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131.
This study investigated whether transient, neonatal (days 2-12) treatment of rats with the potent oestrogen, diethylstilboestrol (DES), altered the structure of the cauda epididymis/vas deferens in adulthood, and if the changes observed related to altered development of basal cells in early puberty. Neonatal treatment with 10 microg DES resulted in the following during adulthood: (a) coiling of the normally straight initial vas deferens, (b) gross epithelial abnormalities, (c) 4-fold widening of the periductal non-muscle layer, (d) infiltration of immune cells across the epithelium into the lumen, and (e) reduction/absence of sperm from the vas deferens lumen. Amongst affected animals>75% exhibited reduced epithelial immunoexpression of androgen receptor and aberrant oestrogen receptor-alpha immunoexpression and 63% exhibited multi-layering of basal cells coincident with increased epithelial cell proliferation. None of the aforementioned changes occurred in rats treated neonatally with 0.1 microg DES.As basal cells play a key role in the development of epithelia such as that in the epididymis and vas deferens, we went on to investigate if neonatal DES treatment affected basal cell development. In controls, basal cells were first evident at day 10 (vas deferens) or day 18 (cauda). Rats treated with 10 microg, but not those treated with 0.1 microg, DES, showed approximately 90% reduction (P<0.001) in basal cell numbers at day 15 and day 18. This decrease coincided with gross suppression of testosterone levels; co-treatment of rats with 10 microg DES+testosterone maintained basal cell numbers at control levels at day 18. However, suppression of testosterone production (GnRH antagonist treatment) or action (flutamide treatment) did not alter basal cell numbers. It is concluded that neonatal exposure to high oestrogen levels coincident with reduced testosterone action results in abnormal changes in the adult cauda/vas deferens that are preceded by delayed differentiation of basal cells. These findings imply a role for androgens and oestrogens in basal cell development and suggest that this may be pivotal in determining normal epithelial (and stromal) development of the cauda/vas deferens.  相似文献   
132.
24 5-6 yr-olds and 24 8-9 yr-olds were given the opportunity to donate money to a charity under conditions varying the characteristics of the recipient (crippled child vs crippled adult) and the situation in which the child acquired the resource for generosity (earned vs windfall). On the basis of previous literature, it was expected that these conditions would affect the age differences often reported in generosity. Contrary to such expectations, there was more generosity toward crippled children than crippled adults across both age groups. There was an increase in generosity with age across conditions, with girls consistently donating more than boys. Methodological issues and reactions to stigmatized others are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
133.
BACKGROUND: Intraradicular or intradural disc herniation is a very rare complication of spinal degenerative processes. The aim of our study is to analyze the clinical spectrum, the mechanism, and the treatment of this acute spinal pathology. METHODS: Retrospective clinical examination was performed in nine personal cases of intradural disc herniation: among these, six were associated with lateral perforation, the remaining three with intradural herniation and ventral perforation. A review of the literature concerning mainly the frequency pathogenesis and diagnosis of intradural disc herniation has also been done. RESULTS: Nine cases of intradural herniations comprise 1.51% of the 593 cases of ruptured lumbar disc that underwent surgery from 1980 to 1992. The site most frequently involved is at level L4-L5, and 30% of patients have previously undergone surgery for lumbar disc herniation. Most patients reported in literature and in our present series have been complaining of a chronic history of sciatica, complicated later by bilateral neurologic signs. In the present series, diagnosis was obtained by means of myelography and computerized tomography; magnetic resonance imaging was performed in one case. All patients underwent surgery, reporting excellent results in five cases and good results in the other four. Surgery was performed either with an interlaminar approach or with a bilateral laminectomy in cases of ventral perforation. CONCLUSIONS: There is no typical neuroradiologic picture of intraradicular herniation, while a total or subtotal block is frequently observed in intradural ventral perforations. Dural perforation is often an unexpected intraoperative finding. Surgical treatment is always necessary. Favorable results are obtained if surgical treatment is carried out before the neurologic deficit becomes too pronounced.  相似文献   
134.
This paper reports an application of the Kolmogorov-Smirnov test for the purpose of detecting changes in the distribution of a sequence of measurements. The ‘probability chart’ of the title gave a value reflecting whether the distribution was constant in the neighbourhood of each observation. The chart had the advantage that the threshold for detection of a change was a dimensionless probability value. The non-parametric nature of the test made it suitable for measurements sampled from a non-Gaussian distribution.  相似文献   
135.
The evolution of floral scent as a plant reproductive signal is assumed to be driven by pollinator behavior, with little attention paid to other potential selective forces such as herbivores. I tested 10 out of the 13 compounds emitted by dioecious Cirsium arvense, Canada thistle, including 2-phenylethanol, methyl salicylate, p-anisaldehyde, benzaldehyde, benzyl alcohol, phenylacetaldehyde, linalool, furanoid linalool oxides (E and Z), and dimethyl salicylate. Single compounds (and one isomer) set out in scent-baited water-bowl traps trapped over 10 species of pollinators and 16 species of floral herbivores. The two dominant components of the fragrance blend of C. arvense, benzaldehyde and phenylacetaldehyde, trapped both pollinators and florivores. Other compounds attracted either pollinators or florivores. Florivores of C. arvense appear to use floral scent compounds as kairomones; by advertising to pollinators, C. arvense also attracts its own enemies.  相似文献   
136.
The present study analyzed the antioxidative effects of various beverages, in vitro, and also the effect of short term consumption of beverages richest in polyphenols by healthy subjects on serum anti-atherogenic properties. Healthy subjects consumed 250 mL of the selected beverages for 2 h, or daily, for up to 1 week.We hypothesized that differences in the anti-atherogenic properties of the studied beverages could be related, not only to the quantity of polyphenols, but also to their quality. Furthermore, we hypothesized that consumption of these juices by healthy subjects for just a short-term, will increase their serum anti-atherogenic properties, as was demonstrated previously in long-term consumption studies.Of 35 beverages studied, both 100% Wonderful-variety pomegranate and 100% black currant juices were the most potent antioxidants in vitro, as they inhibited copper ion-induced LDL oxidation by up to 94% and AAPH-induced serum lipid peroxidation by up to 38%. Furthermore, they increased in vitro serum paraoxonase 1 (PON1) lactonase activity by up to 51%. Consumption of five selected polyphenol rich beverages by healthy subjects increased serum sulfhydryl group (SH) levels and serum PON1 activities after 2 h, and more so after 1 week of drinking these beverages. These effects were most pronounced after the consumption of 100% Wonderful-variety pomegranate and 100% black currant juices. In conclusion, polyphenolic-rich juices with impressive in vitro antioxidant properties, also demonstrate antioxidant effects in vivo when analyzed for short term consumption. In this respect, 100% Wonderful-variety pomegranate and 100% black currant juices were most the potent.  相似文献   
137.
Come together right now with L ‐DOPA : Chemical cross‐linking is widely used to study protein–protein interactions. However, many cross‐linking agents suffer from low reactivity or selectivity. An efficient and selective reaction of site‐specific protein cross‐linking was achieved using genetically incorporated 3,4‐dihydroxy‐L ‐phenylalanine.

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138.
139.
The experimental data concerning kinetics of a continuous mass crystallization in L-sorbose - water system are presented and discussed. Influences of L-sorbose concentration in a feeding solution and mean residence time of suspension in a working volume of laboratory DT MSMPR crystallizer on the resulting crystal size distributions, thus on the nucleation and growth kinetics, were determined. The kinetic parameter values were evaluated on the basis of size-independent growth (SIG) kinetic model (McCabe’s ΔL law). It was observed that within the investigated range of crystallizer productivity (220–2,200 kg of L-sorbose crystals m−3 h−1), a crystal product of mean size Lm from 0.22 to 0.28 mm and CV from 68.8 to 44.0% was withdrawn. The values of linear growth rate show increasing trend (from 6.6·10−8 to 7.6·10−8 m s−1) with the productivity enlargement (assuming constant residence time τ=900 s). Occurrence of secondary nucleation phenomena within the circulated suspension, resulting from the crystals attrition and breakage was observed. The parameter values in a design equation, matching linear growth rate and suspension density with nucleation rate were determined.  相似文献   
140.
鸟粪石结晶法处理猪场污水的研究现状及发展趋势   总被引:8,自引:1,他引:7  
采用乌粪石结晶法处理猪场污水,可实现猪场污水氮磷的去除及资源的回收,有利于畜牧业及磷资源的可持续发展.本文介绍了鸟粪石结晶法用于猪场污水的基本原理和影响因素,总结了目前研究的不足之处,展望了该法处理猪场污水的研究方向和发展前景.  相似文献   
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