The Extended Hybrid Carrier-Based Multiple Access Technology for High Mobility Scenarios

The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering attention.In this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless communication.By employing the EHC modulation,a power layered multiplexing framework is realized,which exhibits enhanced interference suppression capability owing to the more uniform energy distribution design.The implementation method and advantage mechanism are explicated respectively for the uplink and downlink,and the performance analysis under varying channel conditions is provided.In addition,considering the connectivity demand,we explore the non-orthogonal multiple access(NOMA)method of the EHC system and develop the EHC sparse code multiple access scheme.The proposed scheme melds the energy spread superiority of EHC with the access capacity of NOMA,facilitating superior support for massive connectivity in high mobility environments.Simulation results have verified the feasibility and advantages of the proposed scheme.Compared with existing HC multiple access schemes,the proposed scheme exhibits robust bit error rate performance and can better guarantee multiple access performance in complex scenarios of nextgeneration communications.

Analyses of Multiplicity and Stability Patterns of Agglomeration Controlled Precipitation with Both Primary and Secondary Nucleations

The possibility of multiplicity in an isothermal continuous mixed suspension-mixed product removalcrystallizer is explored using the bifurcation theory. A process involving agglomeration controlled precipitationis considered in which secondary nucleation occurs simultaneously with primary nucleation. The determinantequations for the existence of multiple steady states are developed and the multiplicity boundaries dependent on thephysical and kinetic properties and operational parameters of the process are obtained by resolving these determinantequations. The number of steady states in the precipitator for various multiplicity regions is determined and thelinear stability of these steady states is analyzed by using the Routh criterion.

STA-21治疗寻常型银屑病对P-Stat3和IL-17水平的影响

目的研究寻常型银屑病皮损中STA-21对磷酸化信号转导和转录激活因子-3(P-Stat3)和白介素-17(IL-17)的影响。方法利用免疫组织化学法检测STA-21治疗2周前后寻常型银屑病皮损组织中P-Stat3、IL-17的表达。结果 STA-21治疗寻常型银屑病2周后,P-Stat3和IL-17的水平下降,两者差异均有统计学意义(Z=-3.706、-4.931,P<0.01)。结论 STA-21可通过下调P-Stat3和IL-17的表达而达到治疗寻常型银屑病的目的。

STAT3特异性抑制剂STA-21对乳腺癌MCF-7B细胞增殖及凋亡的影响

目的:探讨信号传导与转录活化因子3(signal transducers and activators of transcription 3,STAT3)特异性抑制剂STA-21对乳腺癌MCF-7B细胞增殖及凋亡的影响。方法:空白组为单独培养MCF-7B细胞,实验组采用不同浓度STA-21作用于乳腺癌MCF-7B细胞后,用MTT法观察STA-21对MCF-7B细胞生长抑制的作用;流式细胞仪检测细胞周期及凋亡;Westernblot检测MCF-7B细胞P-STAT3、STAT3、细胞周期蛋白D1(CyclinD1)、Bcl-xl蛋白的表达。结果:MCF-7B细胞经各浓度STA-21(10、30、50μmol/L)作用后,其细胞增殖的抑制率及细胞凋亡率较空白组明显增加(P=0.000);流式细胞仪检测发现STA-21可导致MCF-7B细胞阻滞于G1期;Western blot结果显示与空白组相比,STA-21可降低MCF-7B细胞P-STAT3、CyclinD1、Bcl-xl蛋白的表达(P=0.000),但对STAT3蛋白的表达基本无影响(P=0.367)。结论:STA-21可在一定程度上抑制MCF-7B细胞的增殖及促进凋亡,其作用机制可能与抑制STAT3活性有关。

Finite-time stability and stabilization of Markovian switching stochastic systems with impulsive effects

Many practical systems in physics, biology, engineer- ing and information science exhibit impulsive dynamical behaviors due to abrupt changes at certain instants during the dynami- cal processes. The problems of finite-time stab!lity analysis are investigated for a class of Markovian switching stochastic sys- tems, in which exist impulses at the switching instants. Multiple Lyapunov techniques are used to derive sufficient conditions for finite-time stochastic stability of the overall system. Furthermore, a state feedback controller, which stabilizes the closed loop sys- tems in the finite-time sense, is then addressed. Moreover, the controller appears not only in the shift part but also in the diffu- sion part of the underlying stochastic subsystem. The results are reduced to feasibility problems involving linear matrix inequalities （LMIs）. A numerical example is presented to illustrate the proposed methodology.

Constrained fixed-fulcrum reverse shoulder arthroplasty improves functional outcome in epileptic patients with recurrent shoulder instability

AIM: To report the results of fixed-fulcrum fully constrained reverse shoulder arthroplasty for the treatment of recurrent shoulder instability in patients with epilepsy. METHODS: A retrospective review was conducted at a single facility. Cases were identified using a com-puterized database and all clinic notes and operative reports were reviewed. All patients with epilepsy and recurrent shoulder instability were included for study. Between July 2003 and August 2011 five shoulders in five consecutive patients with epilepsy underwent fixed-fulcrum fully constrained reverse shoulder arthroplasty for recurrent anterior shoulder instability. The mean duration of epilepsy in the cohort was 21 years(range, 5-51) and all patients suffered from grand mal seizures. RESULTS: Mean age at the time of surgery was 47 years(range, 32-64). The cohort consisted of four males and one female. Mean follow-up was 4.7 years(range, 4.3-5 years). There were no further episodes of instability, and no further stabilisation or revision procedures were performed. The mean Oxford shoulder instability score improved from 8 preoperatively(range, 5-15) to 30 postoperatively(range, 16-37)(P = 0.015) and the mean subjective shoulder value improved from 20(range, 0-50) preoperatively to 60(range, 50-70) postoperatively(P = 0.016). Mean active forward elevation improved from 71° preoperatively(range,45°-130°) to 100° postoperatively(range, 80°-90°) and mean active external rotation improved from 15° preoperatively(range, 0°-30°) to 40°(20°-70°) postoperatively. No cases of scapular notching or loosening were noted. CONCLUSION: Fixed-fulcrum fully constrained reverse shoulder arthroplasty should be considered for the treatment of recurrent shoulder instability in patients with epilepsy.

颞肌联合游离STA-脑贴敷融合术治疗ICA系ICVD

目的 评价颞肌联合游离颞浅动脉（STA）-脑贴敷融合术治疗颈内动脉（ICA）系ICVD的临床价值。方法 选取100例ICA系ICVD患者,分为间接组和直接组各50例。间接组给予颞肌联合游离STA-脑贴敷手术治疗,直接组给予STA-大脑中动脉（MCA）搭桥手术治疗,比较2组的治疗效果和并发症情况。结果 2组术前评分和治疗后2周NIHSS评分无明显差异（P〉0.05）;但经过4周~6个月治疗后神经功能障碍恢复评分比较,间接组明显优于直接组,差异有统计学意义（P〈0.01）。2组术后评估：手术血管再狭窄、高灌注脑出血及卒中逆转等间接组发生率低于直接组,差异有统计学意义（P〈0.05）。结论 颞肌联合游离STA-脑贴敷融合术治疗ICVD,手术操作技巧简单、手术时间短,其术后血流动力学稳定,效果显著。

Kinematics analysis for obstacle-surmounting capability of a joint double-tracked robot

A double-tracked robot is designed from mechanical and control perspectives,which consists of two segments connected with a swing joint. As the angle between the two segments of the robot platform can be changed,the robot can move like a four-tracked robot on many terrains. The center of gravity（ CG） kinematics model is established,which plays an important role in the process of traveling over obstacles and climbing up stairs. Using this model,the CG change situation and the maximal height of the climbable obstacle are obtained. Then the relationship between the robot pitch angle and the height of the obstacle is established. Finally,a reasonable system structure for the robot is designed and its kinematics analysis for obstacle-surmounting capability is conducted through experiments.

Stability of equivariant bifurcation problems with two types of state variables and their unfoldings in presence of parameter symmetry

Based on the contact equivalent relation of smooth map-germs in singularity theory, the stability of equivariant bifurcation problems with two types of state variables and their unfoldings in the presence of parameter symmetry is discussed. Some basic results are obtained. Transversality condition is used to characterize the stability of equavariant bifurcation problems.

Extended Collapsibility of Association Measure

In this paper the amalgamation of (I+1)×J tables under consistent significance is considered and the sufficient condition is obtained. The sufficient and necessary conditions are given to avoid the famous paradoxes 'YAP' and 'YRP'. A practical algorithm is given to compute the critical value when pooling tables with odds ratio less than 1.

陆相页岩油开发实验技术现状与展望

随着页岩油勘探开发力度不断加大,页岩油开发实验技术在继承常规油藏和页岩气藏实验技术方法的基础上不断发展完善,初步形成了一套油藏物理与渗流机理实验技术体系,为页岩油藏地质评价、油藏工程优化设计及提高采收率提供了有力技术支撑。系统总结了孔隙度、渗透率、油水饱和度、润湿性、相对渗透率、渗吸等6项实验技术国内外发展现状,结合陆相页岩油成熟度低、非均质性强、纹层和微裂缝发育等特点,从实验技术的测定方法和原理、关键影响因素和实验控制条件、方法优缺点和技术适用性等方面,提出了各实验技术面临的主要问题、发展趋势和攻关方向。研究结果表明:①统一岩样清洗溶剂及清洗时间是提高孔隙度不同测定方法之间可对比性的关键,核磁共振测定孔隙度技术是满足矿场快速分析需求的技术发展方向。②非规则、多方向以及模拟地层压力变化的渗透率测定技术是下步技术发展方向。③酒精浸泡法和二维核磁共振(T_(1)-T_(2))法是页岩油水饱和度测定的技术发展方向,依然面临黏土束缚水、吸附油对测定精度的影响难题。④液滴形态法是页岩油藏润湿性测定技术的未来发展方向之一,需要对实验方法及表面润湿和自发渗吸2个过程的综合评价方法进行深化研究并统一标准。⑤实验测定和数值方法相结合是获取页岩油藏相对渗透率的有效路径,微量油水计量、末端效应校正以及考虑压力时变的技术方法是攻关方向。⑥压后弹性开发中渗吸效果评价、闷井时间优化应采用带压渗吸测定方式,基于核磁共振T_(2)谱、分层T_(2)谱和T_(1)-T_(2)谱的带压渗吸测定方法将是重要技术发展方向之一。

永进油田致密储集层岩石力学参数剖面构建及应用

为评价低渗致密储集层可压裂性,对准噶尔盆地沙湾凹陷永进油田Y301井和Y3井的6块岩心进行实验,获得岩心矿物组分、孔隙度、应力—应变曲线、纵波速度、横波速度等参数,实验结果与测井、录井数据基本吻合,构建了研究区岩石力学参数经验模型。同时,基于等效介质模型,考虑矿物组分和孔隙结构特征建立了一种新的岩石脆性指数计算模型。在此基础上,提出了基于测井数据的低渗致密储集层力学参数剖面构建方法,并以Y301井为例进行了计算,结果表明,Y301井齐古组可压裂性良好,为致密砂岩储集层可压裂性综合评价奠定了基础。

工商业与人权视野下企业环境责任履行的激励机制研究

“企业中心主义”的环境责任理论难以为企业履行环境责任提供充分的内外驱动力,工商业与人权视角则会为要求和激励企业履行环境责任提供一种补充性理解,以及更强的理论和实践支撑。审视当前企业环境责任履行激励机制可以发现,其虽已经形成了若干实践形式,但仍然面临适用标准不完善、社会层面环保响应不到位及责任履行体系欠缺的问题。基于此,应当以人权理念、制度经验及相关规范性文件的实践为有益指引和参考,完善企业履责激励的适用标准,加强环境人权的社会化教育,健全企业环境人权的尽责体系。

一种氟化反应产物生产的风险分析及安全技术措施

利用危险及可操作性方法,结合精细化工反应热评估结果,对一种采用氟化氢溶剂法生产六氟磷酸锂的间歇反应釜生产技术进行安全分析,查找出该工艺氟化反应、合成反应过程存在的反应失控、温度过高、反应釜压力过高等异常事件,及由此引发高毒介质泄漏带来人员中毒的现实风险。提出了本质安全设计、仪表联锁控制、异常情况保护、人员技能提升等削减风险的措施建议。对采取的措施进一步开展保护层分析,可知生产过程风险处在可接受水平。

纳滤膜锂镁分离机理与影响因素研究进展

锂作为21世纪的重要能源金属,被广泛应用于新能源和电池技术领域,但因其存在于盐湖等资源分布不均匀的环境中,使得高效分离锂和镁成为技术挑战。该文聚焦于纳滤膜技术在锂镁分离中的关键影响因素,首先,对膜表面形貌、孔径和孔径分布的调控进行了深入探讨,这些因素直接影响着锂镁分离效率。其次,粗糙度和膜厚度的适度调节被证明能够显著提高水渗透性,但这也引入了抗污染性的问题。同时揭示了纳滤膜正电荷的重要性以及如何调节交联度以增强镁的截留效果。此外,亲水性和官能团的引入被证明也能提高水通量,进一步优化了分离效果。最后,对开发新型膜材料、揭示界面聚合反应机制、提高抗污染性能等方面提出了展望,旨在为锂回收纳滤技术提供参考。

绳索驱动下肢训练机器人系统运动稳定性分析

针对绳索驱动下肢训练机器人的稳定性问题,本文建立了绳索驱动下肢训练机器人的运动学和动力学模型,给出了绳索拉力优化解的计算表达式,并推导获得了机器人的系统刚度解析表达式。考虑不同训练对象承受运动强度的能力不同,定义了速度影响函数。综合考虑绳索拉力、系统刚度和速度影响函数等因素定义了机器人系统的运动稳定性评价指标,并通过稳定工作空间、抗干扰稳定工作空间和不同训练轨迹的实例计算明确了机器人工作空间内中上部区域的运动稳定性能更好,为运动支链中的过轮运动规划和训练任务规划提供了理论依据。

考虑侧壁阻力的顺层边坡失稳机制及稳定性评价

侧壁阻力作用下,顺层边坡主滑方向将偏离岩层倾向,其变形及失稳机制具有典型特征。以四川盆地马边河流域某顺层边坡为例,基于其工程地质条件,总结顺层边坡不同变形区域的特征,结合失稳边界条件研究了考虑侧壁阻力的顺层边坡失稳演化机制;最后,对比主滑方向偏离岩层倾向与否的受力差异,分析考虑侧壁阻力的顺层边坡三维稳定性,并研究了各影响因素的作用效应。结果表明:(1)考虑侧壁阻力的顺层边坡变形可划为失稳滑走区、滑坡区和稳定区,滑坡区包含滑动区和蠕滑变形区,滑动区岩体滑动后解体风化为碎、块石土,蠕滑变形区受侧壁阻力影响岩体仅变形拉裂;(2)顺层边坡经岩体劣化和前缘临空后,总体呈下部滑动、中部蠕滑拉裂的顺层临空-后退式破坏;滑动区边界受前缘及侧壁临空控制,长度与侧壁冲沟下切段长度相近;蠕滑变形区部分侧壁由节理面转化为挤压带,侧壁阻力增大,稳定性高于临界失稳状态;受侧壁阻力及滑体厚度控制,蠕滑变形区与稳定区界限处因滑体厚度削薄而拉裂;(3)建立了考虑侧壁阻力的顺层边坡稳定性系数计算式,以及岩层倾角δ、滑面倾角α、主滑方向偏离岩层倾向夹角β三角度间的换算关系式,侧壁摩擦系数和β越大,侧壁阻力越利于顺层边坡稳定。

基于贝叶斯方法的通信网络运维人误概率研究

为了定量化分析通信网络运维任务中人因失误的发生概率,针对网络运维人员在执行任务中可能发生的40种人误模式,采用专家判断法获取人误概率的估值,进而采用贝叶斯方法进行聚合分析,得到了各项人误模式的基础发生概率水平。结果表明:在无其他突出情境因素影响时,大多数人误模式的基础发生概率量级在1E-3左右,其中由于理解失效和决策制定失效导致的人误发生概率与其他宏认知功能的失效相比较高。在实际应用中,相对概率高的人误模式在安全和质量管理中应得到优先控制。

变形翼无人机纵向动力学建模及飞行力学特性分析

文章建立了变形翼无人机(Morphing Wing UAV, MWUAV)的纵向动力学模型并在此基础上对其飞行力学特性进行了简要分析。首先,针对MWUAV的参数变化特点,建立纵向非线性参数变化(Nonlinear Parameter-Vayring, NPV)模型;其次,分析了参数变化对其静态特性的影响,包括升阻特性、转动惯量特性以及飞行包线的影响;最后,在建立模型和静态特性分析的基础上,在其飞行包线内选择典型分析点,进行了配平和线性化分析,得出了其配平量随参数变化的关系,并计算了其纵向长短周期模态特性。建模和分析结果可以为MWUAV的飞行状态设计以及控制器设计提供设计依据。

新治理观下央地关系动态调整的基本逻辑与优化路径

理顺央地关系是中国推进国家治理体系和治理能力现代化的重要内容之一。随着内外部环境的日趋复杂和治理观念的不断变化,理顺央地关系不仅需要明确央地之间的职责关系,还需要预留一些弹性空间,从而让央地关系可以根据形势的变化进行动态调整。现有研究重在以委托代理关系、利益博弈关系、合作治理关系等静态体制分析为研究主线,而疏于考察央地关系动态调整的基本逻辑和把握央地关系的优化方向。明确中央政府的主导地位、平衡目标任务的确定性与模糊性、限制地方政府的自利性是厘清现阶段央地关系动态调整的基本逻辑。央地关系应对未来复杂形势动态调整的优化路径是:有限度地强化垂直管理制度,设计有弹性的政府职责体系,构建伙伴型政府间关系。这可以为推进治理体系和治理能力现代化提供帮助。