超燃冲压发动机用SCO_(2)闭式回热布雷顿循环的热电转换系统性能分析

针对高超声速飞行器的供电和热防护需求,本文提出了一种基于超临界二氧化碳(SCO_(2))闭式回热布雷顿循环(RCBC)的热电转换系统,建立了一个由超燃冲压发动机燃烧室、壁面冷却通道和SCO_(2),RCBC组成的耦合模型来评估系统性能。对比了燃烧室与冷却通道耦合和不耦合的差距;分析了冷却流体进人冷却通道时的进口参数对系统热防护以及供电的影响。结果表明,热电转换系统通过将部分热量转化为电能,在对发动机进行热防护的同时,可以为高超声速飞行器提供25.14kW的电能。

Mutual Information Maximization via Joint Power Allocation in Integrated Sensing and Communications System

In this paper, we focus on the power allocation of Integrated Sensing and Communication(ISAC) with orthogonal frequency division multiplexing(OFDM) waveform. In order to improve the spectrum utilization efficiency in ISAC, we propose a design scheme based on spectrum sharing, that is,to maximize the mutual information(MI) of radar sensing while ensuring certain communication rate and transmission power constraints. In the proposed scheme, three cases are considered for the scattering off the target due to the communication signals,as negligible signal, beneficial signal, and interference signal to radar sensing, respectively, thus requiring three power allocation schemes. However,the corresponding power allocation schemes are nonconvex and their closed-form solutions are unavailable as a consequence. Motivated by this, alternating optimization(AO), sequence convex programming(SCP) and Lagrange multiplier are individually combined for three suboptimal solutions corresponding with three power allocation schemes. By combining the three algorithms, we transform the non-convex problem which is difficult to deal with into a convex problem which is easy to solve and obtain the suboptimal solution of the corresponding optimization problem. Numerical results show that, compared with the allocation results of the existing algorithms, the proposed joint design algorithm significantly improves the radar performance.

Quantized Decoders that Maximize Mutual Information for Polar Codes

In this paper,we innovatively associate the mutual information with the frame error rate(FER)performance and propose novel quantized decoders for polar codes.Based on the optimal quantizer of binary-input discrete memoryless channels(BDMCs),the proposed decoders quantize the virtual subchannels of polar codes to maximize mutual information(MMI)between source bits and quantized symbols.The nested structure of polar codes ensures that the MMI quantization can be implemented stage by stage.Simulation results show that the proposed MMI decoders with 4 quantization bits outperform the existing nonuniform quantized decoders that minimize mean-squared error(MMSE)with 4 quantization bits,and yield even better performance than uniform MMI quantized decoders with 5 quantization bits.Furthermore,the proposed 5-bit quantized MMI decoders approach the floating-point decoders with negligible performance loss.

New construction of mutually unbiased bases for odd-dimensional state space

We study the construction of mutually unbiased bases in Hilbert space for composite dimensions d which are not prime powers.We explore the results for composite dimensions which are true for prime power dimensions.We then provide a method for selecting mutually unbiased vectors from the eigenvectors of generalized Pauli matrices to construct mutually unbiased bases.In particular,we present four mutually unbiased bases in C^(15).

Analytical modeling and approaches of multihelix cables incorporating with interwire mutual contacts

This study aims to develop an analytical model based on the curve beam theory to capture the mechanical response of a multihelix cable considering the internal contact displacements.Accordingly,a double-helix cable subjected to axial tension and torsion is analyzed,and both the line and point contacts between the neighboring wires and strands are considered via an equivalent homogenized approach.Then,the proposed theoretical model is extended to a hierarchical multihelix cable with mutual contact displacements by constructing a recursive relationship between the high-and low-level multihelix structures.The global tensile stiffness and torsional stiffness of the double-helix cable are successfully evaluated.The results are validated by a finite element(FE)model,and are found to be consistent with the findings of previous studies.It is shown that the contact deformations in multihelix cables significantly affect their equivalent mechanical stiffness,and the contact displacements are remarkably enhanced as the helix angles increase.This study provides insights into the interwire/interstrand mutual contact effects on global and local responses.

中国恩施土家族苗族自治州高度近视患者SCO2基因新突变

目的:探讨SCO2(OMIM 604272)基因在恩施土家族苗族自治州高度近视患者中的致病性变异。方法:共招募384例高度近视患者,其中至少一眼球镜度数≤-6.00 D,且眼轴长度≥26.00 mm。应用苯酚-氯仿法从5 mL外周静脉血中提取DNA。通过Sanger测序以鉴定SCO2第2外显子的致病性变异。运用计算机预测软件对检测到的变异进行评估。来自同一地区的288名健康人群作为正常对照。结果:共检测出7个突变位点,分别为4个同义突变(c.201C>T/p.=,c.576C>T/p=,c.633A>C/p.=,c.780T>C/p.=.),2个错义突变(c.187A>G/p.Ile63Val,c.59G>C/p.Arg20Pro)和1个无义突变(c.544C>T/p.Gln182*)。通过PolyPhen2、SIFT和Provean软件预测,两个错义突变没有致病性。新的无义突变(c.544C>T/p.Gln182*)在1000G中未被发现,在288个正常对照中也未被发现。Variant Taster预测该无义突变位点是保守的。结论:新发现的无义突变可能是我们研究的高度近视患者的致病原因。SCO2与高度近视相关,而这批高度近视人群中SCO2基因突变的发生率低至1/384;该无义突变可能是中国恩施土家族苗族自治州高度近视的一种罕见变异。

Generative Multi-Modal Mutual Enhancement Video Semantic Communications

Recently,there have been significant advancements in the study of semantic communication in single-modal scenarios.However,the ability to process information in multi-modal environments remains limited.Inspired by the research and applications of natural language processing across different modalities,our goal is to accurately extract frame-level semantic information from videos and ultimately transmit high-quality videos.Specifically,we propose a deep learning-basedMulti-ModalMutual Enhancement Video Semantic Communication system,called M3E-VSC.Built upon a VectorQuantized Generative AdversarialNetwork(VQGAN),our systemaims to leverage mutual enhancement among different modalities by using text as the main carrier of transmission.With it,the semantic information can be extracted fromkey-frame images and audio of the video and performdifferential value to ensure that the extracted text conveys accurate semantic information with fewer bits,thus improving the capacity of the system.Furthermore,a multi-frame semantic detection module is designed to facilitate semantic transitions during video generation.Simulation results demonstrate that our proposed model maintains high robustness in complex noise environments,particularly in low signal-to-noise ratio conditions,significantly improving the accuracy and speed of semantic transmission in video communication by approximately 50 percent.

Performance analysis of the mutual coupling effect on Phased Array Feeds

A phased array feed(PAF)is a type of receiving array that places phased array antennas on the focal plane of a radio telescope to expand its field of view and improve observation efficiency.Owing to the mutual coupling effect between elements caused by a tightly arranged feed array,which changes the performance of a PAF,this paper presents a 7×7 rectangular feed array model for a 25 m reflector telescope.By adjusting the element spacings,the performance of a PAF with different spacings is comprehensively analyzed with respect to the mutual coupling effect via performance statistics and comparison.This research aims to provide a reference for the preliminary design of a related PAF.

China-Russian Managed to Achieve Closer Collaboration with Mutual Complementarity

This year marks the 75th anniversary of China-Russia diplomatic relations.Russian President Vladimir Putin paid a state visit to China in May.The heads of state of both China and Russia held a sincere,friendly and informative meeting,signed and issued a joint statement,and witnessed the signing of more than 10 important cooperation documents.These bilateral relations have shown a sound momentum of mutual benefit,in-depth coordination and long-term stability.

Strengthening Exchange and Mutual Learning Between China and the Rest of the World

CPPCC member Du Zhanyuan gives an exclusive interview to China Today on how to enhance international communication and tell positive stories of Chinese modernization.AS an ancient Chinese philosopher said,“Amity between peoples holds the key to sound state-to-state relations.”This is often cited by President Xi Jinping to emphasize the importance of exchanges and mutual learning of civilizations in the development of international relations.

Exchanges,Mutual Learning and Looking Forward to the Future The Exhibition of Oil Paintings of China and Five Central Asian Countries

Exchanges and mutual learning between the Chinese and foreign civilizations are an important part of human cultural development.The Chinese civilization adopts an all-embracing,open and inclusive attitude to understand the different views of different civilizations on the connotation of values.The ancient Silk Road has opened a new window of friendship between countries and written a new chapter in the development of mankind.

Mutual Respect and Win-Win Cooperation 50 years of China-Malaysia relations

Friendly exchanges between China and Malaysia date back more than 2,000 years,and a profound traditional friendship has been forged between the two countries.By adhering to the principles of mutual trust,win-win cooperation,and equal assistance,China and Malaysia have become good neighbors,good friends,and good partners.In 2013,China and Malaysia established a comprehensive strategic partnership,accelerating the development of bilateral relations.

Degree of Freedom Analysis for Holographic MIMO Based on a Mutual-Coupling-Compliant Channel Model

Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless channel.Traditionally,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the antenna number.However,recent studies suggest that the DOF could be less than the antenna number when strong mutual coupling is considered.We utilize a mutual-coupling-compliant channel model to investigate the DOF of the holographic MIMO(HMIMO)channel and give a upper bound of the DOF with strong mutual coupling.Our numerical simulations demonstrate that a dense array can support more DOF per unit aperture as compared with a half-wavelength MIMO system.

Boundless Potential China-Africa cooperation in the space sector exemplifies mutually beneficial partnerships

Exports of Chinese satellites,joint construction of space infrastructure,and joint research and development of satellites...The recent years have seen substantial growth in China-Africa cooperation in the space sector,which is bringing tangible benefits to both sides.

The Study of Mutual Benefits and Potential in China-Mongolia Agricultural Trade

This article aims to explore the mutual benefits and potential of agricultural trade between China and Mongolia,analyzing the current situation of agricultural resources,trade history,and policy environment of the two countries.The study finds that China-Mongolia agricultural trade shows significant economic complementarity.Trade activities not only promote economic growth in both countries but also deepen social and cultural exchanges.However,technical standards,political risks,and logistics costs remain major challenges facing trade cooperation.By strengthening policy coordination,investing in agricultural technology and infrastructure,and expanding the variety and markets of trade,the potential for cooperation in China-Mongolia agricultural trade can be further enhanced.These measures will help improve the efficiency and benefits of bilateral trade,achieving a win-win development.

基于互信息的Fisher Score多标记特征选择

目前,Fisher Score模型在处理多标记数据时没有考虑样本和整个特征空间之间以及特征和标记之间的关系.提出一种基于互信息的Fisher Score多标记特征选择方法.首先,在多标记决策系统中考虑整个样本空间对特征选择的影响,根据异类样本与同类样本之间的欧式距离定义权重公式,并在特征空间下对标记赋予权重衡量标记的重要程度.然后,基于互信息理论定义特征与每个标记之间的互信息来计算每个特征和每个标记之间的相关度,将特征与标记之间的相关度与该标记所占的权重相结合来定义特征和标记集之间的总相关度.将Fisher得分与总相关度结合,定义每个特征的新的Fisher得分,进而构建多标记Fisher Score模型.最后,设计了一种基于互信息的Fisher Score多标记特征选择算法.在六个多标记数据集上的实验证明,提出的算法与其他算法相比,其四种评价指标都表现良好,分类性能出色.

Quankum Effects of a Dissipative Mesoscopic Circuit with Mutual Inductance

We study the quantum fluctuations of the charge and current of two L-C dissipative mesoscopic circuit with the mutual inductance in the vacuum state.Our results show that the system state will evolve to a squeezed coherent state under the effect of external source.We find that the squeezing amplitude parameter is relative to the parameters of circuit and the mutual-inductance coefficient in the existence of dissipation.When the circuit has no dissipation or there is complete coupling between two meshes,the squeezing amplitude parameter only depends on the capacitance's ratio.

Pt状态对Pt/SA和Pt/SSZ-13催化剂上NH_(3)-SCO的N_(2)选择性的影响

氨气选择性催化氧化(NH_(3)-SCO)催化剂是满足国六标准的柴油车尾气后处理系统的不可或缺的组成部分。N_(2)选择性是评价NH_(3)-SCO催化剂性能的重要指标之一,但高于300℃时通常会在NH_(3)-SCO催化剂上发生NH_(3)非选择性氧化反应,导致N_(2)选择性急剧下降。本工作制备了与商用Pt/SiO_(2)-Al_(2)O_(3)(Pt/SA)元素组成相似的Pt/SSZ-13催化剂,其在300℃以上的N_(2)选择性比Pt/SA的高52%。NH_(3)-SCR活性结果显示,在200-500℃的温度范围内,Pt/SSZ-13的NO_(x)转化率显著高于Pt/SA。Pt/SSZ-13在200℃时获得最高NO_(x)转化率(95%),在300℃以上的NO_(x)转化率不低于82%;而Pt/SA在200℃时的NO_(x)转化率仅为68%,并且其NO_(x)转化率随着温度的升高而逐渐降低。XRD和CO-DRIFT光谱结果表明,Pt/SSZ-13上共同存在的Pt^(σ+)和Pt^(0)物种有利于NH_(3)-SCO反应遵循i-SCR反应路径;而Pt在Pt/SA上主要以Pt^(0)形式存在,故其NH_(3)-SCO反应主要遵循NH机制。Pt/SSZ-13的NH_(3)-SCO活性与Pt/SA相似,但其N_(2)选择性明显高于后者。因此,本工作为后续设计并制备同时具有优异NH_(3)-SCO活性和高N_(2)选择性的NH_(3)-SCO催化剂提供了一个新的研究策略。

Automatic Aggregation Enhanced Affinity Propagation Clustering Based on Mutually Exclusive Exemplar Processing

Affinity propagation(AP)is a widely used exemplar-based clustering approach with superior efficiency and clustering quality.Nevertheless,a common issue with AP clustering is the presence of excessive exemplars,which limits its ability to perform effective aggregation.This research aims to enable AP to automatically aggregate to produce fewer and more compact clusters,without changing the similarity matrix or customizing preference parameters,as done in existing enhanced approaches.An automatic aggregation enhanced affinity propagation(AAEAP)clustering algorithm is proposed,which combines a dependable partitioning clustering approach with AP to achieve this purpose.The partitioning clustering approach generates an additional set of findings with an equivalent number of clusters whenever the clustering stabilizes and the exemplars emerge.Based on these findings,mutually exclusive exemplar detection was conducted on the current AP exemplars,and a pair of unsuitable exemplars for coexistence is recommended.The recommendation is then mapped as a novel constraint,designated mutual exclusion and aggregation.To address this limitation,a modified AP clustering model is derived and the clustering is restarted,which can result in exemplar number reduction,exemplar selection adjustment,and other data point redistribution.The clustering is ultimately completed and a smaller number of clusters are obtained by repeatedly performing automatic detection and clustering until no mutually exclusive exemplars are detected.Some standard classification data sets are adopted for experiments on AAEAP and other clustering algorithms for comparison,and many internal and external clustering evaluation indexes are used to measure the clustering performance.The findings demonstrate that the AAEAP clustering algorithm demonstrates a substantial automatic aggregation impact while maintaining good clustering quality.

4-Port Octagonal Shaped MIMO Antenna with Low Mutual Coupling for UWB Applications

A4-port multiple-input multiple-output(MIMO)antenna exhibiting lowmutual coupling andUWBperformance is developed.The octagonal-shaped four-antenna elements are connected with a 50microstrip feed line that is arranged rotationally to achieve the orthogonal polarization for improving the MIMO system performance.The antenna has a wideband impedance bandwidth of 7.5GHz with S11<−10 dB from(103.44%)3.5–11GHz and inter-element isolation higher than 20 dB.Antenna validation is carried out by verifying the simulated and measured results after fabricating the antenna.The results in the form of omnidirectional radiation patterns,peak gain(≥4 dBi),and Envelope Correlation Coefficient(ECC)(≤0.01)are extracted to validate the suggested antenna performance.Aswell,time-domain analysis was investigated to demonstrate the operation of the suggested antenna in wideband applications.Finally,the simulated and experimental outcomes have almost similar tendenciesmaking the antenna suitable for its use in UWBMIMOapplications.