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羌族地区义务教育发展的对策研究 被引量:1
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作者 赵鹏程 《教育评论》 CSSCI 北大核心 2003年第1期73-76,共4页
关键词 义务教育 教育结构 放学率 小学生 初中学 素质教育 羌族地区
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Pharmaceutical Characteristics of Daunorubicin Stealth Liposomes
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作者 张华 齐宪荣 张强 《Journal of Chinese Pharmaceutical Sciences》 CAS 2001年第4期200-202,共3页
This report studied on pharmaceutical characteristics of the stealth liposome containing dau-norubicin (DNR). The shape, size, entrapment efficiency and stability of the daunorubicin stealth liposomes (DNRSL) were exa... This report studied on pharmaceutical characteristics of the stealth liposome containing dau-norubicin (DNR). The shape, size, entrapment efficiency and stability of the daunorubicin stealth liposomes (DNRSL) were examined. Visible spectrophotometry and the HPLC method were established for determination of the DNR in the DNRSL. The release of DNR from DNRSL in HBS (pH 7.5) and rat serum at 37 oC were examined. The results showed that the DNRSL had high entrapment efficiency (>85%), small size and slow release. 展开更多
关键词 Stealth liposomes DAUNORUBICIN Entrapment efficiency Drug release in vitro
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EFFICIENT GRADIENT DESCENT METHOD OFRBF NEURAL ENTWORKS WITHADAPTIVE LEARNING RATE
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作者 Lin Jiayu Liu Ying(School of Electro. Sci. and Tech., National Univ. of Defence Technology, Changsha 410073) 《Journal of Electronics(China)》 2002年第3期255-258,共4页
A new algorithm to exploit the learning rates of gradient descent method is presented, based on the second-order Taylor expansion of the error energy function with respect to learning rate, at some values decided by &... A new algorithm to exploit the learning rates of gradient descent method is presented, based on the second-order Taylor expansion of the error energy function with respect to learning rate, at some values decided by "award-punish" strategy. Detailed deduction of the algorithm applied to RBF networks is given. Simulation studies show that this algorithm can increase the rate of convergence and improve the performance of the gradient descent method. 展开更多
关键词 Gradient descent method Learning rate RBF neural networks
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Leaching Phenomena of Antifouling Agents from Ships' Hull Paints
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作者 Ryuji Kojima Toshiaki Shibata Koichi Ueda 《Journal of Shipping and Ocean Engineering》 2016年第5期269-278,共10页
The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships' hull paint have been investigated by rotating cylinder tests. Additionally, ... The effects ofpH, dissolved ion content and relative water velocity on the release rate of an antifouling agent, cuprous oxide, from ships' hull paint have been investigated by rotating cylinder tests. Additionally, test paint panels were attached to a vessel and recovered after a certain period of voyage for the validation of the laboratory tests. In the initial period, the release rates are influenced by pH, dissolved ion content and water velocity, but once after a certain period of test, those effects become less significant. These phenomena can be explained when the paint film is fresh, the rate is controlled by chemical reaction, the surface and/or diffusion layer in the water phase governs the rate. After the antifouling substance in the paint film leached out from the near-surface region, a diffused layer (leached layer), that has little antifouling agent remained, is formed at the surface of the coating, and the diffusion in that layer can be a rate-determining process. The development of the leached layer is affected by a balance between the leaching rate of the antifouling ingredient and paint resin determined by the chemical properties and speed of the water. Thus, the leaching rates of antifouling agents are affected by the history of the paint in the water. 展开更多
关键词 Antifouling agent leaching rate cuprous oxide rotating cylinder substituted ocean water phosphate buffer solution.
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Influence of Input Pulse Durations on Properties of Er^(3+)/Yb^(3+) Co-doped DCFA
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作者 ZHAN Sheng-bao ZHAO Shang-hong SHI Lei XU Jie ZHAO Xiao-ming 《Semiconductor Photonics and Technology》 CAS 2006年第3期205-210,共6页
Based on propagation-rate equations, the influence of different input pulse durations on the properties of Er^3+/Yb^3+ co-doped double-clad fiber amplifier at dynamic equilibrium was analyzed. The change characteris... Based on propagation-rate equations, the influence of different input pulse durations on the properties of Er^3+/Yb^3+ co-doped double-clad fiber amplifier at dynamic equilibrium was analyzed. The change characteristic of output power sag with pulse duration and repetition rate was shown. Whether single or multichannel input pulses are amplified, the shorter the input pulse duration is, the smaller the power sags of output pulse will be. At low repetition rate, upper gain values(Gupper) of gain swing are almost the same for different input pulse durations, which tend to the small signal gain, but lower gain value(Glower) of short input pulse is larger than that of long input pulse. At highrepetition rate, lower gain value(Glower) approaches to upper gain value(Glower). 展开更多
关键词 Er^3+/Yb^3+ co-doped Double-clad fiber amplifier Pulse duration Pulse repetition rate
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High Accuracy Zoom Magnification Measurement
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作者 曾政东 孙长库 +2 位作者 郑义忠 YAN Mingdong CHANG Sengkeong 《Transactions of Tianjin University》 EI CAS 2010年第4期289-294,共6页
A precise zoom magnification is important for semiconductor industry and biomedical research. A novel measurement method is demonstrated for optical zoom magnification measurement in this paper. The magnification is o... A precise zoom magnification is important for semiconductor industry and biomedical research. A novel measurement method is demonstrated for optical zoom magnification measurement in this paper. The magnification is obtained by pattern correction between barcode image formed by optical zoom and reference image generated by an ideal optical model. Measurement accuracy which is better than 0.06% has been achieved for optical zoom magnification. Compared with traditional concept, the measurement results are only dependent on two line edges. The barcode correlation method can achieve higher accuracy and better robustness by using the information over the whole field of view. 展开更多
关键词 MAGNIFICATION MICROSCOPE optical zoom BARCODE image processing measurement apparatus
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Single Cell HLA Matching Feasibility by Whole Genomic Amplification and Nested PCR
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作者 Xiao-hongLi Fang-yinMeng 《Chinese Medical Sciences Journal》 CAS CSCD 2004年第3期198-198,共1页
关键词 Alleles Gene Amplification Genome GENOTYPE HLA-A Antigens HLA-B Antigens Humans Polymerase Chain Reaction Research Support Non-U.S. Gov't
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Effect of B and Fe substitution on structure of AB_3-type Co-free hydrogen storage alloy
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作者 吴锋 张旻昱 穆道斌 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第10期1885-1891,共7页
A series of hydrogen storage Co-free AB3-type alloys were directly synthesized with vacuum mid-frequency melting method,within which Ni of La0.7Mg0.3Ni3 alloy was substituted by Fe,B and(FeB) alloy,respectively.Alloys... A series of hydrogen storage Co-free AB3-type alloys were directly synthesized with vacuum mid-frequency melting method,within which Ni of La0.7Mg0.3Ni3 alloy was substituted by Fe,B and(FeB) alloy,respectively.Alloys were characterized by XRD,EDS and SEM to investigate the effects of B and Fe substitution for Ni on material structure.The content of LaMg2Ni9 phase within La0.7Mg0.3Ni3 alloy reaches 37.9% and that of La0.7Mg0.3Ni2.9(FeB)0.1 alloys reduces to 23.58%.Among all samples,ground particles with different shapes correspond to different phases.The major substitution occurs in LaMg2Ni9 phase.Electrochemical tests indicate that substituted alloys have different electrochemical performance,which is affected by phase structures of alloy.The discharge capacity of La0.7Mg0.3Ni3 alloy reaches 337.3 mA·h/g,but La0.7Mg0.3Ni2.9(FeB)0.1 alloy gets better high rate discharge(HRD) performance at the discharge rate of 500 mA/g with a high HRD value of 73.19%. 展开更多
关键词 Ni-MH battery AB3-type B substitution Co-free hydrogen storage alloy
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The Past and the Future of the TRIGA Reactor in Vienna
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作者 Helmuth Bock Yuj Hasegawa Erwin Jericha Georg Steinhauser Mario Villa 《Journal of Energy and Power Engineering》 2013年第4期654-660,共7页
During the past five decades, the TRIGA reactor Vienna has reached a top place in utilization among low power research reactors. This paper discussed the highlights of the major neutron physics experiments in the fiel... During the past five decades, the TRIGA reactor Vienna has reached a top place in utilization among low power research reactors. This paper discussed the highlights of the major neutron physics experiments in the field of neutron interferometry and ultra-small angle neutron scattering as well as in the field of radiochemistry, education and training and research in the field of nuclear safeguards and nuclear security. Potential further directions of research are outlined where the Atominstitut of Vienna might concentrate in future. 展开更多
关键词 TRIGA reactors research reactors neutron and solid state physics neutron interferometry ultra small-angle neutronscattering education and training.
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Study of Space Reactors for Exploration Missions
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作者 Elisa Cloquet Jean-Marc Ruault +5 位作者 Frederic Masson Jean-Pierre Roux Nicolas Paris Brice Cazale Laurent Manifacier Christine Poinot-Salanon 《Journal of Energy and Power Engineering》 2014年第8期1393-1408,共16页
Nuclear propulsion has been studied for many decades. The power density of nuclear fission is much higher than chemical process, and for missions to outer solar system requiring several hundred of kilowatts, or for fl... Nuclear propulsion has been studied for many decades. The power density of nuclear fission is much higher than chemical process, and for missions to outer solar system requiring several hundred of kilowatts, or for flexible manned missions to Mars requiring several megawatts, nuclear electric propulsion might be the only option offering a reasonable mass in low earth orbit. Despite the existence of low power experiences--SNAP10 in the 60's or Buk/Topaz in the 60-80's--no high power reactor has been developed: investment cost, long term timeframe, high technological challenges and radioactive hazards are the main challenges we must overtake. However, it seems reasonable to look at the technical challenges that have to be overcome for a next generation of nuclear electric systems for space exploration. This paper will present some recent studies going on in France, on space reactors for exploration. Three classes of power have been considered: 10 kWe, 100 kWe, and several megawatts. Available data from previous studies and developments performed in Russia, USA, and Europe have been collected and gave us a large overview of potential technical solutions. This was the starting point of a trade-off analysis aiming at the selection of the best options, with regards to the technological readiness level in France and Europe. The resulting preliminary designs will be presented and critical technologies needing maturation activities will be highlighted. 展开更多
关键词 Spatial nuclear reactor nuclear energy nuclear propulsion
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Effects of discharge power on the structural and optical properties of TGZO thin films prepared by RF magnetron sputtering technique 被引量:4
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作者 顾锦华 陆轴 +2 位作者 钟志有 龙路 龙浩 《Optoelectronics Letters》 EI 2016年第3期188-191,共4页
The transparent semiconductors of Ti and Ga-incorporated ZnO(TGZO) thin films were prepared by radio frequency(RF) magnetron sputtering onto glass substrates. The effects of discharge power on the physical properties ... The transparent semiconductors of Ti and Ga-incorporated ZnO(TGZO) thin films were prepared by radio frequency(RF) magnetron sputtering onto glass substrates. The effects of discharge power on the physical properties of thin films are studied. Experimental results show that all nanocrystalline TGZO thin films possess preferential orientation along the(002) plane. The discharge power significantly affects the crystal structure and optical properties of thin films. When the discharge power is 200 W, the TGZO thin film has the optimal crystalline quality and optical properties, with the narrowest full width at half-maximum(FWHM) of 1.76×10^(-3) rad, the largest average grain size of 82.4 nm and the highest average transmittance of 84.3% in the visible range. The optical gaps of thin films are estimated by the Tauc's relation and observed to increase firstly and then decrease with the increase of the discharge power. In addition, the optical parameters, including refractive index, extinction coefficient, dielectric function and dissipation factor of the thin films, are determined by optical characterization methods. The dispersion behavior of the refractive index is also analyzed using the Sellmeier's dispersion model. 展开更多
关键词 放电功 光学性质 晶体结构 磁控溅射技术 薄膜 制备 平均晶粒尺寸 光学性能
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Maximizing the ion accessibility and high mechanical strength in nanoscale ion channel MXene electrodes for high-capacity zinc-ion energy storage 被引量:1
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作者 Yongfa Cheng Yimei Xie +6 位作者 Shuwen Yan Zunyu Liu Yanan Ma Yang Yue Jianbo Wang Yihua Gao Luying Li 《Science Bulletin》 SCIE EI CAS CSCD 2022年第21期2216-2224,共9页
Two-dimensional transition-metal carbides(MXenes)have superhydrophilic surfaces and superior metal conductivity,making them competitive in the field of electrochemical energy storage.However,MXenes with layered struct... Two-dimensional transition-metal carbides(MXenes)have superhydrophilic surfaces and superior metal conductivity,making them competitive in the field of electrochemical energy storage.However,MXenes with layered structures are easily stackable,which reduces the ion accessibility and transport paths,thus limiting their electrochemical performance.To fully exploit the advantages of MXenes in electrochemical energy storage,this study reports the etching of large-sized MXene into nanosheets with nanoscale ion channels via a chemical oxidation method.While the resulting ion-channel MXene electrodes retain the excellent mechanical strength and electrical conductivity of large-sized MXene nanosheets,they can effectively shorten the ion transport distance and improve the overall electrochemical activity.The fabricated self-healing MXene-based zinc-ion microcapacitor exhibits a high areal specific capacitance(532.8 mF cm^(-2))at the current density of 2mA cm^(-2),a low self-discharge rate(4.4 mV h^(-1)),and high energy density of 145.1μWh cm^(-2)at the power density of 2800μW cm^(-2).The proposed nanoscale ion channel structure provides an alternative strategy for constructing high-performance electrochemical energy storage electrodes,and has great application prospects in the fields of electrochemical energy storage and flexible electronics. 展开更多
关键词 MXene Ion channel Ion accessibility High strength Zinc-ion microcapacitor
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