扁球壳微分方程的分析解

扁球壳微分方程的分析解窦家维（西安联合大学师范学院数学系西安７１００６１；作者，女，３２岁，讲师）１扁球壳的微分方程在非轴对称变形时，扁球壳的应力函数中和径向位移Ｗ所满足的基本微分方程为，、。＿＿。Ｊ］１１）＿＿＿＿．＿＿．．＿。＿＿＿式中算子而是与...     

NO分子的生物化学及其作用

在过去的几年里,NO分子是被广泛研究和最引人注目的无机小分子,1992年被评为“世界分子”．1998年,三位美国科学家因发现它的生理作用而荣获诺贝尔医学奖．NO作为“生物信息传递者”在人和其它动物的许多生理过程中起着非常重要的作用,其功能包括神经传导、血液凝固、血压控制及免疫系统中的作用等方面．     

A rule-based model for mapping potential exotic plant distribution

Wildland managers need a method to predict which portions of the lands under their stewardship are susceptible to invasion by exotic plants. We combined a database listing exotic plant species known to occur in major environmental types (habitat types) throughout the northern Rocky Mountains with a digital vegetation map of environmental types for a major national park in the region (Yellowstone National Park) to produce maps of areas potentially threatened by major exotic species. Such maps should be helpful to managers concerned with monitoring and controlling exotic plants.     

Stretching the In-between: Embodiment and Beyond

Today??s scientific imaging technologies are able to detect and image emissions and radiations from a much wider range of the electromagnetic spectrum than ever before. Such phenomena lie beyond the horizons of ordinary human perceptibility. I examine here the implications of such ??translation mediations?? for the production of scientific knowledge and show how human embodiment is implicit for all perceptual observational possibilities. The framework is that of a postphenomenology which is able to relate these new phenomena to human embodiment.     

重塑晋南——论山西生产力发展的区域战略大转移

非平衡发展是落后地区的成功发展战略，这种战略的关键则在于新增长区的选择．山西具有建设现代城市群的盆地唯有太原和晋南本文论述了选择晋南做为实施非平衡发展战略的新区优势．     

Subjective confidence in forecasts

Forecasts have little value to decision makers unless it is known how much confidence to place in them. Those expressions of confidence have, in turn, little value unless forecasters are able to assess the limits of their own knowledge accurately Previous research has shown very robust patterns in the judgements of individuals who have not received special training in confidence assessment: Knowledge generally increases as confidence increases. However, it increases too swiftly, with a doubling of confidence being associated with perhaps a 50 per cent increase in knowledge. With all but the easiest of tasks, people tend to be overconfident regarding how much they know These results have typically been derived from studies of judgements of general knowledge. The present study found that they also pertained to confidence in forecasts. Indeed, the confidence-knowledge curves observed here were strikingly similar to those observed previously. The only deviation was the discovery that a substantial minority of judges never expressed complete confidence in any of their forecasts. These individuals also proved to be better assessors of the extent of their own knowledge Apparently confidence in forecasts is determined by processes similar to those that determine confidence in general knowledge. Decision makers can use forecasters assessments in a relative sense, in order to predict when they are more and less likely to be correct. However, they should be hesitant to take confidence assessments literally. Someone is more likely to be right when he or she is ‘certain’than when he or she is ‘fairly confident’; but there is no guarantee that the certain forecast will come true.     

一阶微分方程y′＝（y—x~2）~（－1）初值问题的一种数值解法

在利用福克绕射公式计算地面波传播衰减时，为确定其中的计算参数，需求解微分方程ｙ′＝（ｙ—ｘ２）－１的初值问题。本文提出一种新的数值计算方法来求解这一微分方程数值解。实际数值计算结果表明，同文献［１］中指出的泰勒展开近似计算方法相比，本方法具有推导简单、计算速度快及计算精度高等优点，并可处理一类相似的微分方程。     

Nonsense-mediated decay microarray analysis identifies mutations of EPHB2 in human prostate cancer

The identification of tumor-suppressor genes in solid tumors by classical cancer genetics methods is difficult and slow. We combined nonsense-mediated RNA decay microarrays and array-based comparative genomic hybridization for the genome-wide identification of genes with biallelic inactivation involving nonsense mutations and loss of the wild-type allele. This approach enabled us to identify previously unknown mutations in the receptor tyrosine kinase gene EPHB2. The DU 145 prostate cancer cell line, originating from a brain metastasis, carries a truncating mutation of EPHB2 and a deletion of the remaining allele. Additional frameshift, splice site, missense and nonsense mutations are present in clinical prostate cancer samples. Transfection of DU 145 cells, which lack functional EphB2, with wild-type EPHB2 suppresses clonogenic growth. Taken together with studies indicating that EphB2 may have an essential role in cell migration and maintenance of normal tissue architecture, our findings suggest that mutational inactivation of EPHB2 may be important in the progression and metastasis of prostate cancer.     

浅谈中职教师做个案研究

个案研究是对特定教育现象加以调查分析、弄清其特点及其形成过程的一种研究方法,最适合于教师研究,但在教学实践中教师却由于种种原因对个案研究重视不足.为了帮助教师在实践中有效运用个案研究,文章分析了个案研究的目的、意义和研究中应该注意的几个问题,以求对教师有所帮助.