脂肪酸酯分子结构对酯基钻井液性能的影响          下载免费PDF全文

刘宁  徐会文  韩丽丽  宋佳宇  王莉莉  Pavel Talalay 《探矿工程》2014,41(9):63-66

脂肪酸酯的分子结构对酯基钻井液的性能具有重要的影响。在分析脂肪酸酯分子中酯基基团数、饱和度、分子构型、分子量大小以及分子间作用力的基础上,选取了6种饱和脂肪酸酯作为研究介质,测试了在不同温度条件下介质的粘度与密度,分析了影响介质粘度与密度的机理,得出了在低温下介质的粘度大小主要取决于脂肪酸酯中脂肪醇分子链的长度。介质密度的高低主要取决于脂肪酸酯的分子量,与脂肪酸酯中酯基的位置、α氢的活泼性以及分子间作用力大小无关。  相似文献   

基于网络药理学及分子对接探讨重连口服液治疗流行性感冒的作用机制          下载免费PDF全文

王小乐  李泽庚  李明慧 《应用海洋学学报》2022,38(5):147

目的：利用网络药理学及分子对接探讨重连口服液治疗流行性感冒的作用机制。方法：通过TCMSP、PubChem、Swiss Target Prediction平台以及相关文献获取重连口服液所含中药的活性成分及对应靶点;通过DisGeNET、DrugBank、Herb数据平台获得流感相关靶点;将有效成分的靶点映射到流感靶点,得到交集靶点即为重连口服液抗流感的潜在靶点;利用Cytoscape软件和String数据库建立化合物-靶点网络及靶蛋白互作（PPI）网络;通过R语言clusterProfiler工具包对核心靶点进行基因本体（GO）功能及京都基因与基因组百科全书（KEGG）通路富集分析。结果：根据筛选条件获取160个活性成分,59个潜在靶点;经网络拓扑分析筛选出重连口服液前5位重要成分为：槲皮素、木犀草素、山柰酚、汉黄芩素、β-谷甾醇,2个重要靶蛋白转录因子P65（RELA）、丝裂原活化蛋白激酶14（MAPK14）。通过分子对接显示5个重要成分与RELA、MAPK14结合能均＜-5.0 kcal/mol。GO富集分析发现重连口服液作用的生物途径与调节脂多糖、细菌源分子等有关系;KEGG通路富集分析表明重连口服液治疗流感涉及IL-17信号通路、TNF信号通路等。结论：重连口服液以多种成分通过调控RELA、MAPK14等靶蛋白,作用于多种生物途径以抑制病毒的复制,减轻炎症反应,调节机体免疫,调控氧化应激等,从而起到抗流感的治疗作用。  相似文献   

Molecular cloning and sequencing of a cDNA encoding partial putative molt-inhibiting hormone from Penaeus chinensis     

Wang Zai-zhao  Xiang Jian-hai 《中国海洋湖沼学报》2002,20(3):232-236

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Hydrodynamical simulations of the decay of high-speed molecular turbulence – I. Dense molecular regions     

Georgi Pavlovski  Michael D. Smith  Mordecai-Mark Mac Low  Alexander Rosen 《Monthly notices of the Royal Astronomical Society》2002,337(2):477-487

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New determinations of the critical velocities of C-type shock waves in dense molecular clouds: application to the outflow source in Orion     

J. Le Bourlot  G. Pineau des Forêts  D. R. Flower  S. Cabrit 《Monthly notices of the Royal Astronomical Society》2002,332(4):985-993

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MOLECULAR CLONING AND SEQUENCING OF A cDNA ENCODING PARTIAL PUTATIVE MOLT-INHIBITING HORMONE FROM PENAEUS CHINENSIS     

王在照  相建海 《中国海洋湖沼学报》2002,20(3):232-236

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Formation pumping of molecular hydrogen in the Messier 17 photodissociation region     

M. G. Burton  D. Londish  P. W. J. L. Brand 《Monthly notices of the Royal Astronomical Society》2002,333(4):721-729

We have imaged the emission from the near-infrared   v =1–0  S(1), 1–0 S(7), 2–1 S(1) and 6–4 O(3) lines of molecular hydrogen in the Northern and South Western Bars of M17, together with the hydrogen Br γ and Br10 lines. This includes the first emission-line image ever to be obtained of a line from the highly excited   v =6  level of molecular hydrogen. In both Bars, the H₂ emission is generally distributed in clumps along filamentary features. The 1–0 S(1) and 2–1 S(1) images have similar morphologies. Together with their relative line ratios, this supports a fluorescent origin for their emission, within a photodissociation region. The SW-Bar contains a clumpy medium, but in the N-Bar the density is roughly constant. The 1–0 S(7) line image is also similar to the 1–0 S(1) image, but the 6–4 O(3) image is significantly different from it. Since the emission wavelengths of these two lines are similar (1.748 to 1.733 μm), this cannot be due to differential extinction between the   v =6  and the   v =1  lines. We attribute the difference to the pumping of newly formed H₂ into the   v =6  , or to a nearby, level. However, this also requires a time-dependent photodissociation region (where molecule formation does not balance dissociation), rather than it to be in steady state, and/or for the formation spectrum to vary with position in the source. If this interpretation of formation pumping of molecular hydrogen is correct, it is the first clear signature from this process to be seen.  相似文献   

SELECTION OF BRILLOUIN SHIFT DISCRIMINATOR FOR BRILLOUIN LIDAR   总被引：1，自引：0，他引：1  

吴东  刘智深 《中国海洋湖沼学报》2002,20(3):197-201

For the measurement of vertical profiles of sound speed in the sea using laser excited Brillouin scattering, a high-resolution measurement of Brillouin frequency shift is required. In this work, a molecular absorption cell was selected as the frequency shift discriminator and several kinds of absorption gases were tried. It was found that the strong line ( # 1095) of ^127 I2 at 18783. 3297 cm^-1 and two absorption lines of ^129 I2 located at the two sides of the # 1095 line of ^127 I2 could be used as frequency shift discriminator to detect the changes of the Brillouin frequency shift. This selection is the best one within the range from 532.0131 run to 532.5154 nm. But it is not perfect and there is a lot of work to do before its practical application.  相似文献   

Tracking the shadows through GMRT     

D. Narasimha  N. Kanekar  J. N. Chengalur 《Journal of Astrophysics and Astronomy》2002,23(1-2):165-171

The structures of faint high redshift galaxies cannot be observed directly. But if a luminous quasar is located farther along their line of sight, high resolution absorption lines offer a valuable and reliable probe to their structure. GMRT is suited to monitor the absorption spectra, if the redshifted neutral hydrogen or OH doublet fall in one of the windows of the telescope. We present the OH doublet absorption spectra for the system B0218+357, taken at GMRT this year at resolution of approx. 9.5 km/sec with an rms noise of the order of 1 mJy. Based on our study of the OH doublet and 21cm neutral hydrogen line we infer that, in the lensing spiral galaxy of B0218 + 357, neutral hydrogen and OH coexist in tenous clouds and there is possibly a hole in the central part of the galaxy. In contrast, the gas is seen in high density clouds in the lens in an otherwise similar system PKS1830-211.  相似文献   

基于绿色出行理念的合肥市区空气污染分区调控研究     

顾康康  朱鹏祥  宁杨  汪斐 《地理科学》2019,39(8):1312-1320

空气污染是城市主要的环境问题之一,严重影响到城市人类健康,而交通尾气排放是空气污染的重要原因。绿色出行是基于城市可持续发展的要求,通过发展低碳、绿色、环保的出行方式,缓解城市交通拥堵、城市污染等问题的一种交通理念。基于绿色出行理念的城市空气污染分区调控研究,对于改善城市环境质量、提升人居环境品质具有重大意义。以合肥市区为例,构建基于绿色出行理念的城市空气污染评估框架,提出公共交通、步行及自行车的3类绿色出行评价指标,运用大数据分析绿色出行方式降低空气污染物排放的潜力。结果表明:合肥市区公共交通出行呈现东西、南北2条带状分布,步行及自行车出行集中于路网密度较高的城市二环内,“一核两轴”地区的绿色出行条件较好,改善空气污染物排放的潜力较强;城市空气污染空间呈现城市一环、滨湖新区核心区2个凹地;探讨绿色出行与城市空气污染的空间关系,发现两者存在一定的空间权衡关系;最后,基于绿色出行与城市空气污染的空间分布关系,将合肥市区分为绿色出行区、优化建设区、潜力提升区、出行限制区4类区域,并对不同区域提出城市空气污染优化策略。  相似文献