全文获取类型
收费全文 | 900篇 |
免费 | 1篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 56篇 |
金属工艺 | 9篇 |
矿业工程 | 6篇 |
能源动力 | 3篇 |
轻工业 | 12篇 |
水利工程 | 3篇 |
石油天然气 | 11篇 |
无线电 | 8篇 |
一般工业技术 | 53篇 |
冶金工业 | 724篇 |
原子能技术 | 4篇 |
自动化技术 | 11篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 12篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 11篇 |
2012年 | 5篇 |
2011年 | 10篇 |
2010年 | 7篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 3篇 |
1999年 | 18篇 |
1998年 | 218篇 |
1997年 | 136篇 |
1996年 | 80篇 |
1995年 | 49篇 |
1994年 | 33篇 |
1993年 | 47篇 |
1992年 | 16篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1988年 | 5篇 |
1987年 | 14篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 20篇 |
1978年 | 3篇 |
1977年 | 18篇 |
1976年 | 46篇 |
1975年 | 5篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有901条查询结果,搜索用时 15 毫秒
41.
42.
43.
AS Pavlov VS Datsenko MA Fadeeva OA Zamiatin EV Kizhaev 《Canadian Metallurgical Quarterly》1980,26(3):3-8
The authors present an analysis of the causes of radiation induced complications in 383 patients referred to the Chair of Clinical Radiology from different medical institutions of the country. It was found that under distant gamma therapy, to prevent the development of complications the value of TDF-factor should not exceed 105--110, for the associated radiotherapy--130--140, and that for close focal roentgenotherapy--130--150. In vast majority of patients (95.3%) the complications resulted from surpassing the normal tissue tolerance. To prevent radiation injuries it is suggested to take into consideration the TDF-factor values, while in planning radiotherapy to choose such schedules of irradiation, which preclude any surpassing of the tolerance of normal tissues and organs adjacent to the tumor. 相似文献
44.
45.
Aim of study was to assess trends in lipid profile and nutrition of adolescent population in Novosibirsk during the social and economic reforms in Russia (1989-1999). Three cross-sectional studies of school aged 14-17 in 1989 (657), in 1994 (620) and in 1999 (626) were carried out. Total sample was 1903 (914 males and 989 females). Blood lipids, such as total cholesterol (TC0, high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG), were measured. Diet was estimated with the method of 24-hour dietary recall. During 10-year period mean serum TC decreased from 175 to 158 mg/dl in males and from 191 to 175 mg/dl in females (p < 0.001 for both genders). Females had significantly higher mean NC than did males at all surveys (p < 0.001)/Between 1989 and 1994 mean HDL-C levels decreased in boys both (p < 0.001), but in 1999 these levels were similar to 1989. During 1989-1994, TG levels significantly decreased, but between 1994 and 1999 mean TG levels increased in 1.5 times in both gender groups. Prevalence of high TC (> = 2000 mg/dl) significantly decreased from 17% to 6% in males and from 28% to 14% in females. Frequencies of low HDL-C (> = 40 mg/dl) also decreased in boys (from 28 to 8%) and girls (from 13 to 3%). Trends in diet showed similar changes and characterized by significant decreasing of total energy intakes (from 3021 to 2342 kcal in boys and from 2300 to 1644 kcal in girls) and of basic nutrient intakes (proteins? Fats? Carbohydrates). Negative trends in blood lipid profile and diet in adolescents during the unstable period of socioeconomic reforms in Russia indicate on serious changes in metabolic processes and need in large state economic programs to improve the situation. 相似文献
46.
47.
131I dose-dependent thyroid autoimmune disorders in children living around Chernobyl 总被引:1,自引:0,他引:1
EV Vykhovanets VP Chernyshov II Slukvin YG Antipkin AN Vasyuk HF Klimenko KW Strauss 《Canadian Metallurgical Quarterly》1997,84(3):251-259
The nucleotide sequence of 35,400 bp at approximately 10 kb from the right telomere of chromosome VII was determined. The segment contains the MAL1 locus, one of the five unlinked loci sufficient for maltose utilization. Until now, each of these loci was considered to contain three genes (for regulator, permease and alpha-glucosidase), but a fourth gene, presumably an extra alpha-glucosidase gene, was found at MAL1 adjacent to the usual cluster of three genes. The two glucosidase genes are present in opposite orientation, forming an inverted repeat structure. In addition to the four genes at MAL1, there are 11 complete, non-overlapping open reading frames (ORFs) longer than 300 bp in the sequence presented here. A new ABC transporter gene (YGR281w), required for oligomycin resistance was found (YOR1; Katzman et al., 1995), and the previously sequenced BGL2 (YGR282c), ZUO1 (YGR285c) and BIO2 (YGR286c) genes were located. The sequence of BIO2, a biotin synthetase gene, required substantial correction and the size of Bio2p is 375, rather than 356, amino acids. Two ORFs show rather weak similarities to animal genes: YGR278w to an unknown ORF of Caenorhabditis elegans and YGR284c to the murine Surf-4, a member of a cluster of at least four housekeeping genes. The remaining five ORFs do not encode known functions, but three of these show weak to high similarities to other ORFs in the Saccharomyces cerevisiae genome and one (YGR280c) codes for a particularly lysine-rich protein. 相似文献
48.
Forty patients with temporal epilepsy were operated on with a stereotaxic technique. Eleven patients had a unilateral localization of the epileptic focus, and in 29 bitemporal foci were diagnosed. In evaluating the results of the treatment the dynamics of the epileptic fits, the peculiarities of changes in the mental status, and the degree of social adaptation were taken into consideration. A postoperative improvement was achieved in 73% of the patients with monotemporal lesions, while in those with bitemporal epilepsy and distinct persistent mental disorders the state was improved in 44% of the cases. Indications for the choice of the zone of destruction depending on the clinical peculiarities of the lesion are presented. 相似文献
49.
B Roca C Vilar EV Pérez A Sáez-Royuela E Simón 《Canadian Metallurgical Quarterly》1996,25(17):803-804
OBJECTIVE: The incidence of Pseudomonas aeruginosa in HIV-infected patients has increased over the last years. We describe a case of pseudomonal breast abscess complicated with fatal septicemia in an AIDS patient. CASE REPORT: A 21-year-old woman was admitted for fever, chills, nausea, vomiting and pain in the breast. She had a swelling in the right breast of 3 days duration. HIV infection had been confirmed 6 years earlier. CD4 count was 2/mm3. Surgical drainage produced a blue-green purulent discharge which grew Pseudomonas aeruginosa on culture. Despite cloxacilin, then ceftazidime and amikacin, initial improvement was followed 2 weeks later by nodular pulmonary infiltration with cavitation. P. aeruginosa was recovered from sputum and blood cultures, but stepwise resistance developed and the patient died 3 months after admission. DISCUSSION: Breast abscesses are infrequent in nonlactating women. P. aeruginosa is rarely involved, even in HIV patients. Due to the risk of resistance, prompt administration of appropriate antibiotics is required. 相似文献
50.
A Brewaeys P Devroey FM Helmerhorst EV Van Hall I Ponjaert 《Canadian Metallurgical Quarterly》1995,10(10):2731-2735
This study investigated the development of family relationships in lesbian families who conceived after donor insemination (DI). The main characteristics of this unknown family structure were analysed. An anonymous donor was used to conceive, the family unit consisted of two mothers and a father was non-existent, and both women had a homosexual orientation. A total of 50 lesbian couples who conceived after DI with children aged between 1 and 2 years participated in this study, using a standardized interview created for this study. After the birth of their child, 56% of the lesbian mothers (n = 100) would have wanted the identity of the donor to be registered, while 10% would have done so at the time of the insemination. Opinions differed in 12 of the 50 couples: the biological mother was in favour of identity registration while the social mother was not. Both women considered themselves a parent of the child with equally shared responsibilities. Mothers were open about the special features of their family structure with children and within their immediate social network. Only 30% disclosed their lesbian identity in a broader social environment. The features of these newly created families may influence the psychological development of the children and therefore make long-term follow-up studies indispensable. 相似文献