Arsenic hyperaccumulator Pteris Vittata L. and its arsenic accumulation

An arsenic hyperaccumulator Pteris vittata L. (Chinese brake) was first discovered in China by means of field survey and greenhouse cultivation. Field survey showed that Chinese brake had large accumulating capacity to arsenic; the orders of arsenic content in different parts of the fern were as follows: leaves>leafstalks>roots, which is totally different from that of ordinary plants; bioaccumulation coefficients of the above ground parts of the fern decreased as a power function of soil arsenic contents. In the control of pot trials with normal unpolluted soil containing 9 mg/kg of arsenic, the bioaccumulation coefficients of the above ground parts and rhizoids of Chinese brake were as high as 71 and 80 respectively. Greenhouse cultivation in the contaminated soil from mining areas has shown that more than 1 times greater arsenic can be accumulated in the leaves of the fern than that of field samples with the largest content of 5070 mg/kg As on a dry matter basis. During greenhouse cultivation, arsenic content in the leaves of the fern increased linearly with time prolonging. Not only has Chinese brake extraordinary tolerance and accumulation to arsenic, but it grew rapidly with great biomass, wide distribution and easy adaptation to different environmental conditions as well. Therefore, it has great potential in future remediation of arsenic contamination. It also demonstrates important value for studies of arsenic physiology and biochemistry such as arsenic absorption, translocation and detoxification mechanisms in plants.     

Satellite SAR interferometric observations of displacements associated with urban subsidence in Suzhou, Eastern China

SAR interferometry (InSAR) has a high potential for surface displacement mapping in the range from millimeter to meter. In this paper the potential of ERS-1/2 SAR interferometry for mapping subtle land subsidence has been investigated. A time series of ERS-1/2 SAR data from February 1993 to February 2000 is collected from measurements taken in Suzhou city, Jiangsu Province, China, eight ERS-1/2 SAR images are used to create seven interferograms, and three differential interferograms are produced using the three-pass method, which clearly show the spatial extent of land subsidence. The deformation maps are validated by leveling surveys, the correlation coefficient and standard deviation between them are 0.943 and 0.1706 respectively. Based on seven benchmarks, the subsidence rates are estimated, the overall trends are in close agreement with InSAR results. The results of study show that for the mapping of land subsidence in urban environments InSAR has a strong potential due to its cost-saving, high resolution and accuracy.     

Quasi-cardinality of a Fuzzy Set on a Measurable Universe of Discourse

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｃａｒｄｉｎａｌｉｔｙｏｆａｆｕｚｚｙｓｅｔｉｓｏｎｅｏｆｔｈｅｐｒｏｂｌｅｍｓｔｈａｔｈａｖｅｂｅｅｎｉｎｔｅｒｅｓｔｅｄｉｎｆｕｚｚｙｓｔａｔｉｓｔｉｃｓｄｕｅｔｏｉｔｓｖａｒｉｅｔｙｏｆａｐｐｌｉｃａｔｉｏｎ .Ｆｏｒｅｘａｍｐｌｅｉｎｉｎｓｕｒａｎｃｅａｃｔｕａｒｙ ,ｔｈｅｆｕｚｚｙｓｅｔｏｆｐｅｏｐｌｅｉｎｔｈｅｔｈｉｒｄｓｔａｔｅｉｓｒｅｌａｔｅｄｔｏｔｈｅｃａｒｄｉｎａｌｉｔｙ[1] .Ａｌｓｏｔｈｅｃａｒｄｉｎａｌｉｔｙｉｓｃｌｏｓｅｌｙｒｅｌａｔｅｄｔｏ…     

关于高校健美操比赛中运动状态的调控

分析了高校健美操运动员赛前及比赛过程中产生不良运动状态的原因,指出过高紧张状态及过低紧张状态是导致大学生业余健美操选手比赛失常的症结所在。对此,提出了针对大学生业余选手运动状态的4种调节方法。     

鼻部外形特征的遗传规律

面貌特征是一类遗传率极高的人体性状，通过对家系和群体的鼻部特征进行分类界定，观察记录，确定鼻部的4个性状特征（鼻根高度，鼻背硬骨部，鼻背软骨部，鼻尖方向）为单基因遗传，群体中的偏相关分析和主成分分析显示性状之间有相关性。     

应用灰色系统理论评价机械零件的综合质量

运用灰色系统理论对机械零件质量要求的各项指标进行归纳和计算，判断零件所属的灰类，从而更合理地评价零件的综合质量。     

导入野生大豆DNA小麦后代的农艺性状研究

用花粉管通道法将野生大豆总DNA导入小麦，获得了转基因小麦，其后代的农艺性状有较大的变化。田间实验分析了变异系小麦植株与对照植株在叶片的光合速率、蒸腾速率、叶面积及株高、穗粒、穗重等性状上的差异。t检验结果显示，变异系小麦在叶面性状及产量性状上的差异是显著的，外源DNA的导入改善了植物的农艺性状，并在后代中表达，为选育高产、优质的新小麦品种提供了依据。     

囊虫病的流行与治疗现状

囊虫病是一种人猪共患病 ,对人类健康危害较重 ,流行广泛 ,尤以东北地区多见 .为有效防治囊虫病提供详细资料 ,现就囊虫病的流行病学与防治现状做以下综述 ,结果表明 ,近年来 ,囊虫病的感染率有逐年上升趋势     

论新形式下高校结算中心的存在和发展

首先从不同角度阐述现阶段结算中心存在的必要性 ,然后从结算中心如何提高自身服务职能 ;合理规避融资风险等方面论述了在新形式下结算中心发展前景 .     

人类舌运动类型

介绍了舌运动类型的研究历史和研究成果及5种舌运动类型（卷舌、叠舌、翻舌、三叶舌、尖舌）在不同人群中的出现率，着重论述了近年来我国学者这方面的工作。