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1.
INTRODUCTION Voltage security control as an indispensable fa- cility in power systems aims at mid or long term voltage quality maintenance of power systems in the presence of load and/or transmission line disturbances. Most results of earlier research have been reported on transient stabilization and network control for voltage security of power systems, with various techniques originated from modern control methodology such as dynamic programming (Popovic et al., 2002; Wu et al., 2001), …  相似文献   

2.
INTRODUCTION As the liver is a highly vascular organ located inan obscure space, laparoscopic hepatectomy is diffi-cult (Wu, 2000). Other influencing factors includenarrowed vision of the operative field and limitedentry of the instrument. Laparoscopic hepatectomy isstill in its beginning stages. Few cases are reportedinternationally and only 6 are reported domestically. Recently, Sir Run Run Shaw Hospital has de-veloped a form of laparoscopic hepatectomy, resectingby curet…  相似文献   

3.
Emperor Wu of Liang Dynasty sacrificed himself to Tongtai Temple for four times. The event is very fa-mous in Chinese Buddhism history, but the evaluation for it is quite different. Emperor Wu was enlightened by the worshiping Buddha behavior of Indian Ashoka. Emperor Wu＇s action was a simulation of Ashoka deeds, judging from the similarity between the two charity events and his admiration of Ashoka. Emperor Wu＇s worship for Asoka opened up a new perspective for us to study the history of Chinese Buddhism.  相似文献   

4.
This study is aimed at identifying and determining the percentage of occurrence frequency of cellulose decomposing soil fungi. The soil samples were inoculated into culture plates prepared in Sabouraud medium under sterilized conditions and incubated at 30 ℃ for 4 to 7 d. The identified fungal species were incubated in self-designed cellulose medium for testing their cellulolytic ability. Forty-two species, including2 nova species, representing sixteen genera showed growth and sporulation in the cellulose medium. Most of the isolated species were from genus Aspergillus and Penicillium. Aspergillus niger and Mucor hiemalis showed highest occurrence frequency （45% and 36% respectively）, as these species were collected from about 80% of soil samples. Being agar free and cheaper, the new fungal medium designed showed results equivalent to Sabouraud medium.  相似文献   

5.
俞琳  杨建梅 《海外英语》2012,(21):191-193
Within the framework of Appraisal theory,this thesis attempts to do the discourse analysis of modern evolution of fe males’non-prototype characteristics through six versions of biographies of Wu Zetian(included Lin Yutang’s Lady Wu,and Yuan Baidai’s Wu Zetian) in modern times,which aims to uncover the implicit relationship of language and ideology of these different Wu Zetian’s biographical versions composed by different authors with different genders and nationalities,which can evoke the readers resonance and affection towards them and reflect the interpersonal function between them by means of excavat ing the regularity of Attitude,Engagement and Graduation resources distribution.  相似文献   

6.
They are Big Bertha and Tiny Tina, a couple of piglets. They may look and act differently (hence, their names), but these oinkers are identical. They are the newest cloned animals from Texas A&M University, which with their births leads the academic pack in the number of species cloned. And the fact that animals with the exact same genes can be different sizes and have different character traits may be just the first of many things that scientists hope can be learned from these little pigs.  相似文献   

7.
Practical English Test for Colleges (PRETCO) is a large-scale national standardized EFL test for the students of higher vocational colleges,postsecondary specialized colleges,and colleges for adults.This thesis is for a preliminary research of PRETCO backwash based on previous studies from home and abroad,making use of their research methods and models.It attempts to explore the aspects of practical English learning of students from higher vocational colleges (HVC) influenced by PRETCO,and the nature of the backwash.Based on the results reported in the study,the writer analyzes the factors inducing negative backwash and puts forward some suggestions for promoting positive one.  相似文献   

8.
Insulin is one of the most extensively studied protein hormones, and its structure and function have been elucidated in many vertebrate species, ranging from human to fish. Insulin-like peptides (ILPs) also have been found and characterized in different invertebrates, including nematodes, mollusks and insects. However, insect ILPs turned out to be a structurally diverse group encoded by large multi-gene families that are expressed in the brain and other tissues and serve functions different from vertebrate insulin. Recent physiological and genetic studies have revealed that, in different insect species, the conserved insulin signaling pathway plays a key role in the regulation of a variety of fundamental processes, such as metabolism, growth, reproduction and aging. Here, the structures, distributions, conserved signaling pathways, and physiological functions of insect ILPs are reviewed in detail.  相似文献   

9.
INTRODUCTION Congestion control is a critical issue for ensuring the efficient and fair allocation of network resource among communication flows. In wireline networks, TCP has resolved this issue of concern. However, it was reported that TCP performance in a multihop ad hoc environment degrades severely (Xu and Wu, 2006). Thus, some optimization-based congestion control schemes have been proposed to improve TCP performance in ad hoc networks (Chiang, 2005; Chen et al., 2005; Lee et a…  相似文献   

10.
INTRODUCTION The path planning problem of a mobile robot is to find a safe and efficient path for the robot, given a start location, a goal location and a set of obstacles distributed in a workspace. The robot can go from the start location to the goal location without colliding with any obstacle along the path. In addition to the fundamental problem, we also try to find a way to optimize the plan, say to minimize the time required or distance traveled (Wu et al., 1996; Sadati and Ta-he…  相似文献   

11.
研究目的：开发具有种属特异性序列特征性扩增区域（SCAR）标记物来监测哈茨木霉在其入侵的试验菌群中的定殖和生长,为哈茨木霉应用于生物防治等生态和生物技术中提供支撑。 创新要点：多种木霉属真菌能与各种微观和宏观的生物有机体建立相互作用。利用这些相互作用,木霉可做为原生种群的入侵物种而用于生物防治。本文通过使用试验菌群为研究模型,利用随机扩增多态性DNA（RAPD）技术和序列特征性扩增区域（SCAR）标记物来监测菌群中哈茨木霉的生长状态。 研究方法：利用随机扩增多态性DNA（RAPD）技术,从16个10聚体引物进行多态性筛选,其中1个引物扩增出对应哈茨木霉的条带。对该条带进行克隆测序,并设计5个20-23聚体引物。成功利用引物对2F2／2R2和2F2／2R3278分别特异性地扩增出哈茨木霉BpTloa菌株278bp和448bp的DNA片段。同时,用这两个引物对14个哈茨木霉菌株和几种不同的真菌菌株进行特异性对照试验,也只成功扩增出哈茨木霉菌株。此外,使用真菌DNA混合物和试验真菌群的DNA为模板,采用实时聚合酶链式反应（PCR）对引物对2F2／2R2进行评估。当仅使用100份SCAR标记物或哈茨木霉仅占整个菌群的0．1％时,仍能检测出哈茨木霉。 重要结论：本研究所建立的SCAR分子标记能有效监测菌群中的哈茨木霉的定殖和生长,具有较高特异性、灵敏度和准确度。  相似文献   

12.

Objective

This paper presents comprehensive and up-to-date data covering 4 years of Serious Case Reviews into fatal child maltreatment in England.

Methods

Information on all notified cases of fatal maltreatment between April 2005 and March 2009 was examined to obtain case characteristics related to a systemic classification of 5 broad groups of maltreatment deaths (severe physical assaults; covert homicide/infanticide; overt homicide; extreme neglect/deprivational abuse; deaths related to but not directly caused by maltreatment).

Results

A total of 276 cases were recorded giving an incidence of 0.63 cases per 100,000 children (0-17) per year. 246 cases could be classified based on the data available. Of these the commonest specific group was those children who died as a result of severe physical assaults. Apparently deliberate overt and covert homicide was less common, while deaths as a direct consequence of neglect were rare. In contrast, some evidence of neglect was found in at least 40% of all cases, though not the direct cause of death.

Conclusions

Class characteristics differ between the different categories of death and may suggest the need for different strategies for prevention.  相似文献   

13.
A cross-sectional study tested Danish students' mastery of links between grammar and spelling (cf. the English link between past tense verbs and the -ed spelling for a word final /t/, e.g., miss ed vs. mis t). One hundred and forty-two students aged 10–17 spelled pseudo-word items with ambiguous phonemes, where the choice between a 'conditional' spelling (cf. English ed for /t/) and a simple spelling (cf. t for /t/) was predictable from the grammatical context but not from the sound. Overgeneralisations (conditional spellings used where simple spellings were appropriate) were controlled to obtain pure measures of grammatical spelling competence. The oldest group of participants performed near ceiling on four of five spelling problems studied while three younger groups in the experiment never did. The nature of the apparent grammatical hurdle in Danish spelling acquisition is discussed.  相似文献   

14.
证明了一类紧群在C+代数的完全正映射上的不变群作用可以决定C+代数间的同构。  相似文献   

15.
章报道福建省东部大田上京崆峒山晚二叠世晚期长兴组的Ting类动物群，计有6属20种(含1个新种、1个未定种)，称Palaeo fusulina sinensis-Nanlingella scitula带，这一动物群的层位可与浙江长兴及贵州西部的Palaeo fusulina带和江西乐平鸣山的Palaeo fusulina sinensis带对比。  相似文献   

16.
通过对标准宇宙结构质量密度分析，讨论了宇宙质量密度对减速参量q0以及减速参量对确定宇宙学年龄、宇宙结构——是有限封闭的还是无限开放的的影响。  相似文献   

17.
Recorded are some biographical data about the late professor Freudenthal along with some indications about his mathematical work. In an appendix a tiny part of his mathematical work which can be explained in a fairly direct manner is discussed.This is the somewhat modified text of a commemorative address given at the annual meeting of the Wiskundig Genootschap, the Dutch mathematical society, on April 5, 1991, cf. Nieuw Archief voor Wiskunde, 9 (1991), 131–136.  相似文献   

18.
Research in Religious Education: Perspectives for the Future   总被引：1，自引：0，他引：1  
The impact of committed guests in Religious Education at school is focused in this study. Ten pupils (age 17) were sampled to contribute as informants in semi-structured interviews. The data consist of eight texts (interview excerpts), which are interpreted within a hermeneutic approach, specifically by taking the formal features into consideration (cf. Ricoeur), for example, the occurrence of negations. Some of the texts illuminate I–Thou relations (Buber), whereas other texts are interpreted in relation to the effect histories of certain conceptions (Gadamer).  相似文献   

19.
Growth mixture modeling (GMM) has become a more popular statistical method for modeling population heterogeneity in longitudinal data, but the performance characteristics of GMM enumeration indexes in correctly identifying heterogeneous growth trajectories are largely unknown. Few empirical studies have addressed this issue. This study considered both homogeneous (a k = 1 growth trajectory) and heterogeneous (k = 3 different but unobserved growth trajectories) situations, and examined the performance of GMM in correctly identifying the latent trajectories in sample data. Four design conditions were manipulated: (a) sample size, (b) latent trajectory class proportions, (c) shapes of latent growth trajectories, and (d) degree of separation among latent growth trajectories. The findings suggest that, for k = 1 condition (1 homogenous growth trajectory), GMM's performance is reasonable in correctly identifying 1 latent growth trajectory (cf. Type I error control). However, for the k = 3 conditions (3 heterogeneous latent growth trajectories), GMM's general performance is very questionable (cf. Type II error). Different enumeration indexes varied considerably in their respective performances. Comparing the current results with previous GMM studies, the limitations of this study and future GMM enumeration research avenues are all discussed.  相似文献   

20.
闻喜方言语音面貌多与中原官话一致,也有少许特点;拿上世纪三十年代的《山西闻喜县之方言》比照,可以看出近百年来闻喜方言语音发生了明显的变化.本文描写了闻喜话的音系,指出了变化的情况及原因.  相似文献   

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