全文获取类型
收费全文 | 5486篇 |
免费 | 406篇 |
国内免费 | 287篇 |
学科分类
工业技术 | 6179篇 |
出版年
2024年 | 25篇 |
2023年 | 57篇 |
2022年 | 133篇 |
2021年 | 189篇 |
2020年 | 134篇 |
2019年 | 110篇 |
2018年 | 90篇 |
2017年 | 107篇 |
2016年 | 94篇 |
2015年 | 144篇 |
2014年 | 193篇 |
2013年 | 267篇 |
2012年 | 362篇 |
2011年 | 357篇 |
2010年 | 332篇 |
2009年 | 285篇 |
2008年 | 303篇 |
2007年 | 313篇 |
2006年 | 257篇 |
2005年 | 199篇 |
2004年 | 134篇 |
2003年 | 104篇 |
2002年 | 64篇 |
2001年 | 72篇 |
2000年 | 64篇 |
1999年 | 74篇 |
1998年 | 441篇 |
1997年 | 279篇 |
1996年 | 184篇 |
1995年 | 106篇 |
1994年 | 98篇 |
1993年 | 89篇 |
1992年 | 22篇 |
1991年 | 30篇 |
1990年 | 26篇 |
1989年 | 30篇 |
1988年 | 21篇 |
1987年 | 20篇 |
1986年 | 11篇 |
1985年 | 15篇 |
1983年 | 13篇 |
1982年 | 25篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 11篇 |
1978年 | 12篇 |
1977年 | 64篇 |
1976年 | 106篇 |
1975年 | 11篇 |
1973年 | 14篇 |
排序方式: 共有6179条查询结果,搜索用时 15 毫秒
1.
2.
探讨了直纺83 dtex/114 f波浪扁平涤纶全拉伸丝(FDY)的工艺制备过程。试验证明,在熔体输送温度276~282℃,纺丝温度286~290℃,喷丝板规格DIO φ104 mm-114孔、"王"字形,环吹风压10~15 Pa,含油率1.1%~1.2%,卷绕速度3 800~4 200 m/min的工艺参数下纺制83 dtex/114 f波浪扁平涤纶FDY时,生产稳定,满卷率高,外观情况良好,袜带均匀亮丽,可批量生产。此新产品可用于制作高档布艺沙发表层面料,具有抗倒伏、色彩艳丽等功效。 相似文献
3.
图形点阵式液晶显示器MSP-G320240在高速处理器DSP中的应用 总被引:1,自引:1,他引:0
介绍了内置SD1335控制器的图形液晶显示器MSP-G320240的工作原理及应用方法,给出了MSP-G320240液晶显示器同DSP的简单接口电路,同时给出了相应的液晶显示器的初始化和清显示区的具体程序。 相似文献
4.
5.
6.
7.
R Feldman M Bacher N Campbell A Drover A Chockalingam 《Canadian Metallurgical Quarterly》1998,89(5):I16-I18
Adherence to pharmacologic therapy of hypertension is low (in the range of 50-70%) and has important implications both for blood pressure control and cardiovascular complications. Based on a review of the literature using the levels of evidence grading technique, determinants of adherence to the pharmacologic therapy of hypertension have been assessed. Additionally, interventions to improve compliance were evaluated. Patient-centred, health care provider-centred and drug-specific factors have all been shown to affect adherence rates. We conclude that the extent of adherence to pharmacologic therapy is modifiable. Measurable improvements in adherence can be obtained from simplified medication regimens and a combination of behaviour strategies, including the tailoring of pill-taking to patients' daily habits and rituals, the advocacy of self-monitoring of pills and blood pressure, and the institution of reward systems. 相似文献
8.
Modeling of musculoskeletal structures requires accurate data on anatomical parameters such as muscle lengths (MLs), moment arms (MAs) and those describing the upper limb position. Using a geometrical model of planar arm movements with three degrees of freedom, we present, in an analytical form, the available information on the relationship between MAs and MLs and joint angles for thirteen human upper limb muscles. The degrees of freedom included are shoulder flexion/extension, elbow flexion/extension, and either wrist flexion/extension (the forearm in supination) or radial/ulnar deviation (the forearm in mid-pronation). Previously published MA/angle curves were approximated by polynomials. ML/angle curves were obtained by combining the constant values of MLs (defined by the distance between the origin and insertion points for a specific upper limb position) with a variable part obtained by multiplying the MA (joint radius) and the joint angle. The MAs of the prime wrist movers in radial/ulnar deviation were linear functions of the joint angle (R2 > or = 0.9954), while quadratic polynomials accurately described their MAs during wrist flexion/extensions. The relationship between MAs and the elbow angle was described by 2nd, 3rd or 5th-order polynomials (R2 > or = 0.9904), with a lesser quality of fit for the anconeus (R2 = 0.9349). In the full range of angular displacements, the length of wrist, elbow and shoulder muscles can change by 8.5, 55 and 200%, respectively. 相似文献
9.
10.