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81.
Szenario 2005 . Um sich auf dem Bildungsmarkt behaupten zu k?nnen, müssen Universit?ten und Fachhochschulen ihre St?rken herausstellen und
sich auf die neue Konkurrenz vorbereiten, fordert die Schrift, die von dem Expertenkreis „Hochschulentwicklung durch neue
Medien“ der Bertelsmann Stiftung und der Heinz Nixdorf Stiftung erarbeitet wurde. 相似文献
82.
JM Forbes B Leaker TD Hewitson GJ Becker CL Jones 《Canadian Metallurgical Quarterly》1999,55(1):198-208
BACKGROUND: Endothelin (ET) may be a mediator of injury following ischemia-induced acute renal failure (ARF). ET receptor (ETR) antagonists have been reported to increase survival rates and lower serum creatinines when administered postrenal ischemia-reperfusion injury in the rat. Renal cellular and extracellular matrix responses to this therapy have not been addressed. METHODS: We investigated the use of ETR antagonists, PD 156707 (ETA) and SB 209670 (ETA and ETB) in the treatment of sublethal postischemic ARF. The right kidney of female Sprague-Dawley rats weighing approximately 200 g was removed. After five days, the left renal pedicle was occluded for 45 minutes. Twenty-four hours after renal ischemia, one of two ETR antagonists, PD 156707 (N = 7) or SB 209670 (N = 8), was administered. Experimental animals were compared with an ischemic group receiving only saline (N = 9). Three nephrectomized groups that did not undergo ischemia but that received infusions of saline (N = 6), PD 156707 (N = 6), and SB 209670 (N = 6), respectively, were also studied. Animals were sacrificed one week postischemia. Quantitation of monocytes and macrophages (Mo/Mphi), alpha-smooth muscle actin-positive myofibroblasts, and collagens type III and IV was performed by immunohistochemical staining. Cell kinetics were examined by staining for apoptosis with terminal deoxyuridine triphosphate (dUTP) nick end labeling and for proliferation with proliferating cell nuclear antigen. RESULTS: All ischemic groups of rats initially developed raised serum creatinine levels; however, no significant difference was observed between the groups (Kruskal-Wallis). Creatinines returned to preischemic values in all groups by the time of sacrifice. No significant difference in kidney weights or body weights was found between groups. Histologically, infiltration of Mo/Mphi was significantly reduced in groups treated with ETR antagonists (P < 0.001). The presence of myofibroblasts was also significantly reduced in the antagonist-treated groups (P < 0. 001). This was also paralleled by reduced quantities of collagen IV in the treated rat groups (P < 0.001). The interstitial area was also significantly greater in the saline group (P < 0.001). The amount of collagen III did not significantly differ between rat groups. Apoptosis was reduced (P < 0.001) by treatment with ETR antagonists, whereas proliferation was enhanced (P < 0.005). All non-ischemic groups showed no variation in any parameter studied at this time point. CONCLUSIONS: Treatment of ischemic ARF in the rat with ETR antagonists PD 156707 and SB 209670 attenuated cellular infiltration and matrix accumulation. An advantage of one antagonist over the other could not be determined in this study. The marked discrepancy between function and pathology (former unchanged, latter markedly improved) may be due to the time frame of this experiment, and longer outcome measures need to be assessed. 相似文献
83.
In vitro experiments that characterize DNA-protein interactions by artificial selection, such as SELEX,are often performed with the assumption that the experimental conditions are equivalent to natural ones. To test whether SELEX gives natural results, we compared sequence logos composed from naturally occurring leucine-responsive regulatory protein (Lrp) binding sites with those composed from SELEX-generated binding sites. The sequence logos were significantly different, indicating that the binding conditions are disparate. A likely explanation is that the SELEX experiment selected for a dimeric or trimeric Lrp complex bound to DNA. In contrast, natural sites appear to be bound by a monomer. This discrepancy suggests that in vitro selections do not necessarily give binding site sets comparable with the natural binding sites. 相似文献
84.
EA Sia RJ Kokoska M Dominska P Greenwell TD Petes 《Canadian Metallurgical Quarterly》1997,17(5):2851-2858
We examined the stability of microsatellites of different repeat unit lengths in Saccharomyces cerevisiae strains deficient in DNA mismatch repair. The msh2 and msh3 mutations destabilized microsatellites with repeat units of 1, 2, 4, 5, and 8 bp; a poly(G) tract of 18 bp was destabilized several thousand-fold by the msh2 mutation and about 100-fold by msh3. The msh6 mutations destabilized microsatellites with repeat units of 1 and 2 bp but had no effect on microsatellites with larger repeats. These results argue that coding sequences containing repetitive DNA tracts will be preferred target sites for mutations in human tumors with mismatch repair defects. We find that the DNA mismatch repair genes destabilize microsatellites with repeat units from 1 to 13 bp but have no effect on the stability of minisatellites with repeat units of 16 or 20 bp. Our data also suggest that displaced loops on the nascent strand, resulting from DNA polymerase slippage, are repaired differently than loops on the template strand. 相似文献
85.
GA MacGowan HL Haber TD Cowart C Tedesco C Wu MD Feldman 《Canadian Metallurgical Quarterly》1998,31(6):1344-1351
OBJECTIVES: We sought to determine the precise myocardial effects of OPC-18790 as demonstrated by intracoronary administration. BACKGROUND: Although previous studies have determined the cardiovascular effects of a novel intravenous inotrope, OPC-18790, the observed benefits on contractile and diastolic function may have been confounded by the marked changes in peripheral loading associated with this drug when given intravenously. METHODS: Eight heart failure patients received intracoronary OPC-18790 at 31.25 microg/min for 20 min, and then at 62.5 microg/min for another 20 min. Hemodynamic variables and pressure-volume indexes using the conductance catheter method were determined at baseline and then after the two doses. RESULTS: There were no significant effects on heart rate, cardiac output or loading conditions, including afterload as determined by systemic vascular resistance and arterial elastance (Ea) and preload as determined by end-diastolic volume (EDV). There were significant increases in end-systolic elastance (Ees) from 0.74+/-0.11 to 0.90+/-0.16 mm Hg/ml at 31.25 microg/min and to 137+/-0.33 mm Hg/ml at 62.5 microg/min (p < 0.05 by analysis of variance [ANOVA]). Diastolic function improved, as determined by the time constant for isovolumetric relaxation tau, which decreased significantly from baseline to 31.25 microg/min (94+/-9 to 79+/-9 ms, p < 0.05), and did not shorten further at 62.5 microg/min (78+/-8 ms, p=NS). There were significant decreases in right atrial pressure (9+/-1 to 7+/-1 mm Hg, p < 0.01 by ANOVA) and mean pulmonary artery wedge pressure (21+/-3 to 16+/-2 mm Hg, p < 0.05 by ANOVA). This fall in filling pressures was not accompanied by any change in EDV. Inspection of the diastolic portion of the pressure-volume curve confirmed a downward shift consistent with pericardial release in five of the eight patients. CONCLUSIONS: Intracoronary administration of OPC-18790 demonstrates that the direct myocardial effects of this agent include a modest increase in inotropy and improvement in diastolic function, both of which occur without increases in heart rate, indicating that this agent may be beneficial for the intravenous treatment of congestive heart failure. 相似文献
86.
HW Losken MP Mooney J Zoldos A Tschakaloff AM Burrows TD Smith GM Cooper MR Kapucu MI Siegel 《Canadian Metallurgical Quarterly》1998,102(4):1109-19; discussion 1120-1
Recent studies have identified a subpopulation of craniosynostotic individuals who exhibit progressive or delayed-onset synostosis and mild craniofacial growth abnormalities. These individuals may be good candidates for nonextirpation, distraction osteogenesis therapy. The present study was designed to test this hypothesis by using internal calvarial bone distraction in a rabbit model with familial delayed-onset craniosynostosis. Data were collected from 159 rabbits: 71 normal controls, 72 with delayed-onset coronal suture synostosis, 8 with delayed-onset coronal suture synostosis and coronal suturectomy, and 8 with delayed-onset coronal suture synostosis and distraction. At 10 days of age, all rabbits had amalgam markers placed on both sides of the frontonasal, coronal, and anterior lambdoidal sutures. At 25 days of age, correction was accomplished through either a 5-mm-wide suturectomy or distraction osteogenesis. An internal distraction appliance was fixed to the frontal and parietal bones and percutaneously and intermittently activated at an average of 0.10 mm/day for 42 days (4.11 mm total). Serial radiographs were taken at 10, 25, 42, and 84 days of age. Results revealed that rabbits with delayed-onset synostosis had significantly (p < 0.01) reduced coronal suture growth rates (0.04 mm/day) compared with the other three groups (0.07 mm/day). Rabbits with suturectomy and rabbits with distraction showed similar coronal suture responses. However, from 42 to 84 days of age, rabbits with distraction showed reduced growth at the vault sutures and abnormal growth patterns in cranial vault width, cranial vault shape, and cranial base angulation compared with the other three groups. Results demonstrated that, although the normal coronal suture growth rate was maintained in rabbits with delayed-onset synostosis using intermittent distraction osteogenesis, normal adult craniofacial structure was not achieved. Such anomalous growth was probably a result of altered growth vectors and compressive forces at adjacent sutures during distraction. These findings suggest that distraction osteogenesis without corticotomy may be a treatment alternative in individuals with progressive, delayed-onset synostosis, but that internal appliances that generate low-level, continuous distractive forces should be investigated and developed. 相似文献
87.
TD Bradshaw S Wrigley DF Shi RJ Schultz KD Paull MF Stevens 《Canadian Metallurgical Quarterly》1998,77(5):745-752
OBJECTIVE: To evaluate the results of cervical cytology screening in the National Breast and Cervical Cancer Early Detection Program and to compare the findings with results from other screening programs. METHODS: We analyzed data on 312,858 women aged 18 years and older who received one or more Papanicolaou smears, and follow-up if indicated, from October 1991 through June 1995 at screening sites across the United States providing comprehensive National Breast and Cervical Cancer Early Detection Program services. RESULTS: Of the women screened, more than half were 40 years or older; slightly less than half (44%) were of racial and ethnic minorities. During the first screening cycle, 3.8% of Papanicolaou tests were reported as abnormal (squamous intraepithelial lesion [SIL] or squamous cell cancer); proportions of abnormals decreased with increasing age. The age-adjusted rate of biopsy-confirmed cervical intraepithelial neoplasia (CIN) II or worse among women screened was 7.4 per 1000 Papanicolaou tests; rates of CIN were highest among young women, but cancer rates peaked among women in their 50s and 60s. The percentages of first screening cycle-Papanicolaou tests interpreted as high-grade SIL and squamous cell carcinoma associated with biopsy-confirmed CIN II or worse (the positive predictive value) were 56.0% for CIN II/III and 3.7% for invasive cancer. Of the 150 invasive cancers diagnosed, 54.0% were classified as local disease. CONCLUSION: Observed results emphasize the duality of cervical neoplasia-CIN in younger women and invasive cancer in older women. This finding points to the importance of reaching both younger and older women for cervical cancer screening. 相似文献
88.
This article describes guidelines for developing an effective collaborative/consultative approach to the treatment of stuttering in an elementary school setting. Four primary areas of shared clinician/teacher responsibility are discussed, which include: education, observation, facilitation of fluent speech, and generalization of speech fluency. Although the speech-language pathologist should initiate the teacher's involvement in a child's therapy, both the clinician and teacher should work toward developing a mutually influential partnership, through which the specific needs of individual children who stutter can be addressed in a comprehensive manner. 相似文献
89.
TD Schneider 《Canadian Metallurgical Quarterly》1997,189(4):427-441
Related genetic sequences having a common function can be described by Shannon's information measure and depicted graphically by a sequence logo. Though useful for many purposes, sequence logos only show the average sequence conservation, and inferring the conservation for individual sequences is difficult. This limitation is overcome by the individual information ( R i) technique described here. The method begins by generating a weight matrix from the frequencies of each nucleotide or amino acid at each position of the aligned sequences. This matrix is then applied to the sequences themselves to determine the sequence conservation of each individual sequence. The matrix is unique because the average of these assignments is the total sequence conservation, ad there is only one way to construct such a matrix. For binding sites on polynucleotides, the weight matrix has a natural cut off that distinguishes functional sequences from other sequences. R i values are on an absolute scale measured in bits of information so the conservation of different biological functions can be compared with one another. The matrix can be used to rank-order the sequences, to search for new sequences, to compare sequences to other quantitative data such as binding energy or distance between binding sites, to distinguish mutations from polymorphisms, to design sequences of a given strength, and to detect errors in databases. The R i method has been used to identify previously undescribed but experimentally verified DNA binding sites. The individual information distribution was determined for E. coli ribosome binding sites, bacterial Fis binding sites, and human donor and acceptor splice junctions, among others. The distributions demonstrate clearly that the consensus sequence is highly unusual, and hence is a poor method to describe naturally occurring binding sites. 相似文献
90.
The effect of chenodeoxycholic acid (CDCA) on the reservoir function of the gallbladder was studied in 46 patients with cholesterol cholelithiasis. There was a dependence between a clear increase of filling of the gallbladder in patients treated by this method with subsequent sharp reduction of its size and development of dyspepsia and diarrhea. In 14 patients increase of the gallbladder against the background of chemotherapy was not authentic but no dyspeptic phenomena occurred. Thus, decompensation of the reservoir function of the gallbladder in patients with cholelithiasis against the background of chemotherapy are manifested by a significant increase of the gallbladder size with subsequent emptying of bile into the duodenum and development of collagenous diarrhea. 相似文献