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   179篇
  免费   10篇
电工技术   1篇
化学工业   69篇
机械仪表   2篇
建筑科学   5篇
矿业工程   1篇
能源动力   7篇
轻工业   17篇
水利工程   1篇
无线电   8篇
一般工业技术   23篇
冶金工业   27篇
自动化技术   28篇
  2023年   6篇
  2022年   8篇
  2021年   19篇
  2020年   10篇
  2019年   13篇
  2018年   7篇
  2017年   4篇
  2016年   13篇
  2015年   5篇
  2014年   7篇
  2013年   17篇
  2012年   9篇
  2011年   11篇
  2010年   7篇
  2009年   6篇
  2008年   5篇
  2007年   5篇
  2006年   6篇
  2005年   3篇
  2004年   2篇
  2003年   1篇
  2000年   2篇
  1998年   10篇
  1997年   4篇
  1996年   4篇
  1995年   1篇
  1988年   3篇
  1984年   1篇
排序方式: 共有189条查询结果,搜索用时 218 毫秒
91.
Waste high-density polyethylene (HDPE) was degraded thermally and catalytically using BaCO3 as a catalyst under different conditions of temperature, cat/pol ratio and time. The oil collected at optimum conditions (450 °C, 0.1 cat/pol ratio and 2 h reaction time) was fractionated at different temperatures and fuel property of the fractions and parent oil was evaluated by their physicochemical parameters for fuel tests. The results were compared with the standard values for gasoline, kerosene and diesel oil. Boiling point distribution (BPD) curves were plotted from the gas chromatographic study of the samples and compared with that of the standard gasoline, kerosene and diesel. The oil samples were analyzed using GC/MS in order to find out their composition. The physical parameters and the composition of the parent oil and its fractions support the resemblance of the samples with the standard fuel oils. The light fractions best match with gasoline, the middle fractions match with kerosene and the heavier fractions match with diesel oil in almost all of the characteristic properties.  相似文献   
92.
Traumatic spinal cord injury (SCI) produces lower urinary tract (LUT) dysfunction that has been studied in surgical transection models. Our aim was to assess LUT functional deficit in a clinically relevant model of incomplete SCI to investigate how partial preservation of supraspinal connections might affect LUT dysfunction. Standardized weight-drop contusion (10 g x 2.5 cm) or complete transection, was produced at T8 in female Sprague-Dawley rats. Behavioral tests were used to assess hind limb sensorimotor function at Day 1 after surgery and weekly thereafter. The urometric experiments were conducted on groups (n = 7) of uninjured rats and on injured rats during Weeks 1 and 2 after SCI (before and after spontaneous voiding was established) as well as Week 2 after a complete transection (n = 3). Under anesthesia, the bladder was continuously perfused with saline. Changes in bladder pressure and external urethral sphincter (EUS) electrical activity were monitored. The bladder was then dissected and weighed and both the bladder and spinal cord were fixed for pathoanatomical analyses. Our results indicate that several aspects of LUT dysfunction after contusive SCI were similar to transection, e.g., reduction of voiding efficiency (approximately 5% of normal value), decrease in inter-contraction interval (47%), increase in bladder capacity (8-fold), and weight (4.6-fold). One aspect appeared different from transection--partial recovery from acute bladder/sphincter dyssynergia. Because the coordination of bladder and EUS function is mediated by brainstem pathways, partial recovery of synergy after SCI was likely due to sparing of some relevant bulbospinal projections as was confirmed by retrograde transneuronal viral tracing.  相似文献   
93.
94.
推动对经济型高密度千兆以太网交换机需求不断增长的因素有多方面,如从快速以太网到千兆以太网标准的演进、新的高带宽应用,以及稳步上升的网络业务交易规模及数量。本文将对推动千兆以太网交换机密度和性能提高的应用及趋势作一个全面的评述。  相似文献   
95.
Prognosis of patients with carcinoma of the exocrine pancreas is particularly poor. A combination of chemotherapy with immunotherapy could be an option for treatment of pancreatic cancer. The aim of this study was to perform an immunomonitoring of 17 patients with pancreatic cancer from the CapRI-2 study, and tumor-bearing mice treated with combination of chemo (radio) therapies with interferon-2α. Low doses of interferon-2α led to a decrease in total leukocyte and an increase in monocyte counts. Furthermore, we observed a positive effect of interferon-2α therapy on the dendritic cells and NK (natural killer) cell activation immediately after the first injection. In addition, we recorded an increased amount of interferon-γ and IL-10 in the serum following the interferon-2α therapy. These data clearly demonstrate that pancreatic carcinoma patients also show an immunomodulatory response to interferon-2α therapy. Analysis of immunosuppressive cells in the Panc02 orthotopic mouse model of pancreatic cancer revealed an accumulation of the myeloid-derived suppressor cells in spleens and tumors of the mice treated with interferon-2α and 5-fluorouracil. The direct effect of the drugs on myeloid-derived suppressor cells was also registered in vitro. These data expose the importance of immunosuppressive mechanisms induced by combined chemo-immunotherapy.  相似文献   
96.
97.
98.
The steady-state behavior of an existing plant depends on the independent input variables, process equipment and process controllers. This paper presents a method for formulating models that represent the effects of controllers when they are included within a steady-state process flowsheet. The method replaces the controller equations with the equivalent stationarity conditions representing the relationship between the controlled variables and the implemented manipulated variables at steady state. The method is demonstrated for the centralized multivariable Dynamic Matrix Control algorithm applied to two processes, binary distillation and gasoline blending. The integrated process and control system simulation is used to design controllers that improve the profitability of processes without extensive real-time calculations; this is sometimes termed self-optimizing control. For both processes, controllers were designed that yielded higher profit than standard control methods and that approached the highest possible profit achieved by frequent real-time optimization.  相似文献   
99.
Influenza virus is a well-known respiratory pathogen, which still leads to many severe pulmonary infections in the human population every year. Morbidity and mortality rates are further increased if virus infection coincides with co-infections or superinfections caused by bacteria such as Streptococcus pneumoniae (S. pneumoniae) and Staphylococcus aureus (S. aureus). This enhanced pathogenicity is due to complex interactions between the different pathogens and the host and its immune system and is mainly governed by altered intracellular signaling processes. In this review, we summarize the recent findings regarding the innate and adaptive immune responses during co-infection with influenza virus and S. pneumoniae or S. aureus, describing the signaling pathways involved and how these interactions influence disease outcomes.  相似文献   
100.
Progression to castration resistance is a major problem in the treatment of advanced prostate cancer and is likely to be driven by activation of several molecular pathways, including androgen receptor (AR) and cyclic AMP-dependent protein kinase A (PKA). In this study, we examined the therapeutic efficacy of a combined inhibition of the AR and the regulatory subunit type Iα (RIα) of protein kinase A with second generation antisense oligonucleotides (ODNs) in androgen-sensitive LNCaP and castration-resistant LNCaPabl tumors in vivo. We found that targeting the AR alone inhibited LNCaP, as well as LNCaPabl tumors. Combined inhibition resulted in an improved response over single targeting and even a complete tumor remission in LNCaPabl. Western blot analysis revealed that both ODNs were effective in reducing their target proteins when administered alone or in combination. In addition, treatment with the ODNs was associated with an induction of apoptosis. Our data suggest that dual targeting of the AR and PKARIα is more effective in inhibiting LNCaP and LNCaPabl tumor growth than single treatment and may give a treatment benefit, especially in castration-resistant prostate cancers.  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