基于NOMA的共生反向散射通信的性能分析

非正交多址接入和环境反向散射通信是提高无线通信系统频谱效率的关键技术.针对能量受限问题,提出了一种基于瑞利衰落信道的下行非正交多址接入多路传输的共生反向散射通信系统.该系统由1个源节点S、1个反向散射设备BD和1个目的节点D组成.考虑到实际的非线性能量收集模型,在满足反射设备的能量因果约束的情况下,采用了一种最优动态反射系数以最大化反向散射信号的功率,推导了该系统中断概率的解析表达式,通过仿真验证了理论推导的正确性.仿真结果表明,反射设备电路的自身损耗对系统中断性能有重要影响.此外,通过仿真对比分析了基于非正交多址的共生反向散射通信系统和基于正交多址的共生反向散射通信系统性能,结果表明基于非正交多址的共生反向散射通信系统具有更好的中断性能.

基于3C理论模型的运动员-教练员关系质性研究

为了探讨运动员-教练员关系的本质,研究采用Jowett(2003年)所提出的亲密性、共向性和互补性3因素模型,探讨运动员所知觉到的与教练员的关系。采用半结构化访谈的方法获得质性研究的原始数据,并对运动员的反应进行分析。结果显示:运动员-教练员关系在运动员发展和成长中起着重要作用。这种关系包括运动员-教练员关系的基本需要、社会关系(亲密性);沟通、目标设置(共向性);认可和尊重角色(互补性)。运动员认为和教练员维持好的关系非常重要。结论强调了在个人项目中,运动员-教练员关系的三种人际因素为亲密性、共向性和互补性,这种关系对于提高竞技表现起着重要作用。

Effect of Precipitation Method and Ce Doping on the Catalytic Activity of Copper Manganese Oxide Catalysts for CO Oxidation

The influence of Ce doping and the precipitation method on structural properties and the catalytic activity of copper manganese oxides for CO oxidation at ambient temperature have been investigated. The catalysts were characterized by means of the powder X-ray diffraction and N2 adsorption-desorption, the inductively coupled plasma atomic emission spectrometry, the temperature programmed reduction, diffuse reflectance UV-Vis spectra, and the X-ray photoelectron spectroscopy. It was found that after doping little amount of Ce in copper manganese oxide, CeO2 phase was highly dispersed and could prevent sintering and aggregating of the catalyst, the size of the catalytic material was decreased, the reducibility was enhanced, the specific surface area was increased and the formation of the active sites for the oxidation of CO was improved significantly. Therefore, the activity of the rare earth promoted catalyst was enhanced remarkably.

Audio steganalysis based on “negative resonance phenomenon” caused by steganographic tools

Researching on the impact different steganographic software tools have audio statistical features, revealed the phe- nomenon that when messages are embedded in a WAV file by using a certain tool, the variation of statistical features in the WAV file which already contains messages embedded by the same tool is abruptly smaller than those in which messages have not been embedded. We call it “negative resonance phenomenon” temporarily. With the phenomenon above and Support Vector Machines (SVMs), we can detect the existence of hidden messages, and also identify the tools used to hide them. As shown by the experi- mental results, the proposed method can be very effectively used to detect hidden messages embedded by Hide4PGP, Stegowav and S-Tools4.

Elastoplastic solutions for single piles under combined vertical and lateral loads

In order to improve the reliability of the design and calculation of single piles under the combined vertical and lateral loads, the solutions were presented based on the subgrade reaction method, in which the ultimate soil resistance was considered and the coefficient of subgrade reaction was assumed to be a constant. The corresponding computational program was developed using FORTRAN language. A comparison between the obtained solutions and the model test results was made to show the validity of the obtained solutions. The calculation results indicate that both the maximum lateral displacement and bending moment increase with the increase of the vertical and lateral loads and the pile length above ground, while decrease as the pile stiffness, the coefficient of subgrade reaction and the yielding displacement of soil increase. It is also shown that the pile head condition controls the pile responses and the vertical load may cause the instability problem to the pile. In general, the proposed method can be employed to calculate the pile responses independent of the magnitude of the pile deflection.

A Piezoelectric Screw Dislocation Interacting with an Elliptical Piezoelectric Inhomogeneity Containing a Confocal Elliptical Rigid Core

The electro-elastic interaction between a piezoelectric screw dislocation and an elliptical piezoelectric inhomogeneity, which contains an electrically conductive confocal elliptical rigid core under remote anti-plane shear stresses and in-plane electrical load is dealt with. The anaJytical solutions to the elastic field and the electric field, the interracial stress fields of inhomogeneity and matrix under longitudinal shear and the image force acting on the dislocation are derived by means of complex method. The effect of material properties and geometric configurations of the rigid core on interracial stresses generated by a remote uniform load, rigid core and material electroelastic properties on the image force is discussed.

Comprehensive Alcohol-/Ion-Responsive Properties of Poly(N-Isopropylacrylamide-co-Benzo-18-Crown-6-Acrylamide) Copolymers

In this paper, we report on the comprehensive alcohol-/ion-responsive properties of a smart copolymer poly（N- isopropylacry]amide-co-benzo-18-crown-6-acrylamide） （P（NIPAM-co-BCAm））. The orthogonal design method is adopted for experimental design. The experimental results show that alcohol can trigger the shrinking and Ba2t can induce the swelling of the P（NIPAM-co-BCAm） copolymer. According to the phase transition tempera- ture （LCST） change results of the copolymer, the influence of variables on the LCST changes weakens in the following order： alcohol concentration 〉 alcohol species 〉 metal ion species 〉 BCAm concentration 〉 ion concentration. The larger the alcohol concentration and the larger the molecular size of alcohols, the lower the LCST value; on the contrary, the more the BCAm content in the copolymer or the larger the BCAm/ion complex stability constant （IgK） or the larger the ion concentration is, the higher the LCST value. For a P（NIPAM-co-BCAm ） copolymer with a fixed BCAm content, a binary function of ion concentration and IgK of BCAm/ion is developed to precisely predict the LCST values of the copolymer in different metal ion solutions. The results provide valuable information for fabricating artificial biomimetic G-protein-gated inwardly rectifying potassium （GIRK） channels that are activated by alcohol and inhibited by Ba2＋.

三、实用经济计量方法(续)

(三)资料的收集、整理、选择和运用模型是公式化的产物,资料是测度的结果。测度或经济统计跟计量有不同的实体,从而其结果也有不同的信息含义。所谓测度是对经济实体的某种活动或某类过程而言的,计量是在测度的基础上分析经济关系或经济结构,是测度的深度化和发展。

On conformal vector fields on Randers manifolds

In this paper,we study conformal vector fields on a Randers manifold with certain curvature properties.In particular,we completely determine conformal vector fields on a Randers manifold of weakly isotropic flag curvature.

Self-assembly of conjugated polymers for anisotropic nanostructures

As their potential applications in various electronic devices increase, the preparation of anisotropic conjugated polymer nanostructures are highly desirable. This paper presents a review of the literature and our recent results on the self-assembly of one-, two- and three-dimensional anisotropic nanostructures using conjugated polymers as building blocks, including the formation of one-dimensional (1D) nanofibers and nanotubes, two-dimensional (2D) nanoribbons and nanosheets, and three-dimensional (3D) superstructures. The mechanisms guiding the formation of various nanostructures are analyzed by a cooperative effect of - stacking interaction and other noncovalent interactions.

The “Absence” of Asian Regional Economic Integration and the Development Orientation of the Belt and Road

Asia has a special significance in China’s neighborhood strategy.Geographically,the Belt and Road Initiative faces the countries of Asia or China’s neighbors in the first place.Asia is clearly marked by an imbalance in and“absence”of regional economic integration.This“absence”is two-fold:it is expressed on the one hand as a lack of unified institutional arrangements for regional economic integration,and on the other as the inability of underdeveloped countries in the region to truly participate in regional economic integration and thereby gain opportunities for development.Compared with the rule-oriented nature of existing regional economic integration mechanisms,the Belt and Road Initiative,as a new type of regional cooperation mechanism,displays an orientation towards development.All existing regional economic integration arrangements,regardless of their form,establish specific rules on access thresholds,the rights and duties of member countries,schedules and roadmaps,dispute resolution mechanisms and so forth.This is not the case for the Belt and Road,which is not predicated on specific rules,but establishes its overall framework by orienting itself towards development.Overall,the development orientation of the Belt and Road is helpful not only in overcoming the inherent defects of Asian regional economic integration,but in responding to the new challenge of anti-globalization.This is an institutional public good that China offers to Asia and to the world.

Designed polymeric conjugation motivates tunable activation of molecular oxygen in heterogeneous organic photosynthesis

Photocatalytic oxidative organic reactions are important synthetic transformations,and research on reaction selectivity by reactive oxygen species(ROS)is significant.To date,however,there has rarely been any focus on the directed generation of ROSs.Herein,we report the first identification of tunable molecular oxygen activation induced by polymeric conjugation in nonmetallic conjugated microporous polymers(CMP).The conjugation between these can be achieved by the introduction of alkynyl groups.CMP-A with an alkynyl bridge facilitates the intramolecular charge mobility while CMP-D,lacking an alkynyl group enhances the photoexcited carrier build-up on the surface from diffusion.These different processes dominate the directed ROS generation of the superoxide radical(·O_(2)^(-))and singlet oxygen(^(1)O_(2)),respectively.This theory is substantiated by the different performances of these CMPs in the aerobic oxidation of sulfides and the dehydrogenative coupling of amines,and could provide insight into the rational design of CMPs for various heterogeneous organic photosynthesis.