适用于动态有向图路径检索的一种数据结构

给出一种表达加权有向图的数据结构，它使得对此有向图进行“插入”操作后，只需进行Ｏ（ｎ２）时间的维护工作，就可使得每对结点间的最短路径迅速地得到修整。     

复数,实数及实对称数据下Bruun FFT算法的实现

本文在复数、实数以及实对称数据下研究和实现了Ｂｒｕｕｎ ＦＦＴ算法。文章分析和评价了各种数据下ＢｒｕｕｎＦＦＴ的运算量和特点，提出了算法的实现结构和方法。最后给了ＴＭＳ３２０Ｃ３０上的运算时间，我们实现的算法比基２ＦＦＴ速度提高３５％。     

浮体运动时域解的奇异性讨论

以推板造波的辐射问题为例，求出了线性时域解的解析表达式，并对线性时域解在造波板与自由面交线处的奇异特性进行了讨论，给出了奇异性的量阶。此奇异性结论对造波机的数值模拟有一定的指导意义。     

低强度瞬态电磁场下动物细胞的电穿孔效应

用低强度瞬态电磁场处理动物细胞后,一些胞内蛋白可以溢出细胞,荧光标记抗体蛋白（ＩｇＧ）可以进入细胞,通过扫描电镜观察到红细胞膜上有电致孔洞,证实了低强度瞬态电磁场作用能起电穿孔。     

无限维离散不可控系统二次判据问题讨论

通过构造一个范数，并利用动态规划原理对无限维离散不可控系统二次判据问题进行了讨论，得到了最优反馈控制的存在唯一性，以及自治情形下的Ｒｉｃｃａｔｉ方程。     

Towards sustainability in world fisheries

Fisheries have rarely been 'sustainable'. Rather, fishing has induced serial depletions, long masked by improved technology, geographic expansion and exploitation of previously spurned species lower in the food web. With global catches declining since the late 1980s, continuation of present trends will lead to supply shortfall, for which aquaculture cannot be expected to compensate, and may well exacerbate. Reducing fishing capacity to appropriate levels will require strong reductions of subsidies. Zoning the oceans into unfished marine reserves and areas with limited levels of fishing effort would allow sustainable fisheries, based on resources embedded in functional, diverse ecosystems.     

Microtubules with more than 13 protofilaments in the dividing nuclei of ciliates

Microtubules are largely composed of proteins called tubulins. These are stacked in linear arrays called protofilaments (p). Most microtubules have precisely 13p (ref. 1). The 'incomplete' B and C microtubules (10 or 11p) of cilia, flagella, basal bodies and centrioles are widespread exceptions. Very few examples of 'complete' microtubules with more, or less, than 13p have been found. However, the 'ciliate cell' includes a larger number of highly differentiated types of microtubule arrays than most other cell types. The present study was undertaken to ascertain whether there is variation in p number in two ciliates. In both, all complete cytoplasmic microtubules examined have 13p but microtubules with 13-16p are present in the nucleoplasm of dividing nuclei. These features are probably common to ciliates in general because the free-living hymenostone Paramecium tetraurelia and the parasitic heterotrich Nycotherus ovalis are not closely related in terms of taxonomic criteria or life-style.     

Solution structure of a protein denatured state and folding intermediate

The most controversial area in protein folding concerns its earliest stages. Questions such as whether there are genuine folding intermediates, and whether the events at the earliest stages are just rearrangements of the denatured state or progress from populated transition states, remain unresolved. The problem is that there is a lack of experimental high-resolution structural information about early folding intermediates and denatured states under conditions that favour folding because competent states spontaneously fold rapidly. Here we have solved directly the solution structure of a true denatured state by nuclear magnetic resonance under conditions that would normally favour folding, and directly studied its equilibrium and kinetic behaviour. We engineered a mutant of Drosophila melanogaster Engrailed homeodomain that folds and unfolds reversibly just by changing ionic strength. At high ionic strength, the mutant L16A is an ultra-fast folding native protein, just like the wild-type protein; however, at physiological ionic strength it is denatured. The denatured state is a well-ordered folding intermediate, poised to fold by docking helices and breaking some non-native interactions. It unfolds relatively progressively with increasingly denaturing conditions, and so superficially resembles a denatured state with properties that vary with conditions. Such ill-defined unfolding is a common feature of early folding intermediate states and accounts for why there are so many controversies about intermediates versus compact denatured states in protein folding.     

BP网络应用于黄河水质的预测研究

利用黄河兰州段水质指标浓度时间序列作为学习样本,选取了DO、COD、氨氮、重金属离子等l0项指标作为输出参数,运用人工神经网络BP模型中的Levenberg—Marguardt优化算法对学习样本优化建模,将优化好的网络的预测结果与实测结果进行了比较,表明BP网络可以很好地用于黄河水质指标值及水质类别的预测。