科研管理中瓶颈问题分析   总被引：2，自引：0，他引：2  

周耀烈  张大亮 《科研管理》2003,24(1):28-33

瓶颈问题可通过改变颈口面积和颈口秩序来解决。本文首先建立了颈口面积模型和颈口秩序模型，并用案例说明了其运用方法。该瓶颈模型还可用在经济分析、生产管理等许多问题的分析上。  相似文献   

Comparison of high order aberration after conventional and customized ablation in myopic LASIK in different eyes of the same patient   总被引：4，自引：0，他引：4  

Du CX  Shen Y  Wang Y 《Journal of Zhejiang University. Science. B》2007,8(3):177-180

Purpose: To verify whether there exists any difference in higher order aberrations after undergoing myopic LASIK (laser in situ keratomileusis) with conventional ablation and customized ablation in different eyes of the same patient. Methods: This was a prospective randomized study of 54 myopic eyes (27 patients) that underwent LASIK using the Nidek EC-5000 ex-cimer laser system (Nidek, Gamagori, Japan). Topography-guided customized aspheric treatment zone (CATz) was used in the first eye of the patient (study group) and the other eye of the same patient was operated on with conventional ablation (control group). Higher order aberrations [root-mean-square (RMS) in the 5-mm zone] of both groups were observed with the Nidek OPD-Scan aberrometer before and 3 months after LASIK. Preoperative mean refractive error was similar between two eyes of the same patient (t=?0.577, P>0.05). Results: Preoperatively, higher order aberrations (RMS in the 5-mm zone) in the CATz ablation and conventional groups were (0.3600±0.0341) μm and (0.2680±0.1421) μm, respectively. This difference was not statistically significant (t=1.292, P>0.05). Three months after LASIK, higher order aberrations (RMS in 5-mm zone) in the CATz ablation and conventional groups were (0.3627±0.1510) μm and (0.3991±0.1582) μm, respectively. No statistically significant difference was noted between pre- and postoperative higher order aberrations in the CATz group (t=?0.047, P>0.05). However, a statistically significant increase in higher order aberrations was observed after conventional ablation (t=?5.261, P<0.05). A statistically sig-nificant difference was noted in the increase of higher order aberrations after LASIK between groups (t=?2.050, P=0.045). Con-clusion: LASIK with conventional ablation and topography-guided CATz ablation resulted in the same BSCVA (best specta-cle-corrected visual acuity) 3 month after LASIK. Higher order aberrations were increased, but the increase of higher order ab-errations after customized ablation treatment was less than that after conventional ablation.  相似文献   

论高校学生管理中自由与秩序的限度     

马焕灵 《教育研究》2011,(3)

我国高校学生管理中存在自由与秩序限度模糊问题。在高校内,秩序是达成教育活动、实现人的自由全面发展教育目的的必要而非充分条件,而自由是实现这一教育目的的充分条件。高等学校内部需要最低的秩序和最大化的自由。从低度人权与低度义务来看,低度行为规范应该成为自由与秩序限度的校规落脚点。  相似文献   

论汉维语语序功能变式中的焦点变式     

林青 《喀什师范学院学报》2011,32(5):54-55,59

焦点变式是指由于句中强调点改变而产生的语序功能变式。论文试图通过对汉维语焦点变式的分析,探讨焦点移位对语序的影响,从而发现汉维语两种语言在凸显句子焦点和配置句中语序上的差异。  相似文献   

徐州方言倒装语序的语用考察     

王海燕 《常熟理工学院学报》2011,25(5):104-106

现代徐州方言的倒装语序可划分为主谓倒装、状中倒装、宾语前置、主语和状语同时后置、连谓结构成分顺序倒置等五种类型。从语用角度考察,徐州方言倒装语序的现状和特点与日常口语的表达、理解、特点和类型等关系密切。  相似文献   

"精雕数控"订单班核心课程的建设与实施     

卞化梅  杨晓雪 《北京工业职业技术学院学报》2011,10(1):74-77

＂精雕数控班＂是北京工业职业技术学院与北京精雕科技有限公司合作开办的长期订单班,校企全程共建核心课程、校内实训室,共同实施核心课程的教学和顶岗实习的管理,有效促进了学生职业综合能力的培养。  相似文献   

多义副词“还＂的语法化顺序和习得顺序     

高顺全 《暨南大学华文学院学报》2011,(2):39-45

本文的研究建立在这样的理论假设之上：多义副词的语法化顺序和习得顺序在很大程度上是一致的,可以根据语法化顺序预测习得顺序。文章首先对“还”的意义和用法进行了重新分类,描写了“还”的各个意义和用法的语法化顺序,然后依此构拟了其多个用法的习得顺序,并通过中介语语料库的相关统计分析证明了语法化顺序和习得顺序的一致性。  相似文献   

基于TSC理论的网络社区中知识动员模式研究     

姚伟  吴淑娴  柯平  孙斌  张静 《情报理论与实践》2020,43(4):47-54

[目的/意义]研究网络社区中知识动员参与成员关系结构,探索知识动员模式。[方法/过程]以知乎社区为研究对象,采用TSC(Time-Space-Content)理论进行多维度混合方法研究。TSC理论是指从时间、空间和内容维度对收集的数据进行分析,在时间维度上采用时间序列分析方法,在空间维度采用社会网络分析方法,在内容维度采用扎根理论编码技术,借助Ucinet、NetDraw和Nviv11等工具,对知乎社区中关于知识动员的热门答帖评论进行分析。[结果/结论]结果表明:在网络社区中知识动员活动的成果主要有三类;网络社区中知识动员行为模式包含6个环节;网络社区中知识动员存在"三-四-四"认知模式,可以理解为"认知主体-认知过程-认知客体"模式。  相似文献   

Rapid phenotypic evolution with shallow genomic differentiation during early stages of high elevation adaptation in Eurasian Tree Sparrows     

Yanhua Qu  Chunhai Chen  Ying Xiong  Huishang She  Yong E Zhang  Yalin Cheng  Shane DuBay  Dongming Li  Per G P Ericson  Yan Hao  Hongyuan Wang  Hongfeng Zhao  Gang Song  Hailin Zhang  Ting Yang  Chi Zhang  Liping Liang  Tianyu Wu  Jinyang Zhao  Qiang Gao  Weiwei Zhai  Fumin Lei 《国家科学评论(英文版)》2020,7(1):113

Known as the ‘third polar region’, the Qinghai-Tibet Plateau represents one of the harshest highland environments in the world and yet a number of organisms thrive there. Previous studies of birds, animals and humans have focused on well-differentiated populations in later stages of phenotypic divergence. The adaptive processes during the initial phase of highland adaptation remain poorly understood. We studied a human commensal, the Eurasian Tree Sparrow, which has followed human agriculture to the Qinghai-Tibet Plateau. Despite strong phenotypic differentiation at multiple levels, in particular in muscle-related phenotypes, highland and lowland populations show shallow genomic divergence and the colonization event occurred within the past few thousand years. In a one-month acclimation experiment investigating phenotypic plasticity, we exposed adult lowland tree sparrows to a hypoxic environment and did not observe muscle changes. Through population genetic analyses, we identified a signature of polygenic adaptation, whereby shifts in allele frequencies are spread across multiple loci, many of which are associated with muscle-related processes. Our results reveal a case of positive selection in which polygenic adaptation appears to drive rapid phenotypic evolution, shedding light on early stages of adaptive evolution to a novel environment.  相似文献   

Does STES‐Oriented Science Education Promote 10th‐Grade Students’ Decision‐Making Capability?     

Tami Levy Nahum  David Ben‐Chaim  Ibtesam Azaiza  Orit Herskovitz 《International Journal of Science Education》2013,35(10):1315-1336

Today’s society is continuously coping with sustainability‐related complex issues in the Science‐Technology‐Environment‐Society (STES) interfaces. In those contexts, the need and relevance of the development of students’ higher‐order cognitive skills (HOCS) such as question‐asking, critical‐thinking, problem‐solving and decision‐making capabilities within science teaching have been argued by several science educators for decades. Three main objectives guided this study: (1) to establish “base lines” for HOCS capabilities of 10th grade students (n = 264) in the Israeli educational system; (2) to delineate within this population, two different groups with respect to their decision‐making capability, science‐oriented (n = 142) and non‐science (n = 122) students, Groups A and B, respectively; and (3) to assess the pre‐post development/change of students’ decision‐making capabilities via STES‐oriented HOCS‐promoting curricular modules entitled Science, Technology and Environment in Modern Society (STEMS). A specially developed and validated decision‐making questionnaire was used for obtaining a research‐based response to the guiding research questions. Our findings suggest that a long‐term persistent application of purposed decision‐making, promoting teaching strategies, is needed in order to succeed in affecting, positively, high‐school students’ decision‐making ability. The need for science teachers’ involvement in the development of their students’ HOCS capabilities is thus apparent.  相似文献