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析两类常见题型中的溶液浓度前后变化规律
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作者 李晓峰 《数理化解题研究(高中版)》 2003年第12期57-58,共2页
高中化学学习过程中,常会遇到两类溶液浓度变化后与变化前浓度的一半的比较题型,即一类是:溶液等体积混合后,其质量分数的大小计算或比较(这类题也在高考中频繁出现如1997、1999年高考);另一类是:物质的量浓度为C的溶液,质量分数减少一... 高中化学学习过程中,常会遇到两类溶液浓度变化后与变化前浓度的一半的比较题型,即一类是:溶液等体积混合后,其质量分数的大小计算或比较(这类题也在高考中频繁出现如1997、1999年高考);另一类是:物质的量浓度为C的溶液,质量分数减少一半后.物质的量浓度为C/2的关系.这两类题型中浓度的大小关系都与溶液密度变化有着直接的联系,这里有必要进行归纳总结,找出解决此类问题的规律,以便用来指导化学运算中此方面的学习. 展开更多
关键词 题型 溶液浓度变化问题 高中 化学 解法 质量分数
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初中化学有关溶液质量变化的计算
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作者 吴宏富 《中学化学》 2004年第6期29-31,共3页
关键词 初中 化学 溶液质量变化 计算题 解法
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手持技术测定中和反应过程中溶液pH的变化
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作者 黎碧存 衷明华 《江西化工》 2015年第4期87-88,共2页
传统的科学实验缺乏自动的采集、处理大量数据的功能,手持技术集多种优点于一身:便携、实时、准确、综合、直观、定量、快速和方便。本实验采用手持技术来直观地展示出滴定过程中溶液p H变化,用p H传感器来检测整个过程中的p H变化,并... 传统的科学实验缺乏自动的采集、处理大量数据的功能,手持技术集多种优点于一身:便携、实时、准确、综合、直观、定量、快速和方便。本实验采用手持技术来直观地展示出滴定过程中溶液p H变化,用p H传感器来检测整个过程中的p H变化,并以图像的形式表现出来,由不可见的变为可见的,由抓不住的变为抓住的,达到掌握中和滴定的操作和原理,充分理解"滴定突跃"的目的。 展开更多
关键词 手持技术 中和反应 溶液pH的变化
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聚合物驱数学模型的建立 被引量:1
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作者 宋洪才 张儒 《黑龙江科学》 2013年第3期43-45,共3页
根据聚合物驱油机理,在聚合物驱油的主要数学模型基础上,为了研究聚驱后溶液各组分变化规律和动态,建立了聚驱后溶液变化的数学模型,并采用聚合物线形体和聚合物聚集体共同描述聚合物溶液在多孔介质中的性质变化和渗流特性,有效描述聚... 根据聚合物驱油机理,在聚合物驱油的主要数学模型基础上,为了研究聚驱后溶液各组分变化规律和动态,建立了聚驱后溶液变化的数学模型,并采用聚合物线形体和聚合物聚集体共同描述聚合物溶液在多孔介质中的性质变化和渗流特性,有效描述聚合物溶液的驱油动态,为聚驱后的理论研究和现场分析提供了研究方法。 展开更多
关键词 聚合物驱油 溶液变化 数学模型 方程
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电离平衡中的辩证法 被引量:2
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作者 董广芬 《化学教学》 CAS 北大核心 2004年第3期41-42,共2页
关键词 电离平衡 唯物辩证法 电离程度 溶液体积变化 弱酸根离子 水解平衡
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Effect of Zinc Sulfate against the Red Palm Weevil Rhynchophorus ferrugineus with Reference to Their Histological Changes on the Larval Midgut and Adult Reproductive System
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作者 Zamzam M. Al-Dhafar Aziza Sharaby 《Journal of Agricultural Science and Technology(A)》 2012年第7期888-900,共13页
The red palm weevil Rhynchophorusferrugineus is the most important insect pest for the date palm trees in the Middle East and Gulf states. Zinc sulfate (ZnSOa'H20) was toxicologically, biologically and physiologica... The red palm weevil Rhynchophorusferrugineus is the most important insect pest for the date palm trees in the Middle East and Gulf states. Zinc sulfate (ZnSOa'H20) was toxicologically, biologically and physiologically evaluated as insect development disruptors against the RPW. LCs0 of Zinc sulfate against 10 days old larvae was 0.566%, 3% concentration inhibited the larvae from feeding. LCs0 concentration of zinc sulfate solution was capable to disrupting growth, development and reproduction of R. ferrugineus. Growth and development disruptions are resulted from larval feeding on the treated diet that causing percentage of mortality rate, retardation in larval and pupal duration, percentage of pupation, adults emergence, reduction in deposited eggs that laid by the resulting adults and in the egg fertility. The study further reveals that Zinc sulfate effects on histological structure of epithelial cells of the larval midgut including separation and elongation of their cells, rupture in the peritrophic membrane and in some microvilli and some degeneration of the surrounding muscles. Histological changes also was observed on the adults ovary, in this way, disrupt female gamete production through their action on the accumulation of yolk granules (vitellogenesis) and follicular epithelial cells. Disruption of male gamete production was detected by disorganized of testicular cysts and depopulation of these cysts in addition to degeneration in germ cells. Zinc sulfate may be used among other control methods by injection into the tree trunk or as fertilizer around the tree roots which in turn may have an indirect effect for controlling the RPW. 展开更多
关键词 Red palm weevil zinc sulfate inorganic salt TOXICITY growth disruption histological changes MIDGUT OVARY TESTES Rhynchophorus ferrugineus.
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The compressive strength experimental study of cemented soil under H2SO4 corrosive in earlier period
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作者 HAN Peng-ju BAI Xiao-hong HAO Hai-yan 《Journal of Civil Engineering and Architecture》 2009年第3期54-58,共5页
In order to simulate and study the erosion effect process such as the changes of corrosive depth and unconfined compression strength of cemented soil sample in earlier period from 0 day to 60 days, a series of tests i... In order to simulate and study the erosion effect process such as the changes of corrosive depth and unconfined compression strength of cemented soil sample in earlier period from 0 day to 60 days, a series of tests including unconfined compressive tests, measuring the blocks' sizes, and taking photos, are conducted on the cemented soil blocks which were cured in different concentrations of H2SO4 solutions. The results of tests show that the corrosive depth is increasing and the unconfined compression strength is decreasing with the increase of H2SO4 solution concentration at the same erosion time, and the corrosive degree is increasing with the corrosive time. In the earlier state, the corrosive effect is serious, but the effect becomes slow in the later state in the same concentrated H2SO4 solution. After take statistics the date, a coefficient a is put forward to predict the reduction of the compressive strength of cemented soil in various concentration of H2SO4 solution, which could be used in practical design. 展开更多
关键词 cemented soil corrosive depth unconfined compression strength reduced coefficient
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Time-Dependent Action in φ~6 Potential
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作者 Hatem Widyan Mashhoor Al-Wardat 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第7期19-26,共8页
The false vacuum decay in field theory from a coherently oscillating initial state is studied for φ6 potential. An oscillating bubble solution is obtained. The instantaneous bubble nucleation rate is calculated.
关键词 phase transition TUNNELING scalar field theory
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Facile interconversions of topology and aromaticity of expanded porphyrin in solution
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作者 LIU ZeYu MA Jing 《Science China Chemistry》 SCIE EI CAS 2014年第10期1369-1374,共6页
The dynamic transformations of conformations and aromatic properties of [32]octaphyrins(1.0.1.0.1.0.1.0) through rotating the pyrrolic ring of the macrocycles are demonstrated by theoretical simulations in CH2Cl2 so... The dynamic transformations of conformations and aromatic properties of [32]octaphyrins(1.0.1.0.1.0.1.0) through rotating the pyrrolic ring of the macrocycles are demonstrated by theoretical simulations in CH2Cl2 solution. Facile multistep isomeriza- tions involving antiaromatic-Htickel and aromatic-Mobius topologies were also predicted by density functional theory (DFT). The understanding of changes in topologies and aromaticities of free-base expanded porphrins may provide useful information to build new macrocycles with unique properties. 展开更多
关键词 theoretical investigation expanded porphyrin conformational interconversion AROMATICITY
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