全文获取类型
收费全文 | 1295篇 |
免费 | 2篇 |
国内免费 | 3篇 |
专业分类
综合类 | 1篇 |
化学工业 | 4篇 |
金属工艺 | 4篇 |
轻工业 | 3篇 |
石油天然气 | 1篇 |
一般工业技术 | 4篇 |
冶金工业 | 1282篇 |
自动化技术 | 1篇 |
出版年
2018年 | 1篇 |
2011年 | 1篇 |
2009年 | 2篇 |
2006年 | 1篇 |
2003年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 35篇 |
1998年 | 425篇 |
1997年 | 216篇 |
1996年 | 151篇 |
1995年 | 68篇 |
1994年 | 58篇 |
1993年 | 96篇 |
1992年 | 9篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 13篇 |
1987年 | 15篇 |
1986年 | 20篇 |
1985年 | 17篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1978年 | 4篇 |
1977年 | 27篇 |
1976年 | 74篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有1300条查询结果,搜索用时 31 毫秒
981.
982.
TR Buroker MJ O''Connell HS Wieand JE Krook JB Gerstner JA Mailliard PL Schaefer R Levitt CG Kardinal DH Gesme 《Canadian Metallurgical Quarterly》1994,12(1):14-20
The authors report on a case of trisomy 9 mosaicism syndrome, a rare chromosome abnormality. The common features of this syndrome are growth and mental retardation, low-set malformed ears, wide sutures and fontanelles, bulbous nose, short palpebral fissures, micrognathia, microphthalmia and enophthalmos, abnormal hands and feet, hip dislocation, joint limitation, cardiovascular defects and urogenital abnormalities. Our patient presented some unusual characteristics, such as 13 pairs of ribs, a vertebral malformation, a hemivertebra and a Dandy-Walker syndrome. They compare their clinical findings with the few cases previously described and they try to contribute to the further clinical definition of the syndrome. It is possible that there is a correlation between the variability of the phenotype and the percentage of trisomic cells in the patient. 相似文献
983.
The partial genome sequence of the hepatitis C virus (HCV) was determined in the serum of a Taiwanese patient with chronic community-acquired type C hepatitis. The cDNA fragments synthesized with the HCV RNA as a template were amplified by polymerase chain reaction using specific oligonucleotide primers. The amplified fragments represented the regions coding for the putative core, matrix and envelope proteins as well as the N-terminal amino acid sequence of the nonstructural protein NS1, the partial nonstructural NS3 and NS4 proteins and the region of the partial 5'-end noncoding sequence. The cDNA fragments were cloned and sequenced. Sequence analysis of these clones showed that they share 83.7%, 93.2% and 93.6% similarity at the nucleotide level, and 86.6%, 94.1% and 92.9% homology at the amino acid level, with the previously published American, Japanese and Taiwanese isolates, respectively. Accordingly, the RNA genome we obtained is HCV type II, probably, the predominant subtype in Taiwan. 相似文献
984.
985.
Two hundred forty-three consecutive patients with Hodgkin's disease who relapsed after an initial course of treatment at the Stanford University Division of Radiation Therapy underwent subsequent systematic evaluation and retreatment. An analysis of the influence of numerous parameters, including sex, histopathology, original stage, relapse site, and original and second therapy, on actuarial survival and on relapse-free survival was undertaken. Most relapses (87%) occurred within 3 years of the initial treatment course. The 5-year relapse-free survival measured from the time of second treatment increased from 14% before to 39% after the introduction of multiple agent chemotherapy (MOPP) for relapsing disease. Patients treated with MOPP chemotherapy for nodal relapses showed increased subsequent relapse-free survival (61%) when compared with patients treated only with radiotherapy for nodal relapses. Based on the combined findings of this analysis, recommendations are made regarding the management of patients with Hodgkin's disease who have suffered a relapse. 相似文献
986.
Molecular orbital calculations were used to investigate the antischistosomal agent, niridazole, and an inactive derivative, 1-(5-nitro-2-thiazolyl)-2-ethylurea. The CNDO/2 calculations revealed that the inactive derivative had a preferred conformation stabilized by an intramolecular hydrogen bond. The molecular profile, the relative three-dimensional arrangement of constituent atoms, of the inactive derivative was different than that of the niridazole compound. The likelihood of similar intramolecular interactions rendering niridazole derivatives inactive is discussed. The results of the calculations suggest select structural modifications that might increase the efficacy of niridazole derivatives. 相似文献
987.
1. The influence of a 24 h fast on the concentrations of free amino acids in the plasma, and upon the oxidation rates of methionine, isoleucine and threonine was studied (using early weaned, 4-week-old piglets which were receiving a semi-purified diet. 2. There was no change in the total concentration of the essential amino acids as a result of the 24 h fast: the concentration of the branched-chain amino acids increased, but the effect of this was offset by decreases in the concentrations of arginine, histidine, lysine, methionine and phenylalanine. There was a reduction in the concentration of the non-essential amino acids. 3. The piglets received infusions of L-[I-14C]methionine, L-[U-14C]isoleucine and L-[U-14C]-threonine, and the recovery of the label in carbon dioxide was determined. Less than 5% of the activity from methionine was recovered in the CO2 from the fed piglets, whereas 12% was recovered from the fasted piglets. The corresponding values with threonine were 11 and 19% but there was no effect of fasting on the recovery of the label from isoleucine in CO2. 4. The initial dilution of a single dose of a labelled amino acid infused into the bloodstream depends on the plasma concentration of the amino acid. Nutritional regimens may effect the free amino acid concentration in the plasma. Thus comparisons based upon direct determination of activity recovered in CO2 from the labelled dose of an amino acid with animals on different nutritional regimens could not misleading, unless the differences in the concentrations of the amino acid in the plasma are considered. 相似文献
988.
989.
EH Gilbert JD Earle E Glatstein ML Goris HS Kaplan JP Kriss 《Canadian Metallurgical Quarterly》1976,38(4):1560-1567
One hundred and two previously treated lymphoma patients were studied with 111Indium bone marrow scans and bone marrow biopsies. The biopsies were considered to represent sampling errors when the cellularity of the biopsy did not reflect the general state of the marrow organ cellularity as demonstrated by the scan. In each instance the accuracy of the scan was confirmed by either another biopsy or the subsequent clinical course of the patient. Sampling errors were infrequent (1/51) in patients with normal peripheral blood counts and whose marrow had never been involved with tumor. Errors were especially likely (17/51) in patients who had had marrow involvement or those who had anemia, leukopenia, or thrombocytopenia. The 111Indium bone marrow scan allows the clinician to avoid selecting a biopsy site with a high risk for sampling error. 相似文献
990.