摘要：Silicon(Si)is a promising anode material for next-generation Li-ion *** nanometer-sized Si could alleviate the pulverization caused by large volume changes during deep ***,compression between agglomerated Si particles causes Si cracking and electrode *** this,we engineered a mechanical cushioning space between Si particles via elastic hollow graphene shells(GSs)to flexibly buffer volume changes and maintain the stability of the electrode *** stress generated from the Si volume expansion during lithiation was mechanically buffered and gently released by compression of the hollow space of the *** this Si/GS composite electrode,GS also reduced the local agglomeration of Si particles and effectively improved the overall *** these advantages,the designed Si/GS electrode showed an enhanced cycling performance with more than 1200 mA h g^(-1) at 0.8 A g^(-1) and an excellent rate capability of 1025 mA h g^(-1) at 4 A g^(-1) after 200 cycles.

摘要：为了实现面向对象语言的部分求值,提出了一种绑定时间分析技术.该技术通过针对引用类型变量和指针变量的上下文敏感分析,能够比较精确地分析面向对象语言中诸如对象元素、数组元素等复杂数据结构元素的绑定时间,进而扩大了部分求值的作用范围.这种方法采用两层BTA环境来保存静态变量和局部变量的BTA状态,设置一种专用句柄来表示不同程序点创建的对象,进而采用这种句柄的集合表示引用类型变量的BTA状态.在为面向对象语言程序标注绑定时间信息的过程中,采用一个正向分析和一个反向分析过程,借助于BTA环境来跟踪和设定各种变量、对象和引用变量的绑定时间.该技术已经用于实现Java程序的绑定时间分析,能够有效地分析大多数单线程的Java程序,为实现高性能Java程序部分求值提供了必要的手段.

摘要：在深部巷道中使用的钢管混凝土支架与锚杆-索的耦合支护技术经常失效,导致巷道失稳。其中,增加锚杆-索的长度是一种现场常用的返修方式,但比较浪费支护材料。本文提出通过改变锚杆-索的预紧力来改善钢管混凝土支架的受力状态。首先,总结了钢管混凝土支架常见的破坏模式,并利用弹性中心法获得了钢管混凝土支架与锚索耦合支护情况下的钢管混凝土支架的内力;结果表明,施加锚索可以减小钢管混凝土支架的内力,保证其高承载力。然后,建立了钢管混凝土支架与锚杆-索在不同侧压力系数和不同耦合支护条件下的数值计算模型;进一步研究了不同侧压、不同支护方案以及在不同角度范围内增加锚杆-索预紧力下巷道围岩与支护体的应力和位移演化规律。结果表明,当锚杆和锚索预紧力分别为60和100 kN时,钢管混凝土支架与锚杆-索的耦合支护效果可以达到最佳,且最佳锚杆-索预紧力增加角度范围为15°~45°。最终将钢管混凝土支架与锚杆-索的耦合支护技术进行了现场应用,有效控制了深部巷道大变形,对深部巷道的支护方案设计具有一定的指导意义。

摘要：Exclusive responsiveness to ultraviolet light (~3.2 eV) and high photogenerated charge recombination rate are the two primary drawbacks of pure TiO_(2). We combined N-doped graphene quantum dots (N-GQDs), morphology regulation, and heterojunction construction strategies to synthesize N-GQD/N-doped TiO_(2)/P-doped porous hollow g-C_(3)N_(4) nanotube (PCN) composite photocatalysts (denoted as G-TPCN). The optimal sample (G-TPCN doped with 0.1wt% N-GQD, denoted as 0.1% G-TPCN) exhibits significantly enhanced photoabsorption, which is attributed to the change in bandgap caused by elemental doping (P and N), the improved light-harvesting resulting from the tube structure, and the upconversion effect of N-GQDs. In addition, the internal charge separation and transfer capability of0.1% G-TPCN are dramatically boosted, and its carrier concentration is 3.7, 2.3, and 1.9 times that of N-TiO_(2), PCN, and N-TiO_(2)/PCN(TPCN-1), respectively. This phenomenon is attributed to the formation of Z-scheme heterojunction between N-TiO_(2) and PCNs, the excellent electron conduction ability of N-GQDs, and the short transfer distance caused by the porous nanotube structure. Compared with those of N-TiO_(2), PCNs, and TPCN-1, the H2 production activity of 0.1%G-TPCN under visible light is enhanced by 12.4, 2.3, and 1.4times, respectively, and its ciprofloxacin (CIP) degradation rate is increased by 7.9, 5.7, and 2.9 times, respectively. The optimized performance benefits from excellent photoresponsiveness and improved carrier separation and migration efficiencies. Finally, the photocatalytic mechanism of 0.1% G-TPCN and five possible degradation pathways of CIP are proposed. This study clarifies the mechanism of multiple modification strategies to synergistically improve the photocatalytic performance of 0.1% G-TPCN and provides a potential strategy for rationally designing novel photocatalysts for environmental remediation and solar energy conversion.

摘要：本文研究了一种新型低密度(~6.24 g cm^(-3))双相AlTiVCoNi高熵合金,其组织结构由有序L21高熵金属间化合物、无序体心立方结构和纳米L21相多层次结构构成.该合金在1200℃+24 h热处理下未发生相结构转变,在此条件下具有优异的高温相结构稳定性,其铸态和热处理态的压缩屈服强度相当,达到~1.6 GPa.另外,该合金在室温和600℃条件下表现出了优异的强塑性匹配和优异的比屈服强度,分别达到了约261和210 MPa g^(-1)cm^(3).该合金的超高强度主要源于有序L21相与体心立方相的半共格界面导致的一种强相结构稳定性和多层次结构的复合强化机制.该合金在800和1000℃压缩过程中出现了动态再结晶软化,使得其高温强度有所降低.这种“具有半共格界面L21+体心立方+纳米L21颗粒”的多层次结构设计为开发新型低密度耐高温高熵合金提供了一种新设计思路.

摘要：近年来,超三代移动通信系统的QoS体系结构已成为计算机网络领域和通信领域的一个研究热点.调研了相关的主要研究项目,通过对重点项目和国外该领域相关论文成果进行分析和比较,总结出未来B3G(beyond 3rdgeneration)系统QoS体系结构应是一种全IP的、层次化的、端到端的QoS体系结构,它应具有集成性、可管理性、可扩展性、自适应性和动态资源管理等特点.最后提出了B3G系统QoS体系结构的基本设计原则,并对未来工作进行了展望.

摘要：Large-scale production of polyethylene in industry requires efficient elimination of the trace amount of acetylene ***,zeolite adsorption or the conversion of acetylene to ethylene via selective semi-hydrogenation on Pd catalysts is the commonly used *** this work,we investigate the reaction mechanisms of acetylene hydrogenation on defective graphene(DG)supported singleatom catalysts(SACs),M1/SV-G and M1/DV-G(M=Ni,Pd and Pt)using density functional theory(DFT),where SV-G and DV-G represent DG with single and double vacancies,*** is shown that the metal single-atoms(SAs)as well as their different coordination numbers both affect the activity and selectivity of the hydrogenation process.M1/DV-G provides better H2 dissociation ability than M1/SV-G,which accounts for the poor acetylene hydrogenation activity of M1/*** on the reaction barriers,Pt1/DV-G and Ni1/DV-G are better catalysts than other systems considered here,with Ni1/DV-G exhibiting high selectivity for the semi-hydrogenation product of *** results provide insights for the design of highly selective and noble-metal-free SACs for acetylene hydrogenation on carbon materials.

摘要：The anionic redox chemistry(O^2-→O^-)in P2-type sodium-ion battery cathodes has attracted much ***,determining how to tune the anionic redox reaction is still a major ***,we tune the activity and reversibility of both the anionic and cationic redox reactions of Na0.67Mn0.5Fe0.5O2 though an integrated strategy that combines the advantages of Li2SiO3 coating,Li doping and Si doping,and the initial capacity,rate performance and cycling stability are significantly *** in-depth modulation mechanism is revealed by means of neutron diffraction,X-ray absorption spectroscopy,in situ X-ray diffraction,electron paramagnetic resonance spectroscopy,first-principles calculations and so *** Li2SiO3 coating alleviates the side reactions and enhances the cycling ***^4+doping lowers the Na^+diffusion barrier due to the expanded interlayer ***,Si^4+doping improves the structural stability,oxygen redox activity and ***^+doping in Na sites further increases the structure *** electron density maps confirm the greater activity of Na and O in the modified *** density maps and bond-valence energy landscapes identify the Na^+migration pathway from Nae site to Naf site(the positions of the Na ions in the crystal structure).The proposed insights into the modulation mechanism of the anionic and cationic redox chemistry are also instructive for designing other oxide-based cathode materials.

摘要：针对网格开放性和扩展性的需求,提出了基于Overlay Network网格体系结构的理论模型。形式化了其核心问题:混合Overlay Network拓扑设计问题,证明了该问题在满足一定条件下具有线性复杂度,提出了在一般条件下求解该问题的模拟退火算法。最后,通过仿真实验分析评价了所提出算法对Overlay Network拓扑代价的影响,结果表明这个模拟退火算法是可行的。

摘要：In this work,a set of novel Cu2ZnSnS4/Bi2WO6(CZTS/BWO)two-dimensional(2 D)/two-dimensional(2 D)type-Ⅱheterojunctions with different CZTS weight ratios(1%,2%,and 5%)were successfully synthesized via a brief secondary solvothermal *** successful formation of the heterojunctions was affirmed by characterization methods such as X-ray photoelectron spectroscopy and high-resolution transmission electron *** photocatalytic activity results showed that the prepared CZTS/BWO heterojunctions had excellent photocatalytic behaviors for organic degradation,especially when the mass fraction of CZTS with respect to BWO in the composite was 2%.Moreover,the addition of hydrogen peroxide(H2O2)could further improve the dye and antibiotic degradation *** reinforced photocatalytic and photo-Fenton degradation performance were primarily attributable to the introduction of BWO,which afforded increased active sites,expanded the solar spectral response range,and accelerated the cycle of Cu(Ⅱ)/Cu(Ⅰ);after four cycling times,its catalytic activity did not decrease *** addition,reasonable hypotheses of the photocatalytic and photo-Fenton catalytic mechanisms were *** study is expected to provide a visual approach for designing a novel photo-Fenton catalyst to jointly utilize the photocatalytic and Fenton activities,which can be better applied to the purification of residual organics in wastewater.