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排序方式: 共有438条查询结果,搜索用时 281 毫秒
71.
《Food Control》2016
High speed data processing for online food quality inspection using hyperspectral imaging (HSI) is challenging as over hundred spectral images have to be analyzed simultaneously. In this study, a real-time pixel based early apple bruise detection system based on HSI in the shortwave infrared (SWIR) range has been developed. This systems consists of a novel, homogeneous SWIR illumination unit and a line scan camera. The system performance was tested on Jonagold apples bruised less than two hours before scanning. Partial least squares-discriminant analysis was used to discriminate bruised pixel spectra from sound pixel spectra. As the glossiness of many fruit and vegetables limits the accuracy in the detection of defects, several reflectance calibrations and pre-processing techniques were compared for glare correction and maximizing the signal to noise ratio. With the best combination of first derivative and mean centering, followed by image post-processing, this system was able to detect fresh bruises in thirty apples with 98% accuracy at the pixel level with a processing time per apple below 200 ms. 相似文献
72.
用X射线衍射(XRD)和透射电镜术(TEM)观察Si和Ge基板上PbTe、CdTe及PbGeTe单层薄膜及其与ZnS组合的多层薄膜的显微结构,给出了薄膜附着牢固度与薄膜显微结构的关系 相似文献
73.
J. Shen R. Balasubramanian D. K. Aidun L. L. Regel W. R. Wilcox 《Journal of Materials Engineering and Performance》1998,7(4):555-563
CdTe crystals were uniaxially compressed along several crystallographic axes at temperatures from 773 to 1353 K. The applied
stress ranged from 14 to 74% of the critical resolved shear stress (CRSS) measured in the authors’ laboratory. The deformed
specimens were annealed without applying stress at temperatures from 573 to 1073 K. No twins were observed after the above
operations. Dense slip bands were observed on most of the compressed specimens. Secondary slip systems were activated in some
experiments. CdTe crystals were sheared along {111}<112> at 1073 K with a load of 40% CRSS. Slip bands, but no twins, were
observed. Synchrotron x-ray topography was used to study in situ the effect of stress on crystal deformation. CdTe specimens
were uniaxially stressed in tension along <112> at 293 to 673 K. When the load reached ~50% of the CRSS, the topograph began
to distort, indicating the beginning of plastic deformation. No twins were observed on the stressed specimens. 相似文献
74.
Hee-Jeong Kim Hang-Chong Kim Dow-Bin Hyun Tae-Sung Oh 《Metals and Materials International》1998,4(1):75-81
P-type (Bi0.25Sb0.75)2Te3 powders were fabricated by melting/grinding and mechanical alloying processes. Thermoelectric properties of the hot-pressed
(Bi0.25Sb0.75)2Te3 were characterized with the powder processing method, powder size, hot pressing temperature, and the amount of excess-Te
dopant. Specimens fabricated by melting/grinding exhibited lower Seebeck coefficient, lower electrical resistivity and higher
thermal conductivity, compared to the specimens prepared by mechanical alloying. 3 wt.% excess Te-doped (Bi0.25Sb0.75)2 Te3, fabricated by melting/grinding and hot pressing at 550°C, exhibited a figure-merit of 3.2 x 10-3/K. For 1 wt.% excess Te-doped specimen prepared by mechanical alloying and hot pressing at 550°C, a figure-merit of 3.05
x 10-3/K was obtained. 相似文献
75.
M. J. Mescher T. E. Schlesinger J. E. Toney B. A. Brunett R. B. James 《Journal of Electronic Materials》1999,28(6):700-704
A method for passivating the surface of Cd1−xZnxTe (CZT) x-ray and gamma ray detectors using relatively simple dry processing techniques has been developed. Leakage currents
were significantly reduced for several processing methods. CZT samples were exposed to an oxygen plasma and/or coated with
a reactively sputtered silicon nitride layer. Several parameters of the oxygen plasma step were found to be important for
achieving enhanced surface resistivity. SiNX has been previously characterized and was used because of its high dielectric quality and low deposition temperature. Reduction
in leakage current after passivation by a factor of as much as twenty is demonstrated. Results are also presented which give
a measure of the long-term stability of the passivating layers. 相似文献
76.
H. Yoon M. S. Goorsky B. A. Brunett J. M. Van Scyoc J. C. Lund R. B. James 《Journal of Electronic Materials》1999,28(6):838-842
We investigated the resistivity variation of semi-insulating Cd1−xZnxTe used as room temperature nuclear radiation detectors, in relationship to the alloy composition. The resistivity and the
zinc composition were determined using leakage current measurements and triple axis x-ray diffraction lattice parameter measurements,
respectively. While the zinc content of the nominally xZn∼0.1 ingot varied monotonically according to the normal freezing behavior with an effective segregation coefficient of keff=1.15, the resistivity was found to vary non-systematically throughout the ingot. Furthermore, the “expected” relationship
of higher zinc content with higher resistivity was not always observed. For example, wafer regions of xZn∼0.12 and xZn∼0.08 exhibited resistivity values of ∼1010 and ∼1011 Ω·cm, respectively. In general, the experimental resistivity values can be explained by calculated values which take into
account a compensating deep level defect and various electron and hole mobility values. The relative influence of the parameters
that govern the resistivity (n,p, μe, and μh) are quantitatively investigated. 相似文献
77.
78.
79.
介绍了铜阳极泥预处理碲化亚铜渣沉淀工艺优化和改进方法。探索试验结果表明,采用"碲化亚铜渣还原—铜粉置换"新工艺,碲沉淀率由90%提高至98%以上,铜粉用量由理论量2倍降至1.35倍。应用实践证明,该工艺综合经济效益显著,可实现溶液中碲的高效回收。 相似文献
80.
Density-functional theory and a pseudopotential plane-wave approach are employed to study the structural and electronic properties of oxygen on CdTe (001) and (111) surfaces. The energetically favored configuration for oxygen adsorption on CdTe (001) is that where the O adatoms are located at the Cd-terminated B site, while O adatoms are at the Cd-terminated H3 site of CdTe (111) surface among the structures examined. Some possible surface defects are also examined on CdTe (001) and (111) surfaces. Oxygen can easily diffuse into the CdTe substrate at the (111) surface compared with the (001) surface. 相似文献