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101.
Mike Spillane Ryan Schoch Matt Cooke Travis Harvey Mike Greenwood Richard Kreider Darryn S Willoughby 《Journal of the International Society of Sports Nutrition》2009,6(1):6-14
Numerous creatine formulations have been developed primarily to maximize creatine absorption. Creatine ethyl ester is alleged
to increase creatine bio-availability. This study examined how a seven-week supplementation regimen combined with resistance
training affected body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine
levels in 30 non-resistance-trained males. In a double-blind manner, participants were randomly assigned to a maltodextrose
placebo (PLA), creatine monohydrate (CRT), or creatine ethyl ester (CEE) group. The supplements were orally ingested at a
dose of 0.30 g/kg fat-free body mass (approximately 20 g/day) for five days followed by ingestion at 0.075 g/kg fat free mass
(approximately 5 g/day) for 42 days. Results showed significantly higher serum creatine concentrations in PLA (p = 0.007)
and CRT (p = 0.005) compared to CEE. Serum creatinine was greater in CEE compared to the PLA (p = 0.001) and CRT (p = 0.001)
and increased at days 6, 27, and 48. Total muscle creatine content was significantly higher in CRT (p = 0.026) and CEE (p
= 0.041) compared to PLA, with no differences between CRT and CEE. Significant changes over time were observed for body composition,
body water, muscle strength and power variables, but no significant differences were observed between groups. In conclusion,
when compared to creatine monohydrate, creatine ethyl ester was not as effective at increasing serum and muscle creatine levels
or in improving body composition, muscle mass, strength, and power. Therefore, the improvements in these variables can most
likely be attributed to the training protocol itself, rather than the supplementation regimen. 相似文献
102.
We present an interpretation of belief functions within a pure probabilistic framework, namely as normalized self-conditional expected probabilities, and study their mathematical properties. Interpretations of belief functions appeal to partial knowledge. The self-conditional interpretation does this within the traditional probabilistic framework by considering surplus belief in an event emerging from a future observation, conditional on the event occurring. Dempster's original interpretation, in contrast, involves partial knowledge of a belief state. The modal interpretation, currently gaining popularity, models the probability of a proposition being believed (or proved, or known). The versatility of the belief function formalism is demonstrated by the fact that it accommodates very different intuitions. 相似文献
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106.
GR Hill JM Crawford KR Cooke YS Brinson L Pan JL Ferrara 《Canadian Metallurgical Quarterly》1997,90(8):3204-3213
The influence of bone marrow transplantation (BMT) conditioning regimens on the incidence and severity of graft-versus-host disease (GVHD) has been suggested in clinical BMT. Using murine BMT models, we show here an increase in GVHD severity in several donor-recipient strain combinations after intensification of the conditioning regimen by increasing the total body irradiation (TBI) dose from 900 cGy to 1,300 cGy. Increased GVHD was mediated by systemic increases in tumor necrosis factor alpha (TNF alpha). Histologic analysis of gastrointestinal tracts showed synergistic damage by increased TBI and allogeneic donor cells that permitted increased translocation of lipopolysacharide (LPS) into the systemic circulation. In vitro, LPS triggered excess TNF alpha from macrophages primed by the GVH reaction. In addition, macrophages isolated within 4 hours of conditioning were primed in proportion to the TBI dose itself to secrete TNF alpha. Thus, the higher TBI dose increased macrophage priming and increased gut damage after allogeneic BMT, causing higher systemic levels of inflammatory cytokines and subsequent severe GVHD. These data highlight the importance of conditioning in GVHD pathophysiology and suggest that interventions to prevent LPS stimulation of primed macrophages may limit the severity of GVHD after intensive conditioning for allogeneic BMT. 相似文献
107.
PS Cooke DL Buchanan P Young T Setiawan J Brody KS Korach J Taylor DB Lubahn GR Cunha 《Canadian Metallurgical Quarterly》1997,94(12):6535-6540
Estradiol-17beta (E2) acts through the estrogen receptor (ER) to regulate uterine growth and functional differentiation. To determine whether E2 elicits epithelial mitogenesis through epithelial ER versus indirectly via ER-positive stromal cells, uteri from adult ER-deficient ER knockout (ko) mice and neonatal ER-positive wild-type (wt) BALB/c mice were used to produce the following tissue recombinants containing ER in epithelium (E) and/or stroma (S), or lacking ER altogether: wt-S + wt-E, wt-S + ko-E, ko-S + ko-E, and ko-S + wt-E. Tissue recombinants were grown for 4 weeks as subrenal capsule grafts in intact female nude mice, then the hosts were treated with either E2 or oil a week after ovariectomy. Epithelial labeling index and ER expression were determined by [3H]thymidine autoradiography and immunohistochemistry, respectively. In tissue recombinants containing wt-S (wt-S + wt-E, wt-S + ko-E), E2 induced a similar large increase in epithelial labeling index compared with oil-treated controls in both types of tissue recombinants despite the absence of epithelial ER in wt-S + ko-E tissue recombinants. This proliferative effect was blocked by an ER antagonist, indicating it was mediated through ER. In contrast, in tissue recombinants prepared with ko-S (ko-S + ko-E and ko-S + wt-E), epithelial labeling index was low and not stimulated by E2 despite epithelial ER expression in ko-S + wt-E grafts. In conclusion, these data demonstrate that epithelial ER is neither necessary nor sufficient for E2-induced uterine epithelial proliferation. Instead, E2 induction of epithelial proliferation appears to be a paracrine event mediated by ER-positive stroma. These data in the uterus and similar studies in the prostate suggest that epithelial mitogenesis in both estrogen and androgen target organs are stromally mediated events. 相似文献
108.
Ribonuclease A variants with potent cytotoxic activity 总被引:1,自引:0,他引:1
Select members of the bovine pancreatic ribonuclease A (RNase A) superfamily are potent cytotoxins. These cytotoxic ribonucleases enter the cytosol, where they degrade cellular RNA and cause cell death. Ribonuclease inhibitor (RI), a cytosolic protein, binds to members of the RNase A superfamily with inhibition constants that span 10 orders of magnitude. Here, we show that the affinity of a ribonuclease for RI plays an integral role in defining the potency of a cytotoxic ribonuclease. RNase A is not cytotoxic and binds RI with high affinity. Onconase, a cytotoxic RNase A homolog, binds RI with low affinity. To disrupt the RI-RNase A interaction, three RNase A residues (Asp-38, Gly-88, and Ala-109) that form multiple contacts with RI were replaced with arginine. Replacing Asp-38 and Ala-109 with an arginine residue has no effect on the RI-RNase interaction. In addition, these variants are not cytotoxic. In contrast, replacing Gly-88 with an arginine residue yields a ribonuclease (G88R RNase A) that retains catalytic activity in the presence of RI and is cytotoxic to a transformed cell line. Replacing Gly-88 with aspartate also yields a ribonuclease (G88D RNase A) with a decreased affinity for RI and cytotoxic activity. The cytotoxic potency of onconase, G88R RNase A, and G88D RNase A correlate with RI evasion. We conclude that ribonucleases that retain catalytic activity in the presence of RI are cytotoxins. This finding portends the development of a class of chemotherapeutic agents based on pancreatic ribonucleases. 相似文献
109.
Dietary conjugated linoleic acid normalizes impaired glucose tolerance in the Zucker diabetic fatty fa/fa rat 总被引:2,自引:0,他引:2
KL Houseknecht JP Vanden Heuvel SY Moya-Camarena CP Portocarrero LW Peck KP Nickel MA Belury 《Canadian Metallurgical Quarterly》1998,244(3):678-682
Conjugated linoleic acid (CLA) is a naturally occurring fatty acid which has anti-carcinogenic and anti-atherogenic properties. CLA activates PPAR alpha in liver, and shares functional similarities to ligands of PPAR gamma, the thiazolidinediones, which are potent insulin sensitizers. We provide the first evidence that CLA is able to normalize impaired glucose tolerance and improve hyperinsulinemia in the pre-diabetic ZDF rat. Additionally, dietary CLA increased steady state levels of aP2 mRNA in adipose tissue of fatty ZDF rats compared to controls, consistent with activation of PPAR gamma. The insulin sensitizing effects of CLA are due, at least in part, to activation of PPAR gamma since increasing levels of CLA induced a dose-dependent transactivation of PPAR gamma in CV-1 cells cotransfected with PPAR gamma and PPRE X 3-luciferase reporter construct. CLA effects on glucose tolerance and glucose homeostasis indicate that dietary CLA may prove to be an important therapy for the prevention and treatment of NIDDM. 相似文献
110.
Plain film imaging remains important for the diagnosis and surveillance of scoliosis, as well as for the detection of complications after surgery. New means of treating scoliosis have become established and should be understood by the radiologist. To the well-known postoperative complications, including pneumothorax, pneumonia, and gastrointestinal obstruction, are added new specific potential problems with the new surgical methodology. 相似文献