全文获取类型
收费全文 | 192篇 |
免费 | 5篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 11篇 |
化学工业 | 70篇 |
金属工艺 | 1篇 |
机械仪表 | 1篇 |
建筑科学 | 8篇 |
能源动力 | 5篇 |
轻工业 | 17篇 |
水利工程 | 1篇 |
石油天然气 | 3篇 |
无线电 | 13篇 |
一般工业技术 | 53篇 |
冶金工业 | 6篇 |
自动化技术 | 14篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 11篇 |
2012年 | 12篇 |
2011年 | 10篇 |
2010年 | 4篇 |
2009年 | 10篇 |
2008年 | 7篇 |
2007年 | 13篇 |
2006年 | 7篇 |
2005年 | 14篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 1篇 |
1979年 | 9篇 |
1978年 | 5篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有203条查询结果,搜索用时 23 毫秒
11.
The tropospheric particle extinction-to-backscatter ratio, the depolarization ratio, and the water-vapor mixing ratio were measured by use of a Raman lidar and a polarization lidar during the Asian dust seasons in 2001 and 2002 in Tsukuba, Japan. The apparent (not corrected for multiple-scattering effects) extinction-to-backscatter ratios (Sp) showed a dependence on the relative humidity with respect to ice (RHice) obtained from the lidar-derived water-vapor mixing ratio and radiosonde-derived temperature; they were mostly higher than 30 sr in dry air (RHice < 50%), whereas they were mostly lower than 30 sr in ice-supersaturated air (RHice > or = 100%), where the apparent extinction coefficients were larger than 0.036 km(-1). Both regions showed mean particle depolarization ratios of 20%-22%. Comparisons with theoretical calculations and the previous experiments suggest that the observed dependence of Sp on RHice is attributed to the difference in the predominant particles: nonspherical aerosols (mainly the Asian dust) in dry air and cloud particles in ice-supersaturated air. 相似文献
12.
A classification technique using the neural networks has recently been developed. We apply a neural network of learning vector
quantization (LVQ) to classify remote-sensing data, including microwave and optical sensors, for the estimation of a rice-planted
area. The method has the capability of nonlinear discrimination, and the classification function is determined by learning.
The satellite data were observed before and after planting rice in 1999. Three sets of RADARSAT and one set of SPOT/HRV data
were used in Higashi–Hiroshima, Japan. Three RADARSAT images from April to June were used for this study. The LVQ classification
was applied the RADARSAT and SPOT to evaluate the estimate of the area of planted-rice. The results show that the true production
rate of the rice-planted area estimation of RADASAT by LVQ was approximately 60% compared with that of SPOT by LVQ. It is
shown that the present method is much better than the SAR image classification by the maximum likelihood method. 相似文献
13.
Yuzo Nishida Satoshi Nishino Li Li Guo Mami Kunita Hideaki Matsushima Tadashi Tokii 《Inorganic chemistry communications》1999,2(12):160
We have observed that binuclear cobalt(II) compounds with H(HPTP), Co2(HPTP)(CH3COO)(ClO4)2 and Co2(HPTP)Cl(ClO4)2, react with oxygen molecules when DNA is present in the solution, cleaving the DNA (H(HPTP) denotes N,N,N′,N′-tetrakis(2-pyridylmethyl)-1,3-diaminopropane-2- ol). 相似文献
14.
Hongo Takero Arakawa Hideo Sugimoto Gunji Tange Koichi Yamamoto Yuzo 《Industrial Electronics, IEEE Transactions on》1987,(1):5-10
An automatically guided vehicle, traveling without fixed guide ways, has been developed. In this paper, the construction of the vehicle, the control algorithm, and its general performance are described. 相似文献
15.
Kenta Arima Katsuyoshi Endo Toshihiko Kataoka Kikuji Hirose Hidekazu Goto Yasushi Oshikane Haruyuki Inoue Yoshitaka Tatara Yuzo Mori 《Computational Materials Science》1999,14(1-4):236-240
Local density of states (LDOS) is obtained by the first principles calculation based on the density functional theory on the Si(0 0 1)2 × 1 surface and on the surface with an Al dimer. At an Al dimer, LDOS has a high intensity in the conduction band region, which cannot be seen on the Si(0 0 1)2 × 1 surface. This tendency is observed in STS measurements as well. The possibility for a microelementary analysis is presented by applying this method to other metal atoms on the Si surface. Furthermore, it is pointed out that STS measurements should be always performed at the same tip-sample separation to obtain reproducible STS spectrums. 相似文献
16.
Sumikin Iron and Steel Corporation (SISC) is the main manufacturing base of seamless tube materials in Sumitomo Metals group, and stainless steel making plant is in charge of semi‐manufactured special steel products such as stainless and high alloy steel. Total manufacturing costs of these special steels are heavily dependent on the price of raw material. Therefore, reduction of its usage and optimizing operation process in order to absorb influence of its unstable price are important issues. In this report, we introduce three cases as following: yield improvement in order to reduce raw material usage, optimization of the steel dust usage, and active use of low‐price raw material through dividing refining process. 相似文献
17.
Takayama Y Saito A Moriguchi H Kotani K Suzuki T Mabuchi K Jimbo Y 《Journal of Bioscience and Bioengineering》2011,(6):624-629
Precise control of differentiation processes of pluripotent stem cells is a key component for the further development of regenerative medicine. For this purpose, combining a cell-aggregate-size treatment for regulating intercellular signal transmissions and an electrical stimulation technique for inducing cellular responses is a promising approach. In the present study, we developed microfabricated electrode substrates that allow simultaneous stimulation of embryoid bodies (EBs) of P19 cells. Mouse embryonal carcinoma P19 cells can be induced to differentiate into three germ layers and serve as a promising stem cell model. Microcavity–array patterns were fabricated onto indium–tin–oxide (ITO) substrates using a standard photo-lithography technique, and uniform-sized EBs of P19 cells were inserted into each microcavity. Electrical stimulation was applied to the EBs through substrate electrodes and stimulus-induced intracellular calcium transients were monitored. We confirmed that the developed electrode device could simultaneously stimulate smaller (200 μm diameter) and larger (500 μm diameter) EBs inserted in the microcavities and induce specific spatio-temporal patterns of intracellular calcium transients in the EBs with fine reproducibility. We concluded that the developed microcavity array with embedded electrodes could simultaneously and effectively stimulate uniform-sized EBs inserted in it. Therefore, it is a promising experimental tool for precisely controlling cell differentiation processes. 相似文献
18.
Kentaro Kuratani Masayasu Uemura Minoru Mizuhata Akihiko Kajinami Shigehito Deki 《Journal of the American Ceramic Society》2005,88(10):2923-2927
We report on the direct deposition of high-quality ZrO2 thin films on various kinds of substrates by the liquid phase deposition method. After reaction for 24 h, thin films formed on various kinds of substrates, and the obtained thin film was comprised of densely packed nano-sized particles. The film annealed at 500°C showed a tetragonal phase at room temperature and this phenomenon has been discussed from the viewpoint of crystallite size effect. The result of optical transmittance measurement revealed that high transparency, more than 70% transmittance, has been achieved for the film after annealing at 900°C. 相似文献
19.
A fast and efficient hybrid fractal-wavelet image coder. 总被引:1,自引:0,他引:1
Yuzo Iano Fernando Silvestre da Silva Ana Lúcia Mendes Cruz 《IEEE transactions on image processing》2006,15(1):98-105
The excellent visual quality and compression rate of fractal image coding have limited applications due to exhaustive inherent encoding time. This paper presents a new fast and efficient image coder that applies the speed of the wavelet transform to the image quality of the fractal compression. Fast fractal encoding using Fisher's domain classification is applied to the lowpass subband of wavelet transformed image and a modified set partitioning in hierarchical trees (SPIHT) coding, on the remaining coefficients. Furthermore, image details and wavelet progressive transmission characteristics are maintained, no blocking effects from fractal techniques are introduced, and the encoding fidelity problem common in fractal-wavelet hybrid coders is solved. The proposed scheme promotes an average of 94% reduction in encoding-decoding time comparing to the pure accelerated Fractal coding results. The simulations also compare the results to the SPIHT wavelet coding. In both cases, the new scheme improves the subjective quality of pictures for high-medium-low bitrates. 相似文献
20.
E.s.r. spectra of vanadyl complexes in various carbonaceous materials were measured in a range between room temperature and 435 °C. The e.s.r. spectrum of vanadyl complex doped in Taching reduced crude was a slow tumbling pattern at temperatures between 60 °C and 225 °C. By the rapid freezing technique, it became clear that the vanadyl complex in Taching residue was oriented to the magnetic field in its temperature range. Further, activation energies for rotations of vanadyl complexes in those carbonaceous materials were estimated from Arrhenius plots of the correlation times. Those carbonaceous materials were classified into two groups according to values of the activation energies. This classification was consistent with that based on mesophase textures of the cokes made from them. 相似文献