Totally found 10149028 items.

  • [期刊] 关于维持山西河流健康生命的理念与方法的探讨
    河流是水资源的重要载体,有限的河川径流是人类生存和发展的生命之源,维持河流健康生命越来越受到社会的关注和重视.山西是全国的能源重化工基地,超重型的工业结构,高强度的水资源开发,脆弱的河流生态环境,给山西河流生命健康带来了一系列问题,造成河川径流量严重衰减,河流水质进一步恶化,水源涵养功能急剧下降,河网调蓄容量进一步减少.本文就此从水环境保护和生态环境修复的角度,提出了实施"生态治河"工程的几点设想.
  • [期刊] 关于锅炉燃烧器结构与布置对生成污染物的探究
    当大型电厂产生的二氧化硫、氮氧化物等物质排入到大气中,上升到一定高度时,与空气中的水蒸气相遇,会形成硫酸和硝酸小滴,使雨水酸化,这时落到地面的雨水就成了酸雨,对环境造成极大的危害。简要介绍了锅炉燃烧器的结构布置对污染物产生的影响,其中所指的污染物主要是氮氧化物和硫化物,二者的产生对大气和生态环境有重要的影响,这里着重就二者的产生机理以及如何从燃烧端或燃烧过程中控制进行介绍。
  • [专利] Multifunctional composition and method for treating a metal surface with the multifunctional composition
    (WO201561039) The present invention is directed to an anticorrosion composition and a method for preventing or inhibiting the corrosion of a metal substrate utilizing an anticorrosion compound. The method utilizes an anticorrosion composition comprising at least one amine oxide and at least one N-containing compound. The invention relates to a method for inhibiting the corrosion of metal surfaces by applying the composition to a metal substrate. The composition of the present invention provides corrosion inhibition, cleaning capabilities, and conversion capabilities.
  • [期刊] The pattern of 1‐aminocyclopropane‐1‐carboxylate oxidase induction in the tomato leaf petiole abscission zone is independent of expression of the ribonuclease‐ LXLX ‐encoding Le LX Le LXLX gene
    Abstract

    The abscission of tomato leaves occurs in the petiole abscission zone, and its late stage includes two spatially divided processes: cell separation and programmed cell death (PCD). Both of these processes are regulated by ethylene. The last step in ethylene biosynthesis is conversion of 1‐aminocyclopropane‐1‐carboxylic acid to ethylene, which is catalysed by the enzyme 1‐aminocyclopropane‐1‐carboxylate oxidase (ACO); however, the location of ACO in the leaf petiole abscission zone is not known. The tomato gene LeLX encodes ribonuclease LX, which is a marker for PCD and is induced by ethylene during abscission, but its association with ACO has not been explored. In a tomato transgenic line 1‐7 with inhibited expression of LeLX showing delayed leaf abscission, the morphology and ultrastructure of the leaf petiole abscission zone was examined. In this zone of the cv.’VF36’ and of a transgenic line 1‐7, spatiotemporal differences in expression of LeACO1 and LeACO4 were analysed and ACO protein was detected immunohistochemically. In comparison to wild‐type plants, there were no obvious morphological and ultrastructural features in the abscission zone of plants of a transgenic line 1‐7 before and after abscission induction. LeACO1 expression was low before abscission induction, and increased 24?h after induction, although with no apparent spatial pattern. In contrast, LeACO4 was expressed before abscission induction, an

  • [期刊] 尼龙6/超高分子量聚乙烯合金的性能
    以尼龙6(PA6)为第一主份、超高分子量聚乙烯(PE-UHMW)为第二主份,利用共混改性方法制备了PA6/PE-UHMW合金,研究了增容剂类型、添加量以及PE-UHMW含量变化对合金性能的影响.结果表明,聚烯烃接枝马来酸酐弹性体(POE-g-MAH)、聚乙烯接枝马来酸酐(PE-g-MAH)均可对PA6/PE-UHMW合金起到一定的增容效果,其中,添加PE-g-MAH的合金的综合性能优于添加POE-g-MAH的合金;当PA6添加70份,PE-g-MAH的添加量由5份增至15份时,PA6/PE-UHMW合金的韧性逐步提高,而强度先降低后提高,流动性、耐热性先提高后降低;添加10份的PE-g-MAH增容不同配比PA6/PE-UHMW合金,当PE-UHMW的添加量由0份增至40份时,PA6/PE-UHMW合金的拉伸强度、弯曲强度、维卡软化点、吸水率大体上呈下降趋势,而缺口冲击强度呈现上升趋势,断裂伸长率变化较为复杂呈现先上升再下降再上升最后基本平稳的趋势,且当PE-UHMW与PE-g-MAH的添加量均为10份时,PA6/PE-UHMW合金具有较好的综合性能.
  • [资讯] 塑料输液瓶已占整个药企市场的30%~40%
    在调查中发现,近几年玻璃输液瓶产量出现快速下滑趋势,主要原因是越来越多的药企使用塑料输液瓶。而塑料输液瓶已占到整个药企市场的30%~40%。塑料输液瓶越来越多地为生产输液厂家所青睐和应用,并迅速占领输液包装市场。   随着生产输液厂家的广泛应用,塑料输液瓶的各工艺设备逐渐凸现其缺点,特别是塑料输液瓶口和塑料输液瓶盖的熔封可靠性。因此,塑料输液瓶的检漏就显得格外重要。   由于塑料输液瓶的漏隙可能会引起微生物和空气中的病毒进入瓶内,导致药液被污染和变质,欠妥的应用会引起医疗事故。虽然有各种塑料输液瓶的检漏设备和方法,但还是存在着许多不尽人意的因素,需多加关注。
  • [专利] Basic ashless additives
    (EP3140374) A lubricant composition comprising an oil of lubricating viscosity and an N-hydrocarbyl-substituted δ-aminoester or δ-aminothioester provides exhibits basicity and good seal performance. In certain embodiments the N-hydrocarbyl substituent comprises a hydrocarbyl group of at least 3 carbons atoms, with a branch at the 1 or 2 position of the hydrocarbyl chain. (From US2017051225 A1)
  • [期刊] Combination of Least Square and Monte Carlo Methods for OBS Relocation in 3D Seismic Survey Near Bashi Channel
    The relocation of ocean bottom seismometers (OBSs) is a key step in analyzing the three-dimensional seismic tomographic structure of crust and mantle. In order to get the accurate location of OBSs on the seafloor, we analyze the travel times of direct water waves emitted by air-guns. The Monte Carlo and least square methods have been adopted to calculate the true OBS location. The secondary time correction is necessary if the arrivals of direct water waves show overall time drift during relocation which maybe originates from remnant of linear clock drift correction and average errors of travel time picking, mean water velocity assumption, and experiment geometry. We have improved the original OBS relocation procedure which we used previously for other experiments by deliberateness of a secondary time correction and automatically approaching the really mean water velocity. A series of synthetic tests are carried out firstly to document the feasibility of our procedure and then it is applied on a real experiment. In here, we relocate 28 OBSs in total were relocated in 3D seismic survey near Bashi Channel. Relocation results show that the drifting distances for the 28 OBSs range from 65 to 1136m between the deployed and relocated locations deduced by relocation results. The Pearson correlation coefficient between OBS drifting direction and sea current direction is 0.79, indicating that the two sets of data are highly linearly related and further manifest the sea current as the most possible driving force for OBS drifting during landing on the seafloor but its detailed influence mechanism is unclear by now. This research is necessary and critical for velocity structure modeling, and the optimal relocation program provides valuable experiences for 3D seismic survey in other area.
  • [期刊] Studies on dielectric relaxation in relation to viscosity of some anilines, phenol, and their binary mixtures at microwave frequencies
    In the present work, the study of variation of relaxation time (tau) with viscosity of the medium (eta) is carried out on four polar samples: 2-Nitroaniline, 4-Bromoaniline, 4-Chloroaniline, 4-Chlorophenol, and also on the binary mixture of 2-Nitroaniline + 4-Bromoaniline at room temperature by using microwave bench operating at a frequency of 9.59 GHz. In this regard, the different parameters like dielectric constant (epsilon'), dielectric loss (epsilon ''), relaxation time (tau(s)), macroscopic steady state viscosity (eta(s)), dynamic viscosity (eta(d)), and viscoelastic relaxation time (tau(ve)) were determined for all the systems. It is observed that the relaxation time (tau(s)) increases with the increase in the viscosity of the medium for all the systems. Plots of log(tau(s)) versus log(eta(s)) for all the systems show that variation of relaxation time is found to be nonlinear in the higher viscosity regions. This suggests the failure of Debye's theory at these regions. Further, the nonlinear behaviour of relaxation time with the viscosity is explained by using the viscoelastic model suggested by Barlow et al. (Proc. R. Soc. A 309, 473 (1969). doi: 10.1098/rspa. 1969.0053). It is also observed that macroscopic steady state viscosity (eta(s)) values are greater than the dynamic viscosity (eta(d)), and viscoelastic relaxation time (tau(ve)) values were found to be lower compared to the relaxation time (tau(s)). These results suggest that the effective frictional resistance experienced by the molecules during reorientation is lower and the measured values of macroscopic steady state viscosity (eta(s)) are frequency dependent.
  • [专利] 无​溶剂​条件下​制备​二​氟​乙基​鏻​盐/1,2‑乙烯基​双​鏻​盐​的​方法
    (CN105017320B) 本​发明​涉及​种​无​溶剂​条件下​制备​二​氟​乙基​鏻​盐/1,2‑乙烯基​双​鏻​盐​的​简易​方法,在​无​溶剂​条件下,将​有机磷​和​二​氟​乙基​化​试剂​或​乙烯基​化​试剂​混合,于‑20~150℃下​搅拌​反应​0.5~36h,待​反应​完成​后,洗涤​固体,过滤,所得​固体​用​油泵​干燥​即得​产品。该​方法​具有​底​物​适用​性好,操作​简单,产物​容易​纯化,环境​友好​等​优点。通过​调节​反应​温度​和​改变​有机​膦​的​结构,在​同样​的​体系​中,还可以​实现​二​氟​乙基​鏻​盐​的​制备,二​氟​乙基​鏻​盐​是​类​潜在​的​含​氟​切块,有望​用于​多种​含​氟化​合物​的​合成。
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