全文获取类型
收费全文 | 3556篇 |
免费 | 24篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 13篇 |
综合类 | 1篇 |
化学工业 | 219篇 |
金属工艺 | 27篇 |
机械仪表 | 35篇 |
建筑科学 | 24篇 |
能源动力 | 36篇 |
轻工业 | 197篇 |
水利工程 | 10篇 |
石油天然气 | 11篇 |
无线电 | 70篇 |
一般工业技术 | 143篇 |
冶金工业 | 2645篇 |
原子能技术 | 5篇 |
自动化技术 | 145篇 |
出版年
2023年 | 5篇 |
2022年 | 13篇 |
2021年 | 18篇 |
2020年 | 21篇 |
2018年 | 14篇 |
2017年 | 16篇 |
2016年 | 18篇 |
2015年 | 8篇 |
2014年 | 25篇 |
2013年 | 57篇 |
2012年 | 41篇 |
2011年 | 65篇 |
2010年 | 57篇 |
2009年 | 30篇 |
2008年 | 28篇 |
2007年 | 23篇 |
2006年 | 23篇 |
2005年 | 28篇 |
2004年 | 29篇 |
2003年 | 33篇 |
2002年 | 17篇 |
2001年 | 21篇 |
2000年 | 19篇 |
1999年 | 87篇 |
1998年 | 756篇 |
1997年 | 435篇 |
1996年 | 286篇 |
1995年 | 169篇 |
1994年 | 142篇 |
1993年 | 184篇 |
1992年 | 40篇 |
1991年 | 40篇 |
1990年 | 40篇 |
1989年 | 53篇 |
1988年 | 49篇 |
1987年 | 50篇 |
1986年 | 47篇 |
1985年 | 54篇 |
1984年 | 18篇 |
1983年 | 13篇 |
1982年 | 28篇 |
1981年 | 28篇 |
1980年 | 47篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1977年 | 84篇 |
1976年 | 210篇 |
1975年 | 17篇 |
1973年 | 8篇 |
1939年 | 5篇 |
排序方式: 共有3581条查询结果,搜索用时 171 毫秒
1.
2.
The development of a sustainable energy system throughout an enterprise is a complex task, which requires an agile holistic approach. Such an approach needs to include a variety of objectives including energy strategy formation and strategic decision-making, which are directly related to the analysis and management of the main areas of sustainable development:The economic, technological, environmental, and social. These multidimensional requirements of sustainability are often difficult to achieve within the enterprise, because these aspects are interrelated and influenced by various internal and external environment factors. This paper first reviews the main challenges for an energy system, and then demonstrates how a strategic agile enterprise architecture driven approach could effectively guide the sustainable energy system development. The study presented in this paper provides a holistic approach that contributes to the advancement and usage of literature dealing with issues of sustainable energy system development and agile enterprise architecture, which has not been discussed before to any great extent. 相似文献
3.
4.
Many strains of laboratory mouse are uniquely susceptible to the development of T cell lymphoma/leukemia, either spontaneously or as a result of chemical or radiation exposure. In contrast, T cell leukemias or lymphomas which are relatively uncommon in human populations, are not easily induced by radiation, and are not generally associated with chemotherapy or chemical exposure. Evidence is presented to suggest that differences in the susceptibility to the development of these malignancies is related to subtle but important variations in the regulation of hematopoietic stem cell differentiation between these two species. 相似文献
5.
6.
To clarify whether long-term impaired glucose tolerance (IGT) is associated with dysfunction of peripheral and autonomic nerves, age-matched men with IGT and diabetes mellitus were followed prospectively for 12-15 years, when peripheral and autonomic nerve function was assessed. The patients comprised four subgroups: (1) 51 IGT subjects (duration of IGT at least 12-15 years); (2) 35 diabetic patients, with IGT 12-15 years ago, who later developed diabetes; (3) 34 diabetic patients, duration of diabetes at least 12-15 years; and (4) 62 age-matched non-diabetic control subjects. Mean age of the whole study population was 61 +/- 2 years (mean +/- SD), not different in the four groups. Peripheral nerve function tests included nerve conduction velocities, amplitudes, distal latencies, F-reflexes, and sensory perception thresholds for heat, cold, and vibration. Autonomic nerve function tests included the heart rate reaction during deep breathing (expiration to inspiration ratio) and to tilt (acceleration and brake indices). Despite 12-15 years of IGT, peripheral nerve function did not differ between IGT and control subjects, whereas autonomic nerve function deviated; an abnormal expiration to inspiration ratio (a sign of vagal nerve dysfunction) was significantly more common (15/51 versus 5/62; p < 0.01) in IGT than in control subjects. Diabetic patients (groups 2 and 3) showed lower conduction velocities (in general 2-4 m s-1 lower) than IGT and control subjects in all tested nerves. In conclusion, diabetes but not IGT, is associated with peripheral nerve dysfunction. 相似文献
7.
Entrainment and musicality in the human system interface 总被引:1,自引:1,他引:0
Satinder P. Gill 《AI & Society》2007,21(4):567-605
What constitutes our human capacity to engage and be in the same frame of mind as another human? How do we come to share a sense of what ‘looks good’ and what ‘makes sense’? How do we handle differences and come to coexist with them? How do we come to feel that we understand what someone else is experiencing? How are we able to walk in silence with someone familiar and be sharing a peaceful space? All of these aspects are part of human ‘interaction’. In designing interactive technologies designers have endeavoured to explicate, analyse and simulate, our capacity for social adaptation. Their motivations are mixed and include the desires to improve efficiency, improve consumption, to connect people, to make it easier for people to work together, to improve education and learning. In these endeavours to explicate, analyse and simulate, there is a fundamental human capacity that is beyond technology and that facilitates these aspects of being, feeling and thinking with others. That capacity, we suggest, is human entrainment. This is our ability to coordinate the timing of our behaviours and rhythmically synchronise our attentional resources. Expressed within the movements of our bodies and voices, it has a quality that is akin to music. In this paper, disparate domains of research such as pragmatics, social psychology, behaviourism, cognitive science, computational linguistics, gesture, are brought together, and considered in light of the developments in interactive technology, in order to shape a conceptual framework for understanding entrainment in everyday human interaction. 相似文献
8.
9.
10.
LH Argatoff JM Connors RJ Klasa DE Horsman RD Gascoyne 《Canadian Metallurgical Quarterly》1997,89(6):2067-2078
Mantle cell lymphoma (MCL) is a relatively uncommon yet distinct type of malignant lymphoma whose clinical and pathological characterization has been limited by the small numbers of cases published to date. We studied 80 cases of MCL seen at a single institution over 7 years to determine both clinical and pathological prognostic factors. The patients in this study were predominantly male (70%) and older (mean age, 63 years) and presented with advanced-stage disease (88%). Extranodal involvement was common. Median overall survival (OS) was 43 months. Except for performance status, prognosis was not significantly influenced by clinical prognostic factors. Histologically, MCL architecture was classified as diffuse (78%), nodular (16%), or mantle zone (6%); the OS among these groups was identical. Increased mitotic activity (>20 mitotic figures per 10 high power fields), blastic transformation, and peripheral blood involvement at diagnosis also predicted for a worse outcome, but bone marrow involvement did not. The presence or absence of a translocation t(11; 14) by cytogenetic analysis or a bcl-1 rearrangement by Southern analysis did not significantly predict outcome. In summary, this study of 80 cases of MCL highlights its distinctive clinicopathologic features and shows that increased mitotic activity, blastic morphology, and peripheral blood involvement at diagnosis are prognostically important factors. 相似文献