首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   846篇
  免费   1篇
  国内免费   12篇
电工技术   1篇
综合类   2篇
化学工业   9篇
金属工艺   31篇
机械仪表   11篇
建筑科学   7篇
矿业工程   2篇
能源动力   5篇
轻工业   35篇
水利工程   4篇
石油天然气   2篇
无线电   22篇
一般工业技术   23篇
冶金工业   680篇
原子能技术   3篇
自动化技术   22篇
  2023年   3篇
  2022年   3篇
  2021年   1篇
  2020年   4篇
  2019年   3篇
  2018年   3篇
  2017年   2篇
  2016年   3篇
  2015年   4篇
  2014年   7篇
  2013年   16篇
  2012年   8篇
  2011年   18篇
  2010年   12篇
  2009年   10篇
  2008年   8篇
  2007年   7篇
  2006年   9篇
  2005年   9篇
  2004年   9篇
  2003年   5篇
  2002年   2篇
  2001年   1篇
  2000年   5篇
  1999年   22篇
  1998年   195篇
  1997年   120篇
  1996年   73篇
  1995年   41篇
  1994年   34篇
  1993年   38篇
  1992年   7篇
  1991年   7篇
  1990年   13篇
  1989年   22篇
  1988年   14篇
  1987年   13篇
  1986年   7篇
  1985年   8篇
  1984年   1篇
  1983年   3篇
  1982年   5篇
  1981年   6篇
  1980年   3篇
  1978年   2篇
  1977年   28篇
  1976年   41篇
  1975年   1篇
  1955年   3篇
排序方式: 共有859条查询结果,搜索用时 15 毫秒
41.
42.
Treatment and prognosis of urinary bladder cancer largely are determined by the tumor stage and presence of metastases. MR imaging and clinical staging complement each other. MR imaging is the most accurate technique for differentiating the various stages of deep tumor infiltration and detection of metastases, whereas clinical staging is the best technique for differentiating between postbiopsy effects and the various stages of superficial tumors. The role of MR imaging in staging of this disease and monitoring of therapy is reviewed and illustrated. Finally, the authors present an overview of current and future applications of this technique.  相似文献   
43.
44.
An agile manufacturing workcell design   总被引:1,自引:0,他引:1  
This paper introduces a design for agile manufacturing worked Is intended for light mechanical assembly of products made from similar components (i.e., parts families). We define agile manufacturing as the ability to accomplish rapid changeover from the assembly of one product to the assembly of a different product. Rapid hardware changeover is made possible through the use of robots, flexible part feeders, modular grippers, and modular assembly hardware. The division of assembly, feeding, and unloading tasks between multiple robots is examined with prioritization based upon assembly time. Rapid software changeover will be facilitated by the use of a real-time, object-oriented software environment utilizing graphical simulations for off-line software development. An innovative dual VMEbus controller architecture permits an open software environment while accommodating the closed nature of most commercial robot controllers. These agile features permit new products to be introduced with minimal downtime and system reconfiguration.  相似文献   
45.
Flow profiles of commercially processed whole, two-percent, one-percent and nonfat milks with added solids as well as skim milk without added solids were measured using a rotational steady shear viscometer. Also tested were mixtures of concentrated skim milk added to skim milk over a range of 9.7% to 20.2% total solids. A shear rate range of 121 to 486 s-1 was used with a cone and plate geometry. In all cases, linear plots of shear stress versus shear rate with small nonzero intercepts were obtained.  相似文献   
46.
Tubular members have been used for constructing offshore structures. Large-scale fatigue tests of welded tubular K-joints under the balanced in-plane bending brace were carried out to investigate the fatigue behavior of API 2W Gr.50 steel produced by POSCO. The experimental results were verified by numerical approaches and compared with the IIW, DnV RP-C203 and API RP 2A-WSD design curves. The test results based on the hot spot stress were in agreement with the design curves. The SCF factor for tubular K-jo...  相似文献   
47.
Osseointegration has been used as an index for prediction of long-term success of implant. Osseointegration has been routinely evaluated by measuring bone contact ratio on histology based on two-dimensional (2D) sections or images. However, these both methodologies have been less informative analysis of results and have several disadvantages. The aim of this study is to introduce new methodology for evaluation of a degree of osseointegration between bone and implant based on micro computed tomography (μ-CT) images. Specimen was scanned at a voxel resolution of 35 μ by μ-CT. Three-dimensional (3D) models of bone and implant were reconstructed respectively. Bone contact area (BCA) and bone contact area ratio (BCAR) were measured and calculated. Here, osseointegrated BCA between bone and implant surfaces was determined by computing areas of all bone regions existed within 35μ distance from implant surface. Osseointegration of flapless implant surgery was evaluated by new methodology, compared with that of flap implant surgery. BCA and BCAR in flapless implant surgery was significantly bigger than that in flap implant surgery (p<0.05), suggesting that flapless implant surgery was more effective than flap implant surgery consistent with previous studies. In the conclusion, new methodology for evaluation osseointegration between bone and implant based on μ-CT images was likely to be reliable, useful and more informative analysis of results.  相似文献   
48.
OBJECTIVE: To propose a definition for stage IA1 cervical adenocarcinoma, based on the International Federation of Gynecology and Obstetrics (FIGO) staging system, and to determine if patients meeting criteria might be candidates for conservative surgery. METHODS: Two hundred women were diagnosed with early-stage cervical adenocarcinoma from 1982 to 1996. Histopathologic sections were reviewed by a gynecologic pathologist. Medical records were reviewed, and patients included in this study had microscopically identifiable lesions, up to 3 mm invasive depth, up to 7 mm tumor width, and negative margins if cone biopsy was performed. RESULTS: Twenty-one patients with microinvasive adenocarcinoma met criteria for FIGO stage IA1 carcinoma of the cervix. The median (range) follow-up was 76 (30-172) months and median (range) patient age was 38 (24-75) years. Definitive treatment included type II or III radical hysterectomy in 16 cases, simple abdominal or vaginal hysterectomy in four cases, and loop electrosurgical excision procedure in one case; one patient received adjuvant pelvic radiation. The histologic subtypes were endocervical adenocarcinoma in 18 cases, adenosquamous carcinoma in two cases, and clear-cell adenocarcinoma in one case. There was no evidence of parametrial invasion or lymph node metastases in any patient who had radical surgery, and there were no disease recurrences. CONCLUSION: Patients with microinvasive adenocarcinoma who met criteria for FIGO stage IA1 cervical carcinoma had disease limited to the cervix, and conservative surgery, such as cone biopsy or simple hysterectomy, might offer them definitive treatment.  相似文献   
49.
Our laboratories have documented a significantly high occurrence of chromosome 1p36 rearrangements in non-Hodgkin lymphoma (NHL). The cell division cycle 2-like 1(CDC2L1) (also known as TP58 or PITSLRE) gene, a protein kinase implicated in apoptotic signaling, is located at the very distal region of chromosome 1p36 and is likely to be disrupted by structural rearrangements involving 1p36. To determine the molecular consequences of the recurrent involvement of the 1p36 region, we examined metaphases containing 1p36 abnormalities from 31 specimens derived from 26 patients for the possible deletion of CDC2L1 by fluorescence in situ hybridization (FISH) using the TP58clk-1 DNA probe. Twenty-three cases exhibited the loss of CDC2L1 from the abnormal chromosome 1. In 2 of 26 cases, the gene locus was translocated to the partner chromosome, and in four specimens, all derived from one case, CDC2L1 was not deleted. This pilot investigation suggests that 1p36 rearrangements, and consequently the loss of the CDC2L1 gene locus, is important in NHL. This work also opens avenues for further molecular studies and prognostic correlations.  相似文献   
50.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号