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31.
A punching process of a small hole in a die-quenched steel sheet having high strength using local resistance heating of a shearing zone was developed to decrease the punching load. Uniform temperature in the circular shearing zone of the hole was obtained by optimising heating conditions for a pair of rectangular electrodes. The punch load and the burnished surface area for the heating at 500 °C were about 1/3 smaller and 2 times larger than those for the cold punching, respectively, and the occurrence of delayed fracture around the punched hole was prevented by the heating above 500 °C. 相似文献
32.
M Tomura S Maruo J Mu XY Zhou HJ Ahn T Hamaoka H Okamura K Nakanishi S Clark M Kurimoto H Fujiwara 《Canadian Metallurgical Quarterly》1998,160(8):3759-3765
IL-12 and IL-18 have the capacity to stimulate IFN-gamma production by T cells. Using a T cell clone, we reported that IL-18 responsiveness is generated only after exposure to IL-12. Here, we investigated the induction of IL-18 responsiveness in resting CD8+, CD4+, and CD4-CD8- T cells. Resting T cells respond to neither IL-12 nor IL-18. After stimulation with anti-CD3 plus anti-CD28 mAbs, CD8+, CD4+, and CD4-CD8- T cells expressed IL-12R, but not IL-18R, and produced IFN-gamma in response to IL-12. Cultures of T cells with anti-CD3/anti-CD28 in the presence of rIL-12 induced IL-18R expression and IL-18-stimulated IFN-gamma production, which reached higher levels than that induced by IL-12 stimulation. However, there was a substantial difference in the expression of IL-18R and IL-18-stimulated IFN-gamma production among T cell subsets. CD4+ cells expressed marginal levels of IL-18R and produced small amounts of IFN-gamma, whereas CD8+ cells expressed higher levels of IL-18R and produced more IFN-gamma than CD4+ cells. Moreover, CD4-CD8- cells expressed levels of IL-18R comparable to those for CD8+ cells but produced IFN-gamma one order higher than did CD8+ cells. These results indicate that the induction of IL-18R and IL-18 responsiveness by IL-12 represents a mechanism underlying enhanced IFN-gamma production by resting T cells, but the operation of this mechanism differs depending on the T cell subset stimulated. 相似文献
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Toshio Kikuta Yoshikazu Kawagishi El-maghraby Mohamed El-Maghraby Toshinari Yamazaki Noriyuki Nakatani 《Materials Science and Engineering: B》2005,120(1-3):134-136
Experimental studies are reported concerning polarization reversal in the single crystal of telluric acid ammonium phosphate (TAAP). The switching currents have been measured under various temperatures and external electric fields. The experimental results have been used in order to obtain the effective growth dimension of reversed domain and the characteristic time of the polarization reversal on the basis of the Avrami theory. It becomes clear that the effective growth dimension depends on temperature and applied electric field. 相似文献
35.
Force-controllable, optically driven micromachines fabricated by single-step two-photon microstereolithography 总被引:1,自引:0,他引:1
We have fabricated optically driven micromechanisms and demonstrated their motion under optical force. All of the movable microcomponents are directly fabricated through an assembly-free process using the high-speed scanning of a femtosecond laser focused inside a photocurable resin. Since these movable micromachines are made from photocurable resin transparent to visible and near-infrared light, they can be driven by the force of optical trapping. We demonstrate a simple, versatile method for driving movable micromachines. Part of the movable component is optically trapped by a single laser beam and manipulated according to the desired trajectory. Various types of motion, including rotation and swinging are demonstrated. In addition, the optically driven micromachines can be force-controlled to femtonewton order by adjusting the position trapped by the laser beam. We demonstrated the femtonewton order force-controllable swing motion of micromanipulators. A microturbine was rotated by circular scanning of a trapping laser beam in a liquid. Such force-controllable optically driven micromachines are promising manipulation tools for biomolecules such as DNA and protein. 相似文献
36.
Qualitative research is now published across the family practice and medical literature. This article is designed to help busy family physicians decide which qualitative studies are worth reading and to provide them with the tools to appreciate and evaluate research design and analysis. By using clinical analogies, the qualitative research process can be better understood. 相似文献
37.
In vivo noninvasive measurement of blood glucose by near-infrared diffuse-reflectance spectroscopy 总被引:4,自引:0,他引:4
This paper reports in situ noninvasive blood glucose monitoring by use of near-infrared (NIR) diffuse-reflectance spectroscopy. The NIR spectra of the human forearm were measured in vivo by using a pair of source and detector optical fibers separated by a distance of 0.65 mm on the skin surface. This optical geometry enables the selective measurement of dermis tissue spectra due to the skin's optical properties and reduces the interference noise arising from the stratum corneum. Oral glucose intake experiments were performed with six subjects (including a single subject with type I diabetes) whose NIR skin spectra were measured at the forearm. Partial least-squares regression (PLSR) analysis was carried out and calibration equations were obtained with each subject individually. Without exception among the six subjects, the regression coefficient vectors of their calibration models were similar to each other and had a positive peak at around 1600 nm, corresponding to the characteristic absorption peak of glucose. This result indicates that there is every possibility of glucose detection in skin tissue using our measurement system. We also found that there was a good correlation between the optically predicted values and the directly measured values of blood samples with individual subjects. The potential of noninvasive blood glucose monitoring using our methodology was demonstrated by the present study. 相似文献
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Environmental fate of bisphenol A and its biological metabolites in river water and their xeno-estrogenic activity 总被引:14,自引:0,他引:14
Suzuki T Nakagawa Y Takano I Yaguchi K Yasuda K 《Environmental science & technology》2004,38(8):2389-2396
Monitoring of bisphenol A [BPA; 2,2-bis(4-hydroxyphenyl)propane] and its biological metabolites [4,4'-dihydroxy-alphamethylstilbene (DHMS), 2,2-bis(4-hydroxyphenyl)-1-propanol (BPA-OH), 2,2-bis(4-hydroxyphenyl)propanoic acid (BPA-COOH), and 2-(3,4-dihydroxyphenyl)-2-(4-hydroxyphenyl)propane (3-OH-BPA)] in river waters was performed by solid-phase extraction and GC/MS determination. The concentrations of BPA, BPA-COOH, BPA-OH, and 3-OH-BPA in the river water ranged from 2 to 230 (8.8 x 10(-12) to 1.0 x 10(-9) M), from 5 to 75 (1.9 x 10(-11) to 2.9 x 10(-10) M), from 3 to 16 (1.2 x 10(-11) to 6.6 x 10(-11) M), and from 3 to 11 (1.2 x 10(-11) to 4.5 x 10(-11) M) ng L(-1), respectively. DHMS, an intermediate in the main degradation pathway of BPA, was not detected in any water sample. Under the aerobic conditions in the river water, BPA disappeared within 8 d of incubation, but BPA-COOH, BPA-OH, and tetraol remained in the supernatant after 14 d of incubation. For the xeno-estrogenic activity of BPA and the metabolites, their ability to bind to recombinant human estrogen receptor alpha in competition with fluorescence-labeled 17beta-estradiol was measured. Fifty percent inhibitory concentrations (IC50) of BPA, DHMS, 3-OH-BPA, and BPA-OH were approximately 1 x 10(-5), 1 x 10(-6), 3 x 10(-5), and 1 x 10(-2) M, respectively. In human cultured MCF-7 breast cancer cells, BPA increased cell numbers in a dose-dependent manner at concentrations from 10(-7) to 10(-5) M. For the BPA metabolites, DOHMS, 3-OH-BPA, and BPA-COOH caused the cells proliferation at concentrations from 10(-9) to 10(-6), from 10(-7) to 10(-6), and from 10(-5) to 10(-4) M, respectively. BPA-OH did not cause MCF-7 cells proliferation. These results indicate that BPA is mainly metabolized through oxidative rearrangement by bacteria in the river water, and intermediate bisphenols via minor metabolic pathways exist in river water. The presence of the bisphenols having the xeno-estrogenic effect suggests the necessity of monitoring those in river water, in the effluent waters from sewage plants, or in landfill leachate. 相似文献