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81.
The thermal stress on building‐integrated photovoltaic modules (BIPV) in Espoo, Finland, was studied with field‐testing of amorphous silicon modules. Based on these results, the thermal stress at two other European locations (Paris and Lisbon) was estimated. The estimation procedure entailed thermal modelling of heat transfer in the façade with meteorological data as input. The results indicate that the thermal stress on BIPV modules in Lisbon is, in this case, approximately 50% higher that in Espoo and between 80 and 200% higher than in Paris, depending on the activation energy of the degradation process. The difference in stress between a BIPV module and a free‐standing module in Espoo was 50–200%. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
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Molecular electrostatic potential (MEP) maps of certain 3-methoxy flavone derivatives having different anti-picornavirus activities have been studied. Geometries of the molecules were optimised and charge distributions computed using the AM1 molecular orbital method. Hybridization displacement charges (HDC) were combined with the L?wdin charge distributions to compute the MEP maps. Reliability of the method of computing MEP maps was tested by studying certain other molecules for which ab initio MEP results are available. The anti-picornavirus activities of the flavones have been shown to be related with negative MEP values in two regions, one near the 3-methoxy group and another in a diagonally opposite region near the substituent attached to the C7 atom of the molecules.  相似文献   
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The weak acid sorbic acid transiently inhibited the growth of Saccharomyces cerevisiae in media at low pH. During a lag period, the length of which depended on the severity of this weak-acid stress, yeast cells appeared to adapt to this stress, eventually recovering and growing normally. This adaptation to weak-acid stress was not due to metabolism and removal of the sorbic acid. A pma1-205 mutant, with about half the normal membrane H+-ATPase activity, was shown to be more sensitive to sorbic acid than its parent. Sorbic acid appeared to stimulate plasma membrane H+-ATPase activity in both PMA1 and pma1-205. Consistent with this, cellular ATP levels showed drastic reductions, the extent of which depended on the severity of weak-acid stress. The weak acid did not appear to affect the synthesis of ATP because CO2 production and O2 consumption were not affected significantly in PMA1 and pma1-205 cells. However, a glycolytic mutant, with about one-third the normal pyruvate kinase and phosphofructokinase activity and hence a reduced capacity to generate ATP, was more sensitive to sorbic acid than its isogenic parent. These data are consistent with the idea that adaptation by yeast cells to sorbic acid is dependent on (i) the restoration of internal pH via the export of protons by the membrane H+-ATPase in an energy-demanding process and (ii) the generation of sufficient ATP to drive this process and still allow growth.  相似文献   
86.
Physical activity and risk of colorectal cancer in men and women   总被引:1,自引:0,他引:1  
We examined the association between self-reported occupational and recreational physical activity and the subsequent risk of colorectal cancer in a population-based cohort in Norway. During a mean follow-up time of 16.3 years for males and 15.5 years for females, 236 and 99 colon cancers and 170 and 58 rectal cancers were observed in males and females, respectively, among 53,242 males and 28,274 females who attended the screening between 1972 and 1978. Physical activity at a level equivalent to walking or bicycling for at least four hours a week during leisure-time was associated with decreased risk of colon cancer among females when compared with the sedentary group (RR = 0.62, 95% CI 0.40-0.97). Reduced risk of colon cancer was particularly marked in the proximal colon (RR = 0.51, 95% CI 0.28-0.93). This effect was not observed for occupational physical activity alone, probably due to a narrow range of self-reported physical activity at work among females. However, by combining occupational and recreational physical activity we observed an inverse dose-response effect as increasing total activity significantly reduced colon cancer risk (P for trend = 0.04). Among males 45 years or older at entry to the study, an inverse dose-response effect was observed between total physical activity and colon cancer risk (P for trend = 0.04). We also found in males a stronger preventive effect for physical activity in the proximal as compared to distal colon. In addition, we found a borderline significant decrease in colon cancer risk for occupational physical activity in males 45 years or older when compared to the sedentary group (RR = 0.74, 95% CI 0.53-1.04). All results were adjusted for age, body mass index, serum cholesterol and geographic region. No association between physical activity and rectal cancer was observed in males or females. The protective effect of physical activity on colon cancer risk is discussed in regard to energy balance, dietary factors, age, social class, body mass index and gastrointestinal transit time.  相似文献   
87.
AIM: To assess cell proliferation in early prostate cancer and associated pathological lesions. METHODS: Using the Ki-67 antibody, the cell proliferation index was measured in early stage prostatic carcinoma in 37 incidental tumours diagnosed at transurethral prostatectomy (TURP) and in 20 low volume cancers treated by radical prostatectomy. Proliferation indexes have also been measured in areas of normal peripheral zone, transition zone hyperplasia, atrophic appearing lobules, and high grade prostatic intraepithelial neoplasia in the radical prostatectomy cases. RESULTS: In the TURP series the proliferation index correlated with grade and stage. Logistic regression analysis, however, showed that Gleason grade was the most reliable predictor of biopsy proven residual disease and clinical progression. In the radical series transition zone carcinoma the proliferation index was half that of peripheral zone carcinoma. The atrophic lobules also showed a high proliferation index of the same order as seen in the peripheral zone carcinoma. Normal peripheral zone showed the lowest proliferation index and in hyperplastic transition zone it was also less than the other areas. CONCLUSIONS: There is only limited support for the correlation of proliferation index with grade in early stage prostatic carcinoma. The findings do not suggest that proliferation index adds to the prognostic information given by grade and stage in pT1 disease. The significant difference in proliferation index in transition zone and peripheral zone carcinomas supports the morphological distinction of these tumour types and is consistent with differences in biological behaviour. The high proliferation index in lobules considered morphologically atrophic is reminiscent of previous observations in which carcinoma was spatially associated with atrophy.  相似文献   
88.
Developing retinal axons must follow a stereotypic course directing them to the subcortical visual centres which on arrival they must recognise. Transplantation studies suggest that local substrate cues close to the surface of the brainstem and diffusible factors emanating from the target region are important. To test a role for diffusible factors, we transplanted retinae to the cerebral cortex and have shown that outgrowth can be promoted by BDNF secreting fibroblasts.  相似文献   
89.
BACKGROUND: The aim of this study was to measure changes in total body water (TBW) in surgical patients after gastrointestinal lavage. METHODS: In a prospective, controlled study we used bioelectrical impedance to calculate the change in TBW in two groups of general surgical patients in the pre-operative period: the colonic lavage group consisted of patients fasted overnight who received 3 L of gastrointestinal lavage solution (GLS; n = 30), and the control group consisted of patients fasted overnight only (n = 30). Total body water was measured before and after either lavage and fasting (lavage group) or fasting alone (control group). RESULTS: The lavage group had a mean TBW loss of 729 mL +/- s.e. 217 and the control group a mean loss of 84 mL +/- s.e. 93 (P < 0.01 unpaired t-test). CONCLUSIONS: The results suggest that GLS results in a net loss of TBW. Although this fluid loss is modest, it may be important in surgical patients who have minimal cardiovascular reserve.  相似文献   
90.
BACKGROUND: Australia has a high rate of cardiovascular disease mortality and also a significant proportion of migrants. Little is known about the morbidity experience or cardiovascular risk factors among the larger migrant groups, and this is especially true of the Arabic-speaking population. OBJECTIVES: The objectives of the study were to identify the health profile of Arabic-speaking people in Sydney, Australia, to explore the relationship between level of acculturation and health indicators and to identify the morbidity profile of patients presenting to Arabic-speaking general practitioners (GPs). DESIGN: Adult Arabic-speaking patients aged 18-70 years attending 20 Arabic-speaking GPs in Canterbury, Sydney, during the 2-week study period were asked to complete a self-administered questionnaire in Arabic or English while waiting to see the GP. Data on cardiovascular risk factors, level of acculturation and reasons for seeing the GP were collected. RESULTS: Data were collected from 851 patients (62% response rate). Almost three-quarters (73%) of males and 36% of females were considered overweight or obese (body mass index > 25). Of concern, 37% of males and 28% of females were smokers. Females were significantly less likely to have been tested for diabetes (p < .05) or raised blood pressure (p < 0.05) compared with females in NSW. Respondents consumed less bread per day and more fruits than in NSW overall. Respiratory complaints (flu and colds) were the most frequently reported reasons for patient encounters. Except for the youngest age group, males gave more reasons for encounters than females. CONCLUSIONS: Consecutive sampling of ethnic patients attending a GP who speaks their language holds promise as a method of needs assessment with migrant populations. Further, our results suggest that smoking and weight reduction programs are priorities in the Arabic-speaking community. These risk factors are ideal for intervention by GPs speaking the same language.  相似文献   
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