A Single-Board Integrated Millimeter-Wave Asymmetric Full-Digital Beamforming Array for B5G/6G Applications

In this article,a single-board integrated millimeter-wave(mm-Wave)asymmetric full-digital beamforming(AFDBF)array is developed for beyond-fifth-generation(B5G)and sixth-generation(6G)communications.The proposed integrated array effectively addresses the challenge of arranging a large number of ports in a full-digital array by designing vertical connections in a three-dimensional space and successfully integrating full-digital transmitting(Tx)and receiving(Rx)arrays independently in a single board.Unlike the traditional symmetric array,the proposed asymmetric array is composed of an 8×8 Tx array arranged in a square shape and an 8+8 Rx array arranged in an L shape.The center-to-center distance between two adjacent elements is 0.54k0 for both the Tx and Rx arrays,where k0 is the free-space wavelength at 27 GHz.The proposed AFDBF array possesses a more compact structure and lower system hardware cost and power consumption compared with conventional brick-type full-digital arrays.In addition,the energy efficiency of the proposed AFDBF array outperforms that of a hybrid beamforming array.The measurement results indicate that the operating frequency band of the proposed array is 24.25–29.50 GHz.An eight-element linear array within the Tx array can achieve a scanning angle ranging from-47°to+47°in both the azimuth and the elevation planes,and the measured scanning range of each eight-element Rx array is–45°to+45°.The measured maximum effective isotropic radiated power(EIRP)of the eight-element Tx array is 43.2 dBm at 28.0 GHz(considering the saturation point).Furthermore,the measured error vector magnitude(EVM)is less than 3%when 64-quadrature amplitude modulation(QAM)waveforms are used.

Women on Boards of Directors

This research aims to measure the current gender representation in membership of boards of directors,and to study the factors affecting the presence of women on boards.The results of the study will support the decision makers and policy makers at all levels by providing knowledge that contributes to bridging the current gap in participation of women boards.The methodology used in this research is the descriptive analytical approach,which relies on quantitative methods in the process of collecting and analyzing data.This study represents the boards of directors in the three sectors(public,private,and non-profit)in the Kingdom of Saudi Arabia,The study sample contained 350 targets,where a random sample of 150 people in the public sector,100 people in the private sector,and 100 people in the non-profit sector were selected.The research result found that the majority of the responses believe that the lack of experience and training,and social factors,are the most impact areas of explaining the reasons for the existence of a gap in women’s membership in boards of directors in the three sectors.And the most important reasons for the existence of a gender gap in board membership are:there is no statutory minimum percentage for women’s representation on boards of directors,and scarcity of female competencies in general,and the lack of women occupying leadership positions.

Experimental and numerical study regarding H-steel all-bolted connection steel frame with composite wall boards

H-steel all-bolted connection steel frame structures with heat preservation and decoration composite wall boards were investigated and the seismic performances of three scaled specimens were studied.The failure modes,hysteresis curves,bearing capacity,ductility,energy dissipation capacity,stiffness degradation and strain distribution were discussed.The calculation method of structural theoretical internal force was presented.The results showed that the overall structural seismic performance was better,and the structural ductility met the demands of elastic-plastic inter-story drift angle for seismic design.The H-steel weak-axis connection structure obtained better energy dissipation capacity,and its bearing capacity and stiffness were slightly different from the strong-axis connection.The heat preservation and decoration performance of composite wallboard and the all-bolted connection of the steel frame realized prefabrication during the whole construction period.The plastic hinge of the steel beam can be moved outwards because of the L-angles,which effectively avoids stress concentration in joint areas and expands the plastic hinge range.The errors between the theoretical structural capacity calculated by the plastic analysis method and the test results were within 2.44%.In addition,structural failure mechanisms and bearing capacities were verified by the finite element(FE)analysis,and the effects of the main parameters on the structures were investigated.The FE verification results were the same as in the test.The research results provide theoretical support and technical guidance for the application of thermal insulation and decorative composite wall panels in H-shaped steel all-bolted steel frames.

Effect of copper content on the pyrolysis process of organic components in waste printed circuit boards:Based on experimental and quantum chemical DFT simulations

In recent years,scientists have become increasingly concerned in recycling electronic trash,particularly waste printed circuit boards(WPCBs).Previous research has indicated that the presence of Cu impacts the pyrolysis of WPCBs.However,there may be errors in the experimental results,as printed circuit boards(PCBs)with copper and those without copper are produced differently.For this experiment,we blended copper powder with PCB nonmetallic resin powder in various ratios to create the samples.The apparent kinetics and pyrolysis properties of four resin powders with varying copper concentrations were compared using nonisothermal thermogravimetric analysis(TG)and thermal pyrolysis-gas chromatography mass spectrometry(Py-GC/MS).From the perspective of kinetics,the apparent activation energy of the resin powder in the pyrolysis reaction shows a rise(0.1<a<0.2)-stable(0.2<a<0.4)-accelerated increase(0.4<a<0.8)-decrease(0.8<a<0.9)process.After adding copper powder,the apparent activation energy changes more obviously when(0.2<a<0.4).In the early stage of the pyrolysis reaction(0.1<a<0.6),the apparent activation energy is reduced,but when a?0.8,it is much higher than that of the resin sample without copper.Additionally,it is discovered using thermogravimetric analysis and Py-GC/MS that copper shortens the temperature range of the primary pyrolysis reaction and prevents the creation of compounds containing bromine.This inhibition will raise the temperature at which compounds containing bromine first form,and it will keep rising as the copper level rises.The majority of the circuit board molecules have lower bond energies when copper is present,according to calculations performed using the Gaussian09 software,which promotes the pyrolysis reaction.

Effect of Low pH on Forming Process of Desulfurization Gypsum Composite Boards Strengthened by Melamine-formaldehyde Resin

Through exploring the effects of low pH on the composite system of desulfurization gypsum(DG)enhanced by melamine-formaldehyde resin(MF),it is found that the inducing of sulfate-ion,in contrast to chloride and oxalate ions,favors the longitudinal growth of the crystalline form of the hydration product,which was relatively simple and had the highest length to width(L/D)ratio.At the same time,MF can also improve L/D ratio of gypsum hydration products,which favors the formation of hydrated whiskers.Finally,in a composite system composed of hemihydrate gypsum,MF,and glass fibers,when dilute sulfuric acid was used to regulate pH=3-4,the tight binding formed among the components of the composite system compared to pH=5-6.The hydration product of gypsum adheres tightly to glass fiber surface and produces a good cross-linking and binding effect with MF.The flexural strength,compressive strength,elastic modulus,and water absorption of the desulphurized gypsum composite board is 22.7 MPa,39.8 MPa,5608 MPa,and 1.8%,respectively.

Distribution behavior of valuable elements in oxygen-enriched top-blown smelting process of waste printed circuit boards

Oxygen-enriched top-blown smelting is a promising technology for processing waste printed circuit boards(WPCBs).The distribution behavior of valuable elements in WPCBs during smelting was investigated by varying the oxygen-enriched concentration,oxygen volume,CaO/SiO_(2)(mass ratio),and Fe/SiO_(2)(mass ratio).The optimal operating conditions were obtained by implementing a one-factor-at-a-time method.X-ray diffractometer,scanning electron microscopy−energy dispersive spectrometer,and inductive coupled plasma-atomic emission spectroscopy methods were utilized to detect the chemical composition,occurrence state as well as elemental contents of alloy and slag.It is found that the elements of Cu,Sn and Ni are mainly accumulated in the alloy while Fe is mainly oxidized into the slag.The direct yields of Cu,Sn and Ni are 90.18%,85.32%and 81.10%under the optimal conditions of temperature 1250℃,oxygen-enriched concentration 30%,oxygen volume 24 L,CaO/SiO_(2) mass ratio 0.55,and Fe/SiO_(2) mass ratio 1.05.The results show that the valuable metals are mainly lost in the slag through mechanical entrainment.

Protective benefits of HDPE board sand fences in an environment with variable wind directions on Gobi surfaces:wind tunnel study

The Golmud-Korla Railway in the Gobi area faces operational challenges due to sand hazards,caused by strong and variable winds.This study addresses these challenges by conducting wind tunnel tests to evaluate the protective benefits of High Density Polyethylene(HDPE)board sand fences,focusing on their orientation relative to various wind directions(referred to as'wind angle').This study found that the size of the low-velocity zone on the leeward side of the sand fences(LSF)expanded with an increase in the wind angle(WA).At 1H(the height of the sand fence)and 2H positions on the LSF,the wind speed profiles(WSP)exhibited a segmented logarithmic growth,constrained by Z=H at varying WAs.The efficacy of the sand fence in obstructing airflow escalated as WA increased.The size of the WA has a significant impact on the protective efficiency of HDPE board sand fences.Furthermore,compared to typical sandy surfaces,the rate of sand transport across the Gobi surface diminishes more slowly with height,attributed to the gravel's rebound effect.This phenomenon allows some sand particles to bypass the fences,rendering them less effective at blocking wind and trapping sand than in sandy environments.This paper offers scientific evidence supporting the practical use and enhancement of HDPE board sand fences in varied wind conditions.

Protective benefit of folded linear HDPE board sand fences along the Golmud-Korla Railway,China:Field observation and wind tunnel study

The Milan Gobi area of the Golmud-Korla Railway in northwest China is located in the lower dispersal area of the mountain pass and has strong winds with evident double wind direction characteristics.This study introduced a novel sand fence deployment technique,termed‘folded linear deployment',designed to position the sand fence orthogonally to the two predominant wind directions for optimal protection.This study used wind tunnel and field tests to evaluate the wind and sand flow characteristics,as well as the windproof and sandresistant performance of folded linear HDPE(Highdensity polyethylene)board sand fences.The results suggest that the airflow around the fence creates clear zoning characteristics.The deceleration area on the BSF(backwind side of the sand fence)is much larger than that on the DSF(downwind side of the sand fence).Thus,sand particles are primarily deposited on the BSF.At different wind speeds,the airflow at 2 and 5 h on the DSF is not disturbed.The WSP(wind speed profile)presents a logarithmic distribution.The airflow is disturbed at 1-20 h on the BSF,and the WSP gradually deviates from the logarithmic law.However,as the airflow moves away from the fence,the WSP gradually approaches a logarithmic distribution.Meanwhile,the WPE(windproof efficiency)and SRE(sand-resistant efficiency)of the sand fence exceed 80%.In addition,the results of wind tunnel tests are compared with those of field tests.The overall dispersion is good,and the best dispersion is found at z/H=2.00,indicating good agreement between the two test results.This study provides a scientific basis for the design of sand hazard control measures,similar to the railway project in the Gobi Gale area.

BOB(Bosa On Board)设计研究

采用bosa on board的方式,将光通信电路直接铺设在PCB板上,替代传统的光模块独立器件,实现GPON/EPON产品的低成本高性能。

Development and Characterization of Particle Boards Based on Sorghum Husk

This study tackles current environmental challenges by developing innovative and eco-friendly particle boards utilizing sorghum husk, combined with recycled expanded polystyrene (EPS). This dual eco-responsible approach valorizes sorghum husk, often deemed agricultural waste, and repurposes EPS, a plastic waste, thus contributing to CO2 emission reduction and effective waste management. The manufacturing process involves dissolving recycled polystyrene within a solvent to create a binder, which is then mixed with sorghum husk and cold-pressed into composite boards. The study explores the impact of two particle sizes (fine and coarse) and two different concentrations of the recycled EPS binder. Results demonstrate significant variations in the boards’ mechanical properties, displaying a range of Modulus of Rupture (MOR) from 0.84 MPa to 3.85 MPa, and Modulus of Elasticity (MOE) spanning from 658.13 MPa to 1313.25 MPa, influenced by the binder concentration and particle size. These characteristics suggest that the boards can be effectively used in various construction applications, including interior decoration, false ceilings, and potentially for furniture and door manufacturing when combined with appropriate coatings. This study not only exemplifies the valorization of plastic and agricultural wastes but also offers a practical, localized solution to global climate change challenges by promoting sustainable construction materials.

Diversity and Board Effectiveness： A Case of India

A number of research studies have dealt with the relationship between diversity and effectiveness of corporate boards. The present paper makes an attempt to provide an international perspective on diversity and effectiveness of corporate boards and examines such relationship in detail in the case of India. The paper presents the theory relating to diversity and board effectiveness with particular reference to women on boards. The position of diversity as related to the boards of National Stock Exchange （NSE） listed 511 companies and the 245 state-owned enterprises （SOEs） by the Government of India （GoI） is reflected in the paper. It then examines gender diversity specifically in the case of India and Singapore. Drawing from the evidence of diversity in the case of global companies, it offers the rationale for making boards global in composition and character. The paper highlights an interestiiag issue： whether the boards should have younger or veteran members？ This follows a discussion on diversity of boards in terms of skills, age, and personalities. Finally, the paper makes suggestions for balance boards to enhance their effectiveness and brings out lessons for the corporate organizations to promote diversity of their boards.

Board Members Oversight System- A Polish Example

The goal of the study was the development of a system to monitor the members of supervisory and management boards. The system currently covers 8,454 joint stock companies registered in Poland. The main purpose of the system is to monitor every change in the composition of every board of every joint stock company, from March 2001 up to the present, and it is updated every month. This system, however, also enables us to confirm some of the theories from the field of corporate governance. A generation change has been identified in the boards of the joint stock companies which were examined. Women constitute a large, and continuously increasing, section of the board members. The number of family companies, and of family involvement in boards, is still increasing. Board members of financial institutions （and not just of banks） possess significantly more directorates than board members of non-financial institutions. The number of interlocking directorates is positively linked to the macroeconomic development indicator of the total investment as percentage of GDP for Poland.

Evaluating Board Roles Performance in Adopting Corporate Social Responsibility （CSR） Practices

The purpose of this paper is to evaluate the board roles that make a board effective in the performance of adopting corporate social responsibility （CSR） practices. This paper examines directors＇ perceptions of the three main roles： monitoring, service, and strategic, which provide tools for critically understanding how the board adds the value in moving the organization towards more CSR practices. The stakeholder theory is used to distinguish the influence of the three main roles on the adoption of CSR practices. Primary data were collected for this research by conducting structured questionnaires with a sample of 461 directors from Saudi listed companies for study purpose. The results show that an appropriate mix of directors＇ roles and the development of sound board monitoring and service roles are the most crucial determinants of CSR adoption in Saudi listed companies. As the extant corporate governance and CSR literatures do not provide a clear perspective with contradictory outcomes about board roles in influencing CSR practices, the originality of this research is its contribution by evaluating the directors＇ perceptions of developing a direct relationship between the board roles and the adoption of CSR practices. Furthermore, the use of the stakeholder theory provides additional insights into identifying the most influential board role factors enhancing stakeholders＇ expectations of CSR practices.

基于ZedBoard的SCA架构的设计与实现

Zed Board是Xilinx公司首款融合了ARM Cortex A9双核和7系列FPGA的全可编程片上系统,兼具ARM和FPGA两者的优势,是小型化SCA实现的最佳嵌入式平台之一。本文介绍了Zed Board平台的硬件结构,并针对SCA架构在专用硬件平台上无法实现的问题,通过分析研究MHAL硬件抽象层技术和OCP接口规范,设计了符合ZedBoard平台硬件环境的MHAL硬件抽象接口和FPGA波形组件容器,有效地解决了SCA架构在Zed Board平台上的实现问题,为在Zed Board上实现以SCA架构为核心的系统开发打下了基础。

Influence of Board Mechanisms on Corporate Social Responsibility Disclosures in Nigeria: A Study of Oil and Gas Sector of the Economy

The study examined the influence of board mechanisms on corporate social responsibility disclosure among oil and gas quoted companies in Nigeria for ten(10)years period(2012-2021).Board mechanisms variables of board independence,board size as well as board gender diversity were analyzed to determine their influence on corporate social responsibility disclosures.Data obtained from the financial statement of various sampled companies were suitably analyzed with the help of descriptive statistics,correlation as well as regression analysis by making use of E-view(9.0)econometric packages.Regression result reveals that board independence has significant and negative influence on corporate social responsibility disclosures while board size and board gender diversity have insignificant and negative influence on corporate social responsibility disclosures of various companies.The study therefore arrived at a conclusion that board independence on the board brings about improvement on corporate social responsibility disclosure among quoted oil and gas companies in Nigeria.

宫颈癌IMRT治疗中俯卧位Belly-board不同位置对靶区动度和剂量分布的影响

目的探讨宫颈癌俯卧位IMRT时Belly-board不同位置对靶区动度和剂量分布的影响。方法分别测量10例宫颈癌患者在Belly-board上两种体位(PⅠ:耻骨联合上缘置于Belly-board孔下缘;PⅡ:骶髂关节的下缘置于Belly-board孔下缘)下靶区移动的范围及靶区剂量分布,比较两者的关系。结果靶区在腹背方向存在一定的移动(1～1.5cm),有统计学意义(P<0.05),而在水平及头脚方向的移动无统计学意义(P>0.05);但靶区移动时,靶区本身在各剂量区的受照体积差异无统计学意义(P>0.05)。结论 Belly-board的位置不同会造成靶区的空间位置改变,但靶区移动对靶区剂量分布无影响。

Linux2.6.16在嵌入式模块X-Board(GP8)上的移植

Linux2.6.16在嵌入式模块X-Board(GP8)上的移植,采用的交叉编译环境为VMWareWorkstation5.0+RedHat9.0。步骤包括交叉编译环境的搭建,内核定制,Ramdisk文件系统的定制,RedBoot操作等。其根文件的制作则通过建立相关目录、添加/dev目录下的设备文件、busybox制作等实现。

Reducing resin content and board density without adversely affecting the mechanical properties of particleboard through controlling particle size

Density and resin content are two factors that have a significant effect on the production cost of wood composite. However, particle size affects resin content and density, which suggests that the interaction of these three factors can be manipulated to reduce the board density and resin content of particleboard without adversely influencing its mechanical properties. Some mathematical functional forms based on resin content, board density and slenderness ratio were regressed and an appropriate form was chosen. According to analysis of the results using SHAZAM 9 software, the exponential function best fit the experimental data. Finally, ＂indifference curves＂ of mechanical properties were illustrated and analyzed. The results indicated that negative effects of density or resin content reduction on mechanical properties could be compensated for by controlling particles＇ slenderness ratio. Interestingly, increases in slenderness ratio compensated for the negative effects of decreases in resin content or board density on module of rupture （MOR） and module of elasticity （MOE）. Moreover, this ＂compensation ratio＂ intensified as resin content or density decreased and/or as the MOR or MOE increased. On the other hand, reduction in slenderness ratio indicated a comple- mentary effect on reducing internal bond （IB） strength, a result of decreases in resin content or density. Moreover, this ＂complementary ratio＂ was intensified as resin content or density decreased and/or as IB strength increased.

利用Smart board电子白板解决键盘乐教学难题初探

键盘乐教学,无论在中小学还是在师范类或专业大学,都存在着重复劳动、资源浪费和贵族教育等弊端。本文从Smart board电子白板辅助讲解键盘和曲目、示范演奏、记录保存教学过程等方面对键盘乐教学进行了讨论和建议,希望以此能使中小学不敢涉足或深究的键盘乐教学难题能有所起色。

NANO BOARD隔热板的性能及在铝合金机边保温炉上的应用

为降低炉子能耗，保证铝合金的铝水品质，基于纳米材料的结构特点，采用特殊制备工艺及结合剂，研制生产了NANOBOARD隔热材料。该材料在温度1000℃时的体积密度为0．2～0．4g·cm^-3，热导率比传统隔热材料低20％～50％。在铝合金机边保温炉上应用表明，在砌筑厚度相同的情况下，与其他隔热材料相比，NANO BOARD隔热材料可使炉体表面温度平均降低30～40℃，达到节能目的，而投资成本回收期不到一年。