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   19篇
  免费   0篇
化学工业   1篇
能源动力   2篇
无线电   1篇
冶金工业   14篇
原子能技术   1篇
  2017年   1篇
  2001年   1篇
  1999年   2篇
  1998年   9篇
  1997年   3篇
  1975年   2篇
  1974年   1篇
排序方式: 共有19条查询结果,搜索用时 0 毫秒
1.
2.
The composition of a mixture of several components flowing through a pipe can be determined by means of an X-ray transmission technique/analysis. We present some aspects of the theory relating to an application in which the component volume fractions of an oil, water, and gas mixture are determined. It will be shown that on fundamental grounds, this technique has its limits regarding the number of components that can be distinguished in relation to the achieved accuracy of the measured attenuation  相似文献   
3.
With the many new investigational possibilities allowing access to the gut-brain axis in humans, new techniques, mainly from neurology, as well as interdisciplinary approaches, have produced insights into afferent information processing from the gut to the brain. They have become research tools in recent years, but will eventually become clinical tools for diagnostic purposes in the future. Gut-brain interactions may be seen at different levels: rather simple research models such as recordable perception and pain, on the one hand, can be contrasted and/or supplemented with neurological stimulation and imaging techniques, and clinical models such as spinal cord injury. All have contributed to the development of a new subspecialty in medicine, neurogastroenterology.  相似文献   
4.
OBJECTIVE: A hypoechoic rim around a focal liver lesion as revealed by conventional sonography may be present in malignant liver lesions as well as in benign liver lesions. This study evaluated the potential of color Doppler sonography in differentiating various focal liver lesions with a hypoechoic rim. CONCLUSION: Color Doppler sonography may be helpful in distinguishing focal nodular hyperplasia (FNH) from other focal liver lesions. The characteristic finding of blood flow within the hypoechoic rim of FNH is most likely caused by small vessel abnormalities that have previously been described for FNH.  相似文献   
5.
The treatment of advanced gastric carcinoma by various neoadjuvant and adjuvant multimodal therapy regimes is under current investigation to improve the poor outcome of these patients. Therefore, pretherapeutic tumor staging according to the TNM classification is essential for the optimal application of various therapeutic modalities. According to recent studies, endoscopic ultrasonography (EUS) is the most sensitive technique in measuring tumor infiltration (T-staging). In addition, although less reliable compared to the T-staging, the sensitivity of EUS in assessing lymph node status (N-staging) is superior to computed tomography and conventional ultrasound. Pretherapeutic laparoscopic investigation may give additional important information about tumor stage. This overview describes the significance of various diagnostic techniques that can be applied in tumor staging investigations.  相似文献   
6.
Taste and smell are important quality criteria for chocolate. Beyond this the gloss and texture are relevant. Different process parameters influence the gloss as well as other criteria such as shelf life and fat bloom resistance. In this work a measurement method is introduced and adapted to small chocolate articles. With this, the gloss can be measured reproducible. Then the different process parameters are varied and the gloss of the chocolate is measured. Different methods to improve the gloss are suggested and observed.  相似文献   
7.
BACKGROUND/AIMS: Today, different endoscopic techniques are available to treat choledocholithiasis. These techniques include mechanical lithotripsy (ML), electrohydraulic lithotripsy (EHL), laserlithotripsy (LL), and extracorporal shock-wave lithotripsy (ESWL). These techniques have to compete with laparoscopic stone removal which is performed with increasing frequency at some centers. METHODOLOGY: We report the results of treatment of choledocholithiasis and compare the results with a meta-analysis of studies in whom endoscopic and laparoscopic techniques were applied. From 1994-1995, 217 patients with symptomatic choledocholithiasis were treated using endoscopic retrograde cholangiography (ERC). RESULTS: Overall, complete stone removal was successful in 98% of all patients and only 5 patients had to undergo surgery. Complete endoscopic removal of stones was achieved in 70% during the first ERC session. In 47 patients consecutive ERC sessions with application of EML, EHL, or ESWL were necessary to completely remove the stones. Complication rate was 5% and included pancreatitis and bleeding from papillotomy. There was no procedure-related mortality. CONCLUSION: The study suggests that today ERC remains the treatment of choice in most patients with symptomatic choledocholithiasis.  相似文献   
8.
Describes the development of a German form of the Position Analysis Questionnaire (PAQ) to serve as a structured job analysis procedure. In Phase 1, independent translations of the PAQ, made by 3 groups of psychologists, were incorporated into the PAQ Bd (the German edition). 30 trained graduate students analyzed 61 positions with the PAQ Bd. Average interrater reliability was .79; average reliability of the individual job elements was .65. In Phase 2, 70 industrial psychologists rated the importance of 59 attributes, modified to include better definitions, for each of the 205 job elements. Satisfactory levels of reliability were achieved. It seems possible to construct profiles of job requirements for positions on the basis of the PAQ Bd analyses of jobs in combination with the attribute profiles of the individual elements. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
In 39 patients with acute meningococcal infections, the plasma concentrations of tumor necrosis factor-alpha (TNF) and its soluble receptors (sRs) TNFsR-p55 and TNFsR-p75 were measured from admission till recovery. At admission, patients with shock had significantly higher TNF, TNFsR-p55, and TNFsR-p75 values than patients without shock. In addition, during the first 24 hours, patients with shock had higher TNFsR-p75 to TNFsR-p55 ratios, indicating that in shock the increase of TNFsR-p75 exceeds that of TNFsR-p55. TNF measured more than 12 hours after admission failed to differentiate between shock and nonshock because TNF concentrations normalized within 12-24 hours. However, because concentrations of TNFsRs remained elevated for 5-6 days, at that time plasma TNFsRs still differentiated between shock and nonshock. Plasma exchange or whole blood exchange (PEBE), performed in 20 patients with shock, accelerated the decrease of plasma TNFsRs. However, because of a rebound after each PEBE session, the overall half-lives of both TNFsRs were not affected by PEBE.  相似文献   
10.
The results of a systems analysis and economic study of a photochemical solar energy system are presented and compared with a conventional hot-water solar energy system. Conversion efficiency, energy storage capacity, and life-cycle costs are the primary bases of comparison.

The paper indicates the requirements to make a photochemical solar energy system technically and economically feasible and identifies potential advantages of the photochemical solar energy system—i.e. lower cost and lighter weight collector, cloudy-day effectiveness, smaller storage tank, storage at room temperature and uniform energy levels in the stored fluid, both winter and summer.

Two possible problem areas have been identified for a photochemical system: anticipated higher initial cost of the working fluid, and possible deterioration of the energy storage capacity with time.  相似文献   

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