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The pre- and postnatal findings of a fetus with a de novo del(13)(pter-->q21:) and an occipital encephalocoele are described. Maternal serum alpha-fetoprotein (AFP) screening at 19 weeks' gestation demonstrated a high level of 2.5 multiples of the median (MOM) and ultrasonography at 27 weeks' gestation showed severe intrauterine growth retardation, cardiomegaly, an occipital encephalocoele, and a calvarial defect. Genetic amniocentesis revealed a karyotype of 46,XX,del(13)(pter-->q21:). The proband postnatally displayed additional abnormalities such as microphthalmia, hypertelorism, large low-set ears, and micrognathia. We discuss the association of central nervous system (CNS) malformations with 13q deletions and emphasize that pregnancies with neural tube defects warrant cytogenetic analysis, especially when additional fetal abnormalities and neonatal dysmorphism are observed. 相似文献
13.
1. Animal studies have shown that angiotensin II has a biphasic effect on urinary sodium excretion. To examine whether this is also true in man, we studied seven salt-replete male subjects in a single-blind placebo-controlled manner. 2. While undergoing maximum diuresis, subjects were infused with 0, 1, 2, 5 or 10 ng of angiotensin II min-1 kg-1 over 80 min. Subjects were studied while seated, and stood every 20 min for urine collection. 3. Angiotensin II produced a dose-dependent antidiuretic effect. The urine flow rate, in ml/min expressed as the change from baseline with increasing dose of angiotensin, was: +3.4 +/- 1.77, -1.26 +/- 0.49 (P < 0.05), -2.75 +/- 1.23 (P < 0.05), -4.21 +/- 0.82 (P < 0.05) and -6.51 +/- 1.07 (P < 0.01). 4. In contrast, the effect of angiotensin II on sodium excretion showed a flat dose-response curve beyond 5 ng min-1 kg-1. The urinary sodium excretion, in mumol/min expressed as the change from baseline with increasing dose of angiotensin, was: 9.5 +/- 21.2, -18.9 +/- 29.6, -37.0 +/- 11.6 (P < 0.05), -67.7 +/- 19.6 (P < 0.01) and -63.8 +/- 14.3 (P < 0.01). 5. The fractional distal reabsorption of sodium, determined by using the lithium clearance technique, showed a rise with all doses of angiotensin II used and reached statistical significance with the top two doses. 6. Unlike antidiuresis, antinatriuresis after graded doses of angiotensin II in human subjects showed a flat dose-response curve beyond 5 ng min-1 kg-1. Pressor doses of angiotensin II also have a significant effect on the distal tubule in promoting sodium reabsorption. 相似文献
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Gram-negative shock is thought to result primarily from the effects of endotoxin, a component of the bacterial outer membrane. Accordingly, therapies aimed at inhibiting, neutralizing, or clearing endotoxin have been extensively explored. Despite over 30 years of research, no antiendotoxin approach to the treatment of human septic shock is of proven benefit. In recent randomized clinical trials of monoclonal antibodies against endotoxin, therapeutic efficacy was not convincingly demonstrated. This result, however, does not eliminate the possibility that other antiendotoxin therapies may be effective. The antibodies used in these clinical trials do not appear to neutralize endotoxin in vitro and are not reproducibly protective in animal models of sepsis. Newer agents with well-defined mechanisms of antiendotoxin activity may help clarify the role of endotoxin in septic shock and prove useful therapy for some patients. 相似文献
16.
Cancer statistics, 1993 总被引:1,自引:0,他引:1
17.
Kwok Kee Chan Rao S.K. Morin G.A. Tang M.Q. 《Antennas and Propagation, IEEE Transactions on》1997,45(8):1277-1285
A new method of analysis for the radiation characteristics of dielectric lens antennas with arbitrary inner and outer surfaces is presented. The analysis is based on representing the feed illumination by a contiguous set of ray tubes and including the effects of surface reflections and ray divergence. Radiation patterns and the antenna gain are then computed by evaluating the closed-form expressions developed for the Kirchhoff's integral of the aperture fields. The validity of the analysis method has been demonstrated by comparing the computations with measured results of two different spherical lenses and a shaped lens configurations. The analysis method presented takes into account some of the practical aspects associated with lens design such as surface zoning to reduce the mass and surface matching to minimize the reflection loss 相似文献
18.
MF Berthault J Morin M Dubar A Ktorza P Ferré L Pénicaud 《Canadian Metallurgical Quarterly》1996,89(8):1103-1106
This study was aimed to determine the effects of rilmenidine, an hypertensive drug, in an animal model of hypertension associated with insulin resistance, i.e. rats fed on a high fructose diet. Wistar rats were fed during four weeks either on a standard diet (S) or on a high fructose diet (F, 34.5% de fructose). In half of the F groups, rilmenidine (1 mg/kg/day) was added to the drinking water during the two last weeks of the diet (FR). Arterial blood pressure as well as insulin efficiency were determined at the end of the four weeks. Body weight gain was higher in F than in S rats (66 +/- 8 g versus 45 +/- 8 g; p < 0.05), this was prevented by rilmenidine treatment (32 +/- 2 g). Arterial systolic blood pressure was increased in F rats (162 +/- 2 vs 155 +/- 2 mmHg; p < 0.05), rilmenidine brought this value back to normal (149 +/- 3 mmHg). During the euglycemic hyperinsulinemic clamp, glucose utilization was lower (10 +/- 1 vs 14 +/- 1.5 mg/min/kg; p < 0.05) and hepatic glucose production higher (1 +/- 0.01 vs 0 mg/min/kg; p < 0.01) in F than in S rats. These changes in insulin action were totally abolished by rilmenidine. These data demonstrate that rilmenidine can ameliorate the deleterious effects of a high fructose diet, i.e. weight gain, hypertension and resistance to the effects of insulin Rilmenidine could represent a potential therapeutic agent for the treatment of hypertension associated with metabolic disorders such as syndrom X and obesity. 相似文献
19.
JD Haag LA Shepel BD Kolman DM Monson ME Benton KT Watts JL Waller CC Lopez-Guajardo DJ Samuelson MN Gould 《Canadian Metallurgical Quarterly》2003,63(18):5808-5812
It has previously been shown that the Copenhagen (COP) rat contains several genetic loci that contribute to its mammary tumor-resistant phenotype after 7,12-dimethylbenz(a)anthracene (DMBA) administration. One of these loci, mammary carcinoma susceptibility 1 (Mcs1), is located on the centromeric end of chromosome 2 and appears to act in a semidominant fashion. To confirm the existence and independent action of this locus and also aid in the identification of the physical location of the Mcs1 gene, congenic lines were generated by transferring the Mcs1 COP allele onto a Wistar Furth (WF) genetic background. Male carriers were genotyped using microsatellite markers spanning 20-30 cM of the Mcs1 locus. One of the congenic lines minimally retained the COP allele at D2Mit29 on the centromeric end of chromosome 2 and extended distally to D2Rat201. Heterozygous Mcs1 carrier rats were interbred, and the female offspring were treated with DMBA. The female rats from the Mcs1 congenic line that carried one or two COP alleles of the Mcs1 region had a significantly reduced (65 and 85%, respectively) tumor development (P < 0.001) compared with rats carrying zero COP alleles at this locus. A WF.COP-D2Mit29/D2Rat201 homozygous congenic strain derived at the N10 generation was treated with DMBA, and the COP homozygous rats developed 1.5 +/- 0.3 carcinomas/rat versus 6.3 +/- 0.5 in WF control rats (P < 0.0001). Fine mapping of this congenic interval using several recombinant lines identified three genetic loci within the Mcs1 congenic region that independently supported a tumor resistance phenotype. These genetic loci have been termed Mcs1a, Mcs1b, and Mcs1c. In rats for which each locus was homozygous for the COP allele, tumor development was reduced by approximately 60% compared with littermate controls. The identification of these independent loci within the Mcs1 COP allele provide a model of the genetic complexity of cancer. 相似文献
20.