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Main contents and conclusions are: 1 The ionization current was measured continuously by a charge-integration method with a computer after the introduction of radon into the chamber.
主要内容及结论:1充氡后利用计算机连续进行电离电流累积测量,得到了精细的电流随时间的变化曲线,可清楚看出氡及其子体的生成衰变造成的电离电流的生长—稳定—衰减过程,与理论计算值进行了比较,由电离电流衰减速度的变化得出氡吸附作用的影响,并测量到电离室冲洗后氡的反扩散现象;2由已知活度的标准源定出相对测量的刻度系数K值,K=24.62 Bq/pA,对同一个监测源以半年为周期进行多次测量后得出稳定性符合要求;3通过测量电离电流和气压的关系曲线以及不同气压下的饱和曲线,确定了常规的工作条件;4测量了盐酸清洗电离室内表面降低本底的效果;5不确定度分析表明相对测氡的扩展不确定度(k=2)小于5%,由本底涨落得出探测下限为0.5 Bq;6理论上对壁损失修正进行了计算,实验上保持电离室工作在饱和区的情况下,测量了不同气压下电离电流的变化,从中得出了壁损失随气压变化的规律,可以看出,电离电流的实测值和计算值随气压变化规律基本一致;当气压大于125 kPa时,端效应等其它因素造成的影响不大于2%,因而在此工作条件下,测量电离电流后通过计算修正壁损失可以实现近似的绝对测氡,提出了进一步提高绝对测量准确度的方法。
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This paper first analyses and summarizes the ststus quo and evolution trend of encryption, some common used cryptograph are introduced, including the algorithms used in symmetric cryptosystem and asymmetirc cryptosystem. We describe the theory of each algorithms and compare the elliptic curve cryptosystem with the other two asymmetric cryptosystems to show the advantages of this algorithm. Second, the principle of ECC is discussed, including the math foundation of ECC, basic conception of elliptic curves, constructiong idea of ECC, operation on the elliptic curve and so on. Third, the current attacks of ECC were analyzed deeply, and an algorithm based on limited prime number field was constructed. We analyzed its realizability in theory, and implement it by using certain function of MIRACL software package. Latter half in this paper, the implementation model of a simple elliptic curve encryption system which based on GF has been introduced. The paper also put a deep analysis on the algorithm of point addition and point multiplication.
本文首先对密码技术的发展现状及其发展趋势进行了分析和综述,详细的介绍了私钥密码系统和公钥密码系统的发展,说明各种算法的原理和优缺点,并给出了一些典型的密码体制的简要分析,重点将椭圆曲线算法与其它几种公钥密码算法比较,说明椭圆曲线算法的优势;其次,探讨了椭圆曲线密码体制的原理,包括椭圆曲线密码的数学基础、基本概念、椭圆曲线密码体制的构造思想等问题;第三作者对椭圆曲线的攻击现状作了详细的分析,针对所使用的大素数域F_p,设计了素数域上安全椭圆曲线产生的算法,从理论上做了可实施性分析,从软件上做了具体实现;在本文的后半部分,提出了一个简单的基于有限素数域上的椭圆曲线加密方按算实现模型,并对SECES中设计的点加和点乘运算进行了深入分析。
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In this thesis,the AM1,MNDO,MINDO/3(mainly AM1)and INDO/S-CI semiempirical MO methods were used toinvestigate the excited-state intramolecular protontransfer reactions of salicylic acid derivatives—salicylic acid,methyl salicylate,salicylaldehyde,o-hydroxyaceto-phenone,salicylamide and 3-hydroxy-picolinamide (6 conformers and 2-3 anion species);2-(2'-hydroxy-5' methylphenyl) benzotriazole(4 conformers),2-(2' hydroxyphenyl) benzimidazole (3 conformers and 3anion species),Bis-2,5-(2-benzoxazolyl)hydroquinone(3 conformers),2-(2'-hydroxyphenyl)benzothiazole(2conformers) and 7-azaindole dimer (2 conformers).Theinvestigations were described as follows.Geometry optimization,relative stability andhydrogen bonding energy First,for sylicylic acid derivative molecules,the AM1,MNDO and MINDO/3 methods were used toinvestigate ground-state geometry optimization,energies,relative stabilities and hydrogen-bondingenergies on the five kinds of the molecules(designing 6 conformers and 2-3 anion species).Comparing with experimental data,the optimizedgeometry,the order of stability,the hydrogen-bonding energies and the distances between O-O in O-H..O hydrogen bonds by AM1 method were in agreementwith the experimental data,however,the C-C bondlengths optimized by MNDO and MINDO/3 were longer,C-O and O-H bond lengths were shorter;for C-N bondlengths,the results opitimized by MNDO method werethe same as those by AM1 method,nevertheless the C-Nbond lengths given by MINDO/3 method were muchshorter.For some sylicylic acid derivatives(e.g.methyl salicylate,salicylamide),the order ofstabilities on the conformers given by MNDO andMINDO/3 methods were not in agreement with theexisting conformers deduced by experimental methods,and the hydrogen bonding energies calculated by MNDO.and MINDO/3 methods were smaller.Second,the studyon the other systems found that the optimizedgeometry of the proton-transfered product with INDOmethod could not be obtained,only could theoptimized geometry of reactant be obtained,and thecalculated hydrogen bonding energies were greater.Many results of calculation indicated that the studyon the excited-state intramolecular proton transferreaction system using AM1 method was suitable andreliable.
本论文用AM1、MNDO、MINDO/3(主要是AM1)和INDO/S-CI半经验分子轨道方法对水杨酸衍生物系列——水杨酸、水杨酸甲酯、水杨醛、O-羟基乙酰苯酮、水杨酰胺和3-羟基吡啶酰胺(6种异构体和2-3种阴离子);2-(2'-羟基-5'-甲基苯基)苯并三〓唑(4种异构体);2-(2'-羟基苯基)苯并咪唑(3种异构体和3种阴离子);2,5-二间氮杂氧茚氢醌(3种异构体);2-(2'-羟基苯基)间〓杂硫茚(2种异构体)和7-〓吲哚二体(2种异构体)的激发态分子内质子转移反应在以下几个方面进行了较系统的理论研究:几何构型优化和相对稳定性及氢键能首先以水杨酸衍生物系列分子为例,用AM1、MNDO和MINDO/3方法考察了5种分子(每种分子设计6种异构体和2-3种阴离子)的基态几何构型优化,能量、相对稳定性和氢键能计算,通过和实验数据进行比较,AM1方法给出的优化几何构型、稳定性次序、氢键能和O—H。。。O氢键的0—0距离与实验数据吻合最好,MNDO和MINDO/3方法优化的C-C键长偏长,C-O键和O-H键长偏短;对于C-N键长,MNDO和AM1优化结果差别不大,而MINDO/3给出了过短的C-N键长,MNDO和MINDO/3方法给出的有些水杨酸衍生物分子(如水杨酸甲酯和水杨酰胺)异构体的稳定性次序和实验上推测的可存在异构体结果不一致,MNDO和MINDO/3方法给出的氢键能偏低,对其他体系的研究发现INDO方法常常不能得到质子转移产物的优化几何构型,只能得到反应物的优化构型,并且估算的氢键能偏高,大量的计算结果表明AM1方法对本论文研究的激发态分子内质子转移反应体系是适宜和可靠的。
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The results of the present research are as follows, The correlation between physico-chemical properties of organic compounds and their competitive power was studied, and it was indicated that organic compounds preferable to form H-bonding with organic matter of sorbents have stronger competitive power; Sorption behaviors of ionizable organic compounds in different species and their competitive power were examined, and the results showed that phenols and carbonxylic acids with benzyl circle have much stronger competitive power in molecular species than in ionized species, because negative charges of anionic forms can depressed their adsorption on the surface of the sediment; in contrast, organic bases such as aniline and p-chloroaniline show weaker competitive power in molecular species than in ionized species, and this is because both species of the organic bases could adsorb strongly onto the sediment; there is a correlation between competitive power of organic pollutants in multi-solute systems and their sorption isotherm nonlinearity in single-solute systems, and organic compounds whose sorption isotherms is linear in single-solute systems hardly have competitive power in multi-solute systems; Competitive sorption effects in more than two-solutes systems was studied, and it was exhibited that mixture of two cosolutes each of which could suppress sorption of nominal solute onto the sediment had synergistically competitive sorption effect on the nominal solute; A method about incorporating sorption/desorption of organic pollutants into river water quality model was developed, and discussion about degree of sorption/desorption effect on model prediction for different organic compounds was made, which will provide theoretical basis and practical processes for setting up more accurate water quality model.
论文主要取得了以下研究成果。(1)有机化合物的吸附竞争能力与其物化性质具有相关性,易与沉积物有机质形成氢键的化合物其竞争能力也比较强;(2)可离子化有机化合物的吸附竞争能力与其存在形态有关。酚类、含苯环的羧酸类化合物,其离子态的吸附竞争能力远小于分子态,其机理为有机酸阴离子所带的负电荷抑制了表面吸附能力,主要发生分配作用;而苯胺类化合物,其离子态和分子态都表现出显著的竞争能力,而且离子态的竞争能力略强于分子态,原因在于有机碱阳离子所带的正电荷促进了其表面吸附能力;有机化合物竞争能力的强弱与其单组分吸附等温线的非线性程度具有一定的相关性,吸附等温线近似为线性的化合物没有或只具有微弱的竞争能力;(3)对目标有机化合物的吸附具有竞争效应的有机化合物混合后,将对目标有机化合物的吸附产生协同竞争效应;(4)以京杭运河为例,率先提出了将有机污染物的吸附/脱附作用及水文水力参数耦合到水质模型中的方法,并讨论了吸附/脱附作用对不同有机污染物预测模型的影响,为建立更准确的水质模型及进行更客观的风险和生态评估提供了参考依据。
- 推荐网络例句
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As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.
每逢看到沃林顿那刚毅的脸,那乌黑、忧郁的眼睛,她便会相信,他一定作过不幸的爱情的受害者。
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Maybe they'll disappear into a pothole.
也许他们将在壶穴里消失
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But because of its youthful corporate culture—most people are hustled out of the door in their mid-40s—it had no one to send.
但是因为该公司年轻的企业文化——大多数员工在40来岁的时候都被请出公司——一时间没有好的人选。