全文获取类型
收费全文 | 1814篇 |
免费 | 39篇 |
国内免费 | 4篇 |
学科分类
工业技术 | 1857篇 |
出版年
2022年 | 8篇 |
2021年 | 34篇 |
2020年 | 14篇 |
2019年 | 19篇 |
2018年 | 29篇 |
2017年 | 19篇 |
2016年 | 35篇 |
2015年 | 15篇 |
2014年 | 57篇 |
2013年 | 83篇 |
2012年 | 80篇 |
2011年 | 69篇 |
2010年 | 78篇 |
2009年 | 70篇 |
2008年 | 77篇 |
2007年 | 76篇 |
2006年 | 85篇 |
2005年 | 67篇 |
2004年 | 51篇 |
2003年 | 50篇 |
2002年 | 34篇 |
2001年 | 44篇 |
2000年 | 34篇 |
1999年 | 52篇 |
1998年 | 139篇 |
1997年 | 80篇 |
1996年 | 46篇 |
1995年 | 54篇 |
1994年 | 38篇 |
1993年 | 26篇 |
1992年 | 18篇 |
1991年 | 21篇 |
1990年 | 13篇 |
1989年 | 25篇 |
1988年 | 20篇 |
1987年 | 12篇 |
1986年 | 19篇 |
1985年 | 18篇 |
1984年 | 15篇 |
1983年 | 19篇 |
1982年 | 15篇 |
1981年 | 12篇 |
1980年 | 17篇 |
1979年 | 8篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1970年 | 5篇 |
排序方式: 共有1857条查询结果,搜索用时 296 毫秒
51.
Amoeba-based Chaotic Neurocomputing: Combinatorial Optimization by Coupled Biological Oscillators 总被引:1,自引:0,他引:1
Masashi Aono Yoshito Hirata Masahiko Hara Kazuyuki Aihara 《New Generation Computing》2009,27(2):129-157
We demonstrate a neurocomputing system incorporating an amoeboid unicellular organism, the true slime mold Physarum, known to exhibit rich spatiotemporal oscillatory behavior and sophisticated computational capabilities. Introducing optical
feedback applied according to a recurrent neural network model, we induce that the amoeba’s photosensitive branches grow or
degenerate in a network-patterned chamber in search of an optimal solution to the traveling salesman problem (TSP), where
the solution corresponds to the amoeba’s stably relaxed configuration (shape), in which its body area is maximized while the
risk of being illuminated is minimized.Our system is capable of reaching the optimal solution of the four-city TSP with a
high probability. Moreover, our system can find more than one solution, because the amoeba can coordinate its branches’ oscillatory
movements to perform transitional behavior among multiple stable configurations by spontaneously switching between the stabilizing
and destabilizing modes. We show that the optimization capability is attributable to the amoeba’s fluctuating oscillatory
movements. Applying several surrogate data analyses, we present results suggesting that the amoeba can be characterized as
a set of coupled chaotic oscillators.
相似文献
Kazuyuki AiharaEmail: |
52.
This paper presents an algebraic approach to polynomial spectral factorization, an important mathematical tool in signal processing and control. The approach exploits an intriguing relationship between the theory of Gröbner bases and polynomial spectral factorization which can be observed through the sum of roots, and allows us to perform polynomial spectral factorization in the presence of real parameters. It is discussed that parametric polynomial spectral factorization enables us to express quantities such as the optimal cost in terms of parameters and the sum of roots. Furthermore an optimization method over parameters is suggested that makes use of the results from parametric polynomial spectral factorization and also employs two quantifier elimination techniques. This proposed approach is demonstrated in a numerical example of a particular control problem. 相似文献
53.
Ram C. Sharma Ryutaro Tateishi Keitarou Hara 《International journal of remote sensing》2016,37(11):2706-2723
An up-to-date spatio-temporal change analysis of global snow cover is essential for better understanding of climate–hydrological interactions. The normalized difference snow index (NDSI) is a widely used algorithm for the detection and estimation of snow cover. However, NDSI cannot discriminate between snow cover and water bodies without use of an external water mask. A stand-alone methodology for robust detection and mapping of global snow cover is presented by avoiding external dependency on the water mask. A new spectral index called water-resistant snow index (WSI) with the capability of exhibiting significant contrast between snow cover and other cover types, including water bodies, was developed. WSI uses the normalized difference between the value and hue obtained by transforming red, green, and blue, (RGB) colour composite images comprising red, green, and near-infrared bands into a hue, saturation, and value (HSV) colour model. The superiority of WSI over NDSI is confirmed by case studies conducted in major snow regions globally. Snow cover was mapped by considering monthly variation in snow cover and availability of satellite data at the global scale. A snow cover map for the year 2013 was produced at the global scale by applying the random walker algorithm in the WSI image supported by the reference data collected from permanent snow-covered and non-snow-covered areas. The resultant snow-cover map was compared to snow cover estimated by existing maps: MODIS Land Cover Type Product (MCD12Q1 v5.1, 2012), Global Land Cover by National Mapping Organizations (GLCNMO v2.0, 2008), and European Space Agency’s GlobCover 2009. A significant variation in snow cover as estimated by different maps was noted, and was was attributed to methodological differences rather than annual variation in snow cover. The resultant map was also validated with reference data, with 89.46% overall accuracy obtained. The WSI proposed in the research is expected to be suitable for seasonal and annual change analysis of global snow cover. 相似文献
54.
Daichi Amagata Yuya Sasaki Takahiro Hara Shojiro Nishio 《Distributed and Parallel Databases》2016,34(2):259-287
A nearest neighbor (NN) query, which returns the most similar object to a user-specified query object, plays an important role in a wide range of applications and hence has received considerable attention. In many such applications, e.g., sensor data collection and location-based services, objects are inherently uncertain. Furthermore, due to the ever increasing generation of massive datasets, the importance of distributed databases, which deal with such data objects, has been growing. One emerging challenge is to efficiently process probabilistic NN queries over distributed uncertain databases. The straightforward approach, that each local site forwards its own database to the central server, is communication-expensive, so we have to minimize communication cost for the NN object retrieval. In this paper, we focus on two important queries, namely top-k probable NN queries and probabilistic star queries, and propose efficient algorithms to process them over distributed uncertain databases. Extensive experiments on both real and synthetic data have demonstrated that our algorithms significantly reduce communication cost. 相似文献
55.
56.
New pixel driving circuit using self‐discharging compensation method for high‐resolution OLED micro displays on a silicon backplane
下载免费PDF全文
![点击此处可从《Journal of the Society for Information Display》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kei Kimura Yusuke Onoyama Taizo Tanaka Naobumi Toyomura Hideyuki Kitagawa 《Journal of the Society for Information Display》2017,25(3):167-176
A new 4T2C pixel circuit formed on a silicon substrate is proposed to realize a high‐resolution 7.8‐μm pixel pitch AMOLED microdisplay. In order to achieve high luminance uniformity, the pixel circuit compensates its Vth variation of the MOSFET for the driving transistor internally by using self‐discharging method. Also presented are 0.5‐in Quad‐VGA and 1.25‐in wide Quad‐XGA microdisplays with the proposed pixel circuit. 相似文献
57.
Investigations were made of varistor microstructure, the morphology of Bi2O3 at multiple ZnO grain junctions, Bi2O3/ZnO grain boundaries and ZnO/ZnO grain boundaries (especially whether Bi2O3 is present or not at the ZnO/ZnO grain boundary) by means of high-resolution transmission electron microscopy and X-ray microanalysis in the scanning transmission electron microscope. Bi2O3 at multiple ZnO grain junctions consists of small particles of 0.1m in diameter, and they are vitrified to some extent. It is suggested that bismuth ions dissolve into ZnO grains over a 30 nm range from a Bi2O3/ZnO grain boundary; however, there is no bismuth at ZnO/ZnO grain boundaries. 相似文献
58.
Jun'ichiro Hara 《Journal of Low Temperature Physics》1981,43(5-6):533-548
The diffusive thermal conductivity (t) of superfluid 3He-B is calculated in the s-p-d-wave approximation by solving the Boltzmann equation for the Bogoliubov-Valatin quasiparticles variationally. A new set of Landau para- meters calculated from recent heat capacity data as well as old ones given in Wheatley's review are used to estimate the scattering amplitudes of the collision integral. Landau parameters F
2
s, F
1
a, and F
2
a are treated as free parameters under the constraint that exact(T
c) = exp(T
c), where exact and exp are the exact theoretical value and the experimental value, respectively. We have varied F
2
s, F
1
a, and F
2
a over a wide range % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaai4Eaiabgk% HiTiaaigdacaaIWaGaeyizImQaaeyqamaaDaaaleaacaqGXaaabaGa% ae4CaiaabYcacaqGHbaaaOGaeyyyIORaaeOramaaDaaaleaacaqGXa% aabaGaae4CaiaabYcacaqGHbaaaOGaai4laiaacUfacaaIXaGaey4k% aSIaaeOramaaDaaaleaacaqGXaaabaGaae4CaiaabYcacaqGHbaaaO% Gaai4laiaacIcacaaIYaGaamiBaiabgUcaRiaaigdacaGGPaGaaiyx% aiabgsMiJkaaigdacaaIWaGaaiyFaaaa!570F!\[\{ - 10 \leqslant {\text{A}}_{\text{1}}^{{\text{s,a}}} \equiv {\text{F}}_{\text{1}}^{{\text{s,a}}} /[1 + {\text{F}}_{\text{1}}^{{\text{s,a}}} /(2l + 1)] \leqslant 10\} \] and found the possible range of the reduced diffusive thermal conductivity % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGafqOUdSMbaG% aacaGGOaGaaeivaiaabMcacaqG9aGaeqOUdSMaaeikaiaabsfacaqG% PaGaaeivaiaab+cacqaH6oWAcaGGOaGaaeivamaaBaaaleaacaqGJb% aabeaakiaacMcacaqGubWaaSbaaSqaaiaabogaaeqaaaaa!46ED!\[\tilde \kappa ({\text{T) = }}\kappa {\text{(T)T/}}\kappa ({\text{T}}_{\text{c}} ){\text{T}}_{\text{c}} \]. The behavior of \~(T) in the s-p-d-wave approximation does not much depend on the values of the Landau parameters, and \~(t) decreases monotonically with decreasing tem- perature. 相似文献
59.
Yoshimasa A. Ono Jun'ichiro Hara Katsuhiko Nagai Kiyoshi Kawamura 《Journal of Low Temperature Physics》1977,27(3-4):513-536
The shear viscosity (T) in the Balian-Werthamer (BW) state of superfluid
3
He is calculated variationally throughout the region 0t 1(t=T/T
c) from the transport equation for Bogoliubov quasiparticles. Coherence factors are treated exactly in the calculation of the collision integral. The numerical result for
=s= s(T)/n(Tc) agree very well with experiment in the range 0.8t1.0. Analytic expressions
= 0.577 (1–1.0008t) and
=1–(23/64) [=(T)/k
B
T] are obtained in the low-temperature region and in the vicinity ofT
c, respectively. From the numerical analysis it is shown that the latter equation is valid only in the temperature range 0.9997t1.0.Supported by the Research Institute for Fundamental Physics, Kyoto University. 相似文献
60.
Weidong Ding Ryota Hayashi Kohei Ochi Junya Suehiro Kiminobu Imasaka Masanori Hara Noriaki Sano Eiichi Nagao Tadao Minagawa 《Dielectrics and Electrical Insulation, IEEE Transactions on》2006,13(6):1200-1207
Chemical byproducts analysis has been recognized as a powerful diagnosis method for SF6 gas-insulated switchgear (GIS). The authors have previously demonstrated that a carbon nanotube (CNT) gas sensor could detect partial discharge (PD) generated in SF6 gas. However, PD-generated decomposition gas species, which were responsible for the CNT gas sensor response, have not been identified yet. In this paper, two kinds of experiments were conducted in order to identify the responsible decomposition gas species. At first, the decomposition gas molecules adsorbed on CNTs were analyzed by Fourier transformation infrared (FTIR) spectroscopy. FTIR absorbance was observed around 735 cm-1 after CNTs were exposed to PD generated in SF6. In the second experiment, the CNT gas sensor responses to typical SF6 decomposition products (HF and SF4) were examined. The CNT gas sensor responded to these gases in the same way as to PD generated in SF6. SF4 response was larger than HF response. Based on these results, SF 4 and SOF2 emerged as candidates for the responsible decomposition gases. Electrochemical interactions between adsorbed gas molecules and CNT were discussed based on theoretical predictions of molecular orbital calculations. The calculation results suggested that both of SOF2 and SF4 could increase the CNT gas sensor conductance 相似文献