期刊文献+
共找到32篇文章
< 1 2 >
每页显示 20 50 100
则时"补说 被引量:1
1
作者 葛佳才 《唐都学刊》 2003年第1期66-68,共3页
结合佛教文献中的诸多用例,从词素语义关系、排列次序等角度观察中土文献中偶或一见的"则时"是一个同义并列复词,其词素次序为决定因素。
关键词 佛教 则时 内部结构 词素次序
下载PDF
浅议勤进快销
2
作者 何天瑄 《商业研究》 1986年第7期11-12,共2页
在许多商业企业经营管理的教科书上,都把勤进快销作为商业企业商品进货的一条基本原则。这点,并没疑义。但是,我认为在讲解这一原则时,需要作一些说明,区分不同商业企业以及各种具体情况。
关键词 勤进快销 商业企业 基本原则 商品进货 经营管理 教科书 具体情况 批发商业 疑义 则时
下载PDF
著名军旅作家·北京读者孙景瑞
3
《大舞台》 北大核心 1996年第5期50-50,共1页
在酷暑中,收到寄来的今年1—4期《大舞台》杂志,如同一股友谊的清风吹来,身心顿爽。北京连日阵雨,一来则倾盆,大有岭南天气的时晴时雨。一则因为天热,二则时感胃痛,许多天来已没有执笔。真后悔年轻时没有抓紧时间多写,如今笔滞思迟,颇... 在酷暑中,收到寄来的今年1—4期《大舞台》杂志,如同一股友谊的清风吹来,身心顿爽。北京连日阵雨,一来则倾盆,大有岭南天气的时晴时雨。一则因为天热,二则时感胃痛,许多天来已没有执笔。真后悔年轻时没有抓紧时间多写,如今笔滞思迟,颇觉困难。我计划今年完成《紫泉河》初稿,恐怕力不从心,只好写多少算多少吧! 展开更多
关键词 军旅作家 天热 阵雨 则时 抓紧 舞台 初稿 原野 胃痛 燕赵大地
下载PDF
The Solvability of the Degenerate Differential Systems with Delay 被引量:5
4
作者 蒋威 郑祖庥 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第3期1-7,共7页
In this paper we study the degenerate differential system with delay:E(t)=Ax(t)+Bx(t-1)+f(t),give the canonical form of this systems and study this form of degeneration system with delay,have some results for the so... In this paper we study the degenerate differential system with delay:E(t)=Ax(t)+Bx(t-1)+f(t),give the canonical form of this systems and study this form of degeneration system with delay,have some results for the solvability of such systems and the uniqueness of their solutions. 展开更多
关键词 degenerate differential system with delay regular system SOLVABILITY
下载PDF
农村小规模纳税人有十盼
5
作者 寿纪权 史照贤 齐亚 《财税与会计》 1995年第11期18-18,共1页
一盼新税制改革宣传到家,使税收政策户户皆知,家家明白。 二盼国家税,地方税征收,避免无所适从,重复征收。 三盼税额据实征收,不估算,不包税。 四盼定期公布纳税户纳税情况,避免关系税、人情税。 五盼不征无源税、超前税和无原则的突击... 一盼新税制改革宣传到家,使税收政策户户皆知,家家明白。 二盼国家税,地方税征收,避免无所适从,重复征收。 三盼税额据实征收,不估算,不包税。 四盼定期公布纳税户纳税情况,避免关系税、人情税。 五盼不征无源税、超前税和无原则的突击加税。 展开更多
关键词 小规模纳税人 农村 安阳市 财政局 地方税征收 报站 办公室 布纳 则时 纳税情况
下载PDF
《“精彩极了”和“糟糕透了”》搜索
6
作者 湛蓝 《语文世界(上旬刊)》 2004年第11期25-25,共1页
关键词 解决方案 联系实际 母亲 素养 难点 冲昏 饭厅 则时 点击 头脑
下载PDF
对手,生命因你而精彩
7
作者 文竞 《作文成功之路》 2004年第12期48-48,共1页
我永远也忘不了《老人与海》中那个年老的渔夫,尽管他最终什么都没有得到,但他与星鲨惊心动魄的对抗却使我深深地感到:对手,生命因你而精彩。很难想像,没有对手的赛跑是什么情景。一个人孤零零地在跑道中漫无目的地跑着,没有紧张,也没... 我永远也忘不了《老人与海》中那个年老的渔夫,尽管他最终什么都没有得到,但他与星鲨惊心动魄的对抗却使我深深地感到:对手,生命因你而精彩。很难想像,没有对手的赛跑是什么情景。一个人孤零零地在跑道中漫无目的地跑着,没有紧张,也没有竞争,也就失去了活力。即使你真的跑得很快,最终也会因没有对手而失去目标。你到达终点时也不会有鲜花与掌声,更不会有激动的泪水和热烈的欢呼,因为这样的比赛是苍白的。精彩的瞬间往往定格在历尽千辛万苦战胜对手的喜悦中,奥运精神在这时便得到最充分的诠释。人生的价值总是在与对手抗衡中释放得淋漓尽致。 展开更多
关键词 对手 《老人与海》 奥运精神 无目的地 到达终点 因没有 比赛 星鲨 跑道 则时
下载PDF
Design of super-orthogonal space-time trellis codes based on trace criterion
8
作者 耿嘉 曹秀英 《Journal of Southeast University(English Edition)》 EI CAS 2006年第4期456-460,共5页
A design of super-orthogonal space-time trellis codes (SOSTTCs) based on the trace criterion (TC) is proposed for improving the design of SOSTTCs. The shortcomings of the rank and determinant criteria based design... A design of super-orthogonal space-time trellis codes (SOSTTCs) based on the trace criterion (TC) is proposed for improving the design of SOSTTCs. The shortcomings of the rank and determinant criteria based design and the advantages of the TC-based design are analyzed. The optimization principle of four factors is presented, which includes the space-time block coding (STBC) scheme, set partitioning, trellis structure, and the assignment of signal subsets and STBC schemes in the trellis. According to this principle, systematical and handcrafted design steps are given in detail. By constellation expansion, the code performance can be further improved. The code design results are given, and the new codes outperform others in the simulation. 展开更多
关键词 super-orthogonal space-time trellis codes trace criterion handcrafted and systematical design
下载PDF
SPOT BEAM JUDGEMENT ALGORITHM IN LEO SATELLITE BASED ON OPNET
9
作者 于佳 宗鹏 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2011年第3期269-275,共7页
Low earth orbit(LEO)satellite constellation networks have a predominance of global coverage with low propagation delays.A new spot beam judgement algorithm is presented in LEO satellite constellation.At first,judgem... Low earth orbit(LEO)satellite constellation networks have a predominance of global coverage with low propagation delays.A new spot beam judgement algorithm is presented in LEO satellite constellation.At first,judgement of central spot beam is considered.Then the judgement of outlying spot beam is achieved by two algorithms.One is 2-D space judgement algorithm and the other is 3-D space judgement algorithm.Based on these algorithms,an Iridium model implemented on OPNET with dynamic topology nodes and network layer protocols is presented and simulation results are obtained.The simulation results show that the satellite serving time has obviously increased through the method of longest visible time criterion and the equal beam width model is validated. 展开更多
关键词 satellite communication spot beam JUDGEMENT CONSTELLATION longest visible time
下载PDF
QUANTITATIVE APPROACH TO REAL TIME STARTUP TIME DETERMINATION OF DOWNSTREAM PHASES IN CONCURRENT ENGINEERING
10
作者 吕常魁 姜澄宇 王宁生 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2004年第3期206-212,共7页
Implementation of simultaneous execution phases in the concurrent engineering (CE) needs careful planning when the downstream phase could be activated as the upstream phase developed to a certain point. The determinat... Implementation of simultaneous execution phases in the concurrent engineering (CE) needs careful planning when the downstream phase could be activated as the upstream phase developed to a certain point. The determination of startup time of overlapping jobs in CE has long been a disturbance in manufacturing industry implementing CE programs. A novel model based on both fuzzy logic and neural network is proposed to mathematically formulate the inter-connective information between the two coupled phases in CE projects, and to determine the startup time of downstream phases in real time. The information transferring between the two coupled phases is quantified by using the negative Shannon entropy. Based on this algorithm, a PDM-based framework is proposed to narrow the gap between pro-duct design and manufacture, in which five modules are built to monitor, reshuffle and implement the simultaneous executing processes. Finally, an example is given to illustrate applications of the algorithm in the real world. 展开更多
关键词 concurrent engineering negative entropy multilayer principle decision-making matrix
下载PDF
Single-trial EEG-based emotion recognition using temporally regularized common spatial pattern
11
作者 成敏敏 陆祖宏 王海贤 《Journal of Southeast University(English Edition)》 EI CAS 2015年第1期55-60,共6页
This study addresses the problem of classifying emotional words based on recorded electroencephalogram (EEG) signals by the single-trial EEG classification technique. Emotional two-character Chinese words are used a... This study addresses the problem of classifying emotional words based on recorded electroencephalogram (EEG) signals by the single-trial EEG classification technique. Emotional two-character Chinese words are used as experimental materials. Positive words versus neutral words and negative words versus neutral words are classified, respectively, using the induced EEG signals. The method of temporally regularized common spatial patterns (TRCSP) is chosen to extract features from the EEG trials, and then single-trial EEG classification is achieved by linear discriminant analysis. Classification accuracies are between 55% and 65%. The statistical significance of the classification accuracies is confirmed by permutation tests, which shows the successful identification of emotional words and neutral ones, and also the ability to identify emotional words. In addition, 10 out of 15 subjects obtain significant classification accuracy for negative words versus neutral words while only 4 are significant for positive words versus neutral words, which demonstrate that negative emotions are more easily identified. 展开更多
关键词 emotion recognition temporal regularization common spatial patterns(CSP) two-character Chinese words permutation test
下载PDF
An Invariance Principle for ρ^--Mixing Random Sequences
12
作者 LIU Xiao-ping YAN Han WU Qun-ying 《Chinese Quarterly Journal of Mathematics》 CSCD 2010年第3期470-474,共5页
In this paper,we establish an invariance principle for ρ^--mixing random sequences under some moment condition.The result improve and extend the relevant result of Wu(2003).
关键词 ρ~--mixing random sequence invariance principle moment condition
下载PDF
Marchenko imaging based on self-adaptive traveltime updating
13
作者 Chen Xiao-Chun Hu Ye-Zheng +4 位作者 Huang Xu-Ri Zhang Hou-Zhu Cao Wei-Ping Xu Yun-Gui Tang Jing 《Applied Geophysics》 SCIE CSCD 2020年第1期81-91,168,169,共13页
Marchenko imaging obtains the subsurface reflectors using one-way Green’s functions,which are retrieved by solving the Marchenko equation.This method generates an image that is free of spurious artifacts due to inter... Marchenko imaging obtains the subsurface reflectors using one-way Green’s functions,which are retrieved by solving the Marchenko equation.This method generates an image that is free of spurious artifacts due to internal multiples.The Marchenko imaging method is a target-oriented technique;thus,it can image a user specified area.In the traditional Marchenko method,an accurate velocity model is critical for estimating direct waves from imaging points to the surface.An error in the velocity model results in the inaccurate estimation of direct waves.In turn,this leads to errors in computation of one-way Green’s functions,which then affects the final Marchenko images.To solve this problem,in this paper,we propose a self-adaptive traveltime updating technique based on the principle of equal traveltime to improve the Marchenko imaging method.The proposed method calculates the time shift of direct waves caused by the error in the velocity model,and corrects the wrong direct wave according to the time shift and reconstructs the correct Green’s functions.The proposed method improves the results of imaging using an inaccurate velocity model.By comparing the results from traditional Marchenko and the new method using synthetic data experiments,we demonstrated that the adaptive traveltime updating Marchenko imaging method could restore the image of geological structures to their true positions. 展开更多
关键词 Marchenko imaging Marchenko equation Green’s function principle of equal traveltime self-adaptive traveltime updating
下载PDF
Human thrombin for the treatment of gastric and ectopic varices 被引量:12
14
作者 Norma C McAvoy John N Plevris Peter C Hayes 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第41期5912-5917,共6页
AIM:To evaluate the efficacy of human thrombin in the treatment of bleeding gastric and ectopic varices.METHODS:Retrospective observational study in a Tertiary Referral Centre.Between January 1999-October 2005,we iden... AIM:To evaluate the efficacy of human thrombin in the treatment of bleeding gastric and ectopic varices.METHODS:Retrospective observational study in a Tertiary Referral Centre.Between January 1999-October 2005,we identified 37 patients who were endoscopically treated with human thrombin injection therapy for bleeding gastric and ectopic varices.Patient details including age,gender and aetiology of liver disease/segmental portal hypertension were documented.The thrombin was obtained from the Scottish National Blood Transfusion Service and prepared to give a solution of 250 IU/mL which was injected via a standard injection needle.All patient case notes were reviewed and the total dose of thrombin given along with the number of endoscopy sessions was recorded.Initial haemostasis rates,rebleeding rates and mortality were catalogued along with the incidence of any immediate complications which could be attributable to the thrombin therapy.The duration of follow up was also listed.The study was conducted according to the United Kingdom research ethics guidelines.RESULTS:Thirty-seven patients were included.33 patients(89%) had thrombin(250 U/mL) for gastric varices,2(5.4%) for duodenal varices,1 for rectal varices and 1 for gastric and rectal varices.(1) Gastric varices,an average of 15.2 mL of thrombin was used per patient.Re-bleeding occurred in 4 patients(10.8%),managed in 2 by a transjugular intrahepatic portosystemic shunt(TIPSS)(one unsuccessfully who died) and in other 2 by a distal splenorenal shunt;(2) Duodenal varices(or type 2 isolated gastric varices),an average of 12.5 mL was used per patient over 2-3 endoscopy sessions.Re-bleeding occurred in one patient,which was treated by TIPSS;and(3) Rectal varices,an average of 18.3 mL was used per patient over 3 endoscopy sessions.No re-bleeding occurred in this group.CONCLUSION:Human thrombin is a safe,easy to use and effective therapeutic option to control haemorrhage from gastric and ectopic varices. 展开更多
关键词 Variceal haemorrhage Ectopic Varices Gastric varices Portal hypertension THROMBIN
下载PDF
Application of high temperature heat pipe in hypersonic vehicles thermal protection 被引量:9
15
作者 白穜 张红 许辉 《Journal of Central South University》 SCIE EI CAS 2011年第4期1278-1284,共7页
In order to develop further the application of high temperature heat pipe in hypersonic vehicles thermal protection, the principles and characteristics of high temperature heat pipe used in hypersonic vehicles thermal... In order to develop further the application of high temperature heat pipe in hypersonic vehicles thermal protection, the principles and characteristics of high temperature heat pipe used in hypersonic vehicles thermal protection were introduced. The methods of numerical simulation, theory analysis and experiment research were utilized to analyze the frozen start-up and steady state characteristic of the heat pipe as well as the machining improvement for fabricating irregularly shaped heat pipe which is suitable for leading edge of hypersonic vehicles. The results indicate that the frozen start-up time of heat pipe is long (10 min) and there exists large temperature difference along the heat pipe (47 ℃/cm), but the heat pipe can reduce the temperature in stagnation area of hypersonic vehicles from 1 926 to 982 ℃ and work normally during 1 000-1 200℃. How to improve the maximum heat transfer capability and reduce the time needed for start-up from frozen state of the heat pipe by optimizing thermostructure such as designing of a novel wick with high performance is the key point in hypersonic vehicles thermal protection of heat pipe. 展开更多
关键词 thermal protection high temperature heat pipe heat transfer limit start-up time
下载PDF
A recoverable stress testing algorithm for compression and encryption cards
16
作者 Bao-jun ZHANG Xue-zeng PAN +1 位作者 Jie-bing WANG Ling-di PING 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第10期1398-1405,共8页
This study proposes a recoverable stress testing algorithm (RSTA) for such special devices as compression/decompression card and encryption/deeryption card. It uses a chaos function to generate a random sequence, an... This study proposes a recoverable stress testing algorithm (RSTA) for such special devices as compression/decompression card and encryption/deeryption card. It uses a chaos function to generate a random sequence, and then, according to the random sequence, generates an effective command sequence. The dispatch of command obeys a special schedule strategy we designed for such devices, i.e., the commands are sent according to the command sequence, and the complete commands are put in a buffer for further result check. RSTA is used to test the HIFN compression acceleration card SAICHI-1000. Test results show that RSTA can make the card work continuously and adequately. 展开更多
关键词 Stress testing Random sequence Chaos function SYNCHRONIZATION CONCURRENCY
下载PDF
Machine learning based online fault prognostics for nonstationary industrial process via degradation feature extraction and temporal smoothness analysis 被引量:2
17
作者 HU Yun-yun ZHAO Chun-hui KE Zhi-wu 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第12期3838-3855,共18页
Fault degradation prognostic, which estimates the time before a failure occurs and process breakdowns, has been recognized as a key component in maintenance strategies nowadays. Fault degradation processes are, in gen... Fault degradation prognostic, which estimates the time before a failure occurs and process breakdowns, has been recognized as a key component in maintenance strategies nowadays. Fault degradation processes are, in general,slowly varying and can be modeled by autoregressive models. However, industrial processes always show typical nonstationary nature, which may bring two challenges: how to capture fault degradation information and how to model nonstationary processes. To address the critical issues, a novel fault degradation modeling and online fault prognostic strategy is developed in this paper. First, a fault degradation-oriented slow feature analysis(FDSFA) algorithm is proposed to extract fault degradation directions along which candidate fault degradation features are extracted. The trend ability assessment is then applied to select major fault degradation features. Second, a key fault degradation factor(KFDF) is calculated to characterize the fault degradation tendency by combining major fault degradation features and their stability weighting factors. After that, a time-varying regression model with temporal smoothness regularization is established considering nonstationary characteristics. On the basis of updating strategy, an online fault prognostic model is further developed by analyzing and modeling the prediction errors. The performance of the proposed method is illustrated with a real industrial process. 展开更多
关键词 fault prognostic NONSTATIONARY industrial process fault degradation-oriented slow feature analysis(FDSFA) temporal smoothness regularization
下载PDF
New Oscillatory Criterias of Certain Second Order Neutral Functional Differential Equations
18
作者 LIN Wen-xian 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2005年第4期418-422,共5页
In this paper, the sufficient conditions for the oscillation of all solutions of certain second order nonlinea neutral equations with continuous distributed delay.
关键词 differential equation OSCILLATION continuous distributed delay
下载PDF
Elastic reverse-time migration in irregular tunnel environment based on polar coordinates
19
作者 Qu Ying-Ming Zhou Chang +3 位作者 Worral Qurmet Li Zhen-Chun Wang Chang-Bo Sun Jun-Zhi 《Applied Geophysics》 SCIE CSCD 2020年第2期253-266,316,共15页
When seismic exploration is conducted in a special geological environment such as a tunnel space,the traditional imaging method in the Cartesian coordinate system cannot accurately discretize the air column in that en... When seismic exploration is conducted in a special geological environment such as a tunnel space,the traditional imaging method in the Cartesian coordinate system cannot accurately discretize the air column in that environment.Thus,obtaining Thus,obtaining highquality imaging results is diffi cult.Therefore,an elastic-wave reverse-time migration method based on the polar coordinate system is proposed.In this method,three boundary conditions exist:outer,inner,and corner boundaries.In the outer boundary,the polar-coordinated absorbing boundary in the radial direction is used to suppress the artifi cial-boundary refl ection.The free-surface boundary condition is adopted in the tunnel space at the inner boundary.In the angular boundaries,we use two diff erent boundary conditions for two cases.The air column in the tunnel space is usually not an irregular circle.Therefore,the irregular tunnelspace geological body in the polar coordinate system is meshed into curvilinear grids and transformed into a regular one in an auxiliary polar coordinate system using the mapping method.Finally,elastic reverse-time migration technology is applied into the auxiliary polar coordinate system.In the numerical examples,two typical models are used to test the proposed method,which verify that the proposed method can obtain accurate images from the datasets in the tunnel space. 展开更多
关键词 Polar coordinate system Irregular tunnel ELASTIC Reverse-time migration Free surface
下载PDF
The Application of Wavelet Transform in Analysis of Digital Precursory Observational Data
20
作者 SongZhiping WuAnxu +5 位作者 WangWei GengJie SongXianyue NiYouzhong ZhuJiamiao KanDaoling 《Earthquake Research in China》 2004年第3期225-233,共9页
Digital data of precursors is noted for its high accuracy. Therefore, it is important to extract the high frequency information from the low ones in the digital data of precursors and to discriminate between the trend... Digital data of precursors is noted for its high accuracy. Therefore, it is important to extract the high frequency information from the low ones in the digital data of precursors and to discriminate between the trend anomalies and the short-term anomalies. This paper presents a method to separate the high frequency information from the low ones by using the wavelet transform to analyze the digital data of precursors, and illustrates with examples the train of thoughts of discriminating the short-term anomalies from trend anomalies by using the wavelet transform, thus provide a new effective approach for extracting the short-term and trend anomalies from the digital data of precursors. 展开更多
关键词 Wavelet transform Digital data of precursors High and low frequency variation information Trend anomaly and short-term anomaly
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部