全文获取类型
收费全文 | 4680篇 |
免费 | 595篇 |
国内免费 | 119篇 |
专业分类
电工技术 | 41篇 |
综合类 | 92篇 |
化学工业 | 796篇 |
金属工艺 | 66篇 |
机械仪表 | 86篇 |
建筑科学 | 157篇 |
矿业工程 | 49篇 |
能源动力 | 303篇 |
轻工业 | 2235篇 |
水利工程 | 44篇 |
石油天然气 | 145篇 |
武器工业 | 1篇 |
无线电 | 172篇 |
一般工业技术 | 442篇 |
冶金工业 | 27篇 |
原子能技术 | 20篇 |
自动化技术 | 718篇 |
出版年
2024年 | 60篇 |
2023年 | 265篇 |
2022年 | 301篇 |
2021年 | 296篇 |
2020年 | 280篇 |
2019年 | 225篇 |
2018年 | 174篇 |
2017年 | 243篇 |
2016年 | 281篇 |
2015年 | 265篇 |
2014年 | 354篇 |
2013年 | 303篇 |
2012年 | 390篇 |
2011年 | 328篇 |
2010年 | 263篇 |
2009年 | 265篇 |
2008年 | 104篇 |
2007年 | 216篇 |
2006年 | 181篇 |
2005年 | 76篇 |
2004年 | 39篇 |
2003年 | 45篇 |
2002年 | 68篇 |
2001年 | 53篇 |
2000年 | 32篇 |
1999年 | 45篇 |
1998年 | 29篇 |
1997年 | 10篇 |
1996年 | 17篇 |
1995年 | 18篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 15篇 |
1987年 | 35篇 |
1986年 | 33篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有5394条查询结果,搜索用时 0 毫秒
1.
《Food Control》2006,17(2):108-113
The concept of food safety has lately acquired a new approach due to globalization and free trade in food. Introducing a HACCP system in the production and trade in food has become a necessity. The term “food trade” indicates all the postproduction procedures, from storage, transport and distribution to retail, including export and import. The aim of our 2002 survey was to analyse the situation of cold chain maintaining in food trade in Ljubljana, the capital of Slovenia. The research was based upon two hypotheses: in the first one we supposed that a cold chain is interrupted in retail and in the second one we supposed that the handling of food in retail varies. Seventeen stores were divided in three groups, according to sales area of the store: large ones, medium ones and small ones. Temperature conditions in cooling appliances for storage of 1688 perishable food products were measured. Products were inspected by two criteria, by the “best before” date and by the storage temperature. The results confirmed both of the hypotheses. The storage conditions were properly labelled on the packages of the products inspected. In most of the cases the temperatures measured differed from the required ones, even for up to 10 °C. The biggest differences were detected between temperatures indicated on cooling appliances and temperatures measured by our calibrated thermometers. Conditions during food storage and in retail stores were not documented and there was no system to control the cold chain. Our findings have shown that retailers are not familiar with the importance of maintaining a cold chain. The result of that can be a shorter durability of highly perishable foodstuffs and their safety for consumers is questionable. 相似文献
2.
3.
《Advances in Engineering Software》2007,38(5):295-300
The paper presents the implementation of an association rules discovery data mining task using Grid technologies. For the mining task we are using the Apriori algorithm on top of the Globus toolkit. The case study presents the design and integration of the data mining algorithm with the Globus services. The paper compares the Grid version with related work in the field and we outline the conclusions and future work. 相似文献
4.
5.
6.
设计了基于微电子机械系统(Microelectro mechanical system,MEMS)惯性传感器集成模块ADIS16355的姿态测量系统。该姿态测量系统采用ADIS16355作为惯性测量单元,利用加速度计对重力向量的观测来修正陀螺给出的姿态信息,卡尔曼滤波实现传感器信息融合以计算运动载体的姿态角。介绍了ADIS16355的基本功能模块,阐述了两种传感器融合测量实时姿态角的方法并给出了卡尔曼滤波算法迭代过程。基于ARMv7架构的Cotex-M3微处理器设计了姿态测量系统硬件。采用AHRS500GA对该姿态测量系统性能进行了测量姿态角的验证实验。测试结果表明,该姿态测量系统能在动态条件下准确地测定运动物体实时姿态角,其误差一般在±1°左右。 相似文献
7.
Perceptual scenes and scene swing surveys are the ideas for reminding local and wooded area park executives and scene placement. The maximum precise analysis of panorama visualization, forest park landscapes, planning of essential scenic spots, and visualization and safety of Geographic Information Systems (GIS) cost tools is primarily based on management and historical data. Visual impacts and cultural, historical past adjustments to are expecting visual and natural landscapes. By deciding on points from a panorama attitude, intervention calls for vital signs and symptoms of safety. Among them, studies are being carried out in many towns around the arena. Geographic Information System (GIS) depends simply on noticeable assessment and is remembered for the social legacy plan. The Gate Array (FPGA) and Geographic Information System (GIS) are analyzed based on the panorama in every place within the painting's framework. In these activities, landscape planning is proposed thru the development of scientific Piedmont. Turin is conducting a few research. From a global attitude, the version suggests that these packages reduce the capability use of the era. 相似文献
8.
9.
Engineering with Computers - This paper introduces a new version for the nonlinear Ginzburg–Landau equation derived from fractal–fractional derivatives and proposes a computational... 相似文献
10.
Emad Karrar Isam A. Mohamed Ahmed Muhammad Faisal Manzoor Frederick Sarpong Wei Wei Xingguo Wang 《European Journal of Lipid Science and Technology》2021,123(3):2000104
Cucurbitaceae family seeds are mostly discarded as agro-industrial wastes. Gurum (Citrullus lanatus var. colocynthoide) is an underutilized wild cucurbit plant, closely related to desert watermelon, which is grown abundantly in some African countries. Gurum seeds can play a significant role in health and nutrition due to their high oil content. This review describes the nutritional composition of gurum seeds and their oil profile. Gurum seeds are a good source of oil (27–35.5%), fiber (26–31%), crude protein (15–18%), and carbohydrates (14–17%). Gurum seeds oil is extracted by supercritical CO2 (SFE), screw press, and solvent extraction techniques. The gurum seeds oil is composed of unsaturated fatty acids with a high proportion of linoleic acid (C18:2) and oleic acid (C18:1). Gurum seeds oil contains various bioactive compounds, such as tocopherols, phytosterols, and polyphenols. It is reported that solvent extraction gives a higher yield than the screw press and SFE, but the SFE is preferred due to safety issues. More studies are required for producing better quality gurum seeds oil by using novel extraction techniques that can increase oil yield. 相似文献