全文获取类型
收费全文 | 3213篇 |
免费 | 0篇 |
专业分类
化学工业 | 16篇 |
金属工艺 | 4篇 |
建筑科学 | 2篇 |
矿业工程 | 2篇 |
能源动力 | 2篇 |
轻工业 | 5篇 |
石油天然气 | 1篇 |
无线电 | 1篇 |
一般工业技术 | 5篇 |
冶金工业 | 3166篇 |
原子能技术 | 1篇 |
自动化技术 | 8篇 |
出版年
2020年 | 2篇 |
2018年 | 1篇 |
2015年 | 1篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2008年 | 1篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 4篇 |
1999年 | 70篇 |
1998年 | 923篇 |
1997年 | 538篇 |
1996年 | 391篇 |
1995年 | 235篇 |
1994年 | 162篇 |
1993年 | 183篇 |
1992年 | 20篇 |
1991年 | 33篇 |
1990年 | 27篇 |
1989年 | 29篇 |
1988年 | 24篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 19篇 |
1983年 | 5篇 |
1982年 | 19篇 |
1981年 | 25篇 |
1980年 | 33篇 |
1979年 | 3篇 |
1978年 | 10篇 |
1977年 | 131篇 |
1976年 | 258篇 |
1975年 | 9篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有3213条查询结果,搜索用时 10 毫秒
21.
AA Gubareva 《Canadian Metallurgical Quarterly》1998,(6):141-143
Systemic enzymes (wobenzime and wobe-mugos) were approved, that had been prescribed as part of polychemotherapy to 24 patients with malignant lymphomas, who presented with large masses of lymphatic nodes poorly resorbable against the background of polychemotherapy and who were assigned for a high-total dose irradiation, which fact would undoubtedly entail sclerosing of adjacent intact tissues. The use of the enzymes made for the optimum realization of the polychemotherapy effect and permitted avoiding a good many of undesirable side events and complication thereof. The above systemic enzymes are well tolerated by patients; they induce no significant changes in the cellular composition or in blood biochemical indices. 相似文献
22.
An exploratory, comparative survey design was used to describe and compare similarities and differences in perception of caring behaviors between hospitalized antepartum and short-stay postpartum patients. Forty-two patients completed the 63-item Caring Behavior Assessment instrument (CBA). The scale, based on Watson's theory of caring, contains seven categories. There were no statistically significant differences in age, education, gravida, or para between the two groups. Significantly more women in the postpartum group were married. There were no statistically significant differences or correlations in the total CBA scores and the demographic variables. No statistically significant differences in total CBA scores were found between antepartum participants and postpartum participants. These findings corroborate the results of "caring" studies in other patient populations, that satisfying basic needs--that is, evidence of technical knowledge and skills--is more important to patients than meeting higher order needs. 相似文献
23.
Although enthusiasm for measuring health-related quality of life (HRQL) in clinical trials exists, information is limited on the meaning of scores. We examined the relation between scores from the 34-item Medical Outcomes Study HIV Health Survey (MOS-HIV) and the more detailed HIV Overview of Problems-Evaluation System (HOPES) using the responses of 318 HIV-infected outpatients being treated in Los Angeles and Baltimore. With the HOPES problem statements as independent variables, statistically significant predictors of the variation in MOS-HIV scores for the Physical Function, Mental Health, and Energy/Fatigue scales were identified using stepwise regression. Approximately 60% to 70% of the variation in each of the scores was explained by five to seven different HOPES problem statements, with a single item explaining 47% to 59% of the variation. We created illustrative profiles for each of the three MOS-HIV scales using the HOPES items identified in the regressions. Independent of the scale, persons scoring in the top MOS-HIV quartile tended to report few if any problems, whereas a decline in score to the next quartile was characterized by functional difficulties (e.g., "HIV interferes with work"). The onset of specific problems might trigger further evaluation and potential intervention from health care providers to help maintain patient functioning. 相似文献
24.
We compared two gastrin radioimmunoassay kits ("Immutope" kit, Squibb & Co.; "Gastrin R.I.A." kit, Schwarz/Mann) to the conventional gastrin radioimmunoassay of Yalow and Berson [Gastroenterology 58, 1 (1970)] as run by us and by a second reference laboratory. Although both kits were found to effectively discriminate above-normal and normal values for serum gastrin, they significantly underestimated very high values (greater than 1500 ng/liter). The Schwarz/Mann kit clearly had a superior quality label (lower nonspecific binding and higher specific activity) and a shorter incubation time. However, the 90-min incubation period cited for their kit caused overestimation of gastrin values in the lower range (5-300 ng/liter), which could be corrected by prolonging the incubation to 24 h. The Squibb antibody had fairly good cross reactivity to all gastrin species tested; the Schwarz/Mann antibody had poor affinity for natural human gastrin G34-II. Good correspondence was found for sera run by both reference laboratories (y = 0.96x + 10, r = 0.997), and values obtained with the Schwarz/Mann kit correlated best (+ 0.815) with those from the conventional radioimmunoassay procedure. 相似文献
25.
26.
27.
28.
29.
During the examination of the colon by fibre-optic colonoscopy in 200 consecutive patients it was possible to reach the caecum or suspected lesion in 80% of cases. Careful bowel preparation, sedation and detailed attention to techniques described are necessary for safe and successful performance of this procedure. In 85% of examinations, colonoscopy produced positive results including the definition of uncertain radiological lesions in 45 patients, finding of a cause for rectal bleeding not shown on barium studies in 15 patients, the assessment of inflammatory bowel disease in 28 patients, and the removal of polyps in 40 patients. Important was the finding of a normal colon in 49 cases, which obviated unnecessary surgery. Colonic perforation occurred in 2 patients. The limitations and complications of the procedure must be realised, but it is concluded that the colonoscope provides a valuable and effective means of diagnosis and therapy of lesions in the large bowel. 相似文献
30.
AA Zaninovich 《Canadian Metallurgical Quarterly》1976,82(3):510-516
The reciprocal effects of loading doses of thyroxine (T4) or triiodothyronine (T3) on the deiodination of their 125iodine-labelled isotopes by rat muscle and liver homogenates were studied. In 21 experiments muscle homogenates deiodinated a mean 45.0% of a tracer dose of [125I]T4 and 18.0% of [125I]T3. On addition of graded amounts of nonradioactive T4 or T3 the percentual deiodination of both labelled hormones progressively declined. This effect was significantly greater in homogenates incubated with non-radioactive T4, thus reflecting a stronger affinity of this hormone for muscle deiodinating sites. This correlate with the greater displacment of [125I]T3 as revealed by the percentage of recovered labelled hormone. In 18 experiments liver homogenates deiodinated a mean 14.6% of a tracer amount of [125I]T4 and 8.5% of [125I]T3. The addition of a T4- or a T3-load was followed by a smaller decrease in percentual deiodination of both labelled hormones as compared to muscle homogenates. Unlike the effects observed in muscle, the breakdown of [125I]T4 and [125I]T3 by liver homogenates was equally affected by similar amounts of stable T4 or T3. It is concluded that in the present in vitro system T4 and T3 share cellular sites of deiodination in rat muscle and liver and that, at least in muscle, which constitutes over one-half of the rat body weight T4 appears to be preferentially deiodinated. 相似文献