全文获取类型
收费全文 | 997篇 |
免费 | 30篇 |
国内免费 | 26篇 |
专业分类
电工技术 | 39篇 |
综合类 | 61篇 |
化学工业 | 54篇 |
金属工艺 | 186篇 |
机械仪表 | 53篇 |
建筑科学 | 26篇 |
矿业工程 | 1篇 |
能源动力 | 13篇 |
轻工业 | 285篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 50篇 |
一般工业技术 | 172篇 |
冶金工业 | 24篇 |
原子能技术 | 19篇 |
自动化技术 | 63篇 |
出版年
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 11篇 |
2014年 | 37篇 |
2013年 | 145篇 |
2012年 | 75篇 |
2011年 | 103篇 |
2010年 | 58篇 |
2009年 | 82篇 |
2008年 | 47篇 |
2007年 | 35篇 |
2006年 | 51篇 |
2005年 | 21篇 |
2004年 | 30篇 |
2003年 | 17篇 |
2002年 | 13篇 |
2001年 | 7篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 20篇 |
1997年 | 58篇 |
1996年 | 20篇 |
1995年 | 10篇 |
1994年 | 17篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 4篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 15篇 |
1986年 | 9篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1978年 | 6篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1967年 | 2篇 |
1962年 | 1篇 |
1960年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有1053条查询结果,搜索用时 15 毫秒
61.
62.
YOUNG-NAM KIM SEONG-IL HEO MYEONG-HYEON WANG 《Journal of Food Processing and Preservation》2009,33(1):87-104
Fibrinolytic, antigenotoxic and immunomodulating properties of chungkukjang were evaluated. The purified fibrinolytic enzyme was characterized as an alkaline serine protease with molecular weight of 22 kDa determined by fibrin zymography and stable over pH range 6.0–10.0 below 50C. The comet assay showed that N-methyl-N ' -nitro-N-nitrosoguanidine (MNNG)-induced DNA damage level (190.8 AU) in 3T3 cells was considerably decreased to 121.2 AU with chungkukjang extracts (CB) showing 49.7% of protection. Incubation of the 3T3 cells with CB significantly reduced the cytotoxicity of MNNG. [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay revealed that the addition of CB enhanced the proliferation of RAW 264.7 (mouse leukemic monocyte macrophage cell line) macrophages up to about 150% of the control levels. RAW 264.7 macrophages incubated with CB induced a strong increase in nitric oxide (NO), tumor necrosis factor -α (TNF-α) and interleukin-1α (IL-1α) with a dose-dependent manner. After 24 h incubation with 1 mg/mL of CB, NO, TNF-α and IL-1α showed the highest production of 511, 2.46 and 0.258 ng/mL, respectively. 相似文献
63.
64.
65.
66.
67.
68.
Characterization and Food Application of an Amperometric Needle-Type L-Lactate Sensor 总被引:1,自引:0,他引:1
There have been increasing needs for biosensing in the food industry because it is accurate, rapid and efficient. A needle-type L-lactate sensor with a three-layer membrane system which uses lactate oxidase as the biological component was prepared. The sensor had an optimum pH around 9–10 and an optimum temperature at 45 C. The current response was stable over 40 days and specifically responded to L-lactic acid. The sensor gave accurate L-lactate measurements in kimchi and yogurt of 187.4 ± 4.1 and 734.1 ± 34.5 mg/dL, similar to those of a spectrophotometric L-lactate kit. 相似文献
69.
To increase battery life in IEEE 802.16e systems, it is essential to efficiently manage energy in mobile stations. The sleep-mode operation in power management helps to increase the life of a station by saving energy consumption. In power management, there are two important performance metrics energy consumption and the response delay of awakening medium access control (MAC) service data unit (SDU). While in a base station (BS) initiation of awakening, the two performance metrics should be simultaneously considered, in a mobile subscriber station (MSS) initiation of awakening, the response delay is not considered because it is self-operational. There performance metrics are affected by the minimum sleep interval (Tmin), the maximum sleep interval (Tmax), and the average interarrival time of awakening MAC SDUs (TI) during sleep-mode operation. Therefore, it is imperative to evaluate the two initiations of awakening depending on TI. To reach a fuller understanding of the performance, this paper shows an analytical mode and simulations results for the standard sleep-mode operation in the IEEE 802.16e MAC. 相似文献
70.
The use of design method considering a coil temperature to maximize the thrust density of a double side coreless permanent
magnet linear synchronous motor (PMLSM) was presented. The optimal current density where the coil temperature reaches an allowable
temperature with heat analysis was applied to a magnetic circuit design. Changing optimal current density is verified whenever
the design parameters of the motor are altered. The design parameters of the motor were applied to thrust calculation. In
this way, the optimal model, which is a reversal of the existing design method, is deduced. The results were compared with
the experimental data to verify their validity. When the convection heat transfer coefficient is applied to other models,
the results of the analysis and test values show good concordance. The method proposed has some limitations. 相似文献