期刊文献+
共找到75篇文章
< 1 2 4 >
每页显示 20 50 100
清代染织专著《布经》考 被引量:17
1
作者 李斌 《东南文化》 CSSCI 1991年第1期79-86,共8页
染织是中国悠久的传统技艺,可惜,由于历代统治者轻视科学技术的记录和研究,致使许多优良的技术难得保存.本文作者新近在安徽省图书馆发现一未曾刊行的清代染织专著《布经》.为我们提供了研究清代染织技术的新资料.弥足珍贵.文章不仅考... 染织是中国悠久的传统技艺,可惜,由于历代统治者轻视科学技术的记录和研究,致使许多优良的技术难得保存.本文作者新近在安徽省图书馆发现一未曾刊行的清代染织专著《布经》.为我们提供了研究清代染织技术的新资料.弥足珍贵.文章不仅考察了《布经》记录的具体染织工艺.且考定此书出于东南地区历史上著名的染织之乡松江,书作者是一位具有丰富实践经验的染织工艺师,成书年代约在嘉庆、道光年间. 展开更多
关键词 松江 染织技术 纺车 标布 上海史 铁锭 染坊 木棉 乾隆 村志
下载PDF
一键还原桌面图标排列顺序
2
作者 刘成 《电脑知识与技术(经验技巧)》 2015年第2期20-21,共2页
众所周知,软件安装后桌面上会有快捷方式,时间久了,这些快捷图标越来越多,为方便使用,我们通常对它们进行排列,但是Windows无法保存和固定桌面图标位置,系统故障或操作失误后桌面图标尽数丢失,或是改变屏幕分辨率后再次改回原分辨率,原... 众所周知,软件安装后桌面上会有快捷方式,时间久了,这些快捷图标越来越多,为方便使用,我们通常对它们进行排列,但是Windows无法保存和固定桌面图标位置,系统故障或操作失误后桌面图标尽数丢失,或是改变屏幕分辨率后再次改回原分辨率,原来排好的桌面图标也变得杂乱无章。为此推荐你使用ReIcon一键保存和还原桌面图标排列顺序,该软件可以保存很多套图标布局,还能允许你将"保存/恢复图标的布局"功能添加到Windows右键菜单中。 展开更多
关键词 屏幕分辨率 快捷方式 右键菜单 软件安装 排列位置 菜单项 菜单栏 中文界面 一键恢复 标布
下载PDF
铷原子频标小型化发展现状 被引量:4
3
作者 曹远洪 蒲晓华 +2 位作者 刘勇军 杜伦宇 杨林 《时间频率学报》 CSCD 2007年第2期132-137,共6页
铷原子频标使用最广泛,小型化是其最重要的发展趋势。微波腔小型化、电子线路数字化以及附加特殊功能是铷原子频标小型化的主要技术手段。相干布居囚禁(CPT)频标是一种可以做到芯片级的新型原子频标。目前相干布居囚禁频标的技术方案有... 铷原子频标使用最广泛,小型化是其最重要的发展趋势。微波腔小型化、电子线路数字化以及附加特殊功能是铷原子频标小型化的主要技术手段。相干布居囚禁(CPT)频标是一种可以做到芯片级的新型原子频标。目前相干布居囚禁频标的技术方案有:传统方案,物理系统采用MEMS(micro-electro-mechanical system)[0]技术的方案和整机采用MEMS[0]技术的方案。实现小型化后的原子频标将会迎来蓬勃发展的前景。 展开更多
关键词 铷原子频 微波腔 相干居囚禁频 小型化
下载PDF
Genetic Diversity of Hordeum bogdanii Wilensky Native to Xinjiang, China, Based on STS-PCR Markers 被引量:2
4
作者 郭红 魏育明 +1 位作者 陈放 郑有良 《Acta Botanica Sinica》 CSCD 2002年第11期1327-1332,共6页
The genetic diversity among 32 accessions of Hordeum bogdanii Wilensky native to Xinjiang, China, was evaluated by 22 STS_PCR primer sets derived from RFLP clones of the wheat ( Triticum aestivum L.) or barley ... The genetic diversity among 32 accessions of Hordeum bogdanii Wilensky native to Xinjiang, China, was evaluated by 22 STS_PCR primer sets derived from RFLP clones of the wheat ( Triticum aestivum L.) or barley ( Hordeum vulgare L.) mapping. Out of the 22 STS_PCR markers, only three markers gave products which did not generate polymorphic bands upon digestion with Hin fⅠ, Hha Ⅰ, Hae Ⅲ and Rsa Ⅰ, while 19 out of 22 markers (86.4%) and 46 out of 88 marker/enzyme combinations (52.3%) revealed polymorphisms. Among the 32 H. bogdanii accessions, a total of 315 bands were observed in 88 STS_PCR marker/enzyme combinations, with 3.6 bands each. One hundred and twenty_three out of 315 bands (39.0%) were polymorphic, among which 1 to 6 polymorphic bands were generated by each polymorphic marker/enzyme combination. The STS_PCR_based genetic diversity index ( GD ) among 32 H. bogdanii accessions ranged between 0.078 to 0.352, with a mean of 0.198. Based on the GD matrix, a dendrogram showing the genetic relationships between accessions was constructed using the unweighted pair_group method with arithmetic average (UPGMA). Results showed that all 32 accessions could be distinguished by STS_PCR markers. The accessions originated from the same region were distributed within different groups or subgroups. This study indicates that the genetic diversity of H. bogdanii is not closely correlated with the geographical distribution. 展开更多
关键词 Hordeum bogdanii STS_PCR marker genetic diversity genetic relationship
下载PDF
明清镖局初探 被引量:11
5
作者 李刚 郑中伟 《华夏文化》 1999年第4期36-38,共3页
关键词 镖局 镖师 从业人员 明清 镖客 标布 组织形式 大城市 万历年间 傅衣凌
下载PDF
明清间松江地区棉纺织业中的资本主义萌芽
6
作者 张一中 《湘潭大学学报(哲学社会科学版)》 CSSCI 1989年第2期92-94,101,共4页
明清时期的棉纺织业,在江南以松江为中心的一些地区,不仅普遍地发展起来,而且已经开始走上商品化的道路,出现了新的生产关系——资本主义萌芽。下面我们将就此作一些初步的考察。一、木棉的种植与纺织工具我国开始种植木棉(明清时期的... 明清时期的棉纺织业,在江南以松江为中心的一些地区,不仅普遍地发展起来,而且已经开始走上商品化的道路,出现了新的生产关系——资本主义萌芽。下面我们将就此作一些初步的考察。一、木棉的种植与纺织工具我国开始种植木棉(明清时期的木棉即今之棉花),据历史记载,时在宋元之际。俞正燮《癸已类稿》说:“宋时,中国稍自为之,……元时,则植渐广。”丘浚《大学衍义补》亦谓,木棉“宋元之间。 展开更多
关键词 棉纺织业 松江地区 资本主义萌芽 木棉 明清时期 标布 织工 字号 牙行
下载PDF
Incremental Placement Algorithm for Standard-Cell Layout
7
作者 李卓远 吴为民 +1 位作者 洪先龙 顾钧 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2002年第12期1338-1344,共7页
A new algorithm W ECOP is presented to effect incremental changes on a standard cell layout automatically.This algorithm deals with cell inserting and cell moving based on rows instead of on cells as most placement a... A new algorithm W ECOP is presented to effect incremental changes on a standard cell layout automatically.This algorithm deals with cell inserting and cell moving based on rows instead of on cells as most placement algorithms usually do.An integer programming problem is formulated to minimize the adjustment on the initial placement and a heuristic method is presented to search for a shifting path so as to optimize the wirelength.Test of W ECOP on a group of practical test cases shows that the algorithm can successfully accomplish incremental placement with good quality and high speed. 展开更多
关键词 incremental placement standard cell
下载PDF
New Incremental Placement Algorithm Based on Integer Programming for Reducing Congestion
8
作者 李卓远 吴为民 洪先龙 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2004年第1期30-37,共8页
A new incremental placement algorithm C-ECOP for standard cell layout is presented to reduce routing congestion.It first estimates the routing congestion through a new routing model.Then,it formulates an integer linea... A new incremental placement algorithm C-ECOP for standard cell layout is presented to reduce routing congestion.It first estimates the routing congestion through a new routing model.Then,it formulates an integer linear programming (ILP) problem to determine cell flow direction and to avoid the conflictions between adjacent congestion areas.Experimental results show that the algorithm can considerably reduce routing congestion and preserve the performance of the initial placement with high speed. 展开更多
关键词 CONGESTION standard cell incremental placement
下载PDF
Reconstruction of shock wave pressure field based on distributed test system
9
作者 冯浩 张志杰 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第1期25-29,共5页
A new distributed test system composed of multiple test nodes was designed by adopting storage test technology to test shock waves in explosion field. The advantage of the system is the application of sensor lattice w... A new distributed test system composed of multiple test nodes was designed by adopting storage test technology to test shock waves in explosion field. The advantage of the system is the application of sensor lattice whose rise time is microsecond level, which can quickly response to transient shock wave signals. In order to reduce dynamic response error, shock tube is employed to conduct dynamic calibration on the system. The overpressure peak values of the explosion shock wave collected by sensor lattice were used to construct a shock wave pressure field with B-spline interpolation algorithm. 展开更多
关键词 distributed test system dynamic calibration interpolation algorithm RECONSTRUCTION
下载PDF
Distributing Characteristics of the Charge on the Bomb Body with Capacitance Fuze
10
作者 邓甲昊 詹毅 施聚生 《Journal of Beijing Institute of Technology》 EI CAS 2000年第3期291-295,共5页
For establishing the equation of the capacitive target detection accurately, the distributing characteristics of the charges on the bomb body with capacitance fuze were explored. Continuous charges were analyzed disp... For establishing the equation of the capacitive target detection accurately, the distributing characteristics of the charges on the bomb body with capacitance fuze were explored. Continuous charges were analyzed dispersively. Based on the Coulomb's law, the dynamic equilibrium equations of the inducing charges on the bomb body were set up. For the four cases of d 0/L (the ratio between the electrode distance and the bomb length), the curves of the charge's distribution were given. It was concluded that: ① the charge density decreases steadily from the end near the frontal electrode to the bomb tail; ② the declining rate of the density is governed by d 0/L , the larger the value of d 0/L ,the higher the declining rate, and vice versa. 展开更多
关键词 proximity fuze capacitance fuze target detection distribution characteristic of charge
下载PDF
11
作者 王尚 《文教资料》 2005年第1S期30-30,共2页
关键词 标布
下载PDF
玻纤织机“沼泽”,慎入!
12
作者 墨影 《纺织机械》 2015年第3期16-16,共1页
作为产业用纺织品的重要一类,玻璃纤维织物以其强度高、耐磨性好、摩擦系数低、绝缘性好、不易腐烂等特点,应用越来越广,目前已经普遍用于电子、土建、造纸等行业。这其中释放出的巨大市场需求,也直接刺激了玻纤特种织机产业的发展,记... 作为产业用纺织品的重要一类,玻璃纤维织物以其强度高、耐磨性好、摩擦系数低、绝缘性好、不易腐烂等特点,应用越来越广,目前已经普遍用于电子、土建、造纸等行业。这其中释放出的巨大市场需求,也直接刺激了玻纤特种织机产业的发展,记者熟知的不少织机企业陆续涉足玻纤领域,并以此为新的卖点,跃跃欲试地计划在"新"领域一展拳脚。原本看产业用纺织品发展得如火如荼,记者也为这些"另辟蹊径" 展开更多
关键词 玻纤 产业用纺织品 玻璃纤维织物 中国玻璃 张福祥 复合材料工业 国产设备 标布 纱产量 产品结构
下载PDF
Performance analysis of IEEE 802.11e EDCA in wireless LANs 被引量:7
13
作者 ZHANG Wei SUN Jun +1 位作者 LIU Jing ZHANG Hai-bin 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第1期18-23,共6页
In this paper, we propose an analytical model for the performance evaluation of IEEE 802.1 le enhanced distributed channel access (EDCA). Different from most previous analytical studies based on the saturation assum... In this paper, we propose an analytical model for the performance evaluation of IEEE 802.1 le enhanced distributed channel access (EDCA). Different from most previous analytical studies based on the saturation assumption, we extend the analytical model to non-saturation conditions. An empty state is introduced into the Markov chain to represent the status of transmission queue being empty. This model can be used to calculate the traffic priority, throughput, and MAC layer delay with various configurations of contention parameters. A detailed simulation is provided to validate the proposed model. With the help of this model, the contention parameters can be configured appropriately to achieve specific quality-of-service (QoS) requirements. 展开更多
关键词 IEEE 802.11 e Saturation assumption Non-saturation assumption Enhanced distributed channel access (EDCA)
下载PDF
Constructions of Cheating Immune Secret Sharing Functions 被引量:1
14
作者 卓泽朋 Zhang Weiguo Xiao Guozhen 《High Technology Letters》 EI CAS 2011年第1期102-105,共4页
Based on the relationship between cheating immune secret sharing and cryptographic criteria of Boolean functions, to design a cheating immune secret sharing scheme, a 1-resilient function satisfying the strict avalanc... Based on the relationship between cheating immune secret sharing and cryptographic criteria of Boolean functions, to design a cheating immune secret sharing scheme, a 1-resilient function satisfying the strict avalanche criterion (SAC) is needed. In this paper, a technique on constructing a cheating immune secret sharing function is studied. By using Maiorana-McFarland construction technique, two new methods to construct cheating immune secret sharing functions are proposed. 展开更多
关键词 secret sharing Boolean function correlation immune strict avalanche criterion SAC) resilient function
下载PDF
Localization of Phosphorylated Histone H3 at Mitosis and Meiosis in Wheat 被引量:1
15
作者 杨琴 黄熙泰 +1 位作者 耿朝晖 俞新大 《Acta Botanica Sinica》 CSCD 2002年第12期1403-1408,共6页
One of the prominent cell cycle related modifications of histone proteins, whose function is correlated with chromosome condensation, is the phosphorylation of histone H3. Wheat (Triticum aestivum L.) mitotic and meio... One of the prominent cell cycle related modifications of histone proteins, whose function is correlated with chromosome condensation, is the phosphorylation of histone H3. Wheat (Triticum aestivum L.) mitotic and meiotic cells were analyzed with indirect immunoflurorescence labeling with an antibody recognizing histone H3 phosphorylated at Serine 10 to study the localization of phosphorylated histone H3 at mitosis and meiosis. Our results showed that, during mitotic division, the phosphoryiation of H3 started from early prophase and vanished at telophase, remaining mainly in the pericentromeric regions at metaphase and anaphase. During meiotic division, phosphorylation of H3 initiated at the transition from leptotene to zygotene and remained uniform, along the chromosomes from prophase I until telophase whereas it showed slightly stronger in the pericentromeric regions than along the chromosome arms from metaphase II until Lelophase II The different patterns of H3 phophorylation at mitosis and meiosis in wheat suggested that this evolutionarily conserved post-translational chromatin modification might be involved in more roles besides chromosome condensation. 展开更多
关键词 WHEAT MITOSIS MEIOSIS phosphorylated histone H3 immunofluorescence labeling
下载PDF
Branch Standards as the Possible Way of Optimizing of Capital Structure of the Concrete Firm 被引量:1
16
作者 Milan Hrdy 《Journal of Modern Accounting and Auditing》 2018年第4期165-173,共9页
This article is about the problem of optimizing of the capital structure of the concrete firm and about the possibility to use the passive way of optimizing of this capital structure on the basis of the so-called Bran... This article is about the problem of optimizing of the capital structure of the concrete firm and about the possibility to use the passive way of optimizing of this capital structure on the basis of the so-called Branch standards. Branch standards are defined as some average indebtedness that the firms are trying to follow. There are a lot of theories available, but the final process of optimizing of the capital structure of the concrete firm is very complicated and it is necessary to cope with a lot of application problems. Besides Traditional theory, none of the further theories offer some concrete recommended optimal indebtedness. For that reason, the possibility to optimize the capital structure based on the passive way is represented besides other things by the so-called Branch standards. The aim of this article is to judge if it is possible to identify this average indebtedness in different branches and in different countries. The hypothesis was stated that it is possible only in selected branches in selected countries. The research is realized in the six selected branches: Railroads, Beverages, Steel, Paper Production, Tobacco, and Electrical Equipment in the Czech Republic and in USA. Data for the years 2008-2016 were obtained from the system Albertina Data at the University of Economics in Prague and from the web pages of Prof. Aswath Damodaran in USA. There were identified so-called Branch standards in the Czech Republic for the branches Railroads 45%, Beverages 50%, Tobacco 50%, and Electrical Equipment 40%. There are also identified so-called Branch standards in USA for the branches Railroads 40% and Paper Production 40%-50%. For the branch Paper Production in the Czech Republic and for the branch Beverages in USA were identified ranges of 40%-45% and 40%-50% respectively. The so-called Branch standards were not stated for the branch Steel in both countries and for the branches Tobacco and Electrical Equipment in USA. The values were verified by the data for the year 2016 and the so-called Branch standards were confirmed excluding the branch Steel in both countries and the branches Tobacco and Electrical Equipment in the US. 展开更多
关键词 capital structure optimizing branch standards analysis
下载PDF
Influence of Velocity Shell Correlations on Anomalous Scaling Exponents of Passive Scalars in Shell Models
17
作者 ZHANG Xiao-Qiang WANG Guang-Rui CHEN Shi-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第7期211-214,共4页
We propose a new approach to the old-standing problem of the anomaly of the scaling exponents of passive scalars of turbulence. Different to the original problem, the distribution function of the prescribed random vel... We propose a new approach to the old-standing problem of the anomaly of the scaling exponents of passive scalars of turbulence. Different to the original problem, the distribution function of the prescribed random velocity field is multi-dimensional normal and delta-correlated in time. Here, our random velocity field is spatially correlative. For comparison, we also give the result obtained by the Gaussian random velocity field without spatial correlation. The anomalous scaling exponents H(p) of passive scalar advected by two kinds of random velocity above are determined for structure function up to p= 15 by numerical simulations of the random shell model with Runge-Kutta methods to solve the stochastic differential equations. We observed that the H(p) 's obtained by the multi-dimeasional normal distribution random velocity are more anomalous than those obtained by the independent Gaussian random velocity. 展开更多
关键词 shell models passive scalar distribution function
下载PDF
Label distribution expression recognition algorithm based on asymptotic truth value
18
作者 HUANG Hao GE Hongwei 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第3期295-303,共9页
Ambiguous expression is a common phenomenon in facial expression recognition(FER).Because of the existence of ambiguous expression,the effect of FER is severely limited.The reason maybe that the single label of the da... Ambiguous expression is a common phenomenon in facial expression recognition(FER).Because of the existence of ambiguous expression,the effect of FER is severely limited.The reason maybe that the single label of the data cannot effectively describe complex emotional intentions which are vital in FER.Label distribution learning contains more information and is a possible way to solve this problem.To apply label distribution learning on FER,a label distribution expression recognition algorithm based on asymptotic truth value is proposed.Under the premise of not incorporating extraneous quantitative information,the original information of database is fully used to complete the generation and utilization of label distribution.Firstly,in training part,single label learning is used to collect the mean value of the overall distribution of data.Then,the true value of data label is approached gradually on the granularity of data batch.Finally,the whole network model is retrained using the generated label distribution data.Experimental results show that this method can improve the accuracy of the network model obviously,and has certain competitiveness compared with the advanced algorithms. 展开更多
关键词 facial expression recognition(FER) label distributed learning label smoothing ambiguous expression
下载PDF
Standard and Economical Cascadic Multigrid Methods for the Mortar Finite Element Methods 被引量:3
19
作者 Xuejun Xu Wenbin Chen 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2009年第2期180-201,共22页
In this paper, standard and economical cascadic multigrid methods are considered for solving the algebraic systems resulting from the mortar finite element methods. Both cascadic multigrid methods do not need full ell... In this paper, standard and economical cascadic multigrid methods are considered for solving the algebraic systems resulting from the mortar finite element methods. Both cascadic multigrid methods do not need full elliptic regularity, so they can be used to tackle more general elliptic problems. Numerical experiments are reported to suonort our theorv. 展开更多
关键词 Cascadic multigrid mortar finite elements.
下载PDF
Scaling behavior of nucleotide cluster in DNA sequences
20
作者 CHENG Jun TONG Zi-shuang ZHANG Lin-xi 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2007年第5期359-364,共6页
In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the sc... In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P ( S ) ∝ e ?αS, where S represents nucleotide cluster size. The cluster-size distribution P(S1+S2) with the total size of sequential C-G cluster and A-T cluster S1+S2 were also studied. P(S1+S2) follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L(n) and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence. 展开更多
关键词 Nucleotide cluster DNA sequences Scaling behavior
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部