WLAN与2G/3G移动网络的集成

本文介绍了WLAN与2G/3G移动网络集成的两个标准,即3GPPR6中定义的WLAN与WCDMA的集成,以及UMA定义的WLAN与GSM/GPRS的集成。

5G/5G-Advanced/6G接入网安全技术演进及内生安全

网络安全技术在无线通信技术的演进中不断增强。介绍了现有5G网络的安全技术方案,并结合5G行业应用需求,探讨了5G-Advanced增强安全技术。立足于万物智能互联愿景,从海量设备连接、智能运维、人工智能/机器学习、区块链方面分析了内生安全技术。认为内生安全是6G网络安全研究的热点,轻量化是6G内生安全的主要特征之一。

Prevalence of Severe Anemia (Hb ≤ 5 g/dl) in Non-Dialyzed Chronic Renal Failure Patients in the Nephrology and Hemodialysis Department of Point G University Hospital

Introduction: Chronic renal failure (CRF) is defined as glomerular filtration rate (GFR) less than 60 ml/min/1.73m2 for at least three (3) months. Anemia is one of its most common complications. Anemia increases the risk factor for cardiovascular mortality by 18% per gram of hemoglobin loss. Objectives: To determine the prevalence and characteristics of this severe anemia, to determine the indications for transfusion, the complications related to this anemia, the evolution and the prognosis of these patients. Materials and Methods: This was a descriptive study with retrospective data collection over 18 months (January 1, 2017 to June 30, 2018) that included hospitalized CRF patients. Were included, non-dialyzed chronic renal failure patients with Hb ≤ 5 g/dl hospitalized during the said period. Not included were chronic renal failure patients with an Hb level ≥ 5 g/dl, those followed up and/or hospitalized outside the study period. Results: Among 1176 patients, 26 had severe anemia (Hb level ≤ 5 g/dl) on CRF, a prevalence of 2.21%. The mean age was 40 years ± 32.62 with extremes of 15 and 67 years. Seventeen women and 9 men. The etiology of chronic renal failure (CRF) was hypertensive vascular nephropathy in 50% of cases. CRF was end-stage in 18 patients (69.2%). The mean hemoglobin level was 4.10 g/dl ± 0.64 with extremes of 2 and 5 g/dl. The anemia was microcytic hypochromic in 50% and aregenerative (96.2%). The main symptoms were asthenia in 20 cases (76.9%), dizziness in 20 cases (76.9%), exertional dyspnea in 19 cases (73.1%). Signs of cardiac decompensation (n = 12) were jugular turgor 10 cases (38.5%), hepato-jugular reflux 06 cases (23.1%), mitral insufficiency murmur 06 cases (23.1%). The main complication was left ventricular hypertrophy 17 cases (77.3%). There was no correlation between anemia and sex (p = 0.291), age (p = 0.778), malaria (p = 0.158), etiology of CRF (p = 0.26). The evolution after treatment of anemia was favorable in 19 patients (73.1%), unfavorable in 02 patients (7.7%) and 05 deaths (19.2%). The deaths were of cardiovascular cause: left ventricular insufficiency 04 cases, stroke 01 case. Conclusion: Anemia is frequent in patients with chronic renal failure and remains an important risk factor for cardiovascular disease and poor general condition.

Hybrid Metamodeling/Metaheuristic Assisted Multi-Transmitters Placement Planning

With every passing day,the demand for data traffic is increasing,and this urges the research community not only to look for an alternating spectrum for communication but also urges radio frequency planners to use the existing spectrum efficiently.Cell sizes are shrinking with every upcoming communication generation,which makes base station placement planning even more complex and cumbersome.In order to make the next-generation cost-effective,it is important to design a network in such a way that it utilizes the minimum number of base stations while ensuring seamless coverage and quality of service.This paper aims at the development of a new simulation-based optimization approach using a hybrid metaheuristic and metamodel applied in a novel mathematical formulation of the multi-transmitter placement planning(MTPP)problem.We first develop a new mathematical programming model for MTPP that is flexible to design the locations for any number of transmitters.To solve this constrained optimization problem,we propose a hybrid approach using the radial basis function(RBF)metamodel to assist the particle swarm optimizer(PSO)by mitigating the associated computational burden of the optimization procedure.We evaluate the effectiveness and applicability of the proposed algorithm by simulating the MTPP model with two,three,four and five transmitters and estimating the Pareto front for optimal locations of transmitters.The quantitative results show that almost maximum signal coverage can be obtained with four transmitters;thus,it is not a wise idea to use higher number of transmitters in the model.Furthermore,the limitations and future works are discussed.

Strain-dependent alpha-synuclein spreading in Parkinson's disease and multiple system atrophy

Parkinson's disease(PD) and atypical Parkinsonian syndromes,such as multiple system atrophy(MSA) and Dementia with Lewy bodies,are neurodegenerative movement disorders characterized by the accumulation of alphasynuclein(a-syn) aggregates.These a-syn aggregates propagate throughout the brain in a prion-like manner,where pathological a-syn recruits endogenous a-syn to form insoluble aggregates.Oligomeric forms representing intermediates on the way to insoluble aggregates result in the most pronounced neurotoxic effects.

Advancements,strategies,and prospects of solid oxide electrolysis cells(SOECs):Towards enhanced performance and large-scale sustainable hydrogen production

Solid oxide electrolysis cells(SOECs)represent a crucial stride toward sustainable hydrogen generation,and this review explores their current scientific challenges,significant advancements,and potential for large-scale hydrogen production.In SOEC technology,the application of innovative fabrication tech-niques,doping strategies,and advanced materials has enhanced the performance and durability of these systems,although degradation challenges persist,implicating the prime focus for future advancements.Here we provide in-depth analysis of the recent developments in SOEC technology,including Oxygen-SOECs,Proton-SOECs,and Hybrid-SOECs.Specifically,Hybrid-SOECs,with their mixed ionic conducting electrolytes,demonstrate superior efficiency and the concurrent production of hydrogen and oxygen.Coupled with the capacity to harness waste heat,these advancements in SOEC technology present signif-icant promise for pilot-scale applications in industries.The review also highlights remarkable achieve-ments and potential reductions in capital expenditure for future SOEC systems,while elaborating on the micro and macro aspects of sOECs with an emphasis on ongoing research for optimization and scal-ability.It concludes with the potential of SOEC technology to meet various industrial energy needs and its significant contribution considering the key research priorities to tackle the global energy demands,ful-fillment,and decarbonization efforts.

不依赖GNSS的输电线路双端行波故障测距

双端行波故障测距技术是实现输电线路快速故障恢复的有效手段。传统双端行波测距方法依赖全球卫星导航系统(global navigation satellite system,GNSS)同步线路两侧采样数据,存在信号误差、丢失等风险。基于行波的传播时延和时移不变性,该文提出一种不依赖GNSS的双端行波故障测距方案。理论层面,定量分析时间同步误差及其对故障前工频方向行波相角关系的影响,推导证明通过本地计算方向行波相量进行双端故障测距的可行性。算法层面,首先,通过小波变换检测故障初始行波到达时间;其次,通过对故障前工频方向行波的傅里叶变换求解附加相角差,进而完成双端测距。仿真结果表明,在考虑电压互感器传变特性的条件下,所提方案在不同故障情况、采样频率和噪声干扰等影响下均保持了良好的测距性能。由于无须增设GNSS、硬件时间戳等辅助硬件设备,所提方案便于现存设备的技术更新与工程应用。

基于提升距离保护适应性的改进VSG控制策略研究

随着新能源的大规模并网,新能源虚拟同步发电机(VSG)控制技术得到广泛应用。针对现有VSG控制下传统距离保护动作失效的问题,提出1种基于提升距离保护适应性的改进VSG控制策略。首先,对传统距离保护失效的原理进行分析;然后,以减小故障点两侧电流相位差为控制目标,通过定量设计VSG内环控制中的虚拟阻抗值,实现对换流器输出故障电流特性的主动控制;最后,在Matlab/Simulink中搭建新能源并网交流线路发生短路故障时的仿真模型。仿真分析表明,所提改进VSG控制策略能有效支撑传统距离保护的动作可靠性。

Impact of effective stress on permeability for carbonate fractured-vuggy rocks

To gain insight into the flow mechanisms and stress sensitivity for fractured-vuggy reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of effective stress on permeability for carbonate fractured-vuggy rocks(CFVR).It shows that the permeability performance curves under different pore and confining pressures(i.e.altered stress conditions)for the fractured core models and the vuggy core models have similar change patterns.The ranges of permeability variation are significantly wider at high pore pressures,indicating that permeability reduction is the most significant during the early stage of development for fractured-vuggy reservoirs.Since each obtained effective stress coefficient for permeability(ESCP)varies with the changes in confining pressure and pore pressure,the effective stresses for permeability of four representative CFVR show obvious nonlinear characteristics,and the variation ranges of ESCP are all between 0 and 1.Meanwhile,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,was proposed.It is proved theoretically that the ESCP of CFVR generally varies between 0 and 1.Additionally,the regression results showed that the power model ranked highest among the four empirical models mainly applied in stress sensitivity characterization,followed by the logarithmic model,exponential model,and binomial model.The concept of“permeability decline rate”was introduced to better evaluate the stress sensitivity performance for CFVR,in which the one-fracture rock is the strongest,followed by the fracture-vug rock and two-horizontalfracture rock;the through-hole rock is the weakest.In general,this study provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy reservoirs.

ESG的企业内部收入分配效应——来自中国沪深上市公司的证据

受全球投资理念及我国“双碳”目标影响,改善ESG表现成为中国上市公司近年来的重要目标,但更优外部目标的追求可能会影响企业内部治理效果。本文以2009—2022年中国沪深两市上市公司为样本,研究企业践行ESG理念的内部收入分配效应。结果发现:企业更好的ESG表现会拉大企业内部管理者和职工间的收入差距,经过一系列稳健性检验和内生性处理,研究结论依然成立;机制检验发现:就业规模扩容效应、效率激励损耗效应和群体禀赋分化效应是更好ESG表现拉大企业内部收入差距的作用渠道;异质性检验结果表明,是否更加严格的外部审计和企业所在行业的竞争强度是影响这一效应的重要因素。本文揭示了企业改善ESG目标的同时,可能面临内部不同群体利益的权衡取舍;研究结论提醒企业在积极履行社会责任、助力国家实现“双碳”目标时,应注重企业内部收入不平等问题。

The first factor affecting dryland winter wheat grain yield under various mulching measures: Spike number

Water is the key factor limiting dryland wheat grain yield.Mulching affects crop yield and yield components by affecting soil moisture.Further research is needed to determine the relationships between yield components and soil moisture with yield,and to identify the most important factor affecting grain yield under various mulching measures.A long-term 9-yearifeld experiment in the Loess Plateau of Northwest China was carried out with three treatments:no mulch (CK),plastic mulch (M_(P)) and straw mulch (M_(S)).Yield factors and soil moisture were measured,and the relationships between them were explored by correlation analysis,structural equation modeling and significance analysis.The results showed that compared with CK,the average grain yields of M_(P) and M_(S) increased by 13.0and 10.6%,respectively.The average annual grain yield of the M_(P) treatment was 134 kg ha^(–1) higher than the M_(S) treatment.There were no significant differences in yield components among the three treatments (P<0.05).Soil water storage of the M_(S) treatment was greater than the M_(P) treatment,although the differences were not statistically signifiant.Soil water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of M_(S) were significantly higher than in CK,which increased by 38.5 and 13.6%,respectively.The relationship between M_(P) and CK was not statistically significant for SWSSF,but the SWSS in M_(P) was significantly higher than in CK.In terms of soil water storage after harvest (SWSH) and water consumption in the growth period(ET),there were no signi?cant differences among the three treatments.Based on the three analysis methods,we found that spike number and ET were positively correlated with grain yield.However,the relative importance of spike number to yield was the greatest in the M_(P )and M_(S) treatments,while that of ET was the greatest in CK.Suifcient SWSSF could indirectly increase spike number and ET in the three treatments.Based on these results,mulch can improve yield and soil water storage.The most important factor affecting the grain yield of dryland wheat was spike number under mulching,and ET with CK.These findings may help us to understand the main factors influencing dryland wheat grain yield under mulching conditions compared to CK.

探索6G无线系统设计

1当前6G发展处于技术研发的关键阶段,当前,5G已经在全球范围内实现大规模商用,6G作为新一代综合性信息基础设施,将突破传统移动通信范畴,实现通信与感知、计算、人工智能等深度融合,具备空天地海一体化的全球覆盖能力,将在5G“万物互联”基础上进一步实现“万物智联”。根据移动通信产业发展规律,6G发展大致可分为三个阶段,2020至2024年是6G概念形成、技术突破阶段,形成愿景需求及概念,深入研究移动通信基础理论,实现关键核心技术突破,为6G国际标准奠定技术基础。2025至2029年是国际标准化研制阶段,形成6G技术方案和架构,完成6G国际标准研制。2026至2030年是产业研发阶段,全面推进产业研发,构建完整产业生态,适时启动6G商用。

Recent progress on Sn_(3)O_(4)nanomaterials for photocatalytic applications

Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence states.It has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable attention.This comprehensive review is aimed at providing a detailed overview of the latest advance-ments in research,applications,advantages,and challenges associated with Sn_(3)O_(4)photocatalytic nanomaterials.The fundamental con-cepts and principles of Sn_(3)O_(4)are introduced.Sn_(3)O_(4)possesses a unique crystal structure and optoelectronic properties that allow it to ab-sorb visible light efficiently and generate photoexcited charge carriers that drive photocatalytic reactions.Subsequently,strategies for the control and improved performance of Sn_(3)O_(4)photocatalytic nanomaterials are discussed.Morphology control,ion doping,and hetero-structure construction are widely employed in the optimization of the photocatalytic performance of Sn_(3)O_(4)materials.The effective imple-mentation of these strategies improves the photocatalytic activity and stability of Sn_(3)O_(4)nanomaterials.Furthermore,the review explores the diverse applications of Sn_(3)O_(4)photocatalytic nanomaterials in various fields,such as photocatalytic degradation,photocatalytic hydro-gen production,photocatalytic reduction of carbon dioxide,solar cells,photocatalytic sterilization,and optoelectronic sensors.The discus-sion focuses on the potential of Sn_(3)O_(4)-based nanomaterials in these applications,highlighting their unique attributes and functionalities.Finally,the review provides an outlook on the future development directions in the field and offers guidance for the exploration and de-velopment of novel and efficient Sn_(3)O_(4)-based nanomaterials.Through the identification of emerging research areas and potential avenues for improvement,this review aims to stimulate further advancements in Sn_(3)O_(4)-based photocatalysis and facilitate the translation of this promising technology into practical applications.

医院药学指南制定中的证据与推荐意见GRADE系统评级方法及应用

目前,国际上存在多种证据与推荐意见分级系统,对临床医务工作者阅读指南证据和推荐意见造成困扰。证据推荐分级的评估、制定与评价(GRADE)系统目前是全球使用最为广泛的证据与推荐意见分级系统,本文简单地介绍GRADE系统证据质量评级及影响推荐意见形成的4个主要因素,并结合中国医院药学界发起制定的、在国际上发表的几部药学指南举例阐述,以帮助临床医务工作者了解GRADE系统,以批判性思维运用指南证据和推荐意见指导临床实践行为。

A single micro-LED manipulation system based on micro-gripper

Micro-LEDs(μLEDs)have advantages in terms of brightness,power consumption,and response speed.In addition,they can also be used as micro-sensors implanted in the body via flexible electronic skin.One of the key techniques involved in the fabrication ofμLED-based devices is transfer printing.Although numerous methods have been proposed for transfer printing,improving the yield ofμLED arrays is still a formidable task.In this paper,we propose a novel method for improving the yield ofμLED arrays transferred by the stamping method,using an innovative design of piezoelectrically driven asymmetric micro-gripper.Traditional grippers are too large to manipulateμLEDs,and therefore two micro-sized cantilevers are added at the gripper tips.AμLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system.Experimental results using this system show that it can be used successfully to manipulateμLED arrays.

Root overlap and allocation of above- and belowground growth of European beech in pure and mixed stands of Douglas fir and Norway spruce

Site conditions and species identity have a combined effect on fine root growth of trees in pure and mixed stands.However,mechanisms that may contribute to this effect are rarely studied,even though they are essential to assess the potential of species to cope with climate change.This study examined fine root overlap and the linkage between fine root and stem growth of European beech(Fagus sylvatica)growing in pure and mixed stands with Douglas fir(Pseudotsuga menziesii)or Norway spruce(Picea abies)at two different study sites in northwestern Germany.The study sites represented substantially different soil and climate conditions.At each site,three stands,and at each stand,three pairs of trees were studied.In the pure beech stand,the pairs consisted of two beech trees,while in the mixed stands each pair was composed of a beech tree and a conifer.Between each pair,three evenly spaced soil cores were taken monthly throughout the growing season.In the pure beech stands,microsatellite markers were used to assign the fine roots to individual trees.Changes in stem diameter of beech were quantified and then upscaled to aboveground wood productivity with automatic high-resolution circumference dendrometers.We found that fine root overlap between neighboring trees varied independently of the distance between the paired trees or the stand types(pure versus mixed stands),indicating that there was no territorial competition.Aboveground wood productivity(wood NPP)and fine root productivity(root NPP)showed similar unimodal seasonal patterns,peaking in June.However,this pattern was more distinct for root NPP,and root NPP started earlier and lasted longer than wood NPP.The influence of site conditions on the variation in wood and root NPP of beech was stronger than that of stand type.Wood NPP was,as expected,higher at the richer site than at the poorer site.In contrast,root NPP was higher at the poorer than at the richer site.We concluded that beech can respond to limited resources not only above-but also belowground and that the negative relationship between above-and belowground growth across the study sites suggests an‘optimal partitioning’of growth under stress.

Using deep neural networks coupled with principal component analysis for ore production forecasting at open-pit mines

Ore production is usually affected by multiple influencing inputs at open-pit mines.Nevertheless,the complex nonlinear relationships between these inputs and ore production remain unclear.This becomes even more challenging when training data(e.g.truck haulage information and weather conditions)are massive.In machine learning(ML)algorithms,deep neural network(DNN)is a superior method for processing nonlinear and massive data by adjusting the amount of neurons and hidden layers.This study adopted DNN to forecast ore production using truck haulage information and weather conditions at open-pit mines as training data.Before the prediction models were built,principal component analysis(PCA)was employed to reduce the data dimensionality and eliminate the multicollinearity among highly correlated input variables.To verify the superiority of DNN,three ANNs containing only one hidden layer and six traditional ML models were established as benchmark models.The DNN model with multiple hidden layers performed better than the ANN models with a single hidden layer.The DNN model outperformed the extensively applied benchmark models in predicting ore production.This can provide engineers and researchers with an accurate method to forecast ore production,which helps make sound budgetary decisions and mine planning at open-pit mines.

Adult neurogenesis:a real hope or a delusion?

Adult neurogenesis,the process of creating new neurons,involves the coordinated division,migration,and differentiation of neural stem cells.This process is restricted to neurogenic niches located in two distinct areas of the brain:the subgranular zone of the dentate gyrus of the hippocampus and the subventricular zone of the lateral ventricle,where new neurons are generated and then migrate to the olfactory bulb.Neurogenesis has been thought to occur only during the embryonic and early postnatal stages and to decline with age due to a continuous depletion of neural stem cells.Interestingly,recent years have seen tremendous progress in our understanding of adult brain neurogenesis,bridging the knowledge gap between embryonic and adult neurogenesis.Here,we discuss the current status of adult brain neurogenesis in light of what we know about neural stem cells.In this notion,we talk about the importance of intra cellular signaling molecules in mobilizing endogenous neural stem cell prolife ration.Based on the current understanding,we can declare that these molecules play a role in targeting neurogenesis in the mature brain.However,to achieve this goal,we need to avoid the undesired proliferation of neural stem cells by controlling the necessary checkpoints,which can lead to tumorigenesis and prove to be a curse instead of a blessing or hope.

G3铜陵长江公铁大桥合龙

2024年8月27日,随着重715 t、长21 m的红色钢梁起吊、对位、上螺栓及合龙段最后一段6 m公路面钢桥面板盖面层焊接完成,G3铜陵长江公铁大桥实现顺利合龙(见图1),大桥主体结构完工,下一步将进入大桥附属工程施工阶段。

Design Principles and Mechanistic Understandings of Non-Noble-Metal Bifunctional Electrocatalysts for Zinc-Air Batteries

Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-metal catalysts hinder the practical applications of ZABs.Therefore,feasible and advanced non-noble-metal elec-trocatalysts for air cathodes need to be identified to promote the oxygen catalytic reaction.In this review,we initially introduced the advancement of ZABs in the past two decades and provided an overview of key developments in this field.Then,we discussed the work-ing mechanism and the design of bifunctional electrocatalysts from the perspective of morphology design,crystal structure tuning,interface strategy,and atomic engineering.We also included theoretical studies,machine learning,and advanced characterization technologies to provide a comprehensive understanding of the structure-performance relationship of electrocatalysts and the reaction pathways of the oxygen redox reactions.Finally,we discussed the challenges and prospects related to designing advanced non-noble-metal bifunctional electrocatalysts for ZABs.