期刊文献+
共找到70篇文章
< 1 2 4 >
每页显示 20 50 100
《颜氏字样》与唐代的字样学 被引量:1
1
作者 张孟晋 《中国文字研究》 CSSCI 2016年第2期195-200,共6页
本文考证英藏敦煌文献斯388《正名要录》的作者为唐初郎知年,同卷所载字样书残卷为经郎知年修订过的《颜氏字样》,进而考察总结出当年《颜氏字样》的面貌。结合《颜氏字样》和《正名要录》材料,探讨了郎知年的主张和贡献,描绘了唐代字... 本文考证英藏敦煌文献斯388《正名要录》的作者为唐初郎知年,同卷所载字样书残卷为经郎知年修订过的《颜氏字样》,进而考察总结出当年《颜氏字样》的面貌。结合《颜氏字样》和《正名要录》材料,探讨了郎知年的主张和贡献,描绘了唐代字样学的兴起和发展。 展开更多
关键词 《颜氏样》 《正名要录》 《群书新样》 《干禄书》 样学
下载PDF
抓住两个字来判断化学平衡状态
2
作者 陈亚丽 《中学化学》 2009年第5期41-42,共2页
一、抓住“定”字来判断 例1下列说法可以证明反应2HI(g)←→H2(g)+I2(g)已达到平衡状态的是( )。
关键词 化学平衡状态 “定”字 反应
下载PDF
《韵会定正》声类考 被引量:1
3
作者 邓强 《安庆师范学院学报(社会科学版)》 2009年第2期46-50,共5页
《韵会定正》为明初孙吾与所作的韵书,此书久已亡佚。现存《永乐大典》和《洪武正韵》保存其部分反切。通过考证,《韵会定正》音系共29声类,其声类系统的特点主要有二:保留全浊声类,但将大量全浊音字归入了清音;知照组声类合并,禅部分... 《韵会定正》为明初孙吾与所作的韵书,此书久已亡佚。现存《永乐大典》和《洪武正韵》保存其部分反切。通过考证,《韵会定正》音系共29声类,其声类系统的特点主要有二:保留全浊声类,但将大量全浊音字归入了清音;知照组声类合并,禅部分和澄相混,禅部分和船相混的情况与《洪武正韵》相似。 展开更多
关键词 韵会 声类 助纽
下载PDF
关于《马氏文通》字类理论的再认识 被引量:4
4
作者 张文国 《中央民族大学学报(哲学社会科学版)》 CSSCI 北大核心 2004年第3期100-104,共5页
 《文通》以义定类:一字一义,则一字一类;一字数义,则一字数类。后者即"字无定义,故无定类",实际上就是字的兼类。且《文通》的最小运用单位是字而不是词,因而一字数义的兼类现象就多了起来。而当某个字的甲义临时引申为乙义...  《文通》以义定类:一字一义,则一字一类;一字数义,则一字数类。后者即"字无定义,故无定类",实际上就是字的兼类。且《文通》的最小运用单位是字而不是词,因而一字数义的兼类现象就多了起来。而当某个字的甲义临时引申为乙义时,该字则由甲类字"假借"为乙类字。可见,《文通》的字类理论自成体系,其"字无定类"与"字类假借"并没有自相矛盾。 展开更多
关键词 马氏文通 类假借
下载PDF
Comparative Study on VQ-Based Efficient Mandarin Speech Recognition Method
5
作者 谢湘 赵军辉 匡镜明 《Journal of Beijing Institute of Technology》 EI CAS 2002年第3期266-270,共5页
A VQ based efficient speech recognition method is introduced, and the key parameters of this method are comparatively studied. This method is especially designed for mandarin speaker dependent small size word set r... A VQ based efficient speech recognition method is introduced, and the key parameters of this method are comparatively studied. This method is especially designed for mandarin speaker dependent small size word set recognition. It has less complexity, less resource consumption but higher ARR (accurate recognition rate) compared with traditional HMM or NN approach. A large scale test on the task of 11 mandarin digits recognition shows that the WER(word error rate) can reach 3 86%. This method is suitable for being embedded in PDA (personal digital assistant), mobile phone and so on to perform voice controlling like digits dialing, name dialing, calculating, voice commanding, etc. 展开更多
关键词 speech recognition vector quantization(VQ) speaker dependent digits recognition
下载PDF
住房租赁市场改革的空间与方向
6
作者 张为民 《决策》 2017年第10期I0006-I0007,共2页
始于去年同庆期间的新一轮楼市调控,迄今已经一年多了。这一年,房地产政策密集出台、热闹非凡,特别是进入九月,更是一波接着一波、一环紧扣一环,整个市场弥漫着一股紧张的空气。不难看出,同绕“房子是用来住的、不是用来炒的”这... 始于去年同庆期间的新一轮楼市调控,迄今已经一年多了。这一年,房地产政策密集出台、热闹非凡,特别是进入九月,更是一波接着一波、一环紧扣一环,整个市场弥漫着一股紧张的空气。不难看出,同绕“房子是用来住的、不是用来炒的”这一定位,高层先念“定”字诀,及时坚决地阻击了热点城市飙升的房价,再念“紧”字诀,有力有序地展开了对整个市场调控。从传统的“限购、限贷、限价”再加“限售”的全新亮相,从北京的认房认贷又认离到租售同权、共有产权的横空出世,这些超预期的手段、超常规力度,足以令人们刮目相看、驻足遐思。 展开更多
关键词 市场改革 住房租赁 空间 房地产政策 “定”字 市场调控 共有产权 超常规
下载PDF
A New CMOS Image Sensor with a High Fill Factor and the Dynamic Digital Double Sampling Technique
7
作者 刘宇 王国裕 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第2期313-317,共5页
A single CMOS image sensor based on a 0.35μm process along with its design and implementation is introduced. The architecture of an active pixel sensor is used in the chip. The fill factor of a pixel cell can reach 4... A single CMOS image sensor based on a 0.35μm process along with its design and implementation is introduced. The architecture of an active pixel sensor is used in the chip. The fill factor of a pixel cell can reach 43%,higher than the traditional factor of 30%. Moreover, compared with the conventional method whose fixed pattern noise (FPN) is around 0.5%, a dynamic digital double sampling technique is developed, which possesses simpler circuit architecture and a better FPN suppression outcome. The CMOS image sensor chip is implemented in the 0.35μm mixed signal process of a Chartered by MPW. The experimental results show that the chip operates welt,with an FPN of about 0.17%. 展开更多
关键词 active pixel CMOS image sensor fill factor dynamic digital double sampling fixed pattern noise
下载PDF
Comprehensive analysis of slope stability and determination of stable slopes in the Chador-Malu iron ore mine using numerical and limit equilibrium methods 被引量:18
8
作者 ATAEI M BODAGHABADI S 《Journal of China University of Mining and Technology》 2008年第4期488-493,共6页
One of the critical aspects in mine design is slope stability analysis and the determination of stable slopes. In the Chador- Malu iron ore mine, one of the most important iron ore mines in central Iran, it was consid... One of the critical aspects in mine design is slope stability analysis and the determination of stable slopes. In the Chador- Malu iron ore mine, one of the most important iron ore mines in central Iran, it was considered vital to perform a comprehensive slope stability analysis. At first, we divided the existing rock hosting pit into six zones and a geotechnical map was prepared. Then, the value of MRMR (Mining Rock Mass Rating) was determined for each zone. Owing to the fact that the Chador-Malu iron ore mine is located in a highly tectonic area and the rock mass completely crushed, the Hoek-Brown failure criterion was found suitable to estimate geo-mechanical parameters. After that, the value of cohesion (c) and friction angle (tp) were calculated for different geotechnical zones and relative graphs and equations were derived as a function of slope height. The stability analyses using numerical and limit equilibrium methods showed that some instability problems might occur by increasing the slope height. Therefore, stable slopes for each geotechnical zone and prepared sections were calculated and presented as a function of slope height. 展开更多
关键词 slope stability limit equilibrium method numerical method rock mass classification
下载PDF
NUMERICAL STUDY OF THE INFLUENCE OF WAVES AND TIDE-SURGE INTERACTION ON TIDE-SURGES IN THE BOHAI SEA 被引量:3
9
作者 尹宝树 侯一筠 +4 位作者 程明华 苏京志 林明祥 李明悝 M.I.El-Sabh 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2001年第2期97-102,共6页
The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide sur... The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data. 展开更多
关键词 combined wave and tide surges numerical model influence mechanisms quantitative estimate
下载PDF
Science Letters:On numerical calculation in symplectic approach for elasticity problems 被引量:1
10
作者 Li ZHAO Wei-qiu CHEN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第5期583-588,共6页
The symplectic approach proposed and developed by Zhong et al. in 1990s for elasticity problems is a rational analytical method, in which ample experience is not needed as in the conventional semi-inverse method. In t... The symplectic approach proposed and developed by Zhong et al. in 1990s for elasticity problems is a rational analytical method, in which ample experience is not needed as in the conventional semi-inverse method. In the symplectic space, elasticity problems can be solved using the method of separation of variables along with the eigenfunction expansion technique, as in traditional Fourier analysis. The eigensolutions include those corresponding to zero and nonzero eigenvalues. The latter group can be further divided into α-and β-sets. This paper reformulates the form of β-set eigensolutions to achieve the stability of numerical calculation, which is very important to obtain accurate results within the symplectic frame. An example is finally given and numerical results are compared and discussed. 展开更多
关键词 Symplectic approach EIGENFUNCTION Numerical stability Elasticity problems
下载PDF
Analysis of deformation & destruction mechanism and stability of F0 fault crush zone in Fangezhuang Coal Mine 被引量:1
11
作者 刘伟韬 武强 +1 位作者 姬保静 周瑞光 《Journal of Coal Science & Engineering(China)》 2007年第3期261-265,共5页
Under the mining influence, carried on the electron microscope, the thin section analysis and creep tests to the fault matter's original sample and five groups of duplication samples, which have three kinds of moistu... Under the mining influence, carried on the electron microscope, the thin section analysis and creep tests to the fault matter's original sample and five groups of duplication samples, which have three kinds of moisture. The results of those tests indicate that confining pressure effect, structure effect and moisture effect all have influence to fault matter's nature. Meanwhile, the distortion destruction and stability variation of fault crush zone are the main reason which causes water-inrush lag-effect. Simultaneously, the stimulation computation we made by the numerical simulation software FLAC 3D also describes the mining influence to floor strata, fault crush zone's range and size, the influence of confined water on overburden and the fault zones, also it describes the time effect of bearing influenced by confined water and the rock dank height of confined water along the fault zones influenced by the specific water head. 展开更多
关键词 crush zone DEFORMATION DESTRUCTION stability numerical simulation
下载PDF
Determination of Precise Instantaneous Height at Multibeam Transducer 被引量:6
12
作者 ZHAO Jianhu ZHANG Hongmei John E. Hughes Clarke 《Geo-Spatial Information Science》 2007年第4期250-254,共5页
To overcome the shortcomings of the traditional multibeam survey and data processing, a new method is presented for the precise determination of the instantaneous height at the multibeam transducer by the blend of GPS... To overcome the shortcomings of the traditional multibeam survey and data processing, a new method is presented for the precise determination of the instantaneous height at the multibeam transducer by the blend of GPS height and heave signals. Before signal blend, GPS height and heave signals need to be corrected first to the transducer center by attitude correction. Second, the GPS height needs to be checked and modified by heave check and modification itself. Butterworth and FFT (fast Fourier transformation) were used in the signal blend. Finally, FFT is thought to be appropriate in signal processing. The new method efficiently overcomes the shortcomings of the traditional method, and this is proven well by the MBS (multibeam bathymetric system) experiment. 展开更多
关键词 MULTIBEAM digital signal processing GPS HEAVE
下载PDF
A New Browder Fixed Point Theorem in Noncompact Hyperconvex Metric Spaces and Its Applications to Section Questions and Intersection Questions 被引量:3
13
作者 WEN Kai-ting 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第1期112-116,共5页
In this paper, a new Browder fixed point theorem is established in the noncompact sub-admissible subsets of noncompact hyperconvex metric spaces. As application, a Ky Fan section theorem and an intersection theorem ar... In this paper, a new Browder fixed point theorem is established in the noncompact sub-admissible subsets of noncompact hyperconvex metric spaces. As application, a Ky Fan section theorem and an intersection theorem are obtained. 展开更多
关键词 hyperconvex metric space fixed point sub-admissible set noncompact measure SECTION INTERSECTION
下载PDF
“Digital Region” in the Context of the “Grid Computing” 被引量:1
14
作者 LIQi CAOJian 《Geo-Spatial Information Science》 2004年第2期101-103,共3页
This paper is to construct a “digital local, regional, region” information framework based on the technology of “SIG” and its significance and application to the regional sustainable development evaluation system.... This paper is to construct a “digital local, regional, region” information framework based on the technology of “SIG” and its significance and application to the regional sustainable development evaluation system. First, the concept of the “grid computing” and “SIG” is interpreted and discussed, then the relationship between the “grid computing” and “digital region” is analyzed, and the framework of the “digital region” is put forward. Finally, the significance and application of “grid computing” to the “region sustainable development evaluation system” are discussed. 展开更多
关键词 grid computing SIG (spatial information grid) digital region
下载PDF
Determination of fractional energy loss of waves in nearshore waters using an improved high-order Boussinesq-type model
15
作者 何海伦 宋金宝 +1 位作者 Patrick J. Lynett 李爽 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第3期621-629,共9页
Fractional energy losses of waves due to wave breaking when passing over a submerged bar are studied systematically using a modified numerical code that is based on the high-order Boussinesq-type equations.The model i... Fractional energy losses of waves due to wave breaking when passing over a submerged bar are studied systematically using a modified numerical code that is based on the high-order Boussinesq-type equations.The model is first tested by the additional experimental data,and the model's capability of simulating the wave transformation over both gentle slope and steep slope is demonstrated.Then,the model's breaking index is replaced and tested.The new breaking index,which is optimized from the several breaking indices,is not sensitive to the spatial grid length and includes the bottom slopes.Numerical tests show that the modified model with the new breaking index is more stable and efficient for the shallow-water wave breaking.Finally,the modified model is used to study the fractional energy losses for the regular waves propagating and breaking over a submerged bar.Our results have revealed that how the nonlinearity and the dispersion of the incident waves as well as the dimensionless bar height(normalized by water depth) dominate the fractional energy losses.It is also found that the bar slope(limited to gentle slopes that less than 1:10) and the dimensionless bar length(normalized by incident wave length) have negligible effects on the fractional energy losses. 展开更多
关键词 breaking waves Boussinesq-type equations nearshore wave modeling fractional energy loss
下载PDF
Dealing with Climate Change in a Digital Age
16
作者 Rose A. Dyson 《Journal of Philosophy Study》 2017年第8期437-444,共8页
Digital technologies offer unprecedented opportunities in addressing climate change as public policy requirements increasingly pervade national boundaries. Health issues now merge with those in education, the environm... Digital technologies offer unprecedented opportunities in addressing climate change as public policy requirements increasingly pervade national boundaries. Health issues now merge with those in education, the environment, energy, culture, gender, security, and the economy. They offer enormous potential in mobilizing for political action. But they also have a dark side. Outgoing U.S. President Barack Obama issued a warning that social media in particular poses an existential threat to democracy. Their pervasive influence during the 2016 American presidential election highlighted the potential for the spread of fake news and alternative facts. These realities must be recognized and addressed if meaningful policies on climate change and future sustainability are to be achieved. The challenges ahead require a re-examination of overarching trends in mass media that date back to the middle of the last century. Warnings from scientists, scholars, and community activists indicate that, on the issue of climate change, time is running out. In his Encyclical on Climate Change and Inequality, Pope Francis amplified the urgent call to action. But collectively, we need to rethink the profit driven ways in which our proliferating digital technologies mitigate potential steps toward a sustainable future. In a myriad of forms that go well beyond the seductive and addicting trends of endless hours spent online, new and proliferating digital toys and gadgets are neither carbon neutral, nor as some proponents would have us believe, do they hold the sole promise of innovation and job creation. Additionally, their potential must be harnessed to maintain rather than disrupt social stability. 展开更多
关键词 digital health CLIMATE culture ECONOMY policy media sustainability DEMOCRACY WARNINGS DISRUPTION seduction
下载PDF
Stability analysis unit and spatial distribution pattern of the terrain texture in the northern Shaanxi Loess Plateau 被引量:4
17
作者 DING Hu NA Jia-ming +2 位作者 HUANG Xiao-li TANG Guo-an LIU Kai 《Journal of Mountain Science》 SCIE CSCD 2018年第3期577-589,共13页
Terrain texture analysis is an important method of digital terrain analysis in quantitative geomorphological research and in the exploration of the spatial heterogeneity and autocorrelation of terrain features. Howeve... Terrain texture analysis is an important method of digital terrain analysis in quantitative geomorphological research and in the exploration of the spatial heterogeneity and autocorrelation of terrain features. However, a major issue often neglected in previous studies is the calculation unit of the terrain texture, that is, the stability analysis unit. As the test size increases, the derived terrain textures become increasingly similar so that their differences can be ignored. The test size of terrain texture is defined as the stability analysis unit. This study randomly selected 48 areas within the Loess Plateau in northern Shaanxi in China as the study sites and used the gray level co-occurrence matrix to calculate the terrain texture. The stability analysis unit of the terrain texture was then extracted, and its spatial distribution pattern in the Loess Plateau was studiedusing spatial interpolation method. Four terrain texture metrics, i.e., homogeneity, energy, correlation, and contrast, were extracted on the basis of the stability analysis unit, and the spatial variation patterns of these parameters were studied. Results showed that the spatial distribution pattern and the terrain texture metrics reflected a trend of high–low–high from north to south, which correlated with the spatial distribution of the landforms at the Loess Plateau. In addition, the terrain texture measures was significantly correlated with the terrain factors of gully density and slope, and this relationship showed that terrain texture measures based on the stability analysis unit could reflect the basic characteristics of terrain morphology. The stability analysis unit provided a reasonable analytical scale for terrain texture analysis and could be used as a measure of the regional topography to accurately describe basic terrain characteristics. 展开更多
关键词 Digital terrain analysis Terrain texture Stability analysis unit Spatial distribution Loess Plateau
下载PDF
Numerical Simulation of the Morphology and Moving Velocity for Electrospun Stable Jet
18
作者 李妮 薛花 熊杰 《Journal of Donghua University(English Edition)》 EI CAS 2011年第1期15-17,共3页
GAMBIT,POLYFLOW and FLUENT POST were used to simulate the morphology and the velocity of electrospun stable jet.Simulation results shows that jet diameter decreases with the increased draw force acted on the stable je... GAMBIT,POLYFLOW and FLUENT POST were used to simulate the morphology and the velocity of electrospun stable jet.Simulation results shows that jet diameter decreases with the increased draw force acted on the stable jet.But too great draw force would lead to thick knots appearing along the jet or stable jet disappearing during electrospinning.There is a linear relationship between the velocity and the moving distance.But the linear relationship does not exist under great draw force. 展开更多
关键词 ELECTROSPINNING stable jet numerical simulation
下载PDF
Digital Synthetic-heterodyne Interferometric Demodulation Based on Embedded System 被引量:4
19
作者 MENG Ju WANG Jin-hai +1 位作者 CHEN Cai-he ZHANG Cheng 《Semiconductor Photonics and Technology》 CAS 2006年第3期194-199,共6页
Optical fiber acceleration seismometer as an important instrument can offer high sensitivity, anti-jamming and non-touched advantage which has an extensive application field. Its signal processing ability will decide ... Optical fiber acceleration seismometer as an important instrument can offer high sensitivity, anti-jamming and non-touched advantage which has an extensive application field. Its signal processing ability will decide whole system’s performance to some extent because it will affect directly the factors such as resolving power, precision and dynamic range. The signal processing is usually realized by analog circuits which was more inferior in stability, flexibility and anti-jamming to digital processing system. A digital processing system of optical fiber acceleration seismometer has been designed based on the embedded system design scheme. Synthetic-heterodyne demodulation has been studied, and signal processing has been realized. The double processors of ARM and DSP are employed to implement respectively the system control and signal processing, and to provide the output interfaces such as LCD, DAC and Ethernet interface. This system can vary with the measured signal in real time and linearly, and its work frequency bandwidth is between 10Hz and 1kHz. The system has better anti-jamming ability and can work normally when the SNR is 40dB. 展开更多
关键词 Synthetic-heterodyne Optical fiber sensor Embedded system Digital signal processing
下载PDF
IMPROVING THE FREQUENCY RESOLUTION OF DIGITALLY SYNTHESIZED PERIODIC SIGNALS BY A SEQUENTIAL ADDRESSING SCHEME 被引量:2
20
作者 Tian Xinguang Duan Miyi +1 位作者 Sun Chunlai Chen Hong 《Journal of Electronics(China)》 2008年第5期661-666,共6页
In the digital synthesis of wideband periodic signals using an Arbitrary Waveform Gen-erator(AWG),the frequency resolution and spectral complexity of the synthesized signals are com-monly limited by the memory capacit... In the digital synthesis of wideband periodic signals using an Arbitrary Waveform Gen-erator(AWG),the frequency resolution and spectral complexity of the synthesized signals are com-monly limited by the memory capacity and clock frequency of the AWG.This paper proposes a novel sequential addressing scheme and then presents several sequences to improve the frequency resolution of the synthesized periodic signals without changing their spectral envelopes and basic time-domain characteristics under the condition of a fixed memory capacity and a fixed clock fre-quency.The main idea of the scheme is using the address generator in an AWG to program and produce addresses to read fixed waveform data in variable order,and thus to generate waveforms of various periods and profiles.The scheme is applied in simulating signal scenarios for military com-munication countermeasure experiments,and achieves high performance. 展开更多
关键词 Digital synthesis Frequency resolution Spectral envelope Sequential addressing
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部