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221.
Kuniaki Murase Takeshi Honda Tetsuji Hirato Yasuhiro Awakura 《Metallurgical and Materials Transactions B》1998,29(6):1193-1198
An antimony microelectrode was prepared by quenching a molten Sb-Sb2O3 mixture (2 pct Sb2O3). The local pH in the vicinity of a nickel-plated copper cathode was directly measured using the microelectrode during the
chloride electrowinning of nickel for a MCLE (matte chlorine leach electrowinning) process, where nickel metal is electrodeposited
with a high current efficiency, 94 to 97 pct, from low-pH baths. The local pH at 328 K was increased by proton consumption
during the electrolysis of aqueous electrolytes containing NiCl2 (1.20 mol dm−3) and NaCl (0.43 mol dm−3) with the same concentrations as employed for the MCLE process. The difference in pH between the cathode surface and bulk
solution increased with increasing cathodic current density. Nickel deposits with a metallic luster were obtained when the
difference was not more than 1.2 pH units. The current efficiency was a maximum for electrolysis with a current density of
265 A m−2 and bulk pH of 1.0 to 1.5; these optimal conditions coincided with those reported for the MCLE process: temperature 328 to
333 K, bulk pH 1.1 to 1.5, and current density 230 to 260 A m−2. Electrolytes with lower NiCl2 and NaCl concentrations resulted in a drop in current efficiency. 相似文献
222.
H Eguchi Y Takaue Y Kawano A Watanabe T Watanabe A Kikuta S Koizumi T Matsumura A Sawada Y Horikoshi Y Sekine T Koyama T Shimokawa K Shimizu K Kawasaki H Mugishima J Takayama M Ohira M Ogawa 《Canadian Metallurgical Quarterly》1998,21(10):1011-1014
This is the first report of the long-term therapeutic results in 22 children more than 1 year old with stage IV neuroblastoma who were treated with autologous peripheral blood stem cell transplantation (PBSCT). The median age of the patients at PBSCT was 4 years (1 to 10 years) and seven of the 17 patients who were evaluated for N-myc amplification were positive. PBSC were collected by a median of four aphereses per patient. The patients underwent PBSCT from 6 to 21 months after the start of therapy (median 10.5 months) at which time 13 patients were in CR, seven were in PR, and two had refractory disease. Multi-drug therapy using the 'high-MEC' regimen consisting of carboplatinum (400 mg/m2) and VP-16 (200 mg/m2) on days -7 to -4, and melphalan (90 mg/m2) on days -3 and -2, was the primary cytoreductive regimen. The median number of infused MNC and CFU-GM was, respectively, 4.3 x 10(8)/kg and 2.4 x 10(5)/kg. After PBSCT, three patients died of regimen-related toxicities and one patient who was transplanted with refractory disease died of disease progression without any benefit from transplantation. Hematological recovery was evaluated in 21 patients, excluding one early death. The median number of days required to achieve an AGC of >0.5 x 10(9)/l and platelet count of >50 x 10(9)/l were, respectively, 11 and 46. Eleven patients relapsed 3 to 50 months after PBSCT, and currently seven patients (5/13 who were transplanted in CR and 2/7 in PR) are surviving disease-free at 52 to 84 months. Although the retrospective nature of this study and several variables prevent a meaningful analysis, the overall results still support the feasibility of developing a prospective study of PBSCT with a larger number of children with high-risk neuroblastoma. 相似文献
223.
Film-air (F-A) and film-substrate (F-S) interfaces of silicone-modified acrylic coatings were characterized using attenualed total reflectance Fourier transform infrared (ATR FT-IR)spectroscopy. Previous studies suggested that when silicone linkages are part of a polymer backbone-containing polymers, they tend to accumulate near the F-A interface. These studies show that when polysiloxanes are dispersed in a silicone-modified acrylic/polysiloxane solution, they appear to accumulate near F-S interfaces. When polysiloxanes were added to a dispersion of silicone-modified acrylic resin, the distribution of polysiloxanes between F-A and F-S interfaces became less pronounced. These differences result from the mobility of polysiloxanes, and are attributed to the molecular weight dependence and compatibility differences between the systems. 相似文献
224.
Tamoxifen, a nonsteroidal estrogen antagonist, has been widely used in a hormonal treatment for breast cancer. The side effects of tamoxifen are generally recognized to be mild. However, we experienced three cases of severe hypertriglyceridemia and/or hyperglycemia induced by tamoxifen. For normalization of their hypertriglyceridemia we need to stop giving tamoxifen. In one of three cases we analyzed her lipoprotein profile in detail with lipoprotein lipase activities and apolipoprotein E phenotype. The case was a 49 year-old woman. After 15 months of tamoxifen administration, she was diagnosed as severe hypertriglyceridemia. Consecutively, severe hyperglycemia was occurred to need insulin therapy. After tamoxifen withdrawal, her triglyceride and glucose levels improved. Her lipolytic enzyme was reduced during tamoxifen treatment. Apolipoprotein E phenotype was uncommon E4/2. Although hypertriglyceridemia was not considered to be a risk factor for coronary heart disease, a marked hypertriglyceridemia might occasionally produce severe lethal pancreatitis. We recommend that a periodic plasma lipid analysis is needed for patients treated with tamoxifen, especially for diabetic and hypertriglyceridemic patients, to avoid such complications. 相似文献
225.
Y Nishi H Izumi J Kawano K Oguri Y Kawaguchi M Ogata A Tonegawa K Takayama T Kawai M Ochi 《Journal of Materials Science》1997,32(14):3637-3639
The influence of electron-beam irradiation on the wettability of hydroxy apatites (HAP) has been investigated. The wettability
was evaluated from the interfacial energy between HAP and water. It was measured by the contact angle of distilled water on
HAP. Electron-beam irradiation increases the wettability. Based on the rate process, the influence of electron-beam irradiation
on wettability is discussed. Using electron-beam irradiation, we can precisely control the surface condition of HAP.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
226.
S Yokota M Nakao S Horiike T Seriu T Iwai H Kaneko H Azuma T Oka T Takeda A Watanabe A Kikuta K Asami I Sekine T Matsushita T Tsuhciya J Mimaya S Koizumi M Miyake K Nishikawa Y Takaue Y Kawano A Iwai Y Ishida K Matsumoto T Fujimoto 《Canadian Metallurgical Quarterly》1998,67(4):379-387
Many antibiotic resistance mutations arise in pathogenic bacteria that harbor plasmids (R-plasmids). Resistance to third generation cephalosporins, for instance, largely occurs by one or more point mutations in plasmid bla genes that expand the resistance spectrum of beta-lactamases. Here I review relevant evidence underlying the worldwide emergence of extended spectrum beta-lactamases (ESBLs). The conclusion reached is that the origin of these resistance-conferring mutations cannot be explained by a series of single point mutation and selection events. Instead, highly advantageous stochastic processes might exist that generate alterations in the sequence or the conformation of particular regions in chromosomal or plasmid genomes such as bla, i.e., recombination or mutation. Several explanations for the origin of ESBLs are reviewed but direct experimental evidence to support or to invalidate them is still lacking. The cellular conditions under which ESBLs arise are unknown; however, involvement of nutritional stresses inside natural animal hosts and of plasmid conjugal functions appear likely. 相似文献
227.
Y Matsubara M Murata K Kawano T Zama N Aoki H Yoshino G Watanabe K Ishikawa Y Ikeda 《Canadian Metallurgical Quarterly》1997,17(11):3006-3012
The cardiovascular protective effects of estrogen are known to be mediated by its beneficial effects on lipid metabolism and its direct actions on the vessel wall. The latter can be mediated by a specific receptor for estrogen present on smooth muscle cells and endothelial cells. The gene for the receptor (the classic estrogen receptor [ER]) has three known polymorphisms, Pvu II, Xba I, and B-variant polymorphisms, which are reportedly associated with receptor expression and altered receptor function and with some disorders including breast cancer, hypertension, and spontaneous abortion. However, the significance of genetic variations of the ER in vascular diseases has not been reported. We have examined the association between coronary artery disease (CAD) and the three polymorphisms in ER. Genotypes (P1/P2, X1/X2, and B-wild type/B-variant type) were determined in 87 men and postmenopausal women with myocardial infarction or angina pectoris whose lesions were confirmed by coronary angiography, as well as from 94 control individuals from the general population with no coronary heart disease and normal resting ECG. For B-variant polymorphism, all individuals examined had B-wild type, which contrasts with the reported allele frequency for B-variant type (0.1) in the white population. Genotype distributions and allele frequencies of Pvu II or Xba I polymorphisms were not significantly different between control subjects and patients (P > .05 for Pvu II or Xba I genotypes; P > .05 for Pvu II or Xba I allele frequencies). When the allele frequencies were analyzed separately by sex, there was still no statistically significant difference for both polymorphisms (P > .05 for men; P > .05 for women). No association was found between the polymorphisms and the angiographic severity of CAD. Total cholesterol, triglyceride, or HDL-cholesterol levels were not significantly different among ER genotypes. These findings suggest that the three polymorphisms in ER are not associated with the prevalence and severity of CAD and that the polymorphisms are unrelated to the serum lipid levels in control subjects and patients. 相似文献
228.
Kawashima Y. Ichikawa T. Nakamura N. Obata S. Den Y. Kawano H. Ide T. Kudo M. 《Semiconductor Manufacturing, IEEE Transactions on》2002,15(4):497-505
A double interlayer of high-density plasma fluorinated silica glass (FSG) and SiO/sub 2/ has been developed to control fluorine instability for sub-0.18-/spl mu/m devices. However, the interlayer conditions need further study for robust integration. The authors investigate the optimum conditions to prevent Al wiring delamination. The correlation between the incidence of delamination and F concentration at Ti-SiO/sub 2/ was demonstrated by the three-dimensional mapping of interfacial F concentrations with various thicknesses of SiO/sub 2/ and F contents in FSG. Detailed analysis of the Ti-SiO/sub 2/ interface reveals that the anomalous growth of the interface layer by absorbing F atoms into the Ti layer causes delamination. The properties of SiO/sub 2/, such as the compressive stress and the density of oxygen deficiency, were adjusted to reduce F diffusion. In addition, the thickness was controlled to above 4500 /spl Aring/ to suppress F accumulation at Ti-SiO/sub 2/ to within the permissible level. These conditions resulted in preventing delamination and obtaining integration reliability without increasing the capacitance between adjacent metal lines. 相似文献
229.
We show both gas pressure and species sensing capabilities based on the electrothermal effect of a multiwalled carbon nanotube (MWCNT). Upon exposure to gaseous environments, the resistance of a heated MWCNT is found to change following the conductive heat-transfer variances of gas molecules. To realize this mechanism, a suspended MWCNT is constructed by synthesis and assembly in localized chemical vapor deposition that is accomplished within seconds via real-time electrical feedback control. Vacuum pressure sensitivity and gas species differentiability are observed and analyzed. Such MWCNT electrothermal sensors are compact, fast and reversible in responses, and fully integratable with microelectronics. 相似文献
230.
A series of experiments was carried out using a rolling-type tribometer to investigate the effects on friction behavior of the entraining velocity of the lubricant at the inlet to the contact zone (V) and sliding velocity during deformation (ΔV). Experiments with stainless steel sheets of two different surface roughnesses showed that the variations in the friction coefficient with entraining velocity V and sliding velocity ΔV are largely dependent on the initial surface texture of the workpiece. For a smooth workpiece, the friction coefficient decreases with increasing sliding velocity ΔV but keeps almost constant with increasing entraining velocity V. However, for a rough workpiece, the friction coefficient initially decreases slowly and increases largely with increasing sliding velocity ΔV or decreasing entraining velocity V. Observation of the rolled surface for a smooth workpiece shows that, with increasing entraining velocity V, the slip band becomes more marked, and with increasing sliding velocity ΔV, the rubbed portions become more conspicuous. For a rough workpiece, galling occurs at high sliding velocity ΔV. The critical condition for galling outbreak is shown on the V-ΔV graph. The galling outbreak process is observed by interrupting the rolling process. 相似文献