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171.
Associations between coping responses, drinking motivations, expectations of meeting social and academic goals, and family of origin problem drinking and measures of college students' quantity/frequency of alcohol use and social complications of alcohol use were investigated in a sample of 218 college students. Positive associations were found between "emotion-focused" forms of coping such as detachment and the criterion measures, whereas "problem-focused coping" was not significantly associated with quantity/frequency of alcohol use or drinking complications. Positive correlations were also found between drinking motives, goal attainment expectancies and family models measures and the criterion measures. Regression models constructed for alcohol quantity/frequency and drinking complications implicated the total number of drinking motives, family models of problem drinking and the coping strategy of self-blame as strongly related to criterion measures. Positive social drinking motives and coping by seeking social support were implicated as possible protective factors. 相似文献
172.
Eighty subjects viewed and visually imagined upright or rotated alphanumeric characters and later judged whether test characters were previously seen or imagined (reality monitoring). Identification and test characters were presented verbally or visually. When characters were identified and tested verbally, source confusions (misjudging a seen character as "imagined" and vice-versa) were infrequent and were comparable for rotated and upright characters. When characters were identified and tested visually, source confusions were more frequent and were influenced by character rotation. Memories for imagined characters were especially susceptible to source confusion. Also source confusions for seen characters increased when characters were rotated. These results are consistent with the proposal that increasing sensory similarity between perceived and imagined items increases source confusion and that perceived rotation generates cognitive operations similar to those generated when the subject imagines a character rotated. 相似文献
173.
We have previously described in tuberous sclerosis (TSC) hamartomas the phenomenon of loss of heterozygosity (LOH) for DNA markers in the region of both the TSC2 gene on chromosome 16p13.3 and the TSC1 gene on 9q34. We now describe the spectrum of LOH in 51 TSC hamartomas from 34 cases of TSC. DNA was extracted from leucocytes or normal paraffin embedded tissue, and from frozen paraffin embedded hamartoma tissue from the same patient. The samples were analysed for 11 markers spanning the TSC1 locus and nine markers spanning the TSC2 locus. Twenty-one of 51 hamartomas showed LOH (41%). There was significantly more LOH on 16p13.3, with 16 hamartomas showing LOH around TSC2, and five in the vicinity of TSC1. No hamartoma showed LOH for markers around both loci. All the areas of LOH on chromosome 9 were large, but the smallest region of overlap lay between the markers D9S149 and D9S114, providing independent evidence for the localisation of the TSC1 gene. These data show that LOH is a common finding in a wide range of hamartomas, affecting the same TSC locus in different lesions from the same patient but not affecting both loci. These data support the hypothesis that both the TSC genes act as tumour suppressors and that the manifestations of TSC in patients with germline TSC mutations rise from "second hit" somatic mutations inactivating the remaining normal copy of the TSC gene. 相似文献
174.
JR McFarlane LM Foulds A Pisciotta DM Robertson DM de Kretser 《Canadian Metallurgical Quarterly》1996,134(4):481-489
BACKGROUND: The aim of this morphological investigation was to obtain more information about the structural and cellular mechanisms of interalveolar pore formation in postnatal lung development. Assuming that alveolar pore formation is related to the general thinning of interalveolar walls observed in the postnatal period, we have focused our attention on the topographical relationship between epithelial cells and connective tissue in the septum. Thereby we tried to formulate a uniform concept of pore formation. METHODS: After fixation with glutaraldehyde and osmiumtetroxide, tissue blocks of rat lungs aged 44 days were embedded in Epon. Serial sections were obtained in order to analyse precisely pores and supposed sites of pore formation (type II cells and thin spots in transsections of interalveolar walls). RESULTS: We made the following observations: there are pores with or without type II cells in the neighbourhood, and "pre-pores" with either fully transseptal granular pneumocytes, or thin spots in the interalveolar wall consisting of one or two layers of type I cell epithelium or of type II and type I cells without intervening connective tissue. CONCLUSIONS: From these findings we deduce that there is a general principle of interalveolar pore formation which consists in the formation of transseptal interepithelial cell contacts (i.e., between cells of type II and type I or type I and type I), promoted by the thinning of interalveolar walls in the stage of microvascular maturation. Within the zone of contact the cells thin out and give way to form an interalveolar opening. 相似文献
175.
J Iida AM Meijne JR Knutson LT Furcht JB McCarthy 《Canadian Metallurgical Quarterly》1996,7(3):155-162
Genes that encode enzymes that convert inactive "prodrugs" into anticancer metabolites may be therapeutically useful against brain tumors. Unlike other genes tested to date in brain tumor models, the Escherichia coli gpt gene is unique in that it not only sensitizes cells to the prodrug 6-thioxanthine (6TX) but also encodes resistance to a different regimen (mycophenolic acid, xanthine, and hypoxanthine), thus providing a means to select for gpt-positive cells. In the present study, rat C6 glioma cells were infected with a retrovirus vector that transduces this gene. A clonal line (C6GPT-7) was derived that exhibited significant 6TX susceptibility in vitro with an ID50 of 2.5 mumol/L, whereas 50% growth inhibition of parental C6 cells was not achieved at concentrations tested (up to 50 mumol/L). This line also exhibited significant sensitivity to 6-thioguanine (6TG), with an ID50 of 0.05 mumol/L, whereas 50% growth inhibition of parental C6 cells was achieved at 0.5 mumol/L. In a "bystander" assay, C6GPT-7 tumor cells efficiently transferred 6TX sensitivity to C6 cells at ratios as low as 1:9 (C6GPT-7:C6). This in vitro bystander effect was abrogated when C6GPT-7 and C6 cells were separated by a microporous membrane, suggesting that it was not mediated by highly diffusible metabolites. In vivo both 6TX and 6TG significantly inhibited the growth of subcutaneously transplanted C6GPT-7 cells but not that of C6 cells in athymic mice. In an intracerebral model, both 6TX and 6TG exhibited significant antiproliferative effects against tumors formed by C6GPT-7 cells. These findings provide a basis for exploring further gene therapy strategies based on in vivo transfer of the E coli gpt gene to provide chemosensitivity against 6TX and 6TG. 相似文献
176.
Reliability-based design optimization with confidence level under input model uncertainty due to limited test data 总被引:2,自引:2,他引:0
Yoojeong Noh K. K. Choi Ikjin Lee David Gorsich David Lamb 《Structural and Multidisciplinary Optimization》2011,43(4):443-458
For obtaining a correct reliability-based optimum design, the input statistical model, which includes marginal and joint distributions
of input random variables, needs to be accurately estimated. However, in most engineering applications, only limited data
on input variables are available due to expensive testing costs. The input statistical model estimated from the insufficient
data will be inaccurate, which leads to an unreliable optimum design. In this paper, reliability-based design optimization
(RBDO) with the confidence level for input normal random variables is proposed to offset the inaccurate estimation of the
input statistical model by using adjusted standard deviation and correlation coefficient that include the effect of inaccurate
estimation of mean, standard deviation, and correlation coefficient. 相似文献
177.
Multi-spectral fusion for surveillance systems 总被引:1,自引:0,他引:1
Simon Denman Author Vitae Todd Lamb Author Vitae Author Vitae Vinod Chandran Author Vitae Author Vitae 《Computers & Electrical Engineering》2010,36(4):643-663
Surveillance systems such as object tracking and abandoned object detection systems typically rely on a single modality of colour video for their input. These systems work well in controlled conditions but often fail when low lighting, shadowing, smoke, dust or unstable backgrounds are present, or when the objects of interest are a similar colour to the background. Thermal images are not affected by lighting changes or shadowing, and are not overtly affected by smoke, dust or unstable backgrounds. However, thermal images lack colour information which makes distinguishing between different people or objects of interest within the same scene difficult.By using modalities from both the visible and thermal infrared spectra, we are able to obtain more information from a scene and overcome the problems associated with using either modality individually. We evaluate four approaches for fusing visual and thermal images for use in a person tracking system (two early fusion methods, one mid fusion and one late fusion method), in order to determine the most appropriate method for fusing multiple modalities. We also evaluate two of these approaches for use in abandoned object detection, and propose an abandoned object detection routine that utilises multiple modalities. To aid in the tracking and fusion of the modalities we propose a modified condensation filter that can dynamically change the particle count and features used according to the needs of the system.We compare tracking and abandoned object detection performance for the proposed fusion schemes and the visual and thermal domains on their own. Testing is conducted using the OTCBVS database to evaluate object tracking, and data captured in-house to evaluate the abandoned object detection. Our results show that significant improvement can be achieved, and that a middle fusion scheme is most effective. 相似文献
178.
This paper describes the implementation and evaluation of a nonsanction seat belt law enforcement program in two experimental communities of contrasting size in a state with a mandatory belt law. The main ingredients of the program were seat belt "salutes," public information and education, and limited use of inexpensive economic incentives. Driver shoulder belt use data collected before, during, and after the experimental programs, compared to similar data collected in a comparison community, showed the approach to be effective. While standard seat belt enforcement activities without incentives have been shown to be effective, many police departments, especially in smaller communities, are reluctant to make wholesale increases in seat belt citations. Although requiring some additional level of manpower and resources, a nonsanction approach to seat belt law enforcement can provide an alternate way of increasing belt use in these communities. 相似文献
179.
E. J. Thrush G. Wale-Evans J. E. A. Whiteaway B. L. Lamb D. R. Wight N. G. Chew A. G. Cullis R. J. M. Griffiths 《Journal of Electronic Materials》1984,13(6):969-988
The composition profiles of GaAs/Ga1?xAlxAs heterostructures prepared in two different Metal-Organic Chemical Vapour Deposition (MOCVD) reactors have been studied. Transmission electron microscopy (TEM). and Auger and secondary ion mass spectrometry (SIMS) sputter profiling results are in good agreement and interface widths below 20 å have been achieved. Significant new results on transient phenomena have been obtained. showing that large and sometimes very sharp excursions in composition can be associated with valve switching actions. Direct evidence is presented that gas pressure or flow transients can occur during valve operations. and it is suggested that such instabilities are the cause of the effects observed. 相似文献
180.
ME Lamb 《Canadian Metallurgical Quarterly》1978,49(4):1189-1192
24 infants and their preschool-aged siblings were observed in a laboratory playroom in the presence of their parents. Observations took place when the infants were 12 months old and again 6 months later. Analysis of the social behavior revealed that, at both ages, the children assumed differentiable roles in their interactions: The infants "followed" by observing and imitating while the preschoolers "led" by drawing the infants' attention and by assertive dominance. Over time, infants became increasingly willing to direct social behaviors toward their siblings. There was remarkable behavioral stability across time, with the infants' early propensities seemingly causally related to later pre-schoolers' behavior. Older girls directed more social behaviors to siblings than boys did. The amount of parent-directed behavior was affected by the number of adults present, whereas the amount of sibling-directed behavior was unaffected. 相似文献