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排序方式: 共有165条查询结果,搜索用时 0 毫秒
61.
研究了新鲜石灰石和经过煅烧/碳酸化反应(CCR)反复循环后的石灰石在烟煤煤焦CO2气化反应中的催化特性.结果表明,固定碳转化率随新鲜石灰石添加比例的增加而增大,石灰石添加比例为5%时其催化特性达到最佳,且催化活性随气化温度的升高而降低;在不同热解温度下添加2.5%新鲜石灰石制得的煤焦的气化特性与气化温度密切相关,当气化温度高于热解温度时,催化活性基本不受热解温度影响;随着CCR循环次数的增加,低温气化时石灰石催化活性比新鲜石灰石略低,但仍可作为煤焦气化反应的有效催化剂.  相似文献   
62.
板壳式换热器在燕山石化重整装置中的应用   总被引:2,自引:1,他引:1  
介绍了反应进出料板壳式换热器在燕山石化重整装置中的应用情况,并与管壳式换热器进行了对比。  相似文献   
63.
Glioblastoma multiforme (GBM) is a brain tumor with a very poor prognosis. For this reason, researchers worldwide study the impact of the tumor microenvironment in GBM, such as the effect of chemokines. In the present study, we focus on the role of the chemokine CCL18 and its receptors in the GBM tumor. We measured the expression of CCL18, CCR8 and PITPNM3 in the GMB tumor from patients (16 men and 12 women) using quantitative real-time polymerase chain reaction. To investigate the effect of CCL18 on the proliferation and migration of GBM cells, experiments were performed using U-87 MG cells. The results showed that CCL18 expression was higher in the GBM tumor than in the peritumoral area. The women had a decreased expression of PITPNM3 receptor in the GBM tumor, while in the men a lower expression of CCR8 was observed. The hypoxia-mimetic agent, cobalt chloride (CoCl2), increased the expression of CCL18 and PITPNM3 and thereby sensitized U-87 MG cells to CCL18, which did not affect the proliferation of U-87 MG cells but increased the migration of the test cells. The results indicate that GBM cells migrate from hypoxic areas, which may be important in understanding the mechanisms of tumorigenesis.  相似文献   
64.
高东斌  彭昌根 《广州化工》2014,(5):121-123,153
介绍了催化重整Cyclmax Chlosorb技术工艺原理以及工艺流程,并介绍了Cyclmax Chlosorb技术工业运用中出现的低温氯腐蚀及下料腿堵塞导致再生偏烧的问题,通过传热计算得到分离料斗内壁面温度为112.1℃,低于露点温度,导致了低温氯腐蚀。通过增加伴热和提高操作温度改善了氯腐蚀问题,并提出提高预热气温度和改进催化剂除尘的建议进一步改善分离料斗下料腿堵塞问题。  相似文献   
65.
胡鸿飞 《石化技术》2004,11(4):29-32
介绍了国内首套1.0 Mt/a连续重整装置的工业运行及标定情况,根据标定数据分析,在反应温度290℃,空速7.0 h,氢油体积比92,反应压力2.42MPa的条件下,原料油中硫含量为4.0×10-4mg/L左右,精制油的硫含量为4.0×10-5mg/L.催化剂装填及装置开工过程中控制较好,催化剂使用效果好,强度能满足工艺要求.  相似文献   
66.
67.
The HIV coreceptor CCR5 is a validated target for both the prevention and therapy of HIV infection. PSC-RANTES, an N-terminally modified analogue of one of the natural chemokine ligands of CCR5 (RANTES/CCL5), is a potent inhibitor of HIV entry into target cells. Here, we set out to engineer the anti-HIV activity of PSC-RANTES into another natural CCR5 ligand (MIP-1beta/CCL4), by grafting into it the key N-terminal pharmacophore region from PSC-RANTES. We were able to identify MIP-1beta/CCL4 analogues that retain the receptor binding profile of MIP-1beta/CCL4, but acquire the very high anti-HIV potency and characteristic inhibitory mechanism of PSC-RANTES. Unexpectedly, we discovered that in addition to N-terminal structures from PSC-RANTES, the side chain of Lys33 is also necessary for full anti-HIV potency.  相似文献   
68.
Chemokines interact with chemokine receptors in a promiscuous network, such that each receptor can be activated by multiple chemokines. Moreover, different chemokines have been reported to preferentially activate different signalling pathways via the same receptor, a phenomenon known as biased agonism. The human CC chemokine receptors (CCRs) CCR4, CCR7 and CCR10 play important roles in T cell trafficking and have been reported to display biased agonism. To systematically characterize these effects, we analysed G protein- and β-arrestin-mediated signal transduction resulting from stimulation of these receptors by each of their cognate chemokine ligands within the same cellular background. Although the chemokines did not elicit ligand-biased agonism, the three receptors exhibited different arrays of signaling outcomes. Stimulation of CCR4 by either CC chemokine ligand 17 (CCL17) or CCL22 induced β-arrestin recruitment but not G protein-mediated signaling, suggesting that CCR4 has the potential to act as a scavenger receptor. At CCR7, both CCL19 and CCL21 stimulated G protein signaling and β-arrestin recruitment, with CCL19 consistently displaying higher potency. At CCR10, CCL27 and CCL28(4-108) stimulated both G protein signaling and β-arrestin recruitment, whereas CCL28(1-108) was inactive, suggesting that CCL28(4-108) is the biologically relevant form of this chemokine. These comparisons emphasize the intrinsic abilities of different receptors to couple with different downstream signaling pathways. Comparison of these results with previous studies indicates that differential agonism at these receptors may be highly dependent on the cellular context.  相似文献   
69.
Psoriasis is a common skin disease accompanied by chronic inflammation. In previous studies, erythroid differentiation regulator 1 (ERDR1) was shown to have a negative correlation with proinflammatory cytokine IL-18. However, the role of ERDR1 in the inflammatory skin disease psoriasis has not been evaluated. In this study, to investigate the role of ERDR1 in psoriasis, recombinant ERDR1 was injected intraperitoneally into a psoriasis mouse model. Recombinant ERDR1 (rERDR1) significantly alleviated the symptoms of psoriasis-like skin inflammation and reduced the mRNA of various psoriasis-related markers, including keratin 14, S100A8, and Th17-related cytokines IL-17 and IL-22, suggesting that rERDR1 exerts therapeutic effects on psoriasis via the regulation of Th17 functions. Additionally, the expression of CCL20, a well-known Th17 attracting chemokine, was determined. CCL20 expression significantly decreased in the rERDR1-injected group compared with the vehicle (PBS)-injected group. CCR6 expression in the psoriatic lesional skin was also decreased by rERDR1 administration, implying the inhibition of CCR6-expressing Th17 cell chemotaxis via the downregulation of CCL20. Taken together, this study provides the first evidence that ERDR1 may be a potential therapeutic target for psoriasis.  相似文献   
70.
路守彦 《广东化工》2013,(19):82-83
文章对我国催化重整生产现状、工艺技术、催化剂和发展趋势进行分析,目前连续重整为最有竞争力的工艺,大力发展芳烃等石油化工行业,加快连续重整生产工艺国产化的推广,有利于我国催化重整的可持续发展。  相似文献   
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