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91.

The World Wide Web(WWW) comprises a wide range of information, and it is mainly operated on the principles of keyword matching which often reduces accurate information retrieval. Automatic query expansion is one of the primary methods for information retrieval, and it handles the vocabulary mismatch problem often faced by the information retrieval systems to retrieve an appropriate document using the keywords. This paper proposed a novel approach of hybrid COOT-based Cat and Mouse Optimization (CMO) algorithm named as hybrid COOT-CMO for the appropriate selection of optimal candidate terms in the automatic query expansion process. To improve the accuracy of the Cat and Mouse Optimization (CMO) algorithm, the parameters are tuned with the help of the Coot algorithm. The best suitable expanded query is identified from the available expanded query sets also known as candidate query pools. All feasible combinations in this candidate query pool should be obtained from the top retrieved documents. Benchmark datasets such as the GOV2 Test Collection, the Cranfield Collections, and the NTCIR Test Collection are utilized to assess the performance of the proposed hybrid COOT-CMO method for automatic query expansion. This proposed method surpasses the existing state-of-the-art techniques using many performance measures such as F-score, precision, and mean average precision (MAP).

  相似文献   
92.
While the internet has a lot of positive impact on society, there are negative components. Accessible to everyone through online platforms, pornography is, inducing psychological and health related issues among people of all ages. While a difficult task, detecting pornography can be the important step in determining the porn and adult content in a video. In this paper, an architecture is proposed which yielded high scores for both training and testing. This dataset was produced from 190 videos, yielding more than 19 h of videos. The main sources for the content were from YouTube, movies, torrent, and websites that hosts both pornographic and non-pornographic contents. The videos were from different ethnicities and skin color which ensures the models can detect any kind of video. A VGG16, Inception V3 and Resnet 50 models were initially trained to detect these pornographic images but failed to achieve a high testing accuracy with accuracies of 0.49, 0.49 and 0.78 respectively. Finally, utilizing transfer learning, a convolutional neural network was designed and yielded an accuracy of 0.98.  相似文献   
93.
Data available in software engineering for many applications contains variability and it is not possible to say which variable helps in the process of the prediction. Most of the work present in software defect prediction is focused on the selection of best prediction techniques. For this purpose, deep learning and ensemble models have shown promising results. In contrast, there are very few researches that deals with cleaning the training data and selection of best parameter values from the data. Sometimes data available for training the models have high variability and this variability may cause a decrease in model accuracy. To deal with this problem we used the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) for selection of the best variables to train the model. A simple ANN model with one input, one output and two hidden layers was used for the training instead of a very deep and complex model. AIC and BIC values are calculated and combination for minimum AIC and BIC values to be selected for the best model. At first, variables were narrowed down to a smaller number using correlation values. Then subsets for all the possible variable combinations were formed. In the end, an artificial neural network (ANN) model was trained for each subset and the best model was selected on the basis of the smallest AIC and BIC value. It was found that combination of only two variables’ ns and entropy are best for software defect prediction as it gives minimum AIC and BIC values. While, nm and npt is the worst combination and gives maximum AIC and BIC values.  相似文献   
94.
The effect of the initial annealing temperature on the evolution of microstructure and microhardness in high purity OFHC Cu is investigated after processing by HPT. Disks of Cu are annealed for 1 h at two different annealing temperatures, 400 and 800 °C, and then processed by HPT at room temperature under a pressure of 6.0 GPa for 1/4, 1/2, 1, 5, and 10 turns. Samples are stored for 6 months after HPT processing to examine the self‐annealing effects. Electron backscattered diffraction (EBSD) measurements are recorded for each disk at three positions: center, mid‐radius, and near edge. Microhardness measurements are also recorded along the diameters of each disk. Both alloys show rapid hardening and then strain softening in the very early stages of straining due to self‐annealing with a clear delay in the onset of softening in the alloy initially annealed at 800 °C. This delay is due to the relatively larger initial grain size compared to the alloy initially annealed at 400 °C. The final microstructures consist of homogeneous fine grains having average sizes of ≈0.28 and ≈0.34 µm for the alloys initially annealed at 400 and 800 °C, respectively. A new model is proposed to describe the behavior of the hardness evolution by HPT in high purity OFHC Cu.  相似文献   
95.
Periovular granuloma formation during Schistosoma mansoni infection is a complex, multifaceted immunologic response. Products of arachidonic acid metabolism have been shown to contribute to this response through studies in which general inhibitors of lipoxygenase function reduce granulomatous inflammation. To determine which lipoxygenases are important for granuloma development in schistosomiasis, wild type mice or mice deficient for 5-lipoxygenase (5-LO) or "leukocyte-type" 12-lipoxygenase (12-LO) were infected with S. mansoni and studied for responses to schistosome eggs and egg antigens. At the acute stage of infection, when granuloma formation is usually maximal, 5-LO deficient mice developed smaller granulomas around liver-deposited schistosome eggs compared with wild type or 12-LO deficient mice. 5-LO mice also displayed less antibody-mediated (5 h) and cell-mediated, delayed-type (24 h) hypersensitivity to schistosome egg antigens than did the other two infection groups. In an attempt to determine possible mechanisms for the reduced inflammatory responses, we also measured hepatic mRNA levels of cytokines that have been shown to influence granuloma size (IL-4, IL-10, and IFN-gamma). The mRNA levels for IL-10 were significantly lower in 5-LO-deficient mice, but SEA-stimulated spleen cells did not demonstrate a significant difference in IL-10 production between wild type and 5-LO mice. These data suggest that 5-LO plays a role in host responses to schistosomiasis via a mechanism that cannot be explained solely by changes in expression of these cytokines.  相似文献   
96.
The nuclear matrix is defined as the insoluble framework of the nucleus and has been implicated in the regulation of gene expression, the cell cycle, and nuclear structural integrity via linkage to intermediate filaments of the cytoskeleton. We have discovered a novel nuclear matrix protein, NRP/B (nuclear restricted protein/brain), which contains two major structural elements: a BTB domain-like structure in the predicted NH2 terminus, and a "kelch motif" in the predicted COOH-terminal domain. NRP/B mRNA (5.5 kb) is predominantly expressed in human fetal and adult brain with minor expression in kidney and pancreas. During mouse embryogenesis, NRP/B mRNA expression is upregulated in the nervous system. The NRP/B protein is expressed in rat primary hippocampal neurons, but not in primary astrocytes. NRP/B expression was upregulated during the differentiation of murine Neuro 2A and human SH-SY5Y neuroblastoma cells. Overexpression of NRP/B in these cells augmented neuronal process formation. Treatment with antisense NRP/B oligodeoxynucleotides inhibited the neurite development of rat primary hippocampal neurons as well as the neuronal process formation during neuronal differentiation of PC-12 cells. Since the hypophosphorylated form of retinoblastoma protein (p110(RB)) is found to be associated with the nuclear matrix and overexpression of p110(RB) induces neuronal differentiation, we investigated whether NRP/B is associated with p110(RB). Both in vivo and in vitro experiments demonstrate that NRP/B can be phosphorylated and can bind to the functionally active hypophosphorylated form of the p110(RB) during neuronal differentiation of SH-SY5Y neuroblastoma cells induced by retinoic acid. Our studies indicate that NRP/B is a novel nuclear matrix protein, specifically expressed in primary neurons, that interacts with p110(RB) and participates in the regulation of neuronal process formation.  相似文献   
97.
The purpose of this paper is to determine whether using off-axis isoseparation curves to optimize the collimator rotation angle improves dose homogeneity. Eleven intact breast irradiation patients underwent computerized tomography (CT) treatment planning with 1 cm abutting slices. Central plane treatment planning, using 6 MV photons, tissue inhomogeneity corrections, and isocentric opposed tangent treatment fields, was performed. Collimators were rotated to match chest wall slope through the use of a beam's-eye-view setting. Patient separations were measured from the apex of the breast to the posterior field border on each axial CT slice. Sagittal-plane isoseparation curves were constructed from these measurements. Using these curves, the collimator rotation that minimized off-axis separation differences was determined. A comparison of off-axis dose inhomogeneity was performed for patients with a > or =10 degrees difference between this optimized collimator angle and the angle determined by chest wall slope. These comparative treatment plans differed only with respect to collimator angle rotation. The mean optimal collimator rotation angle differed significantly from the mean rotation angle which matched the chest wall slope (5.4 degrees vs. 11 degrees, respectively, P < 0.001). Four of the 11 patients had rotation angle differences of 10 degrees. In these patients, the optimization of collimator angle reduced the percentage of breast volume to "that" received > or =110% of the prescribed dose. For the patient with the largest breast size to the patient with the smallest breast size the decreases were, respectively, 5% (15% to 10%), 3% (24% to 21%), 1% (4% to 3%), and 1% (0.9% to 0%). The mean reduction in dose inhomogeneity was greatest in the inferior breast quadrants. At 6 cm and 4 cm off axis, the mean reductions in the percentages of the breast tissue to "that" received 110% of the prescribed dose were respectively 15.1% and 5.3 %. Optimizing the collimator angle through the use of isoseparation curves decreases dose inhomogeneity. The greatest improvements are in the inferior quadrants of the intact breast. The improved dose homogeneity may have clinical relevance in the treatment of patients with large breast sizes.  相似文献   
98.
OBJECTIVES: An understanding of the validity and usefulness of self-reported measures (as distinct from clinically determined measures) of oral health is emerging. These self-reported measures include self-rated oral health (SROH). Three objectives were to: (1) describe self-rated oral health in dentate adults, (2) quantify associations between self-rated oral health and other measures of oral health (oral disease and tissue damage, pain and discomfort, functional limitation, and disadvantage), and (3) assess the construct validity of a model of oral health proposed herein. METHODS: The Florida Dental Care Study is a longitudinal study of oral health, which included at baseline 873 subjects who had at least one tooth, were 45 years or older, and who participated for an interview and clinical examination. RESULTS: The prevalence of self-rated oral health decrements was substantial; approximately one fourth of subjects reported their oral health as only fair or poor. Bivariate and multivariate results provided consistent evidence of the construct validity of the proposed model of oral health. Additionally, the salience of one measure of dental appearance suggests that persons may use esthetic cues when rating their oral health. CONCLUSIONS: The proposed multidimensional model of oral health has construct validity. Self-rated oral health is affected by oral disease and tissue damage, oral pain and discomfort, oral functional limitation, and oral disadvantage. These self-reported measures and the proposed model should provide useful information for dental care effectiveness research. General health status has been disaggregated into the "physical" and the "mental;" an additional separation into the "oral" aspects of health seems warranted.  相似文献   
99.
Implanted biomaterials trigger acute and chronic inflammatory responses. The mechanisms involved in such acute inflammatory responses can be arbitrarily divided into phagocyte transmigration, chemotaxis, and adhesion to implant surfaces. We earlier observed that two chemokines-macrophage inflammatory protein 1alpha/monocyte chemoattractant protein 1-and the phagocyte integrin Mac-1 (CD11b/CD18)/surface fibrinogen interaction are, respectively, required for phagocyte chemotaxis and adherence to biomaterial surfaces. However, it is still not clear how the initial transmigration of phagocytes through the endothelial barrier into the area of the implant is triggered. Because implanted biomaterials elicit histaminic responses in the surrounding tissue, and histamine release is known to promote rapid diapedesis of inflammatory cells, we evaluated the possible role of histamine and mast cells in the recruitment of phagocytes to biomaterial implants. Using i.p. and s. c. implantation of polyethylene terephthalate disks in mice we find: (i) Extensive degranulation of mast cells, accompanied by histamine release, occurs adjacent to short-term i.p. implants. (ii) Simultaneous administration of H1 and H2 histamine receptor antagonists (pyrilamine and famotidine, respectively) greatly diminishes recruitment and adhesion of both neutrophils (<20% of control) and monocytes/macrophages (<30% of control) to implants. (iii) Congenitally mast cell-deficient mice also exhibit markedly reduced accumulation of phagocytes on both i.p. and s.c implants. (iv) Finally, mast cell reconstitution of mast cell-deficient mice restores "normal" inflammatory responses to biomaterial implants. We conclude that mast cells and their granular products, especially histamine, are important in recruitment of inflammatory cells to biomaterial implants. Improved knowledge of such responses may permit purposeful modulation of both acute and chronic inflammation affecting implanted biomaterials.  相似文献   
100.
Cytotoxic T lymphocyte (CTL) activation requires specific T cell receptor (TCR)-class I major histocompatibility complex (MHC) antigen complex interactions as well as the participation of coreceptor or accessory molecules on the surface of CTL. CD8 can serve as a coreceptor in that it binds to the same MHC class I molecules as the TCR to facilitate efficient TCR signaling. In addition, CD8 can be "activated" by TCR stimulation to bind to class I molecules with high avidity, including class I not recognized by the TCR as antigenic complexes (non-antigen [Ag] class I), to augment CTL responses and thus serve an accessory molecule function. A Glu/Asp227-->Lys substitution in the class I alpha 3 domain acidic loop abrogates lysis of target cells expressing these mutant molecules by alloreactive CD8-dependent CTL. Lack of response is attributed to the destruction of the CD8 binding site in the alpha 3 domain which is likely to disrupt CD8 coreceptor function. The relative importance of the class I alpha 3 domain acidic loop Glu227 in coreceptor as opposed to accessory functions of CD8 is unclear. To address this issue, we examined CTL adhesion and degranulation in response to immobilized class I-peptide complexes formed in vitro from antigenic peptides and purified class I molecules containing wild-type or Glu227-->Lys substituted alpha 3 domains. The alpha 3 domain mutant class I-peptide complexes were bound by CTL and triggered degranulation, however to much lower levels than wild-type class I-peptide complexes. In further experiments, it is directly demonstrated that the alpha 3 domain mutant class I molecules, which lack the Glu227 CD8 binding site, still serve as TCR-activated, avidity-enhanced CD8 accessory ligands. However, mutant class I peptide Ag complexes failed to effectively serve as CD8 coreceptor ligands to initiate TCR-dependent signals required to induce avidity-enhanced CD8 binding to coimmobilized non-Ag class I molecules. Thus the Glu227-->Lys mutation effectively distinguishes CD8 coreceptor and avidity-enhanced CD8 accessory functions.  相似文献   
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