摘要：通过设计特定的时空调制,合成磁性的概念最近被提出以实现对光子和声子等电荷中性粒子的非互易操控,但现有方案存在着隔离度低、信号频率变化等问题.本文设计了一种新型耦合共振腔系统,其中动态耦合的相位作为实现声学合成磁场的新机制并打破了系统的时间反演对称性,最终取得了优异的声波非互易传输.基于旋转波近似方法,作者严格推导出了实现系统强非互易声传输的参数条件.通过优化动态耦合之间的相位差以及耦合强度,实验展示了隔离度达45-dB和正向传输率达0.85的优异单向声传输.此外,这种单向声传输具有始末态频率不变和隔离方向可电控等重要特性.该研究突破了现有声波单向操控机制在效率和隔离度方面的局限,并为实现弗洛奎和非线性声学拓扑绝缘体提供了新途径.

摘要：本文采用分子动力学计算方法和Tersoff作用势研究了无定型碳(amorphous carbon,a-C)涂层厚度对Si C纳米纤维/Si C纳米复合材料断裂方式及力学性能的影响.分析结果发现,随着涂层厚度的增加,纳米纤维的平均应力集中系数下降,即足够厚度涂层可以同时起到增强和补韧的作用.当a-C涂层厚度t 0.3 nm时,裂纹直接穿透纤维,纳米复合材料表现出典型的脆性断裂方式;t=4.0 nm时,裂纹发生偏转,Si C纳米纤维发生拔出现象,此时纳米复合材料的拉伸强度约为无涂层纳米复合材料的4倍,断裂能则提高一个数量级.计算结果表明,a-C涂层的厚度是Si C纳米纤维/Si C纳米复合材料中产生韧性机理的重要因素,即传统微米级陶瓷基复合材料的增韧理论在纳米复合材料中仍适用.研究结果可望为设计同时具有高强度、高韧性的陶瓷基纳米复合材料提供理论基础.

摘要：基于Lustre文件系统，对并行文件系统的性能评估和性能建模进行了研究．通过对性能因子的调研，进行了一系列性能评估实验，并提出性能相关性模~（PRModel）．在实验评估和PRModel分析中发现，在不同的性能因子之间存在着紧密的性能相关性，为了挖掘并利用这种相关性信息，提出了一种相对性能预测模（RPPModel）来预测不同性能因子条件下的性能．为了验证RPPModel的有效性，设计了大量实验用例．结果表明，预测结果的平均相对误差能够控制在170／o---28％的范围内，易于使用且具有较好的预测准确度．

摘要：庄周之梦蝶翅膀具有亮蓝色的反光. 我们设计了蝴蝶翅膀的发射光谱随其中填充液体挥发的变化实验, 证实了这种颜色的产生是因为多层微结构的干涉, 而不是因为蝴蝶本身色素颜色的漫反射. 这种对可见光的选择性反射是由于蝴蝶翅膀中的二维光子带隙结构作用.

摘要：The paper examines thoroughly how utilizing the latest technology, such as a PC （personal computer）, an iPad, or an iPhone, can entertain many people and allow them to learn about the archaeological findings that have become broadly available through the application of new technology. The paper assesses web usage through the difference in availability and convenience of PC and compact devices by connection to 3D augmented reality applications. Modem technology has allowed access to this information to become radically altered, whereas historical records and remains are dwindling. However, the development of 3D technology means that the general public can experientially pursue the dignity of historical buildings. It also becomes easier through the use of the latest technology to decipher the effectiveness of people＇s interaction with inclusive descriptions of the documentation. This research aims at verifying the visualization of Fort Frontenac by the use of a chronological renovation process. This paper is composed of five elements： an introduction, the historical records about the necessity of 3D modeling, heritage visualization by means of 3D modeling, web design, and iPad and iPhone usage, a comparison of the architectural change that occurred in the

摘要：Hybrid perovskite possesses excellent photoelectric properties,including large light-absorption capacity and high carrier mobility,and is an ideal light-absorbing material for photoelectric *** grain size and compactness of hybrid perovskite are key factors affecting the performance of photoelectric *** photocurrent and photoresponsivity of these devices are relatively low because of the rapidly recombined photoexcited electron-hole pairs in hybrid ***,we develop a facile two-step chemical vapor deposition(CVD)method to synthesize a high-quality van der Waals(vd Ws)MAPb I3/graphene heterostructure for high-performance image *** introduced inorganic sources(PbI2)to vd Ws epitaxially grown Pb I2 film on a seamless graphene monolayer film template through *** iodide(MAI)was then reintroduced to prepare the vd Ws MAPb I3/graphene *** MAPb I3 layer is composed of densely packed,large-size grains and displays a smooth *** photoresponsivity of 107A/W is achieved in the corresponding *** by the human visual system,we designed a flexible photodetector array containing(24?24)pixels,achieving perfect image recognition and color *** study may greatly facilitate the construction of high-performance optoelectronic devices in artificial retina,biomedical imaging,remote sensing,and optical communication.

摘要：β-Glucuronidase(GUS)plays a key role in tumor initiation,metastasis,and progression,and thus,has been proposed as a promising cancer *** this study,we designed an enzyme-activatable near-infrared(NIR)fluorescent probe(DCM-βGlcA)for the rapid and accurate detection of GUS activity in vitro,in vivo and ex *** DCM-βGlcA was prepared by linking a glucuronic acid residue to dicyanomethylene-4 H-pyran(DCM).This probe exhibited significant light-up NIR fluorescent signals at 680 nm after reacting with GUS and the Stokes shift could reach 150 *** DCM-βGlcA showed a high sensitivity toward GUS and an excellent linear relationship at concentrations ranging between 0 and 4 U L^(-1)(R^(2)=0.9974)with the limit of detection as low as 0.19 U L^(-1).We used the DCM-βGlcA to identify GUS serum levels in both cancer patients and healthy individuals with a similar accuracy as that of an enzyme-linked immunosorbent assay(ELISA)while being easier and faster to ***,the DCM-βGlcA was used for tracking endogenous GUS in living cells,thereby discriminating GUSoverexpressed liver cancer from normal ***,the DCM-βGlcA was able to detect and image endogenous GUS in liver cancer tissue and tumor-bearing mouse *** findings demonstrate the potential of the DCM-βGlcA as a promising tool for detecting and monitoring GUS activity in preclinical applications.

摘要：Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical ***,the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain ***,superfine Pt and PtCu nanoparticles supported by novel S,N‐co‐doped multi‐walled CNT(MWCNTs)were prepared through the innovative pyrolysis of a poly(3,4‐ethylenedioxythiophene)/polyaniline copolymer as a source of S and *** uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment,facilitating the uniform distribution of ultrafine Pt and PtCu ***,the Pt_(1)Cu_(2)/SN‐MWCNTs show an obviously larger electroactive surface area and higher mass activity,stability,and CO poisoning resistance in methanol oxidation compared to Pt/SN‐MWCNTs,Pt/S‐MWCNTs,Pt/N‐MWCNTs,and commercial Pt/*** functional theory studies confirm that the co‐doping of S and N considerably deforms the CNTs and polarizes the adjacent C ***,both the adsorption of Pt1Cu2 onto the SN‐MWCNTs and the subsequent adsorption of methanol are enhanced;in addition,the catalytic activity of Pt_(1)Cu_(2)/SN‐MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N‐CNT *** work provides a novel method to fabricate high‐performance fuel cell electrocatalysts with highly dispersed and stable Pt‐based nanoparticles on a carbon substrate.

摘要：本研究针对铝供应链中日益凸显的碳排放问题和水资源消耗问题,建立了一套决策模型框架,该框架由生命周期分析、绿色供应链网络优化模型和基于epsilon约束方法的多目标优化模型组成,同时考虑煤电、生物质发电、光伏+储能的组合等多种电力供应方式选择以及碳市场不确定性的影响,对铝供应链在多种资源约束下的多目标优化问题进行了深入分析.模型计算结果表明:经济成本和水资源消耗是一对彼此矛盾的目标;决策偏好以及碳市场不确定性会影响供应商的选择;资源约束更加严格的情况下倾向于选择低碳技术,同时产生减少水资源消耗的协同效应.高碳价下所有的帕累托解都不会选择煤电,而更多地倾向于选择光伏加储能的电力供应模式.案例研究证明了该模型在资源产业链多目标决策方面的有效性.本文提出的模型方法为环境资源约束下的资源型制造业决策提供了理论支持.

摘要：Wax esters were derived from long chain fatty acids and long chain alcohols with chain length of 12 carbons or more. These compounds have many potential applications in cosmetics, pharmaceuticals and food industries. The present work focuses on the synthesis of wax esters using palm fatty acid distillate and oleyl alcohol catalyzed by Amberlyst 15. Response surface methodology （RSM） based on a five-level, three-variable central composite design （CCD） was used to evaluate the interactive effects of synthesis, of amount of Amberlyst 15 catalyst （21.6-38.4% w/w）, reaction time （18-102 min） and molar ratio （palm fatty acid distillate to oleyl alcohol, 1：1.16-1：2.84） on the percentage conversion of palm fatty acid distillate. The optimum conditions derived via RSM were： amount of catalyst 33% w/w, reaction time 95 minute and palm fatty acid to oleyl alcohol molar ratio 1：2.7. The actual experimental conversion was 81.52% under optimum condition, which compared well to the maximum predicted value of 80.50%. Analysis of the yield showed that at optimum condition, 80.54% wax esters were produced.