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   22篇
  免费   1篇
  国内免费   1篇
电工技术   4篇
化学工业   6篇
机械仪表   1篇
建筑科学   1篇
轻工业   4篇
无线电   1篇
一般工业技术   4篇
冶金工业   3篇
  2018年   1篇
  2017年   1篇
  2010年   1篇
  2007年   1篇
  2005年   1篇
  2004年   2篇
  2003年   1篇
  2001年   2篇
  2000年   1篇
  1998年   4篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1993年   1篇
  1991年   2篇
  1988年   1篇
  1980年   1篇
排序方式: 共有24条查询结果,搜索用时 62 毫秒
1.
The extraction equilibria of various di- and tripeptides with di-2-ethylhexylphosphoric acid (D2EHPA) were studied at low pH values. The complex extracted to organic phase consisted of one molecule of peptide and two molecules of D2EHPA dimer. The extraction constants of the peptides correlated well with the distribution coefficients of peptides between 1-octanol and water, which is a measure of hydrophobicity. The permeation rates of peptides through an emulsion liquid membrane were examined by using D2EHPA as a carrier, Span 80 as an emulsifier and kerosene as a diluent. The rates varied considerably with peptide type, depending upon the hydrophobicity.  相似文献   
2.
The effects of Ni(II) in a synthetic wastewater on the activity of activated sludge microorganisms and sequencing batch reactor (SBR) treatment process were investigated. Two parallel lab-scale SBR systems were operated. One was used as a control unit, while the other received Ni(II) concentrations equal to 5 and 10 mg/l. The SBR systems were operated with FILL, REACT, SETTLE, DRAW and IDLE modes in the time ratio of 0.5:3.5:1.0:0.75:0.25 for a cycle time of 6 h. The addition of Ni(II) into SBR system caused drastically dropped in TOC removal rate (k) and specific oxygen uptake rate (SOUR) by activated sludge microorganisms due to the inhibitory effects of Ni(II) on the bioactivity of microorganisms. The addition of 5 mg/l Ni(II) caused a slight reduction in TOC removal efficiency, whereas 10 mg/l Ni(II) addition significantly affected the SBR performance in terms of suspended solids and TOC removal efficiency. Termination of Ni(II) addition led to almost full recovery of the bioactivity in microorganisms as shown in the increase of specific oxygen uptake rate (SOUR) and SBR treatment performance.  相似文献   
3.
We report the case of a 52-year-old man with papillary adenocarcinoma arising in placentoid bullous lesion of the lung, which is a rare cystic lung disease. Macroscopically, the cyst contained a soft villous tumor closely resembling the placental chorionic villi of early gestation. Histologic examination revealed the tumor to be papillary adenocarcinoma with an abundant stromal core, which comprised vascular and lymphatic vessels, lymphocytes, fat cells, and smooth muscle. Immunohistochemically, adenocarcinoma cells were positive for CAM 5.2, epithelial membrane antigen, and PE10 (antisurfactant apoprotein A antibody). These results indicate that the adenocarcinoma was derived from the component epithelial cells of the cyst. Based on the tumor's macroscopic and microscopic appearance and on the results of the immunohistochemical studies, we conclude that the cystic tumor in our case arose in a placentoid bullous lesion of the lung.  相似文献   
4.
This study investigates the adverse and persistent effects of ethinylestradiol (EE2) on mature gonads of transgenic olvas-GFPIST II-YI medaka (Oryzias latipes). The measurement of gonadal size calculating the GFP-fluorescent area was used as a technique that enabled monitoring gonads in living specimens by GFP fluorescence. First, mature medaka were exposed to EE2 (47.8-522 ng/L) for 4 weeks. The gonads showed a significant reduction of the GFP-fluorescent area and Gonadosomatic Index in males exposed to EE2 at >216 ng/L and females exposed at 522 ng/L. Histologically, males at all treatments exhibited testis-ova and additionally, high connective tissue prevalence at > or =216 ng/L. Next, mature male medaka were exposed to EE2 (43.7-473 ng/L) for 3 weeks and allowed to depurate for 6 weeks, to investigate persistent effects of EE2. Continuous gonad observation showed that GFP began to decline 3 weeks after initial exposure to > or =215 ng/L. After depuration, the gonad's fluorescent areas gradually recovered, with no statistical difference at the end of the depuration period; normal spermatogenesis was present in these individuals. Alterations in GFP fluorescence clearly indicate the condition of the gonad in transgenic medaka and this strain showed a facilitated screening fish model to detect the adverse effects on the gonad by estrogenic chemicals.  相似文献   
5.
Efforts have been made to reproduce shitogi, a finely pounded rice powder and to make sake from shitogi of the type produced in ancient times in Japan. As the particle size of the shitogi became smaller, the rate of degradation of shitogi by glucoamylase increased. The pounding of shitogi enhanced the saccharification of starchy materials. The ancient Japanese alcoholic beverage known as shitogi sake was made with cooked rice, dry yeast and tap water, using mould‐infected shitogi as the saccharifying agent. It contained 10.7–14.3% ethanol (v/v) and had a fine aroma but a sour taste. We believe that we have reproduced the alcoholic beverage, shitogi sake which might have been one of original Japanese alcoholic beverages.  相似文献   
6.
1. This study was undertaken to evaluate the preventive effects of locally administered argatroban, a competitive inhibitor of thrombin-induced platelet activation, on restenosis after balloon angioplasty. 2. A hydrogel-coated balloon catheter was immersed three times in argatroban/saline solution (1 mg/mL) for 60 s, inflated to a pressure of 606 kPa and left in the rabbit common carotid artery for 1 min. The same procedure was performed, without drug, as a control. The pharmacokinetics of delivered argatroban in the arterial wall were assessed using [14C]-argatroban. Platelet deposition 2 h after balloon injury was quantified by fluorescence studies using antiplatelet antibody. Vascular smooth muscle cell (VSMC) proliferation 3 days after balloon injury was assessed by immunohistochemical staining for proliferative cell nuclear antigen (PCNA). In a clinical study, we divided 50 elective patients into two groups: argatroban and control. 3. In the experimental study, the mean quantities of argatroban at 0, 2 and 6 h after deflation were 24.63, 0.49 and 0.11 nmol/g wet weight of artery, respectively. Argatroban was undetected 24 h after deflation. Two hours after deflation, argatroban-treated arteries showed less platelet adhesion than saline-treated controls. The mean number of PCNA-positive cells was 16.9 and 43.8% in the argatroban and control groups, respectively (P < 0.01). In the clinical study, the mean late gain loss was 8.2 and 27.3% in the argatroban and control groups, respectively (P < 0.05). The mean late restenosis rate was 11.1 and 41.4% in the argatroban and control groups, respectively (P < 0.05). 4. These data suggest that blood coagulation plays a significant role in VSMC proliferation after balloon injury and that locally administered argatroban using hydrogel-coated balloon catheter may prevent post-percutaneous transluminal coronary angioplasty restenosis.  相似文献   
7.
The TE-TM mode conversion efficiency when a Gaussian beam wave propagates in thin-film optical waveguides is discussed. For film thicknesses at which strong coupling between the TE and TM modes is obtained, two hybrid modes have oppositely rotating circular polarizations, or linear polarizations perpendicular to each other with equal magnitude of TE-wave and TM-wave components. In the former (i.e. circular polarization), complete TE-TM mode conversion is impossible. In the latter (i.e. linear polarization) complete TE-TM mode conversion is available. These claims are based on the fact that the direction of power flow of the hybrid modes depends on the polarization  相似文献   
8.
A premenopausal female patient presented with acute myocardial infarction of 3 different coronary vessels at different times within 1 year. These events were caused not by restenotic lesions after balloon angioplasty but by new lesions, which were successfully treated by primary angioplasty. Although she had a history of hypertension, type IIB hyperlipidemia, and diabetes, they had been well-controlled on medication. An elevated serum lipoprotein(a) level may have played a role in this rapid angiographic progression.  相似文献   
9.
10.
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