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71.
幼虫消化液酯酶活性与中肠酯酶活性表现出一定的负相关关系,消化液酯酶活性与全茧量、蛹重存在显正相关关系,中肠酯酶活性和茧层率性状呈显正相关关系,卵的酯酶活性与茧质性状呈高度正相关。酯酶活性与茧质性状的杂种优势率的强弱表现也一致。因此可以认为Fl代消化液酯酶和中肠酯酶活性的提高是茧质性状杂种优势形成的原因之一。酯酸活性可用来预测F1代的茧质性状的优劣。  相似文献   
72.
用大功率CO2激光器熔制WO3/Fe2O3新型烯烃歧化反应催化剂。考查了催化剂组成、激光功率及熔炼时间与丙烯歧化反应催化活性之间的关系。  相似文献   
73.
双子表面活性剂(C12-2-12.2Br-1)表面活性与驱油效率研究   总被引:3,自引:0,他引:3  
用滴体积法测定了几种双子表面活性剂和对应常规单链表面活性剂的表面张力-浓度曲线,确定了各自的临界胶束浓度,筛选出高效驱油用表面活性剂—C12-2-12. 2Br^-1;并在不同条件下对其进行了室内模拟驱油评价实验。表面张力测试表明,双子表面活性剂—C12-2-12. 2Br^-1的临界胶束浓度仅为547mg/L,对应表面张力为30.72mN/m,较对应单链表面活性剂DTAB具有更优的表面活性。驱油实验表明C12-2-12. 2Br^-1的驱油效率与浓度呈同向变化关系,其浓度为500mg/L即可提高采收率6.45%,其效果明显优于常规单链表面活性剂-DTAB;该剂更适合于中、低渗油藏水驱采收率的提高。  相似文献   
74.
研究两种内蒙古煤系高岭土(1、2)的化学组成、晶体结构并与苏州高岭土进行了比较。对三种高岭土进行酸改性,利用BET、吡啶-TPD和微反测试分别研究改性前后高岭土的性能特点。并将内蒙古高岭土1与苏州高岭土采用半合成方法合成了FCC催化剂,测定了其裂化活性。研究结果表明,内蒙古1具有较良好的晶体结构和化学组成,经酸改性后比表面积大大增加,具有合适的孔径分布,裂化活性较好,可以取代苏州高岭土作为FCC催化剂的基质。  相似文献   
75.
In order to control a project, construction management requires project information. This is obtained through accounting, estimating, cost management and scheduling functions which produce project reports. These reports are best obtained by subdividing the project into small parts. The ways in which each of these functions subdivides a project in order to produce its reports is discussed, together with a means of interrelating this information with a technique known as the work breakdown structure.  相似文献   
76.
ABSTRACT: In a screening of South African indigenous food plants for antioxidant activity by testing for inhibition of lipid peroxidation, the "potherbs" Amaranthus sp., Sisymbrium thellungii , and Urtica dioica had very high activity. This activity was greatest in the boiled extract of Amaranthus sp. and the boilet and aqueous extracts of Sisymbrium thellungii and Urtica dioica. The activity in the aqueous extract of Nasturtium aquatica was lost by boiling. High activity was also obtained with the teas Galium aparine and Aspalathus linearis (Rooibos) and with the tuber Colocasia esculenta.  相似文献   
77.
魏娟明  李美蓉  娄来勇  庄岩 《油田化学》2007,24(4):324-327,378
从孤岛原油中分离出正戊烷和正庚烷沥青质,元素分析和红外光谱分析结果表明,相对分子质量较大的正庚烷沥青质,含杂原子和极性基团较多。将两种沥青质溶于甲苯配制的模型油,分别与蒸馏水、模拟地层水、0~900mg/LHPAM溶液、0~500mg/L黏土液按1:10体积比充分乳化,测定静置时水相(水包油乳状液)透光率,据以考察沥青质的乳化能力,结果表明:正庚烷沥青质的乳化能力强于正戊烷沥青质;矿化离子使沥青质的乳化能力减弱;随聚合物浓度增大,沥青质乳化能力增强;黏土在浓度小于200mg/L时使乳化能力减弱,浓度大于200mg/L时使乳化能力增强。模型油与HPAM溶液间的界面张力,在聚合物浓度100mg/L时有最小值,在500mg/L时有最大值,正庚烷沥青质模型油的界面张力随聚合物浓度的变化较剧烈。正庚烷模型油在聚合物溶液中的乳化油滴直径分布范围较正戊烷模型油窄,聚合物浓度较大时,油滴直径分布范围较宽。正庚烷沥青质模型油与黏土液闸的界面张力,在黏土液浓度增至300mg/L时略有升高,浓度继续增大时大幅升高,而正戊烷模型油的界面张力在黏土液浓度300mg/L时有最低值。图9表3参7。  相似文献   
78.
Antioxidative properties of sour (cottage) were evaluated with (thermized) and without (native) heat treatment (80°C for 30 min). A model system comprising a Tween 20 stabilized peanut oil in phosphate buffer (pH 7.0) emulsion containing lipid oxidation catalysts, FeCl 3, H2O2 and ascorbate was used. Native sour whey powder (SWP) was significantly better than thermized whey in terms of limiting the formation of thiobarbituric acid‐reactive substances and peroxide value. Antioxidative ability was best at pH 3.0 and decreased with increasing pH. SWP (20%, w/v) was significantly better than all commonly used antioxidants tested after 96 h of incubation at 40°C.  相似文献   
79.
The presence of protease inhibitors in soybean prohibits the utilisation of the raw beans for food and feed. However, little information is available about environmental influences and the effects of nitrogen and sulphur supply on the antinutritional constituents of soybean. As these factors may influence protease inhibitors, soybean genotypes segregated according to the presence or absence of the Kunitz trypsin inhibitor have been evaluated for trypsin inhibitor activity (TIA) in field trials. TIA was affected significantly by environment (geographical location), fertilisation treatment and genotype. Environmental means of TIA were between 69.5 and 104.8 mg g?1. Nitrogen application, which caused an increase in seed protein content, resulted in a reduction in TIA by about 15% as compared with the control. Remarkably, simultaneous application of nitrogen and sulphur in the form of ammonium sulphate had a similar reductive effect on TIA to that of nitrogen application alone, although soybean protease inhibitors are rich in sulphur amino acids. Significant genetic variation in TIA was found both within the genotype class with the Kunitz inhibitor present as well as within the class lacking this inhibitor. The results suggest that TIA of soybean may be modified considerably by genetic improvement and appropriate agronomic management. Copyright © 2003 Society of Chemical Industry  相似文献   
80.
Withdrawal from an escalating-dose, bingelike regimen of cocaine administration in rats produced significantly depressed levels of locomotor activity during the nocturnal portion of the day-night cycle. This effect was observed during the first 48 hrs of testing. Extracellular single-unit recordings of ventral tegmental area (VTA) dopamine (DA) neurons revealed no differences between saline- and cocaine-treated rats with respect to basal firing rates. However, significantly fewer spontaneously active VTA DA neurons were encountered in rats withdrawn from binge cocaine. As with the nocturnal hypoactivity, this effect was observed only during the first 48 hrs of withdrawal. These findings suggest that short-term DA neuron dysfunction during cocaine withdrawal temporally corresponds to behavioral disruptions that are similar to those described in human addicts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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