A Retrodirective Array Enabled by CMOS Chips for Two-Way Wireless Communication with Automatic Beam Tracking

This article proposes and demonstrates a retrodirective array(RDA)for two-way wireless communication with automatic beam tracking.The proposed RDA is enabled by specifically designed chips made using a domestic complementary metal-oxide semiconductor(CMOS)process.The highly integrated CMOS chip includes a receiving(Rx)chain,a transmitting(Tx)chain,and a unique tracking phaselocked loop(PLL)for the crucial conjugated phase recovery in the RDA.This article also proposes a method to reduce the beam pointing error(BPE)in a conventional RDA.To validate the above ideas simply yet without loss of generality,a 2.4 GHz RDA is demonstrated through two-way communication links between the Rx and Tx chains,and an on-chip quadrature coupler is designed to achieve a nonretrodirective signal suppression of 23 dBc.The experimental results demonstrate that the proposed RDA,which incorporates domestically manufactured low-cost 0.18 lm CMOS chips,is capable of automatically tracking beams covering±40with a reduced BPE.Each CMOS chip in the RDA has a compact size of 4.62 mm^(2) and a low power consumption of 0.15 W.To the best of the authors’knowledge,this is the first research to demonstrate an RDA with a fully customized CMOS chip for wireless communication with automatic beam tracking。

Reference-frame-independent quantum key distribution with two-way classical communication

The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In this study,we apply the TWCC method to improve the performance of reference-frame-independent quantum key distribution(RFI-QKD),and analyze the influence of the TWCC method on the performance of decoy-state RFI-QKD in both asymptotic and non-asymptotic cases.Our numerical simulation results show that the TWCC method is able to extend the maximal transmission distance from 175 km to 198 km and improve the tolerable bit error rate from 10.48%to 16.75%.At the same time,the performance of RFI-QKD in terms of the secret key rate and maximum transmission distance are still greatly improved when statistical fluctuations are considered.We conclude that RFI-QKD with the TWCC method is of practical interest.

Beamforming Design for IRS-and-UAV-Aided Two-Way Amplify-and-Forward Relay Networks in Maritime IoT

In this paper,an intelligent reflecting surface(IRS)-and-unmanned aerial vehicle(UAV)-assisted two-way amplify-and-forward(AF)relay network in maritime Internet of Things(IoT)is proposed,where ship1(S1)and ship2(S2)can be viewed as data collecting centers.To enhance the message exchange rate between S1 and S2,a problem of maximizing minimum rate is cast,where the variables,namely AF relay beamforming matrix and IRS phase shifts of two time slots,need to be optimized.To achieve a maximum rate,a low-complexity alternately iterative(AI)scheme based on zero forcing and successive convex approximation(LC-ZF-SCA)algorithm is presented.To obtain a significant rate enhancement,a high-performance AI method based on one step,semidefinite programming and penalty SCA(ONSSDP-PSCA)is proposed.Simulation results show that by the proposed LC-ZF-SCA and ONS-SDP-PSCA methods,the rate of the IRS-and-UAV-assisted AF relay network surpass those of with random phase and only AF relay networks.Moreover,ONS-SDP-PSCA perform better than LC-ZF-SCA in aspect of rate.

Improved Segmented Belief Propagation List Decoding for Polar Codes with Bit-Flipping

Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) decoding.In this work, an improved segmented belief propagation list decoding based on bit flipping(SBPL-BF) is proposed. On the one hand, the proposed algorithm makes use of the cooperative characteristic in BPL decoding such that the codeword is decoded in different BP decoders. Based on this characteristic, the unreliable bits for flipping could be split into multiple subblocks and could be flipped in different decoders simultaneously. On the other hand, a more flexible and effective processing strategy for the priori information of the unfrozen bits that do not need to be flipped is designed to improve the decoding convergence. In addition, this is the first proposal in BPL decoding which jointly optimizes the bit flipping of the information bits and the code bits. In particular, for bit flipping of the code bits, a H-matrix aided bit-flipping algorithm is designed to enhance the accuracy in identifying erroneous code bits. The simulation results show that the proposed algorithm significantly improves the errorcorrection performance of BPL decoding for medium and long codes. It is more than 0.25 d B better than the state-of-the-art BPL decoding at a block error rate(BLER) of 10^(-5), and outperforms CA-SCL decoding in the low signal-to-noise(SNR) region for(1024, 0.5)polar codes.

Security-Reliability Analysis and Optimization for Cognitive Two-Way Relay Network with Energy Harvesting

This paper investigates the security and reliability of information transmission within an underlay wiretap energy harvesting cognitive two-way relay network.In the network,energy-constrained secondary network(SN)nodes harvest energy from radio frequency signals of a multi-antenna power beacon.Two SN sources exchange their messages via a SN decode-and-forward relay in the presence of a multiantenna eavesdropper by using a four-phase time division broadcast protocol,and the hardware impairments of SN nodes and eavesdropper are modeled.To alleviate eavesdropping attacks,the artificial noise is applied by SN nodes.The physical layer security performance of SN is analyzed and evaluated by the exact closed-form expressions of outage probability(OP),intercept probability(IP),and OP+IP over quasistatic Rayleigh fading channel.Additionally,due to the complexity of OP+IP expression,a self-adaptive chaotic quantum particle swarm optimization-based resource allocation algorithm is proposed to jointly optimize energy harvesting ratio and power allocation factor,which can achieve security-reliability tradeoff for SN.Extensive simulations demonstrate the correctness of theoretical analysis and the effectiveness of the proposed optimization algorithm.

Bawei Biotechnology Listed

On Mar.29th,2024,Bawei Biotechnology was listed at Beijing Stock Exchange.So far,Bawei Biotechnology has smoothly become“the first cosmetics OEM listed at Beijing Stock Exchange”,as well as the first A-share cosmetics enterprise listed in 2024.At the opening quotation,the stock price increase of Bawei Biotechnology exceeded 200%,and the total market value exceeded 1.4 billion yuan.Bawei Biotechnology mainly engages in the R&D,production,sales and detection of cosmetics,with the product category covering skin care product,facial mask,toiletry,and makeup.So far,it has served a total of 1,000 cosmetics brands,including Unilever,Renhe Ingenuity,HBN,SKINTIFIC,Marubi Biotechnology,PROF.

通用学术词表Academic Vocabulary List(AVL)修订述略

学术英语词汇是学术英语教学的重点和难点,不同时代和学科曾编写过各类学术词表。加德纳和戴维斯(2014)基于学术语料容量达1.2亿的COCA语料库推出学术词表Academic Vocabulary List(AVL),该词表在学术英语教学和研究中得到广泛应用。然而实践表明,AVL词表收录的3015个词元存在词汇重复、以词元为单位排列的词表和以词族为单位排列的词表不相吻合等问题。本研究尝试以科学性原则、适切性原则、时效性原则为指导,基于AVL词表原有的比率、分布、离散度、学科指数四条选词标准,增加最低频次和经验判断两条新标准对AVL词表予以完善和修订。完善修订后的AVL词表由先前的1991个词族、3015个词元缩减至709个词族1715个词元,较修订前更具简洁性和高效性。希望依据3项原则和6项标准所做的修订为学术英语教与学以及学术英语教材编写和选用带来新的参考。

Evolution and Governance of the Structure of Marine Economic Networks in China’s Coastal Areas: Based on Sea-related A-share Listed Companies

Data on discrete,isolated attributes of the marine economy are often used in traditional marine economic research.However,as the focus of urban research shifts from internal static attributes to external dynamic linkages,the importance of marine economic net-work research is beginning to emerge.The construction of the marine economic network in China’s coastal areas is necessary to change the flow of land and sea resources and optimize regional marine economic development.Employing data from headquarters and branches of sea-related A-share listed enterprises to construct the marine economic network in China,we use social network analysis(SNA)to discuss the characteristics of its evolution as of 2010,2015,and 2020 and its governance.The following results were obtained.1)In terms of topological characteristics,the scale of the marine economic network in China’s coastal areas has accelerated and expan-ded,and the connections have become increasingly close;thus,this development has complex network characteristics.2)In terms of spatial structure,the intensity of the connection fluctuates and does not form stable development support;the group structure gradually becomes clear,but the overall pattern is fragmented;there are spatial differences in marine economic agglomeration radiation;the radi-ation effect of the eastern marine economic circle is obvious;and the polarization effect of northern and southern marine economic circles is significant.On this basis,we construct a framework for the governance of a marine economic network with the market,the government,and industry as the three governing bodies.By clarifying the driving factors and building objectives of marine economic network construction,this study aims to foster the high-quality development of China’s marine economy.

List接口的教学案例设计与实现

List接口的概念与应用是Java程序设计课程的重点内容之一。为培养学生分析和解决实际问题的能力,本文探讨在List接口知识点训练时,以模拟实现学生信息管理系统项目作为教学案例,并引入瀑布模型的教学方法。实践结果表明,选择合适的教学案例,在教学过程中引入瀑布模型思维方式,可以有效培养学生分析问题和解决问题的能力。

Belief Propagation List Decoding for Polar Codes:Performance Analysis and Software Implementation on GPU

Belief propagation(BP)decoding outputs soft information and can be naturally used in iterative receivers.BP list(BPL)decoding provides comparable error-correction performance to the successive cancellation list(SCL)decoding.In this paper,we firstly introduce an enhanced code construction scheme for BPL decoding to improve its errorcorrection capability.Then,a GPU-based BPL decoder with adoption of the new code construction is presented.Finally,the proposed BPL decoder is tested on NVIDIA RTX3070 and GTX1060.Experimental results show that the presented BPL decoder with early termination criterion achieves above 1 Gbps throughput on RTX3070 for the code(1024,512)with 32 lists under good channel conditions.

Investigating the Efficiency Coefficient of Pile Group in Clay Under Two-Way Lateral Load

This research investigates the behavior of a 2×2 pile group under two-directional lateral loads in addition to the vertical load.Through three-dimensional numerical modeling based on Flac 3D software,the study examines the total bearing capacity and efficiency coefficient of the pile group,considering factors such as the angle of lateral load,relative pile spacing,and relative stiffness of the pile-soil system.The findings highlight the significance of these factors in understanding and predicting the response of pile groups to changing lateral load directions.The results reveal that increasing the angle of the lateral load from 0°to 45°enhances both the maximum total lateral load and the efficiency coefficient of the pile group.When the relative stiffness of the pile-soil system significantly increases,soil stiffening occurs and reducing the relative spacing of the piles from 7 to 3 times the diameter of the piles diminishes the influence of the pile group.Consequently,the response of the pile group to lateral loads becomes more linear,with only a slight alteration in the maximum total lateral load and the efficiency coefficient when the lateral load is angled from 0°to 45°.Conversely,increasing the relative distance between the piles,specifically from 3 to 7 times the diameter of the piles,amplifies the influence of the pile group.Both the maximum total lateral load and the efficiency coefficient of the pile group exhibit an observed increase.These provide insights for designing pile groups and optimizing their performance under lateral loading conditions.

List-Serial Pipelined Hardware Architecture for SCL Decoding of Polar Codes

For polar codes,the performance of successive cancellation list(SCL)decoding is capable of approaching that of maximum likelihood decoding.However,the existing hardware architectures for the SCL decoding suffer from high hardware complexity due to calculating L decoding paths simultaneously,which are unfriendly to the devices with limited logical resources,such as field programmable gate arrays(FPGAs).In this paper,we propose a list-serial pipelined hardware architecture with low complexity for the SCL decoding,where the serial calculation and the pipelined operation are elegantly combined to strike a balance between the complexity and the latency.Moreover,we employ only one successive cancellation(SC)decoder core without L×L crossbars,and reduce the number of inputs of the metric sorter from 2L to L+2.Finally,the FPGA implementations show that the hardware resource consumption is significantly reduced with negligible decoding performance loss.

Lesening's Parent Company dencare got listed in market

On April 10th,2023,Dencare(stock code:001328),parent company of Lesening,was listed in Shenzhen Stock Exchange.There were 43,043,500 new shares issued this time,with the issue price as 20.68 yuan and raised fund as 890 million yuan,accounting for 25%of the total capital stock after issuing.It thus became the“first share of anti-sensitivity toothpaste”in A share.Such fundraising will mainly be used to invest in intelligent manufacturing upgrading and construction projects.The opening price on that day was 41 yuan,rising 98.3%comparing with the issue price;the closing price was 56.64 yuan,increasing by 174%comparing with the issue price.It is also one of the first IPOs approved since the full registration system was officially implemented.

Secrecy Outage Probability for Two-Way Integrated Satellite Unmanned Aerial Vehicle Relay Networks with Hardware Impairments

In this paper,we investigate the secrecy outage performance for the two-way integrated satellite unmanned aerial vehicle relay networks with hardware impairments.Particularly,the closed-form expression for the secrecy outage probability is obtained.Moreover,to get more information on the secrecy outage probability in a high signalto-noise regime,the asymptotic analysis along with the secrecy diversity order and secrecy coding gain for the secrecy outage probability are also further obtained,which presents a fast method to evaluate the impact of system parameters and hardware impairments on the considered network.Finally,Monte Carlo simulation results are provided to show the efficiency of the theoretical analysis.

Rare earth listed in the Catalogue of Energy and Resources Products Subject to Export Reporting

China’s Ministry of Commerce(MOFCOM)on 7 November announced revisions to a list of bulk commodities whose imports and exports should be reported for keeping statistical record.Fourteen commodities including Soybeans,rapeseed,soybean oil,palm oil and so on will continue to be regulated by current import reporting system.Five new items are included.Crude oil,iron ore.

欧美新污染物监测进展及启示

新污染物监测是新污染物环境和健康风险评估及管控的重要基础。欧美发达国家环保部门在20世纪70年代就开展了新污染物监测工作,并且2000年后形成了相应的监测制度,而我国新污染物监测工作正处于业务化起步阶段。通过深入调研欧美国家水中新污染物监测为主的发展历程、监测清单、监测要求等内容,总结出3个特点:建立动态更新的新污染物清单监测机制;将规范的新污染物监测方法作为开展监测的重要前提;充分考虑监测可行性和经济成本。结合我国现阶段新污染物监管需求及监测现状,提出我国新污染物监测工作的3点建议:明晰国家、地方新污染物监测的职责分工,建立优先监测新污染物清单动态更新机制;加强新污染物监测能力建设,建立新污染物监测标准体系;循序渐进开展新污染物监测,注重监测的可行性和可持续性。

数据交易安全刑事合规的“软法”治理及清单模式

数据交易安全合规指参与数据交易活动的企业内外部各方主体进行的维护数据安全合规的治理活动。刑事治理是由各方主体参与的惩治和预防犯罪的过程,具有过程性。数据交易安全刑事合规是刑事治理的重要方面,可分为事前合规和事后合规两个阶段。《信息安全技术数据交易服务安全要求(征求意见稿)》和《上海数据交易所数据交易安全合规指引》及配套清单采取正面清单和负面清单的管理模式,列举了数据交易主体、数据安全管理体系、数据来源、数据产品可交易性等方面的合规要求。数据交易安全合规清单具有“软法”性质,“软法”与“硬法”相结合,形成企业刑事合规的规范体系。刑法根据数据交易主体及行为场景的差异,以不同的罪刑规范保护数据交易行为所涉及的多元法益。数据犯罪的空白罪状具有定罪指引作用,也为企业合规的开展留下了空间。在实践中应注重数据安全关联罪名适用与刑行衔接,将企业刑事合规融入刑事司法过程并与行政监管相协调。同时,积极发挥企业合规清单的刑事治理机能,构建和完善激励机制、滤罪机制、评估机制,实现合规清单治理的出罪机能与治本效果。

新型能量隔离防护智能管控系统的设计与应用

为解决现有的危险能量隔离/上锁挂牌程序存在的现场操作繁琐、安全管理缺乏统筹管理等问题,设计了新型能量隔离防护智能管控系统,对现有的程序进行了改进。结果表明,新型能量隔离防护智能管控系统能有效提升企业的生产/检修作业安全管理水平,对降低危险能量意外释放、减少员工人身伤害有显著的改善效果。

工程总承包计价中的价格清单问题研究

为了推动工程总承包规范发展,有必要对其计价中的价格清单问题进行讨论。首先,对国内与国际惯例中的价格清单模式进行阐述和比较;其次,从价格清单的属性和使用两个角度出发,分析了价格清单存在的问题;最后,从价格清单的编制、作用以及变更三个层面提出完善建议,以期促进我国工程总承包高质量规范发展。

任务导向的翻转课堂在《医学影像技术学》理论教学中的应用

《医学影像技术学》作为医学影像技术本科专业的核心课程,教师在理论课教学期间需重视学生知识内化与综合素质提升。传统教学模式中教师长时间处于教学主体地位传授知识,学生鲜少自主学习、主动思考及表达看法,难以获得理想教学效果。任务导向的翻转课堂以学生为教学主体,设置目标明确、难度适中的个人自学任务与团队课堂讲授任务,督促学生主动学习,积极参加团队协作。此类翻转课堂将拓展学习时间与场景,拓宽知识获取渠道,鼓励学生积极学习思考,与团队成员交流看法并协作制定课堂讲授资料,完成课堂讲授。教学过程中,学生不仅完成多层次知识内化,还将获得一定程度综合素质提升。本文将回顾传统教学模式的局限性,分析任务导向翻转课堂的特点与优势,探讨其用于影像技术本科专业学生《医学影像技术学》理论课教学的可行性,为本课程教育改革提供新思路与参考。