全文获取类型
收费全文 | 1019篇 |
免费 | 61篇 |
国内免费 | 8篇 |
学科分类
工业技术 | 1088篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 8篇 |
2021年 | 64篇 |
2020年 | 30篇 |
2019年 | 27篇 |
2018年 | 39篇 |
2017年 | 36篇 |
2016年 | 37篇 |
2015年 | 42篇 |
2014年 | 37篇 |
2013年 | 99篇 |
2012年 | 63篇 |
2011年 | 66篇 |
2010年 | 41篇 |
2009年 | 42篇 |
2008年 | 35篇 |
2007年 | 54篇 |
2006年 | 38篇 |
2005年 | 39篇 |
2004年 | 35篇 |
2003年 | 20篇 |
2002年 | 18篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 18篇 |
1997年 | 16篇 |
1996年 | 15篇 |
1995年 | 5篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 10篇 |
1991年 | 3篇 |
1990年 | 10篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1973年 | 3篇 |
1972年 | 4篇 |
排序方式: 共有1088条查询结果,搜索用时 382 毫秒
991.
Perforation of the gallbladder is a serious complication of acute cholecystitis, with significant morbidity and mortality rates. We present the case of a diabetic adult in whom the usual signs and symptoms of acute cholecystitis were obscured. A high index of suspicion at the time of admission prompted emergent evaluation. Computerized axial tomography revealed a large perihepatic abscess extending from a perforated gallbladder. Fourteen hundred milliliters of malodorous brown fluid were drained by ultrasound-guided percutaneous aspiration from the collection. Early clinical suspicion combined with conservative surgical management may prevent serious morbidity and/or mortality in diabetic patients with complicated cholecystitis. 相似文献
992.
NN Sokolov OT Samko NV Anike?cheva AA Kalugin EB Khoroshutina OV Plutalov KR Birikh IuA Berlin 《Canadian Metallurgical Quarterly》1994,20(12):1334-1341
In a search for new restriction endonucleases type II, among forty bacterial strains of the Bacillus genus two strains producing site-specific endonucleases have been found. Endonucleases BbvAIII and BspFI, isolated from B. brevis BLM B-677 and B. species F, are shown to be true isoschisomers of BspMII (Kpn2I) and Sau3AI, respectively. 相似文献
993.
This paper proposes a distributed two-rail checker architecture which is specifically targeted to self-checking bus-based systems. The architecture makes use of a single bus line to provide error indication. With respect to conventional two-rail checkers additional diagnosing capabilities are provided. The checker is totally-self-checking with respect to stuck-at faults. It features also good self-testing properties with respect to parametric faults, such as bridgings and delay faults. 相似文献
994.
SE Kimmel MA Sekeres JA Berlin N Ellison VJ DiSesa BL Strom 《Canadian Metallurgical Quarterly》1998,32(7):1916-1922
OBJECTIVES: The purpose of this study was to determine risk factors for adverse events following protamine administration after cardiopulmonary bypass. BACKGROUND: Intravenous protamine administration is associated with a risk of severe systemic reactions. However, risk factors for these events have not been well delineated, thus hampering development of preventive strategies. METHODS: A case-control study nested within a cohort of consecutive patients undergoing surgery requiring cardiopulmonary bypass was performed. The primary case definition included those events (pulmonary hypertensive and systemic hypotensive) occurring within 10 min of protamine administration in the absence of other measurable causes of hemodynamic compromise. RESULTS: Comparing the 53 cases to the 223 control subjects, three risk factors were independently associated with events (multivariable odds ratio [95% confidence interval]): neutral protamine Hagedorn insulin use (8.18 [2.08, 32.2]); fish allergy (24.5 [1.24, 482.3]), and a history of nonprotamine medication allergy (2.97 [1.25, 7.07]). These risk factors demonstrated an increasingly strong association with progressively more specific case definitions. An estimated 39% of cardiopulmonary bypass patients had one or more of these risk factors. Prior intravenous protamine, central venous pressure prior to protamine, preoperative ejection fraction and the need for inotropes when coming off bypass did not exhibit statistically significant associations with events (all p > 0.15). Prior protamine allergy was associated specifically with an increased risk of pulmonary hypertension (multivariable odds ratio 189; 95% confidence interval 13, 2,856). CONCLUSIONS: Immunologic factors are important in predisposing individuals to protamine reactions, and a substantial proportion of patients are at considerably increased risk Strategies to reduce the risk of protamine-associated events are needed. 相似文献
995.
Solano Cecilia H.; Batten Phillip G.; Parish Elizabeth A. 《Canadian Metallurgical Quarterly》1982,43(3):524
The 1st study examined the hypothesis that feeling lonely is related to a self-perceived lack of self-disclosure to significant others. 37 male and 38 female undergraduates rated themselves on the UCLA Loneliness Scale and the Jourard Self-Disclosure Questionnaire. Analyses showed that for males and females, loneliness was significantly and linearly related to a self-perceived lack of intimate disclosure to opposite-sex friends. For females, loneliness was also associated with a perceived lack of self-disclosure to same-sex friends. The 2nd study investigated the relationship between loneliness and actual disclosure behavior. 24 lonely and 23 nonlonely Ss were paired with nonlonely partners in a structured acquaintanceship exercise. Both opposite-sex and same-sex pairs were included in the design. Postexercise ratings by partners indicated that lonely Ss were less effective than nonlonely Ss in making themselves known. Analysis of the intimacy level in the conversations showed that lonely Ss had significantly different patterns of disclosure than nonlonely Ss. The authors suggest that the self-disclosure style of the lonely person impairs the normal development of social relationships. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
“Automatic imitation” is a type of stimulus-response compatibility effect in which the topographical features of task-irrelevant action stimuli facilitate similar, and interfere with dissimilar, responses. This article reviews behavioral, neurophysiological, and neuroimaging research on automatic imitation, asking in what sense it is “automatic” and whether it is “imitation.” This body of research reveals that automatic imitation is a covert form of imitation, distinct from spatial compatibility. It also indicates that, although automatic imitation is subject to input modulation by attentional processes, and output modulation by inhibitory processes, it is mediated by learned, long-term sensorimotor associations that cannot be altered directly by intentional processes. Automatic imitation provides an important tool for the investigation of the mirror neuron system, motor mimicry, and complex forms of imitation. It is a new behavioral phenomenon, comparable with the Stroop and Simon effects, providing strong evidence that even healthy adult humans are prone, in an unwilled and unreasoned way, to copy the actions of others. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
997.
This paper takes an empirical point of departure in the development of a new steam turbine. Project work here relied on a process of iteration between a small core group of team members with extensive experience and team members with less of that currency. In this project, the core group had a major integrative role, whereas other team members were mainly responsible for the specific tasks assigned to them. Quite a few of the latter category felt uneasy about their role and felt ‘decoupled’ from the project. In our analysis we use the Teamwork Quality (TWQ) construct proposed by Hoegl and Gemuenden (2001). In conclusion, our findings suggest that in highly complex projects of this type, team-based knowledge integration need not presuppose equality of participation and we introduce the notion of a Segregated Team to account for these findings. 相似文献
998.
999.
David M. Onyango Paul S. Orina Rose C. Ramkat Chrispine Kowenje Cecilia M. Githukia Dorcas Lusweti Henry B. O. Lung'ayia 《Lakes & Reservoirs: Research and Management》2020,25(3):350-361
Microcystins are part of algal toxins produced intracellularly within algal cells, being in the family of hepatotoxic cyclic peptides from various species of blue‐green algae. Blue‐green algae are widely abundant in many equatorial eutrophic lakes, including Lake Victoria, with microcystin mainly from cyanobacterial blooms released into the water column, with different effects along the aquatic ecosystem trophic levels. Depending on the length of exposure and exposure route, microcystin effects on fish can include embryonic hatching perturbations, reduced survival and growth rates, changes in behavior, osmoregulation, increased liver activities and heart rates, as well as histopathological effects. While bioaccumulation is confirmed among fish, biomagnification along food webs is debatable. Lake Victoria the second largest freshwater lake in the world, and the source of livelihoods to millions reported near the gulf and shore MCs of 190 ± 51 to 543 ± 26 ng MC/g DW, respectively. Little is known, however, on the effects of microcystin on the Lake Victoria fishery and, ultimately, on the human population against the WHO recommended human microcystin intake levels of 0.04 µg/kg, thereby being the basis for this review. 相似文献
1000.
Abbes Wiem Sellami Dorra Marc-Zwecker Stella Zanni-Merk Cecilia 《Multimedia Tools and Applications》2021,80(17):25517-25538
Multimedia Tools and Applications - Melanoma is the most dangerous type of skin cancer when discovered in an advanced stage. Early detection of melanoma improves survival. Several Computer -Aided... 相似文献