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991.
K Farker H Schweer R Vollandt N Nassr U Nagel HW Seyberth A Hoffmann M Oettel 《Canadian Metallurgical Quarterly》1997,54(3):655-664
The purpose of the present work was to study the prostaglandin excretion in young nonpregnant ovulatory women during the menstrual cycle on the one hand and in postmenopausal women on the other hand and to investigate the influence of female sex hormones (estradiol, progesterone) on urinary prostanoid excretion. Urinary excretion rates of prostaglandin E2 (PGE2), 6-keto-PGF1 alpha, thromboxane B2 (TxB2) and their metabolites PGE-M (11 alpha-hydroxy-9, 15-dioxo-2,3,4,5,20-pentanor-19-carboxyprostanoic acid), 2,3-dinor-6-keto-PGF1 alpha, 2,3-dinor-TxB2 and 11-dehydro-TxB2 were determined by gas chromatography-triple stage quadrupole mass spectrometry (GC/MS/MS) in 41 young non-pregnant women during the follicular phase and during the luteal phase and in 23 postmenopausal women. Excretion rates of all urinary prostanoids were not significantly different in the follicular phase when compared with the luteal phase. In contrast to the young ovulatory women, PGE2 and TxB2 were significantly higher in postmenopausal women. Concerning the other prostaglandins significant differences between these groups of women did not exist. Although serum levels of estradiol and progesterone were different in young and postmenopausal women, sex hormones have not been shown to correlate with prostaglandins. Our data do not suggest sex hormones to be responsible for the difference in the prostaglandin excretion in women of reproductive age and in women in the menopause. Further systematic investigations into age dependency of prostaglandin excretion in women are necessary. 相似文献
992.
Changes in mice haemopoietic cellular populations and in the radiosensitivity of CFU-C and BFUe progenitors cells were determined in vivo for mixed field radiations composed of a gamma-ray component and a neutron component. Five Dgamma/Dtotal ratios (gamma-rays over total dose ratios, quoted as tau in this report) were obtained (tau = 0.95, 0.83, 0.67, 0.33 and 0.09). Myelogram changes were enlarged with the increase of the neutron component. Radiosensitivity of the two progenitor cell lineages were increased with lower tau values (excess of neutrons). The radiosensitivity of haemopoietic progenitor cells exposed in vivo varies with the ratio of the high- and low-LET components in the mixture. The D0 value varied from 3.3 +/- 0.22 to 0.85 +/- 0.04 Gy with the decrease of tau for CFU-C and from 2.08 +/- 0.22 to 0.64 +/- 0.07 Gy for BFUe. The obtained relative biologic efficiency (RBE) varied from 1.2 +/- 0.08 to 4.7 +/- 0.24 for CFU-C and from 1.1 +/- 0.1 to 3.6 +/- 0.16 for the BFUe. The relation between RBE and tau could be somewhat non-linear for CFU-C and seems to be close to linear for BFUe. The higher is the neutron component, the higher is the radiosensitivity. These results indicate that variations of the quality of the mixed field in the haemopoietic local territory are of great importance in terms of radiation damage and cell killing as well as in terms of the ability to restore the haemopoietic system. 相似文献
993.
Sphingomonas yanoikuyae B1 is extremely versatile in its catabolic ability. An insertional mutant strain, S. yamoikuyae EK504, which is unable to grow on naphthalene due to the loss of 2-hydroxychromene-2-carboxylate isomerase activity, was utilized to investigate the role of this enzyme in the degradation of anthracene by S. yanoikuyae B1. Although EK504 is unable to grow on anthracene, this strain could transform anthracene to some extent. A metabolite in the degradation of anthracene by EK504 was isolated by high-pressure liquid chromatography (HPLC) and was identified as 6,7-benzocoumarin by UV-visible, gas-chromatographic, HPLC/mass-spectrometric, and 1H nuclear magnetic resonance spectral techniques. The identification of 6,7-benzocoumarin provides direct chemical and genetic evidence for the involvement of nahD in the degradation of anthracene by S. yanoikuyae B1. 相似文献
994.
We have identified and characterized a novel protein from adult zebrafish retina, which we named ES1. Database search revealed that the ES1 gene has significant similarity to two genes with unknown functions: the Escherichia coli sigma cross-reacting protein 27a (scrp27a) and the human KNP-I/GT335. In situ hybridization and immunohistochemistry experiments showed that both ES1 mRNA and protein are expressed specifically in adult photoreceptor cells. ES1 seems to be a cytoplasmic protein. An ES1-like antigen was also detected in photoreceptor cells of goldfish with anti-ES1 antibodies. The retina specific expression and the evolutionary conservation suggest that ES1 protein may be important for maintaining normal retina structure and function. 相似文献
995.
996.
OBJECTIVES: A low level of education is associated with an increased risk of developing a dementia disorder, as well as with a higher risk of cardiovascular disease. The aim of this study was to investigate the association between education and cardiovascular risk factors, and to study the relation between these factors and cognitive function in elderly men. DESIGN: Cross-sectional population-based study. SETTING: Uppsala, Sweden. SUBJECTS: 504 men aged 69-74 years, participants in a longitudinal health survey concerning cardiovascular risk factors. MAIN OUTCOME MEASURE: Cognitive function as measured by a composite score of 13 standard psychometric tests. RESULTS: A low level of education was associated with poorer cognitive performance, as well as with obesity, smoking, diabetes, high concentrations of serum triglycerides and plasma fibrinogen. In the entire cohort, subjects with obesity, smoking, diabetes or hypertriglyceridaemia showed impaired cognitive test results, independent of socio-economic factors. When stroke cases were excluded, obesity and smoking were still related to impaired cognitive function. CONCLUSIONS: Smoking and obesity with associated metabolic disturbances are inversely related both to educational level and to cognitive function. Cognitive decline of vascular origin is potentially preventable by treatment of risk factors. The question of whether the increased vascular risk contributes to the higher prevalence of cognitive disorders in individuals with low socio-economic status, needs to be further evaluated in longitudinal population-based studies. 相似文献
997.
Statistical analysis of normally occurring cortisol levels in serum and urine of horses served to recommend thresholds for this corticosteroid in these body fluids, as application of exogenous cortisol as well as ACTH may elevate the cortisol concentrations above the proposed threshold. The present study contributes to the general issue of how to establish thresholds for trotting horses upon sportive examination. 100 randomly selected post competition serum and urine samples, respectively, were submitted to cortisol analysis by means of HPLC. Concentrations of the endogenous corticosteroid in serum and urine followed a log-normal distribution with mean values of 61 and 49 ng/ml, respectively. The probability was 1: 100,000 to exceed concentration limits of 230 (serum) and 394 ng/ml (urine). Designation of thresholds for cortisol has proven problematic and is discussed here. 相似文献
998.
999.
BACKGROUND: Because patients may be taking clonidine chronically or may be receiving it as a premedication before surgery, the authors investigated its effect on cerebral hemodynamics. METHODS: In nine volunteers, middle cerebral artery mean blood flow velocity (Vm) was measured using transcranial Doppler ultrasonography (TCD). CO2 vasoreactivity was measured before clonidine administration (preclonidine), 90 min after clonidine, 5 microg/kg orally, then following restoration of mean arterial pressure (MAP) to the preclonidine level. In addition, Vm was measured after a phenylephrine-induced 30-mmHg increase in MAP. RESULTS: After clonidine administration, Vm decreased from 62 +/- 9 to 48 +/- 8 cm/s (P < 0.01), and MAP decreased from 86 +/- 10 to 63 +/- 5 mmHg (P < 0.01; mean +/- SD). Clonidine decreased the CO2 vasoreactivity slope from 2.2 +/- 0.4 to 1.2 +/- 0.5 cm x s(-1) x mmHg(-1) (P < 0.05); restoring MAP to the preclonidine level increased the slope to 1.60 +/- 0.5 cm x s(-1) x mmHg(-1), still less than the preclonidine slope (P < 0.05). CO2 vasoreactivity expressed as a percentage change in Vm, decreased after clonidine, 3.5 +/- 0.8 versus 2.4 +/- 0.8 %/mmHg (P < 0.05); this difference disappeared after restoration of MAP, 3.1 +/- 1.2 %/mmHg. With a 30-mmHg increase in MAP, Vm increased by 13% before and after clonidine (P < 0.05). CONCLUSIONS: Clonidine, 5 microg/kg orally, decreases Vm and slightly attenuates cerebral CO2 vasoreactivity, therefore decreased cerebral blood flow and mildly attenuated CO2 vasoreactivity should be anticipated. 相似文献
1000.
G Schmid-Ott B J?ger HW Künsebeck R Ott P Malewski F Lamprecht 《Canadian Metallurgical Quarterly》1997,48(8):547-555
We analyzed how psoriasis patients sought professional help and correlated it to their illness attitudes and feeling of stigmatization. Semi-structured interviews of 400 patients were reanalyzed to identify homogeneous groups concerning initial reactions at first manifestations of the disease. Four groups ("isolated", "stigmatized", "socially supported" and "non-stigmatized" patients) were found and cross-tabulated with five resulting groups of a second cluster-analysis concerning the "style" of the seeking behaviour of professional and paraprofessional help and medical measures against the psoriasis ("multi-users", "arranged mini-users", "waiting-room patients", "optimists" and "self-therapists"). We were able to describe typical courses of illness behaviour depending on the initial reaction. The results are discussed with regard to the desirable identification of problematic patients within professional care units. 相似文献