全文获取类型
收费全文 | 2198篇 |
免费 | 5篇 |
专业分类
化学工业 | 22篇 |
金属工艺 | 1篇 |
建筑科学 | 1篇 |
能源动力 | 1篇 |
轻工业 | 3篇 |
石油天然气 | 1篇 |
无线电 | 14篇 |
一般工业技术 | 10篇 |
冶金工业 | 2137篇 |
自动化技术 | 13篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2006年 | 3篇 |
2004年 | 3篇 |
2003年 | 2篇 |
1999年 | 69篇 |
1998年 | 624篇 |
1997年 | 359篇 |
1996年 | 265篇 |
1995年 | 154篇 |
1994年 | 117篇 |
1993年 | 126篇 |
1992年 | 21篇 |
1991年 | 34篇 |
1990年 | 26篇 |
1989年 | 39篇 |
1988年 | 43篇 |
1987年 | 38篇 |
1986年 | 25篇 |
1985年 | 36篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 10篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1978年 | 3篇 |
1977年 | 40篇 |
1976年 | 88篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有2203条查询结果,搜索用时 31 毫秒
81.
82.
83.
Noncirrhotic portal fibrosis is a common cause of portal hypertension in India. We report the development of noncompressive myelopathy after a lienorenal shunt in a patient with noncirrhotic portal fibrosis. 相似文献
84.
85.
86.
87.
DA Brown SK Effgen RJ Palisano 《Canadian Metallurgical Quarterly》1998,78(9):934-47; discussion 948-50
BACKGROUND AND PURPOSE: Do individuals with severely limited physical and cognitive abilities improve their gross motor abilities when given physical therapy intervention, and does improvement transfer to nontreatment settings? SUBJECTS: The subjects were 24 individuals (10 female, 14 male), aged 3 to 30 years (X = 20.1, SD = 8.1), who were nonambulatory and had limited adaptive behavior. METHODS: Change in gross motor ability during 18 weeks of twice-weekly therapy was measured using goal attainment scaling (GAS). Three gross motor goals were developed for each subject based on individual or caregiver needs, with one goal randomly selected as a control. Physical impairments were treated, and behavioral management principles, low-level communication approaches, high-repetition practice of goals, and a progressive reduction of both physical assistance and multisensory cues were used. An independent rater scored goal level from randomly ordered videotapes recorded during therapy and in recess and home settings. RESULTS: Mean GAS T scores were higher for treatment goals (X = 45.6, SD = 10.5) compared with control goals (X = 34.6, SD = 11.8). When the expected goal level (50) was met during therapy, mean GAS T scores in recess settings ( X = 35.9, SD = 11.5) and home settings (X = 42.2, SD = 12.2) were lower. At the conclusion of therapy, there were no differences in goal levels between treatment and control goals in both the recess and home settings. CONCLUSION AND DISCUSSION: The subjects demonstrated improvement of gross motor abilities practiced during therapy. Level of ability during therapy, however, did not consistently transfer to the recess of home settings. [Brown DA, Effgen SK, Palisano RJ. Performance following ability-focused physical therapy intervention in individuals with severely limited physical and cognitive abilities. 相似文献
88.
89.
90.
To identify pertinent target epitopes for contraceptive vaccine development, rabbit polyclonal antibodies were raised against four peptides synthesized from the deduced amino acid (aa) sequence of porcine zona pellucida macromolecule ZP3 beta and coupled to diphtheria toxoid (DT). Synthetic peptides consisted of: P1, 23-37 aa; P2, 164-179 aa with an additional C-terminal cysteine; P3, 246-263 aa with an extra C-terminal cysteine; and P4, 310-321 aa residues corresponding to pZP3 beta precursor protein. Selected sequences were based upon B cell epitopes identified previously by monoclonal antibodies. Immune sera reacted with their respective peptides and DT in an ELISA, and also recognized porcine SIZP and pZP3 beta both in ELISA and Western blot and zona pellucida of porcine oocytes in an indirect immunofluorescence assay. None of the four anti-peptide sera recognized pZP3 alpha in Western blot, emphasizing the specificity of these antibodies to pZP3 beta. The anti-peptide sera, individually, failed to inhibit in vitro attachment of boar sperm to antibody treated zona encased porcine oocytes. However, combinations of immune sera against peptides such as P1 + P4, P2 + P4 and P1 + P2 + P4, did significantly inhibit porcine sperm-oocyte interaction. These results identify combinations of peptides that could potentially be used in the design of an immunocontraceptive vaccine based upon synthetic peptides corresponding to pZP3 beta or its homologues in other species. 相似文献