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71.
Four experiments were conducted to identify several factors that might improve the accuracy and reproducibility of Zn bioavailability assays for chicks. Response of tissue Zn and metallothionein (MT) concentrations to various elevated levels and soluble sources of dietary Zn were measured, as well as the effect of delaying high Zn administration until 7 d posthatching to alleviate the detrimental effect of Zn sulfate on feed intake to 3 wk of age. Bone Zn increased (P < 0.01) in all experiments in response to increasing dietary Zn concentrations. Liver and pancreas MT were affected (P < 0.01) by a source by age interaction and variability that made this criterion unsuitable for bioavailability assays. Lastly, 1-d-old chicks were used to study the effect of delaying feeding of a high-Zn diet up to 7 d of age. The basal diet was fed continuously for 21 d as a control. A diet containing 1,000 ppm Zn was either fed continuously from Day 1, or started on Day 3, 5, or 7. Chicks given high Zn on Day 3, 5, or 7 decreased (P < 0.01) feed intake within 24 h of feeding. Delayed feeding of high dietary Zn might help to alleviate decreased feed intake observed in previous studies. Delaying the onset of high Zn feeding by several days may help alleviate feed intake problems observed with Zn sulfate. Use of either Zn gluconate or Zn acetate as a standard in assays or use of MT synthesis as a bioavailability criterion will probably not be useful to improve accuracy of the estimates.  相似文献   
72.
It has been suggested that adenosine cardioprotection occurs via adenosine A1 receptor-mediated activation of protein kinase C (PKC). However, adenosine has well-known vasodilatory effects in the myocardium, whereas PKC is a vasoconstrictor. This study examined whether adenosine A1 receptor activation alters the effects of the PKC activator. 1,2-dioctanoyl-s,n-glycerol (DOG) in isolated perfused rat hearts (left-ventricular developed pressure) and rat ventricular myocytes ([Ca2+]i and cell shortening). Exposure to DOG decreased left-ventricular developed pressure by 30%, an effect that was completely reversible. Pretreatment of isolated hearts with either the PKC inhibitor chelerythrine or the adenosine A1 agonist 2-chloro-N6-cyclo-cyclo-isolated pentlyadenosine (CCPA) attenuated the negative inotropic effects of DOG. In the isolated myocytes, DOG decreased [Ca2+]i and cell shortening by 25 and 28%, respectively, effects that were attenuated by both chelerythrine and CCPA. The CCPA attenuation of the DOG-induced decrease in [Ca2+]i and cell shortening was blocked by pretreating the myocytes with the adenosine A1 antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX). These results indicate that in rat ventricular myocardium, adenosine A1 receptor activation attenuates the apparent PKC-dependent negative inotropic effects of DOG via preservation of [Ca2+]i levels.  相似文献   
73.
Alcohol withdrawal often causes severe complications. However, many addicts deny any abuse. Thus, the diagnosis of alcohol abuse frequently becomes difficult. Laboratory parameters are often used to support the diagnosis of alcohol abuse. Furthermore, laboratory parameters should facilitate the prediction of the severity of alcohol withdrawal syndrome (AWS). The most promising laboratory parameter indicating a recent elevated alcohol consumption is carbohydrate-deficient transferrin (CDT). The aim of this study was to examine whether the measurement of CDT at admission can indicate a higher risk for the development of a complicated AWS. The severity of AWS was assessed by the AWS scale, consisting of two subscales for somatic and mental symptoms. CDT was measured by different methods (radioimmunoassay and HPLC). The radioimmunoassay for CDT (CDTect) yielded the best prediction. Our results showed a weak correlation between CDTect and the severity of AWS. However, there were great gender differences. In men, CDTect had the highest positive predictive value for a severe AWS (86.7%), whereas in women mean corpuscular volume was the best predictor (77.8%). However, the sensitivity of CDTect in men (25.5%), as well as mean corpuscular volume in females (29.2%), was too low for a screening test in a general hospital.  相似文献   
74.
Asymmetric acetylcholinesterase (AChE) is anchored to the basal lamina (BL) of cholinergic synapses via its collagenic tail, yet the complement of matrix receptors involved in its attachment remains unknown. The development of a novel overlay technique has allowed us to identify two Torpedo BL components that bind asymmetric AChE: a polypeptide of approximately 140 kDa and a doublet of 195-215 kDa. These were found to stain metachromatically with Coomassie blue R-250, were solubilized by acetic acid, and were sensitive to collagenase treatment. Upon sequence analysis, the 140 kDa polypeptide yielded a characteristic collagenous motif. Another AChE-binding BL constituent, identified by overlay, corresponded to a heparan sulfate proteoglycan. Lastly, we established that this proteoglycan, but not the collagenous proteins, interacted with at least one heparin binding domain of the collagenic tail of AChE. Our results indicate that at least two BL receptors are likely to exist for asymmetric AChE in Torpedo electric organ.  相似文献   
75.
PURPOSE: We investigated the ability of In-111-capromab pendetide to separate patients who have failed radical prostatectomy into categories of those who would versus those who would not respond to salvage radiotherapy. METHODS: Prostate-specific antigen (PSA) levels in 32 men with prostate cancer who had failed radical prostatectomy and had undergone a whole-body In-111-capromab pendetide scan were followed-up for 13 months (median) after salvage radiotherapy to the pelvis. A logistic regression model was used to determine whether the scan findings, as well as other clinical variables, were associated with a durable complete response (DCR), a nondurable response (NDR), or no response (NR). RESULTS: Sixteen of 23 (70%) men with a normal scan outside the prostatic fossa achieved a DCR after salvage radiotherapy versus two of nine (22%) who had a positive scan outside the prostate fossa and pelvis (P = .0225, Fisher's exact test). Predicted probability (95% confidence interval [CI]) that a DCR would be obtained with a normal scan was 0.88 (0.55 to 0.98); for men with a positive scan limited to the prostatic fossa it was 0.62 (0.42 to 0.79); and for men with a positive scan outside the pelvis it was 0.27 (0.09 to 0.58). No other variables before radiotherapy showed a significant association with the DCR rate. CONCLUSION: Salvage radiotherapy is statistically more likely to lead to a durable complete PSA response in men with prostate cancer who have failed radical prostatectomy and have a negative In-111-capromab pendetide scan outside the pelvis as compared with those who have a positive scan.  相似文献   
76.
The EMS1 and CCND1 genes at chromosome 11q13 are amplified in about 15% of primary breast cancers but appear to confer different phenotypes in ER positive and ER negative tumours. Since there are no published data on EMS1 expression in large series of breast cancers we examined the relationship of EMS1 expression with EMS1 gene copy number and expression of mRNAs for cyclin D1 and ER. In a subset of 129 patients, where matched tumour RNA and DNA was available, EMS1 mRNA overexpression was associated predominantly with gene amplification (P = 0.0061), whereas cyclin D1 mRNA overexpression was not (P = 0.3142). In a more extensive series of 351 breast cancers, there was no correlation between cyclin D1 and EMS1 expression in the EMS1 and cyclin D1 overexpressors (P = 0.3503). Although an association between EMS1 mRNA expression and ER positivity was evident (P = 0.0232), when the samples were divided into quartiles of EMS1 or cyclin D1 mRNA expression, the increase in the proportion of ER positive tumours in the ascending EMS1 mRNA quartiles was not statistically significant (P = 0.0951). In marked contrast there was a significant stepwise increase in ER positivity in ascending quartiles of cyclin D1 mRNA (P = 0.030). A potential explanation for this difference was provided by the observation that in ER positive breast cancer cells oestradiol treatment resulted in increased cyclin D1 gene expression but was without effect on EMS1. The relationship between EMS1 expression and clinical outcome was examined in a subset of 234 patients with median follow-up of 74 months. High EMS1 expression was associated with age > 50 years (P = 0.0001), postmenopausal status (P = 0.0008), lymph node negativity (P = 0.019) and an apparent trend for worse prognosis in the ER negative subgroup. These data demonstrate that overexpression of EMS1 mRNA is largely due to EMS1 gene amplification, is independent of cyclin D1 and ER expression and, in contrast to cyclin D1, is not regulated by oestrogen. Independent overexpression of these genes may confer different phenotypes and disease outcomes in breast cancer as has been inferred from recent studies of EMS1 and CCND1 gene amplification.  相似文献   
77.
Longitudinal division of the corpus callosum was performed in six normal beagles to determine surgical morbidity. The corpus callosum was divided sagittally on the midline and the effect on neurological function was determined. Five of six dogs were clinically normal within 14 days or less after surgery. One dog had persistent but improving clinical signs consistent with a forebrain disturbance at 30 days after surgery. Overall, minimal morbidity and no mortality was associated with this surgical procedure. Further study is indicated to determine the efficacy of this surgical treatment for seizure control in dogs with idiopathic epilepsy.  相似文献   
78.
STUDY DESIGN: A case report of a patient in whom atlantoaxial instability developed secondary to repeat radiation therapy for recurrent nasopharyngeal carcinoma. OBJECTIVES: To illustrate a dramatic and previously unreported complication of local radiation to the posterior nasopharynx. SUMMARY OF BACKGROUND DATA: Nasopharyngeal carcinoma is an unusual tumor that usually is managed with local, external-beam radiation. It is not thought to involve the cervical spine directly, although local invasion of the skull base is common. METHODS: A review of the medical records and radiographs of the only patient known to develop this complication of radiation used to manage nasopharyngeal carcinoma. RESULTS: Atlantoaxial instability developed in a patient as a result of repeat radiation for a locally recurrent tumor. The instability was associated with intrusion of the anterior arch of C1 into the posterior nasopharynx and was managed successfully with a posterior stabilization using transarticular screws and supplemental wiring. CONCLUSIONS: Patients who have undergone local irradiation for nasopharyngeal carcinoma may be at risk for developing atlantoaxial instability.  相似文献   
79.
In a duplicate study during 1987-1991, 478 24-h duplicate samples from 14 homes for elderly people and 10 homes for youth were investigated for their contents of selected harmful substances. The analyses covered 45 active substances of pesticides, 17 PCB-congeners as well as lead, cadmium, and nitrate contents. Pesticides could be detected only in 15% of the investigated samples. The pesticide contents reached max. 8% of the respective FAO/WHO-limits. As the mean intake of the three most important PCB-congeners (sum of the congeners 138, 153, and 180) values of 0.9 and 1.1 micrograms per day and ration or person, respectively, were found. Also in the worst case the daily PCB intake was below the recommended ADI value of the FDA of 1 microgram/kg of body weight. The daily nutritional intake of lead and cadmium via the investigated daily rations reached about 5.6% and 20% of the Provisionally Tolerably Weekly Intake values of the FAO/WHO. The mean nitrate content of the duplicate portions was 101 mg per day and person (median: 79 mg per day and person). Referred to the median value the WHO limit (3.65 mg/kg body weight and day) was exhausted to about 36%.  相似文献   
80.
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