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1.
对矩形虾池在水车式增氧机作用下产生的环流特点进行理论分析，结果表明，在转角处会形成涡旋，边壁附近在一定条件下会产生回流；利用ANSYS软件的FLOTRAN CFD进行数值计算，获得与理论分析一致的结果，与现场实际情况吻合。并进一步对虾池阻力进行分析，提出了一些减阻措施。 相似文献
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亲爱的朋友，当你在开满鲜花的崇山峻岭中行走，在溪水潺潺的山沟里漫步，在一望无际的田野上踏青时，你可能会看到各种形状、各种颜色的岩石，也就是大家俗称为石头时，你也许会产生这样的疑问：这些石头是怎样产生的呢？它与人类生三存生活有什么关系？ 相似文献
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一对前期工作的影响
土地开发整理项目勘测成果的主要体现是现状图，它是能够反映项目区现状地形、地物和土地利用状况的图纸。现状图是用来编制可行性研究报告和初步设计的重要依据，现状图勘测的是否真实、准确、全面对整个项目的规划和设计会产生重要影响。 相似文献
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一、水冷却系统散热
众所周知,发动机是汽车的心脏,它工作时会产生非常大的热量。这些热量必须及时散发掉,不然就会影响发动机的工作效力,严重时（比如缺水状态工作）会损坏发动机缸体,直至瘫痪。 相似文献
6.
和谐的人力资源关系是构建和谐社会的重要组成部分，没有和谐的人力资源劳动关系，对单位就会产生各种冲突，将会影响本单位或企业的发展；对社会来说，如果人力资源矛盾深化，就会进一步产生对抗，影响社会的稳定。因此，建立一种和谐的人力资源劳动关系是构建和谐社会最重要的因素。笔者就如何构建企业和谐人力资源关系，做如下探讨。 相似文献
7.
随着当今人们生活水平的不断提高，黄金饰品已成为普通百姓日常的流行时尚，可您知道如何保养您的黄金饰品，以使其历久常新吗？在此，我们特向您介绍一些黄金饰品的保养方法和注意事项。 金饰品并不十分娇气，但是不细心保养，也会失去它最初的光泽和魅力。一般来说，下面几点是要当心的： 1、洁净的化学物质会改变金子的色泽，所以做清洁工作之前应该脱掉金饰品。 2、避免直接与香水、发胶等高挥发性物质接触，否则容易导致金饰品褪色。 3、游泳时要取下金饰品，以免碰到海水或池水后，表层产生化学变化。 4、保管的时候要… 相似文献
8.
对矩形虾池在水车式增氧机作用下产生的环流特点进行理论分析,结果表明,在转角处会形成涡旋,边壁附近在一定条件下会产生回流;利用ANSYS软件的FLOTRANCFD进行数值计算,获得与理论分析一致的结果,与现场实际情况吻合。并进一步对虾池阻力进行分析,提出了一些减阻措施。 相似文献
9.
工作学业：你的人际圈会改变，随着认识一些新的朋友，并跟对方建立不错的关系。财运分析：1月会有几笔大的开销。5到7月中旬会有更大的开销。血型：A型：在工作上有守强攻弱的倾向；站在攻的立场能发挥超群的实力，反之则脆弱无能。如果将两方面的优点结合起来，则会产生攻守皆强的无敌力量。 相似文献
10.
锅炉结焦是燃煤工业锅炉运行中比较普遍的现象，它会破坏正常燃烧，减少锅炉出力，破坏正常水循环。易造成爆管事故，严重时还会使炉膛出口堵塞而被迫停炉。 相似文献
11.
在脉冲电晕放电条件下,探讨了O2和H2O对NO分解反应过程的影响,并对复杂组分中NO的分解特性进行了实验研究。研究结果表明,脉冲电晕放电对NO分解反应具有一定的促进作用,可有效地分解模拟烟气中的NO,脱除效率随脉冲电压的增加而缓慢增加;受O2和H2O影响,NO分解转化率较N2氛围略有降低。 相似文献
12.
Lin Lizhou Shan Kun Xiong Qian Zhou Qichao Li Lin Gan Nanqin Song Lirong 《中国海洋湖沼学报》2018,36(6):2231-2242
Microcystis blooms are an environmental and ecological concern that has received a serious attention. Hydrogen peroxide(H_2O_2) is an environment-friendly cyanocide that is commonly used to control Microcystis blooms. While the ecological safety of H_2O_2 has been previously studied, its influence on bacterioplankton has not been investigated to date. In this study, we used mesocosm experiments to determine the influence of H_2O_2 on the dynamic changes of the community structure of bacterioplankton. By using deep-sequencing and metagenomics strategy we determined the community structures of phytoplankton and bacterioplankton assemblages that were dominated by M icrocystis at a highly eutrophic Dianchi Lake, China. The results showed that M icrocystis was more sensitive to H_2O_2 than other eukaryotic algae. More interestingly, application of H_2O_2 changed the community structure of bacterioplankton, evidenced by the emergence of F irmicutes as the dominant species in place of B acteroidetes and Proteobacteria. The H_2O_2 treatment resulted in the community of bacterioplankton that was primarily dominated by E xiguobacterium and Planomicrobium. Our results show that the abundance changed and the bacterioplankton diversity did not recover even after the concentration of H_2O_2 reached to the background level. Thus, the response of bacterioplankton must be considered when assessing the ecological risks of using H_2O_2 to control Microcystis blooms, because bacterioplankton is the key player that forms the basis of food web of aquatic environment. 相似文献
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采用微波辐射加热法使壳聚糖与水杨醛反应生成壳聚糖希夫碱,然后将其与铜盐配位得到壳聚糖希夫碱铜配合物,用UV、FTIR、TG表征产物的结构,并探讨该配合物对过氧化氢分解的催化性能。研究结果表明:壳聚糖希夫碱铜配合物对过氧化氢有良好的催化活性,常温(25℃)常压,pH=7.0的条件下放置12 h,催化H2O2的分解达99.8%,该配合物重复使用3次还保持较好的催化活性。 相似文献
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ItwasreportedthatthegrOwthofthedrinediatomffelassforiraPsethenana(Hust.)HasleetHeiIndaldependedonSe(Priceetal.,1987).ThisreqUirementissPecificforSe;nootherelementscansubstituteforit,becauseSecaninduceglutathioneperoxidase(GSH-PoD)activityinthisdiatom(PriceandHarrison,l988),andinlow-CO2-grooCham~nasreinhandiiDangerad(Yokotaetal.,l988).ThisenZyInac-tivitywdetectedinextractsOfablue-greenalgaGleeoCaPasp.LB795(TotaandGallon,l979),andalsoincultUredhigherplancells(Drotaretal.,1985),butw… 相似文献
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矿物中包裹体温度、压力和气、液相成分的测定数据是阐明矿床成因、成矿物质来源、成矿物质化学条件和成矿元素运移方式等的重要地球化学参数。本文介绍了用载气热爆—气相色谱法测定气相成分(H_2、O_2、N_2、CH_4、CO、CO_2、H_2O)和用超声波提取液相成分,再用原子吸收分光光度计法和数字离子计法分别测定阳离子(K~+、Na~+、Ca~(2+)、Mg~(2+))、阴离子(F~-、Cl~-)。对实验装置、工作条件和分析步骤等本文均有叙述。并以石英标样,对实验结果作了初步讨论。其中对气相成分的提取,用载气热爆法代替真空热爆法可提高工作效率五倍。 相似文献
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Heparin has been used as an anticoagulant drug for many years, but it has significant side ef fects. In the search for good substitutes, low molecular weight(MW) polysaccharides from S argassum fusiforme have been examined and confi rmed to possess biological activities. Here, S. fusiforme polysaccharides(SFP) were extracted and subjected to a hydrogen peroxide(H_2O_2) oxidation method for the preparation of low-MW SFP(LSFP). The effects of temperature, pH, and H_2O_2 concentration on the degradation process were also examined. Several LSFP of 36, 9, 5.7, and 2.7 kDa were obtained under different conditions, and their anticoagulant activities studied in vitro. The results showed that SFP and LSFP prolonged activated partial thromboplastin(APTT), prothrombin(PT) and thrombin times(TT) significantly, indicating that these low MW polysaccharides possessed anticoagulant activity in the intrinsic, extrinsic, and common coagulation pathways. As these ef fects were related to the MW of the polysaccharides in APTT and TT but not in PT, the contents of the monosaccharide fucose and sulfate and the polysaccharide MW could have exerted combined ef fects. The details of this mechanism require further verifi cation. 相似文献
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《中国海洋大学学报(英文版)》2016,(4)
In this study, molecular weight controllable degradation of algal Laminaria japonica polysaccharides(LPS) was investigated by ultrasound combined with hydrogen peroxide. Three main factors, i.e., ultrasonic power(A), ultrasonic time(B), and H_2O_2 concentration(C) were chosen for optimizing parameters by employing three-factors, three-levels BBD. The influence of degradation on structure change and antioxidant activities was also investigated. A second-order polynomial equation including molecular weight(Y) of Laminaria japonica polysaccharides and each variable parameter, i.e., ultrasonic power(A), ultrasonic time(B), and H_2O_2 concentration(C), was established: Y=20718.67-4273.13A-4000.38B-1438.75C+2333.25AB+1511.00AC+873.00BC+2838.29A~2 + 2490.79B~2+873.04C~2. The equation regression coefficient value(R~2 = 0.969) indicated that this equation was valid. The value of the adjusted determination coefficient(adjusted R~2 = 0.914) also confirmed that the model was highly significant. The results of selected experimental degradation conditions matched with the predicted value. FT-IR spectra revealed that the structures of LPS before and after degradation were not significantly changed. Antioxidant activities of LPS revealed that low Mws possessed stronger inhibitory than the original polysaccharides. The scavenging effects on superoxide radicals was the highest when IC50 of crude LPS was 4.92 mg mL~(-1) and IC50 of Mw 18.576 KDa was 1.02 mg mL~(-1), which was fourfold higher than initial polysaccharide. 相似文献
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本文应用模糊集合理论和计算机研究百里酚酞-茜素黄R混合指示剂的变色现象。发现其变色存在滞后现象。讨论了产生滯后现象的原因。 相似文献
19.
《中国海洋大学学报(英文版)》2021,(5)
Oxidative stress is involved in the progression of neurodegenerative diseases. Previous evidences showed that plasmalogens could improve neurodegenerative diseases. In this study, we investigated the function of phosphoethanolamine plasmalogens enriched with EPA(EPA-p PE) and phosphatidylethanolamine enriched with EPA(EPA-PE) on oxidative damage prevention after hydrogen peroxide(H_2 O_2) and tert-butylhydroperoxide(t-BHP) challenge in primary hippocampal neurons. Results showed that neurons pretreated with EPA-p PE and EPA-PE demonstrated the ability to alleviate oxidative damage, which was proved by the increased cell viability. Moreover, the shape and number of neurons were more similar to those of the control group. Antioxidant activity, apoptosis, as well as Trk B/ERK/CREB signaling pathway were investigated to explore the mechanisms. The results suggested that EPA-PE was superior to EPA-p PE in regulating mitochondrial apoptosis. EPA-p PE was more prominent than EPA-PE in upregulating Trk B/ERK/CREB signaling pathway. Phospholipids with EPA exerted neuroprotective effects via inhibiting oxidative stress, suppressing apoptosis, and regulating Trk B/ERK/CREB signaling pathway. Therefore, the results provide a scientific basis for utilization of phospholipids enriched with EPA on the treatment of neurodegenerative disease. 相似文献
20.
改进重铬酸钾法快速测定水样CODcr 总被引：7，自引：0，他引：7
研究了用硫酸锰代替贵金属硫酸银作催化剂,在H2SO4-H3PO4介质中,重铬酸钾回流法测定水样中CODcr的新方法.通过实验,确定了最佳测定条件:MnSO4浓度为1×10-1mol.L-1;混酸溶液(H2SO4:H3PO4)=5:1(体积比);回流时间10min.并与标准方法进行了对比,准确度和精密度同标准法相近,大大节约了分析时间. 相似文献