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991.
Xia Haihong Zhao Zhixiang Li Jigen Shi Yongqian Han Yinlu Zhu Shengyun Xu Yongli Guan Xialing Cui Baoqun Fu Shinian 《Frontiers of Energy and Power Engineering in China》2007,1(2):135-140
The conceptual study on the accelerator driven system (ADS) that lasted for about five years ended in 1999 in China. As one
project of the National Basic Research Program of China (973 Program) in the energy domain, which is sponsored by the China
Ministry of Science and Technology (MOST), a five-year-program of fundamental research of ADS physics and related technology
was launched in 2000 and passed national review at the end of 2005. The China Institute of Atomic Energy (CIAE), the Institute
of High Energy Physics (IHEP), the Institute of Heavy Ion Physics in Peking University (PKU-IHIP) and other institutions jointly
carried out the research. The research activities were focused on HPPA physics and technology, reactor physics of external
source driven sub-critical assembly, nuclear data base and material study. For HPPA, a high current injector consisting of
an ECR ion source, LEBT and an RFQ accelerating structure of 3.5 MeV was built. In reactor physics study, a series of neutron
multiplication experimental study has been carried out and still being done. The VENUS facility has been constructed as the
basic experimental platform for neutronics study in ADS blanket. It’s a zero power sub-critical neutron multiplying assembly
driven by external neutron produced by a pulsed neutron generator. The theoretical, experimental and simulation study on nuclear
data, material properties and nuclear fuel circulation related to ADS is carrying on to provide the database for ADS system
analysis. The main results on ADS related researches will be reported. 相似文献
992.
Stresses and strains near a rapidly propagating crack tip are affected by the mass density of the material. This paper starts with a brief summary of analytical results for near-tip dynamic fields as predicted by linear elastic fracture mechanics. Next, exact expressions are derived for dynamic crack-line strains, for mode-III crack propagation in a nonlinear elastic material and in an elastic perfectly-plastic material. These expressions are valid on the crack line from the moving crack tip to the moving boundary with the region of linearly elastic deformation. For steady-state crack growth, a critical strain criterion is used to compute the relation between external load and crack tip speed. The required external load increases with crack-tip speed. 相似文献
993.
994.
995.
SAPO-34/SiO_2催化甲醇制烯烃 总被引:2,自引:0,他引:2
采用水热法合成了SAPO-34分子筛,并用X射线粉末衍射仪和扫描电子显微镜对SAPO-34分子筛的结构进行了表征,同时探讨了黏合剂种类、甲醇分压、催化剂粒径和硅源等对SAPO-34分子筛催化甲醇制烯烃(MTO)反应性能的影响。实验结果表明,在MTO反应中,三烯(乙烯、丙烯和丁烯)选择性在反应初期存在明显的诱导期;以S iO2为黏合剂合成的SAPO-34/S iO2催化剂不但可缩短MTO反应的诱导期,三烯选择性也较未添加黏合剂或以A l2O3为黏合剂时高1~2个百分点;且当催化剂活性明显下降时,三烯选择性下降的幅度较小。催化剂粒径、甲醇分压及硅源对催化剂的诱导期也有明显的作用。在甲醇分压低于19kPa、催化剂粒径0.25~0.38mm、S iO2为黏合剂、硅酸四乙酯为硅源时,SAPO-34/S iO2催化剂的MTO性能明显提高。 相似文献
996.
企业信息化水平提高后,随着Internet的接入,企业网络的安全状况发生了很大变化。网络信息的安全问题也日益突出。本文由技术安全、安全管理等两方面具体措施的实施,说明了企业网络安全系统的构建方法。希望与各位同行共享和探讨。 相似文献
997.
Y. Zhang G.R. Lumpkin H. Li M.G. Blackford M. Colella M.L. Carter E.R. Vance 《Journal of Nuclear Materials》2006,350(3):293-300
An amorphous natural brannerite sample was chosen to study the annealing of the radiation damage through thermal recrystallisation, and subsequently to evaluate the effect of radiation damage on its aqueous durability. Microstructural characterisation of the natural brannerite revealed minor alteration along the rim of the crystal and within cracks. The formation of UO2 particles and soluble Pb–Ca-rich aluminosilicate glass is responsible for the higher U and Pb releases from the recrystallised brannerite. In general, natural brannerite has been shown to be resistant to dissolution over geological time, therefore minor brannerite inclusions in ceramic formulations for immobilisation of actinide-rich radioactive wastes should not have a detrimental effect on the long-term chemical durability of the wasteforms. 相似文献
998.
999.
With the “orthogonal experimental design” (OED), the dependence of conductivity and transparency of tin oxide films and open circuit voltage Voc of SIS solar cells on the spray deposition process factors was studied. The OED technique was found to be a powerful method for realizing the best factor combination. Using OED, curves were obtained which clearly depict the effects of each factor on the SIS characteristics. The results of the experiments also illustrate exactly which variation in fabrication technique most affects the sheet resistance, Voc, and film transparency. Under the optimal combination of conditions, a thin film doped with NH4F was obtained, with about 90% transmission and a sheet resistance of about 80 Ω/□, along with an SIS structure with a Voc of about 0.61 V. 相似文献
1000.
新城金矿采场落矿控制爆破技术 总被引:1,自引:1,他引:0
新城金矿为蚀变岩型金矿床,由于受地质构造影响,顶板稳定性较差,局部和较大面积的顶板冒落现象时有发生,为了解决采场顶板安全问题和提高落矿主要技术经济指标而进行了“上向水平分层尾砂胶结充填法采场控制爆破技术”的试验研究工作,试验达到了预期效果。 相似文献