期刊文献+
共找到40篇文章
< 1 2 >
每页显示 20 50 100
英语的范围构式“from A to B”研究
1
作者 倪涛 《通化师范学院学报》 2015年第5期34-37,共4页
以构式理论为基础"from A to B"的其结构变化、句法功能、表义类型以及范围特征的考察发现:"from A to B"是英语中一种表达起讫范围的习语性构式,主要表示空间范围,其认知机制是"部分-整体"的转喻。同时... 以构式理论为基础"from A to B"的其结构变化、句法功能、表义类型以及范围特征的考察发现:"from A to B"是英语中一种表达起讫范围的习语性构式,主要表示空间范围,其认知机制是"部分-整体"的转喻。同时,在语言使用中,"from A to B"也常表示时间、数量、事物和事件等范围,这些范围类型都来自于其空间概念的隐喻投射。 展开更多
关键词 范围 from A to B 转喻 隐喻
下载PDF
低压真空式全范围熔断器的研究
2
作者 王季梅 《华通技术》 2002年第2期18-20,共3页
介绍一种低压真空式全范围熔断器的结构和基本原理。此外,描述了该熔断器的试验及其结果分析,并得出很多特点和结论。
关键词 低压真空范围熔断器 真空断路器 熔体
下载PDF
高压真空式全范围限流熔断器
3
作者 王季梅 《电世界》 2003年第7期16-16,共1页
为满足电力系统容量不断扩大的需要,迫切要求生产一种全范围限流熔断器。经西安交通大学设计,由杭州博达电器有限公司密切配合,研制了高压真空式全范围限流熔断器。现介绍如下: 1.结构如图1所示。
关键词 高压真空范围限流熔断器 玻璃外壳 电流密度 额定电流 真空熔断器 限流熔断器
下载PDF
淹没式堰流时逐步图解法定线推流公式的使用范围
4
作者 程洁 《科学大众(智慧教育)》 2008年第1期45-,47,共2页
通过对淹没式堰流流量的不确定度的计算,指出图解法定线、推流时,为满足计算流量的不确定度的要求,水位差在大于一定范围时可以用自记水位推流,水位差较小时,不能用自记水位推流。
关键词 逐步图解法定线 推流公 淹没堰流时的使用范围
下载PDF
初中数学中求变式取值范围的几种常用方法
5
作者 王玲 《数学教学研究》 2002年第10期21-23,共3页
关键词 初中 数学竞赛题 取值范围问题 解题方法
下载PDF
川中地区须家河组天然气藏大范围成藏机理与富集条件 被引量:111
6
作者 赵文智 王红军 +3 位作者 徐春春 卞从胜 汪泽成 高晓辉 《石油勘探与开发》 SCIE EI CAS CSCD 北大核心 2010年第2期146-157,共12页
以广安、合川等典型气藏解剖研究为基础,对川中地区天然气成藏条件与机理等进行研究。川中须家河组天然气为"大范围斑块式"成藏:平缓构造背景和生储盖组合"三明治"结构为大面积成藏提供了基础,但源灶生气强度平面... 以广安、合川等典型气藏解剖研究为基础,对川中地区天然气成藏条件与机理等进行研究。川中须家河组天然气为"大范围斑块式"成藏:平缓构造背景和生储盖组合"三明治"结构为大面积成藏提供了基础,但源灶生气强度平面分布不均衡和储集层横向非均质性决定不能大面积连片式成藏,而是大范围斑块式成藏;白垩纪末期以来的整体抬升是一次重要的卸载排烃、成藏事件,成藏是大范围的,成岩和构造作用以后保留下来的有效储集空间是"斑块状"而非"席状"分布的,决定经济性的天然气成藏是"大范围斑块状"而非"大面积连片式"的。须家河组天然气成藏具有源控性,天然气富集主要受气源灶、主砂体、构造背景和裂缝发育的联合控制,应细化气源灶研究,在高生气强度区内,寻找主砂体和裂缝共生发育带。此外,加强与须家河组一、三、五段源岩同期沉积砂体的评价研究,应有新气藏发现。 展开更多
关键词 范围斑块成藏 大面积连片成藏 经济性成藏 天然气 须家河组 川中地区
下载PDF
“谁、什么”的词类归属及其所构成的句式 被引量:2
7
作者 张莹 《兰州学刊》 CSSCI 2011年第8期134-138,共5页
"谁、什么"属于名词,分别用来表示无特定特征的人和物,它们的语义特征由常量[+人]/[+物]和变量组成。由"谁、什么"所构成的疑问句、否定句、反问句其实都和"谁、什么"独特的语义特征有关。"谁、什么... "谁、什么"属于名词,分别用来表示无特定特征的人和物,它们的语义特征由常量[+人]/[+物]和变量组成。由"谁、什么"所构成的疑问句、否定句、反问句其实都和"谁、什么"独特的语义特征有关。"谁、什么"和疑问句不过是焦点的实现关系,如果它们所具有的特征变量要求赋值,就会携带焦点特征[+F]进入句法结构,从而形成疑问句。反之,在句中表示所有的人或物,因此否定它们也就否定了全部。带"谁、什么"的反问句表示否定不过是一般疑问句的语用功能。语言中有两种范围限定式——前加式和后加式来限定"谁、什么"的指称范围。 展开更多
关键词 什么 词类归属 相关句 范围限定
下载PDF
试论英语情态中否定范围的界定与教学
8
作者 张志清 刘向荣 《当代教育论坛(教学版)》 2010年第9期94-95,共2页
文章从句法学的角度多方面探析了英语情态语法范畴同否定的相互关系,在此基础上提出了区分宽式否定范围和窄式否定范围的三种手段,即通过情态助动词互补的手段;轻、重音的使用;否定词not的两种形式"n’t"和"not"来... 文章从句法学的角度多方面探析了英语情态语法范畴同否定的相互关系,在此基础上提出了区分宽式否定范围和窄式否定范围的三种手段,即通过情态助动词互补的手段;轻、重音的使用;否定词not的两种形式"n’t"和"not"来区分宽式否定范围和窄式否定范围。 展开更多
关键词 情态 语法标记 否定范围 否定范围 否定范围
下载PDF
基于谓词分类的语义缓存查询裁剪 被引量:6
9
作者 李东 杨小鹏 罗鹏飞 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2008年第1期44-49,共6页
为了解决传统查询裁剪在时间和空间上的高复杂性,提出了一种基于谓词分类的语义缓存查询裁剪算法.首先从语义上将谓词分成范围谓词和约束谓词两类,并分别对这两类谓词进行"满足"、"相交"和"包含"的定义;... 为了解决传统查询裁剪在时间和空间上的高复杂性,提出了一种基于谓词分类的语义缓存查询裁剪算法.首先从语义上将谓词分成范围谓词和约束谓词两类,并分别对这两类谓词进行"满足"、"相交"和"包含"的定义;然后基于谓词分类提出了一种新的查询裁剪算法,并对算法的复杂度进行了分析.模拟实验结果表明,所提出的裁剪算法是有效的,特别是在处理查询和缓存相交的情况下,与基于谓词模型的传统串型裁剪算法和基于逻辑规则的裁剪算法相比,文中算法可明显改善查询裁剪效率. 展开更多
关键词 查询裁剪 语义 约束 范围式 语义缓存
下载PDF
特高压变压器的阻抗快速后备保护 被引量:10
10
作者 贺家李 贺继红 +1 位作者 汪国新 薛士敏 《电力系统保护与控制》 EI CSCD 北大核心 2014年第22期1-8,共8页
研究了由三个单相变压器组成的特高压三相变压器组的后备保护,提出了用阻抗纵联保护作为特高压大容量变压器相间短路的快速后备保护的方案。分析了采用超范围允许式和超范围闭锁式阻抗纵联保护方案的可行性和优越性。说明了阻抗保护受... 研究了由三个单相变压器组成的特高压三相变压器组的后备保护,提出了用阻抗纵联保护作为特高压大容量变压器相间短路的快速后备保护的方案。分析了采用超范围允许式和超范围闭锁式阻抗纵联保护方案的可行性和优越性。说明了阻抗保护受励磁涌流影响小的原理,并用数字仿真证明了此论断的正确性。建立了特高压变压器的仿真模型,仿真结果证明在变压器空投和外部故障切除时产生的励磁涌流不会使阻抗保护误动,而在变压器出口相间短路时能够快速切除故障。采用所提出的保护方案可提高特高压变压器保护的可靠性。 展开更多
关键词 变压器保护 阻抗保护 纵联保护 范围允许 范围闭锁
下载PDF
一起500kV线路高频零序保护误动分析 被引量:2
11
作者 赵晓明 黄晓明 +1 位作者 杨涛 余志慧 《电力系统保护与控制》 EI CSCD 北大核心 2008年第17期94-96,99,共4页
介绍了浙江省一起500 kV线路高频零序保护误动事故实例,并从保护应用和配置情况及区外故障时保护正常动作行出发,结合线路两侧变电站及电厂的事件顺序记录以及超范围允许式第二种保护逻辑(POR2)和高频收信逻辑,深入分析了高频零序保护... 介绍了浙江省一起500 kV线路高频零序保护误动事故实例,并从保护应用和配置情况及区外故障时保护正常动作行出发,结合线路两侧变电站及电厂的事件顺序记录以及超范围允许式第二种保护逻辑(POR2)和高频收信逻辑,深入分析了高频零序保护误动的原因。再次提出保护投产前核对定值单的重要性,应引起运行和检修人员的高度重视。 展开更多
关键词 保护误动 高频保护 范围允许逻辑 误整定
下载PDF
基于无线CDMA通信的馈线纵联保护研究 被引量:5
12
作者 苏永智 潘贞存 +2 位作者 刘志清 王葵 丛伟 《电网技术》 EI CSCD 北大核心 2006年第14期88-92,共5页
提出了一种配电网馈电线路的多断路器间纵联保护方案,在该方案中保护设备之间的通信采用了以公用移动CDMA系统为基础的通信模型。为满足继电保护的选择性、速动性、灵敏性和可靠性的要求,不仅修改了多路通信同步技术以大大降低用户间的... 提出了一种配电网馈电线路的多断路器间纵联保护方案,在该方案中保护设备之间的通信采用了以公用移动CDMA系统为基础的通信模型。为满足继电保护的选择性、速动性、灵敏性和可靠性的要求,不仅修改了多路通信同步技术以大大降低用户间的干扰,还提出了快速建立通信链接的方案。最后对保护的可靠性和快速性进行了评价,结果表明该方案能够实现馈线保护的全线速动。 展开更多
关键词 码分多址(CDMA) 允许范围纵联保护 基站 可靠性 馈线
下载PDF
Gastric carcinogenesis 被引量:25
13
作者 Ismail Gomceli Baris Demiriz Mesut Tez 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第37期5164-5170,共7页
Gastric cancer is the second most common cancer worldwide and the second most common cause of cancer-related deaths. Despite complete resection of gastric cancer and lymph node dissection, as well as improvements in c... Gastric cancer is the second most common cancer worldwide and the second most common cause of cancer-related deaths. Despite complete resection of gastric cancer and lymph node dissection, as well as improvements in chemotherapy and radiotherapy, there are still 700 000 gastric cancer-related deaths per year worldwide and more than 80% of patients with advanced gastric cancer die of the disease or recurrent disease within 1 year after diagnosis. None of the treatment modalities we have been applying today can influence the overall survival rates:at present, the overall 5-year relative survival rate for gastric cancer is about 28%. Cellular metaplasia due to chronic inflammation, injury and repair are the most documented processes for neoplasia. It appears that chronic inflammation stimulates tumor development and plays a critical role in initiating, sustaining and advancing tumor growth. It is also evident that not all inflammation is tumorigenic. Additional mutations can be acquired, and this leads to the cancer cell gaining a further growth advantage and acquiring a more malignant phenotype. Intestinalization of gastric units, which is called "intestinal metaplasia"; phenotypic antralization of fundic units, which is called "spasmolytic polypeptide-expressing metaplasia"; and the development directly from the stem/progenitor cellzone are three pathways that have been described for gastric carcinogenesis. Also, an important factor for the development of gastrointestinal cancers is peritumoral stroma. However, the initiating cellular event in gastric metaplasia is still controversial. Understanding gastric carcinogenesis and its precursor lesions has been under intense investigation, and our paper attempts to highlight recent progress in this field of cancer research. 展开更多
关键词 Gastric Cancer Cancer Stem Cell Carcino-genesis ONCOGENESIS TUMORIGENESIS
下载PDF
Seismic reliability analysis of shield tunnel faces under multiple failure modes by pseudo-dynamic method and response surface method 被引量:3
14
作者 ZHANG Jia-hua XU Peng +1 位作者 SUN Wang-cheng LI Bo 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第5期1553-1564,共12页
In order to investigate the stability problem of shield tunnel faces subjected to seismic loading,the pseudodynamic method(P-DM)was employed to analyze the seismic effect on the face.Two kinds of failure mechanisms of... In order to investigate the stability problem of shield tunnel faces subjected to seismic loading,the pseudodynamic method(P-DM)was employed to analyze the seismic effect on the face.Two kinds of failure mechanisms of active collapse and passive extrusion were considered,and a seismic reliability model of shield tunnel faces under multifailure mode was established.The limit analysis method and the response surface method(RSM)were used together to solve the reliability of shield tunnel faces subjected to seismic action.Comparing with existing results,the results of this work are effective.The effects of seismic load and rock mass strength on the collapse pressure,extrusion pressure and reliability index were discussed,and reasonable ranges of support pressure of shield tunnel faces under seismic action were presented.This method can provide a new idea for solving the shield thrust parameter under the seismic loading. 展开更多
关键词 shield tunnel face pseudo-dynamic method seismic effect multi-failure mode support pressure range
下载PDF
Future Changes of Drought and Flood Events in China under a Global Warming Scenario 被引量:15
15
作者 CHEN Huo-Po SUN Jian-Qi CHEN Xiao-Li 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第1期8-13,共6页
This study investigates the impact of global warming on drought/flood patterns in China at the end of the 21st century based on the simulations of 22 global climate models and a regional climate model(RegCM3) under th... This study investigates the impact of global warming on drought/flood patterns in China at the end of the 21st century based on the simulations of 22 global climate models and a regional climate model(RegCM3) under the SRES(Special Report on Emissions Scenarios) A1B scenario.The standardized precipitation index(SPI),which has well performance in monitoring the drought/flood characteristics(in terms of their intensity,duration,and spatial extent) in China,is used in this study.The projected results of 22 coupled models and the RegCM3 simulation are consistent.These models project a decrease in the frequency of droughts in most parts of northern China and a slight increase in the frequency in some parts of southern China.Considering China as a whole,the spatial extents of droughts are projected to be significantly reduced.In contrast,future flood events over most parts of China are projected to occur more frequently with stronger intensity and longer duration than those prevalent currently.Additionally,the spatial extents of flood events are projected to significantly increase. 展开更多
关键词 standardized precipitation index drought/ flood PROJECTION
下载PDF
Chinese word segmentation with local and global context representation learning 被引量:2
16
作者 李岩 Zhang Yinghua +2 位作者 Huang Xiaoping Yin Xucheng Hao Hongwei 《High Technology Letters》 EI CAS 2015年第1期71-77,共7页
A local and global context representation learning model for Chinese characters is designed and a Chinese word segmentation method based on character representations is proposed in this paper. First, the proposed Chin... A local and global context representation learning model for Chinese characters is designed and a Chinese word segmentation method based on character representations is proposed in this paper. First, the proposed Chinese character learning model uses the semanties of loeal context and global context to learn the representation of Chinese characters. Then, Chinese word segmentation model is built by a neural network, while the segmentation model is trained with the eharaeter representations as its input features. Finally, experimental results show that Chinese charaeter representations can effectively learn the semantic information. Characters with similar semantics cluster together in the visualize space. Moreover, the proposed Chinese word segmentation model also achieves a pretty good improvement on precision, recall and f-measure. 展开更多
关键词 local and global context representation learning Chinese character representa- tion Chinese word segmentation
下载PDF
辅助函数的应用
17
作者 卢莲芬 《河南教育学院学报(自然科学版)》 2003年第4期10-12,共3页
本文通过详尽的实例,讲明了辅助函数在证明等式中、在求函数表达式中、在证明不等式中、在确定参数式范围中和在几何中的运用。
关键词 辅助函数 函数表达 不等 参数范围 几何
下载PDF
Special Wide Area Path Planning Method of an Autonomous Mobile Robot Using GPS
18
作者 Seo-young HWANG Sung-ha KIM Jang-myung LEE 《Journal of Measurement Science and Instrumentation》 CAS 2011年第1期34-37,共4页
Using sensor and GPS to make a trajectory planning for the stationary obstacle, autonommus mobile robot can asstmae that it is placed at the center of the map, and from the distance information between autonomous mobi... Using sensor and GPS to make a trajectory planning for the stationary obstacle, autonommus mobile robot can asstmae that it is placed at the center of the map, and from the distance information between autonomous mobile robot and obstacles. But in case of active moving obstacle, many components and information need to process since their moving trace should be considered in real time. This paper mobile robot's driving algorithm of unknown dynamic envirormaent in order to drive intelligently to destination using ultrasonic and Global Positional Systern (GPS). Sensors adjusted the placement dependment on driving of robot, and the robot plans the evasion method according to obstacle which are detected by sensors. The robot saves GPS coordinate of complex obstacle. If there are many repeated driving, robot creates new obstacles to the hr, ation by itself. And then it drives to the destination resolving a large range of local minirmnn point If it needs an intelligent circtmtantial decision, a proposed algorithm is suited for effective obstacle avoidance and arrival at the destination by performing simulations. 展开更多
关键词 GPS Fuzzy path planning optimal path
下载PDF
印尼BATAM燃煤电站线路距离保护试验
19
作者 陈伟 《华电技术》 CAS 2013年第11期76-78,81,共4页
根据海外电网线路保护的特点,并遵循因地制宜的原则,对中国华电工程(集团)有限公司首个海外项目BATAM KASAM燃煤电站线路距离保护配置及试验进行研究,从线路距离保护配置原理着手,重点分析了国内外线路距离保护的不同原则,得出海外电网... 根据海外电网线路保护的特点,并遵循因地制宜的原则,对中国华电工程(集团)有限公司首个海外项目BATAM KASAM燃煤电站线路距离保护配置及试验进行研究,从线路距离保护配置原理着手,重点分析了国内外线路距离保护的不同原则,得出海外电网距离保护的解决办法,可为其他海外项目提供借鉴。 展开更多
关键词 倒送电 允许范围保护 线路距离保护 联跳 配置
下载PDF
A force feedback master finger in exoskeleton type
20
作者 Fang Honggen Liu Hong Xie Zongwu 《High Technology Letters》 EI CAS 2010年第3期299-305,共7页
In order to eliminate the drawbacks of conventional force feedback gloves, a new type of master fin- ger has been developed. By utilizing three "four-bar mechanism joint" in series and wire coupling mecha- nism, the... In order to eliminate the drawbacks of conventional force feedback gloves, a new type of master fin- ger has been developed. By utilizing three "four-bar mechanism joint" in series and wire coupling mecha- nism, the master finger transmission ratio is kept exactly 1:1.4:1 in the whole movement range and it can make active motions in both extension and flexion directions. Additionally, to assure faster data transmission and near zero delay in the master-slave operation, a digital signal processing/field programmable gate array (DSP/FPGA-FPGA) structure with 200μs cycle time is designed. The operating modes of the master finger can be contact or non-contact, which depends on the motion states of a slave finger, free motion or constrained motion. The position control employed in non-contact mode ensures unconstrained motion and the force control adopted in contact mode guarantees natural contact sensation. To evaluate the performances of the master finger, an experiment between the master finger and a DLR/HTT dexterous finger is conducted. The results demonstrate that this new type master finger can augment telepresence. 展开更多
关键词 force feedback master finger digital signal processing (DSP) field programmable gate array (FPGA) TELEPRESENCE
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部