全文获取类型
收费全文 | 2520篇 |
免费 | 10篇 |
专业分类
电工技术 | 8篇 |
综合类 | 4篇 |
化学工业 | 66篇 |
金属工艺 | 4篇 |
机械仪表 | 10篇 |
建筑科学 | 19篇 |
矿业工程 | 1篇 |
能源动力 | 30篇 |
轻工业 | 52篇 |
水利工程 | 2篇 |
石油天然气 | 4篇 |
无线电 | 79篇 |
一般工业技术 | 128篇 |
冶金工业 | 2029篇 |
原子能技术 | 22篇 |
自动化技术 | 72篇 |
出版年
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 10篇 |
2017年 | 6篇 |
2016年 | 13篇 |
2014年 | 14篇 |
2013年 | 34篇 |
2012年 | 15篇 |
2011年 | 19篇 |
2010年 | 15篇 |
2009年 | 32篇 |
2008年 | 34篇 |
2007年 | 17篇 |
2006年 | 26篇 |
2005年 | 19篇 |
2004年 | 22篇 |
2003年 | 20篇 |
2002年 | 16篇 |
2001年 | 25篇 |
2000年 | 16篇 |
1999年 | 81篇 |
1998年 | 681篇 |
1997年 | 344篇 |
1996年 | 208篇 |
1995年 | 117篇 |
1994年 | 99篇 |
1993年 | 132篇 |
1992年 | 31篇 |
1991年 | 29篇 |
1990年 | 36篇 |
1989年 | 43篇 |
1988年 | 30篇 |
1987年 | 20篇 |
1986年 | 42篇 |
1985年 | 29篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 14篇 |
1981年 | 18篇 |
1980年 | 18篇 |
1978年 | 9篇 |
1977年 | 44篇 |
1976年 | 83篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1969年 | 3篇 |
1968年 | 5篇 |
1966年 | 4篇 |
排序方式: 共有2530条查询结果,搜索用时 46 毫秒
81.
Lars Mönch John W. Fowler Stéphane Dauzère-Pérès Scott J. Mason Oliver Rose 《Journal of Scheduling》2011,14(6):583-599
In this paper, we discuss scheduling problems in semiconductor manufacturing. Starting from describing the manufacturing process,
we identify typical scheduling problems found in semiconductor manufacturing systems. We describe batch scheduling problems,
parallel machine scheduling problems, job shop scheduling problems, scheduling problems with auxiliary resources, multiple
orders per job scheduling problems, and scheduling problems related to cluster tools. We also present important solution techniques
that are used to solve these scheduling problems by means of specific examples, and report on known implementations. Finally,
we summarize some of the challenges in scheduling semiconductor manufacturing operations. 相似文献
82.
83.
Hospital foodservice directors & dietitians are facing the greatest challenge of their careers -- to prepare, along with their institutions, for the most thoroughgoing reform of America's healthcare system ever proposed. Healthcare institutions across the country are seeking the means to offer enhanced patient services & gain competitive advantages by forming new alliances, new patient-centered care systems & cost-reduction programs. To aid in these efforts, their foodservices are developing comprehensive cross-training schemes, inter-departmental teams with other service groups & new ways to cut operating subsidies. Here's how five hospital foodservice departments are using cost controls, revenue building, quality management processes & enhanced efficiencies to help their institutions prepare for the changes ahead. 相似文献
84.
CS Walpole R Wrigglesworth S Bevan EA Campbell A Dray IF James KJ Masdin MN Perkins J Winter 《Canadian Metallurgical Quarterly》1993,36(16):2381-2389
Structural variants of the hydrophobic side chain ("C region") of the capsaicin molecule have been incorporated into a series of vanillylamides and vanillylthioureas. These compounds have been tested in an in vitro assay for agonism (45Ca2+ influx into dorsal root ganglia neurones), previously shown to be predictive of analgesic activity. The results of this study have established the requirement for a hydrophobic substituent of limited size (molar refractivity, MR, < 55) in order to obtain high potency. Combination of the information gained here about the "C-region" of the capsaicin molecule with the studies described in the preceding two papers provides a rational basis for the design of compounds of increased potency. 相似文献
85.
MA Bloomberg HS Jordan KO Angel MH Bailit KJ Goonan J Straus 《Canadian Metallurgical Quarterly》1993,19(12):586-595
This article describes a collaborative effort between a major health care purchaser, three area health maintenance organizations, and a state Medicaid agency to develop clinical indicators as the basis for a comparison database. Some of the difficulties in developing a "common yardstick" of quality and value are candidly discussed. 相似文献
86.
GG Stone MM Chengappa RD Oberst NH Gabbert S McVey KJ Hennessy M Muenzenberger J Staats 《Canadian Metallurgical Quarterly》1993,5(3):378-385
The polymerase chain reaction was employed to correlate Salmonella serovars isolated from fecal material of greyhounds suffering from gastroenteritis with those isolated from the diet fed to the greyhounds prior to onset of diarrhea. Kennels around the Abilene, Kansas, area were contacted and supplied with materials needed to collect a portion of the diet each day. With the onset of diarrhea, the kennels were instructed to ship the fecal material and diet from the previous 10 days to the laboratory for testing. Forty-one fecal samples and corresponding diets were screened for Salmonella, Clostridium perfringens, Campylobacter jejuni, Staphylococcus aureus, Staphylococcus intermedius, and pathogenic (piliated) Escherichia coli by direct culture using standard procedures. The fecal material was also screened for coronavirus and parvovirus using electron microscopy. Thirty-five "normal" fecal samples were screened for all of the above mentioned microorganisms as a control. In addition, the fecal material was screened for E. coli verotoxins I and II and clostridial enterotoxins. A total of 61 Salmonella isolates were recovered from the 41 samples of feces and diet submitted for testing; 31 were recovered from the feces and 30 from the diet. Four Salmonella isolates were recovered from the normal fecal samples. Results obtained by PCR, plasmid profiles, antigenic analysis, and antibiogram profiles indicated that 16 of the 31 isolates recovered from the fecal material were the same strain as that recovered from the diet. 相似文献
87.
88.
Skin tests on patients suffering from pollinosis suggest frequently an antigenic relationship between various grass and cult. rye pollens. This problem was further studied using both, RAST and RAST inhibition test. The tests were performed with commercial grass pollen discs as well as with self-prepared disc labeled with cult. rye pollens and a combination of various grass antigens. Good agreement was found between self-made and commercial (single antigen) grass pollen discs (95.9%). RAST and skin test correlated also extremely well (92.3%). Mutual inhibition between grass and cult. rye pollens was measured by RAST inhibition test using self-prepared discs. High antigenic relationship between grass and cult. rye pollens was found, however, it could be demonstrated that the antibody pattern varies and contains "grass specific" antibodies. 相似文献
89.
When I started programming computers, I began with fairly primitive languages, such as Fortran 4 and various early flavors of Basic. One of the first things you learn using such languages - indeed, even using more up-to-date languages - is which types your language supports. Being oriented toward number crunching, Fortran supported integer and real types, with the interesting rule that any variable whose name started with the letters I through N was an integer, and all other variables were floats. I'm glad that convention hasn't caught on, although Perl is close. Furthermore, using object-oriented languages, you can define your own types and in the best languages, they act just as well as built-in ones. 相似文献
90.
Solution of a Well-Field Design Problem with Implicit Filtering 总被引:1,自引:0,他引:1
Fowler Kathleen R. Kelley Carl T. Miller Cass T. Kees Christopher E. Darwin Robert W. Reese Jill P. Farthing Matthew W. Reed Mark S. C. 《Optimization and Engineering》2004,5(2):207-234
Problems involving the management of groundwater resources occur routinely, and management decisions based upon optimization approaches offer the potential to save substantial amounts of money. However, this class of application is notoriously difficult to solve due to non-convex objective functions with multiple local minima and both nonlinear models and nonlinear constraints. We solve a subset of community test problems from this application field using MODFLOW, a standard groundwater flow model, and IFFCO, an implicit filtering algorithm that was designed to solve problems similar to those of focus in this work. While sampling methods have received only scant attention in the groundwater optimization literature, we show encouraging results that suggest they are deserving of more widespread consideration for this class of problems. In keeping with our objectives for the community problems, we have packaged the approaches used in this work to facilitate additional work on these problems by others and the application of implicit filtering to other problems in this field. We provide the data for our formulation and solution on the web. 相似文献