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951.
提出了一个量子投票方案。投票者利用局域幺正操作进行投票,计票员可根据测量的结果计算出投票的结果。通过对方案的正确性和秘密性进行分析,表明该方案是安全的。而且,与采用Ⅳ维量子纠缠态的量子投票方案相比,该方案只涉及二维量子态,测量较为简单,这在现有的技术条件下是更易于实现的。 相似文献
952.
王健林 《大连海事大学学报(自然科学版)》2009,(Z1)
通过分析对比船旗国主管机关、船级社在技术力量和全球分支机构的分布情况,探讨主管机关如何认可和委托合格的检验和发证机构来对新造船舶检验发证,以切实履行有关国际公约和保证海上航运安全. 相似文献
953.
综合性医院临床护士心理健康状况调查与分析 总被引:1,自引:0,他引:1
目的探讨本省临床一线护士心理健康状况,为管理者提供参考依据。方法采用SCL-90量表对1100名临床护士进行问卷调查,调查数据采用SPSS11.0统计软件包进行统计分析。结果被调查护士SCL-90各项因子中恐怖因子分显著高于常模(P〈0.001)、精病性二项因子分高于常模(P〈0.05);调查显示:工作来源于地不同的护士躯体化因子分有差异;工作性质不同的护士躯体化因子分有差异;已婚与未婚护士躯体化因子分有显著差异;不同级别医院护士恐怖因子分有差异;三级医院阳性项目数比例较高。结论临床护士工作压力导致护士出现恐惧现象,并伴随精神病性症状,提示医院管理者应适当减轻或调整护士工作压力,促进护士身心健康。 相似文献
954.
冯长根 《科技导报(北京)》2010,28(8):125-125
依据中国科协2010年4月发布的<中国科协科技期刊发展报告(2010)>,论述了中国科协科技期刊2009年度的发展状况,分析了其发展规律、经验和特点,通过调研中国科协科技期刊在学术质量建设、数字化和网络化建设、办刊队伍建设等方面的进展,探讨了科技期刊的发展趋势和策略. 相似文献
955.
《Acta Mechanica Solida Sinica》2011,(Z1):22-33
The aim of this study is to describe the main behavior of cement-based materials under large compression state based on the recent experimental research. In this paper, the strainstress relations are firstly analyzed and confining pressure state is regarded as low/medium/high state. A generalized cup modeling is introduced by a coupled deviatoric shearing, pore collapse and damage mechanism within thermodynamic framework. A series of numerical simulations are performed for the considered cement paste and concrete. Comparisons between numerical predictions and experimental results show that the proposed model is able to describe the main features of mechanical behavior under large range of compression state. 相似文献
956.
Abstract On the basis of experimental results obtained in the present and some other works a model of melting of rare gas solids within bubbles formed in a crystalline metal matrix as a result of ion implantation is proposed. Rare gas solid is supposed to melt on heating at the expense of the bubble volume expansion by emission of a dislocation loop. On this basis the melting temperature can be estimated as one which is enough to provide for a pressure inside a bubble sufficient for the initiation of the dislocation loop punching. Values of melting temperatures obtained in this way are in good agreement with available experimental data. 相似文献
957.
EDOT‐diketopyrrolopyrrole copolymers for high bulk hole mobility and near infrared absorption 下载免费PDF全文
Christian J. Mueller Chetan R. Singh Mukundan Thelakkat 《Journal of Polymer Science.Polymer Physics》2016,54(6):639-648
To obtain novel low‐bandgap materials with tailored hole‐transport properties and extended absorption, electron rich 3,4‐ethylenedioxythiophene is introduced as a comonomer in diketopyrrolo[3,4‐c]pyrrole copolymers with different aryl flanking units. The polymers are characterized by absorption and photoluminescence spectroscopy, dynamic scanning calorimetry, cyclic voltammetry, and X‐ray diffraction. The charge transport properties of these new materials are studied carefully using an organic field effect transistor geometry where the charge carriers are transported over a narrow channel at the semiconductor/dielectric interface. These results are compared to bulk charge carrier mobilities using space‐charge limited current (SCLC) measurements, in which the charge carrier is transported through the complete film thickness of several hundred nanometers. Finally, charge carrier mobilities are correlated with the electronic structure of the compounds. We find that in particular the thiophene‐flanked copolymer PDPP[T]2‐EDOT is a very promising candidate for organic photovoltaics, showing an absorption response in the near infrared region with an optical bandgap of 1.15 eV and a very high bulk hole mobility of 2.9 × 10?4 cm2 V?1 s?1 as measured by SCLC. This value is two orders of magnitudes higher than SCLC mobilities reported for other polydiketopyrrolopyrroles and is in the range of the well‐known hole transporting polymer poly(3‐hexylthiophene). © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 639–648 相似文献
958.
A narrow linewidth continuous wave Ho:YAP laser with two Fabry-Perot etalons pumped by a Tm:YLF laser is reported. The maximum output power reaches 8.3 W when the incident pump power is 15.8 W, with 52.5% optical-to- optical conversion efficiency and 62.6% slope efficiency. A stable laser output at 2118.1 nm is achieved, with a linewidth less than 0.4 nm (full width at half maximum). The beam quality factor is M2- 1.25, measured by the traveling knife-edge method. 相似文献
959.
Dr. Julyan H. E. Cartwright Dr. Denis Gebauer Dr. C. Ignacio Sainz‐Díaz 《Angewandte Chemie (International ed. in English)》2012,51(48):11960-11970
Although the polymorphism of calcium carbonate is well known, and its polymorphs—calcite, aragonite, and vaterite—have been highly studied in the context of biomineralization, polyamorphism is a much more recently discovered phenomenon, and the existence of more than one amorphous phase of calcium carbonate in biominerals has only very recently been understood. Here we summarize what is known about polyamorphism in calcium carbonate as well as what is understood about the role of amorphous calcium carbonate in biominerals. We show that consideration of the amorphous forms of calcium carbonate within the physical notion of polyamorphism leads to new insights when it comes to the mechanisms by which polymorphic structures can evolve in the first place. This not only has implications for our understanding of biomineralization, but also of the means by which crystallization may be controlled in medical, pharmaceutical, and industrial contexts. 相似文献
960.
《Physics and Chemistry of Liquids》2012,50(2):257-271
This work presents experimental liquid densities and ultrasonic velocities for a collection of substituted aromatic compounds (isobutylbenzene, 1,3,5-trimethylbenzene, butylbenzene, isopropylbenzene, p-xylene, m-xylene and o-xylene) at the range of temperature 278.15–323.15 K and atmospheric pressure of a collection of halogenated and aromatic hydrocarbons. Fitting equations were applied to data in order to correlate for later computer-based design. The estimation of the studied properties was made by the application of different theoretical procedures. An equation of state based on the generalised Van der Waals theory which combines the Staverman–Guggenheim combinatorial term of lattice statistics with an attractive lattice gas expression and the free length theory (FLT) showed a good response at the studied conditions. 相似文献