类

The new representation proposed in this paper deals with the partitional clustering problem by regarding it as a multi-objective optimal problem; in this approach the niche Pareto genetic algorithm is used to solve the problem.

动态聚类算法从本质上讲是单目标组合优化算法，一般需要事先给定目标分类数和初始聚类中心，且初始聚类中心的选择对数据划分结果影响较大。

At present, there are several partitional clustering algorithms which are more popular and used more often, such as K-means, K-harmonic means, fuzzy C-means and spectral clustering .

目前聚类算法中比较流行且应用比较广泛的划分聚类算法主要有K-均值、K-调和均值、模糊C-均值和谱聚类等划分算法。

The best theoretical solution to a partitional clustering problem is to find all possible partitions and choose the partition that minimizes the objective function. However, the enumeration of all possible partitions is impractical even for data sets of moderate size. Therefore, as an alternative, most partitional approaches use an iterative optimization technique. And this could be cause local minimum.

本文在分析了目前聚类的基本方法的基础上，指出以K平均法等为代表的分割聚类虽然理论上找到类的所有划分并使得目标函数最小就可以获得最优解，但由于对于相当尺度的数据集列举所有可能的划分并不现实，因而多数分割方法采用迭代优化技术作为变通。

A relative low lake level between 8660～6010 cal.yr BPwas reflected by the clayey silt sediment with the median size less than 25μam and the sandcontent less than 4%,and the Pediastrum concentration was normally low.Between 6010 and2250 cal.yr BP,the median size and sand content increased greatly,and the Pediastrumconcentration raised sharply,suggesting a relative low lake level.After 2250 cal.yr BP,boththe median size and the Pediastrum abundance abruptly declined,suggesting the lake returnedto high level and the climate changed to humid.

UG04孔硅藻记录重建的湖泊水位变化基本上支持孢粉重建的古植被和古气候：8660～7230 cal.yr BP硅藻组合以浮游类主导，浮游／底栖比达40以上，指示水位较高，气候略湿润；7230～2330 cal.yr BP浮游类硅藻丰度和浮游／底栖比降低，湖泊处于低水位，气候干旱；2330～930 cal.yr BP浮游类硅藻丰度和浮游／底栖比增加，湖泊水位升高，气候湿润。

The results of asymmetric reduction of latent chiral ketones by carbonyl reductase showed that the enzyme had a high specificity for pentanone in aliphatic ketones and for the acetophenone derivates that contained a withdrawing group at α-position.

利用羰基还原酶不对称催化还原潜手性酮类化合物发现，对于芳香酮类化合物，酶对α位为强电负性基团的底物专一性较强；对于脂肪酮类化合物，酶对五碳脂肪酮的专性较高。

The influence factors on decomposition efficiency, such as digestion time and pH were identified. It was shown that non-condensed phosphate could be decomposed completely by persulphate.

结果表明：在碱性条件下过二硫酸钾高温氧化可使海水中非聚磷类化合物完全回收，而聚磷类化合物回收率不高，延长消化时间聚磷类化合物的回收率有一定提高。

The influence factors on decomposition efficiency, such as digestion time and pH were identified. It was shown that non-condensed phosphate could be decomposed completely by persulphate. But in alkali condition, condensed phosphate can only be decomposed partly.

结果表明：在碱性条件下过二硫酸钾高温氧化可使海水中非聚磷类化合物完全回收，而聚磷类化合物回收率不高，延长消化时间聚磷类化合物的回收率有一定提高。

The influence factors on decomposition efficency, such as digestion time and pH were identified. It was shown that noncondition phosphate could be decomposed completely by persulphate. But in alkali condition, condensed phosphate could only be decomposed partly.

结果表明，在碱性条件下过二硫酸钾高温氧化可使海水中非聚磷类化合物完全回收，而聚磷类化合物回收率不高，延长消化时间聚磷类化合物的回收率有一定提高。

In Hongyuan cituy of Northwest Sichuan(altitude 3504m) is 99.8%.4. In seed study on prematurity and late-maturity types of Phleum pratense L, require of prematurity type"s growing days are sufficed, ration of seed germinate low, namely 45.6%, require of late-maturity type"s growing days are not sufficed.

在猫尾草早熟、晚熟类结籽的研究中，发现早熟类虽然在生育期上满足了要求，但所结种子发芽率不高，仅为45.6％，晚熟类不能完成其整个生育期。

The preparation of the membrane is that the phthalazine polyether-sulfone-ketone polymer is mixed with chloroform, Ethanol or butanol according to certain quality proportion; after the magnetic stirring, the evenly mixed casting solution is obtained, filtered and carried out with vacuum deaeration; The casting solution is scraped into membrane of certain thickness on the non-woven fabric by adopting the scraper; the membrane is standed for 24 hours in the air of certain humidity and temperature to obtain the plate ultrafiltration membrane of phthalazine polyether-sulfone-ketone.

本发明公开了属于高分子膜分离技术领域的一种二氮杂萘聚醚砜酮类聚合物平板超滤膜的制备方法，所述膜的制备方法为：用二氮杂萘聚醚砜酮类聚合物与氯仿、无水乙醇或正丁醇按照一定的质量比混合，磁力搅拌后得到混合均匀的铸膜液，过滤并真空脱泡；将铸膜液采用刮刀在无纺布上刮制成一定厚度的膜，该膜在一定湿度和温度的空气中静置24h后即得到二氮杂萘聚醚砜酮类平板超滤膜。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。