛙蝌蚪红细胞微核试验,检测了城市生活污水处理厂各级处理工艺出水的诱变活性。在l6d生话污水处理的实验中,青蛙蝌蚪红细胞微核细胞率及核异常率2d后就呈现统计上的显著增加,并随暴露时间的延长而增高,第8天达到最大值。在不同浓度混合污水暴露实验中,蝌蚪红细胞微核细胞率和核异常率呈现明显的剂量依赖性增加。实验结果表明:城镇生活污水具有较强的诱变活性,一级和二级处理工艺出水也具有一定的诱变活性。现有污水处理工艺有待于进一步改进。

武汉东湖上覆水和沉积物中磷形态的垂直分布特征

武汉东湖是有代表性的城市浅水型湖泊。于春、夏两季对东湖庙湖湖区的上覆水和沉积物柱状样品进行了磷的形态分析,研究了各种磷形态在上覆水及沉积物垂直方向上的分布特征。结果表明,春夏两季东湖上覆水总磷(TP)含量分别为1.11和1.25mg·L-1,超过国家标准近6倍,富营养化程度严重。春季湖水中磷主要以颗粒态形式存在,夏季主要以溶解态形式存在。春季湖区沉积物中铁结合磷(Fe-P)比例最大,占沉积物TP的44.3%,夏季闭蓄磷(OcP)比例最大,占TP的36.3%,高比例的Fe-P从沉积物角度说明了庙湖湖区的污染