SPECTRAL MAPPING THEOREM FOR ASCENT,ESSENTIAL ASCENT, DESCENT AND ESSENTIAL DESCENT SPECTRUM OF LINEAR RELATIONS

In [7], Cross showed that the spectrum of a linear relation T on a normed space satisfies the spectral mapping theorem. In this paper, we extend the notion of essential ascent and descent for an operator acting on a vector space to linear relations acting on Banach spaces. We focus to define and study the descent, essential descent, ascent and essential ascent spectrum of a linear relation everywhere defined on a Banach space X. In particular, we show that the corresponding spectrum satisfy the polynomial version of the spectral mapping theorem.

Ascent schedules,acute altitude illness,and altitude acclimatization:Observations on the Yushu Earthquake

During the Yushu Earthquake on April 14,2010,a large number of rescuers from sea level or lowlands ascended to the quake areas very rapidly or rapidly less than 24 h. However,Yushu Earthquake is the highest quake in the world at altitudes between 3 750 m and 4 878 m where is a serious hypoxic environment. A high incidence of acute altitude illness was found in the unacclimatized rescuers;the mountain rescue operation changed as "rescue the rescuers". Lesson from the Yushu Earthquake is that the occurrence of acute altitude illness may be closely related to the ascent schedules. This prompted us to study the relationship between ascent rate and the incidence and severity of acute altitude illness;five different groups were compared. The first group was 42 sea level male young soldiers who ascended to quake area very rapidly within 8 h at 4 000 m;the second group was 48 sea level male young soldiers who ascended to 4 000 m rapidly less than 18 h;the third group was 66 acclimatized medical workers from 2 261 m who ascended to 4 000 m rapidly within 12 h;the fourth group was 56 Tibetan medical workers from 2 800 m who ascended to 4 000 m rapidly within 8 h;the fifth group was 50 male sea level workers who ascended to 4 000 m gradually over a period of 4 d. The results showed that the sea level rescuers ascended to 4 000 m very rapidly or rapidly had the highest incidence of acute mountain sickness (AMS) with the greatest AMS scores and the lowest arterial oxygen saturation (SaO2);the sea level workers ascended to 4 000 m gradually had moderate incidence of AMS with moderate AMS scores and SaO2 values;whereas the acclimatized and adapted rescuers had the lowest incidence of AMS,lowest AMS scores and higher SaO2;especially none AMS occurred in Tibetan rescuers. AMS score is inversely related to the ascent rate (r=-0.24,p< 0.001). Additionally,acute altitude illness is significantly influenced by altitude acclimatization. The ascent rate is inversely re- lated to the period of altitude acclimatization whereas the time of perfect recovered from AMS is positively correlated to the time taken to acclimatize. Generally,the best means of preventing acute altitude illness is slow and gradual ascent to high altitude,as this allows time for establishing altitude acclimatization and tolerance to the hypoxic environment. However,during an emergency circumstance,such as mountain rescue operation,the rescuers must rapidly ascend to high altitude,so a series of preventive strategies including pre-acclimatization,using some prophylactic drugs and oxygen supplementary are sorely necessary.

Comparison of gait properties during level walking and stair ascent and descent with varying loads

This study aimed to compare gait properties during level walking and during stair ascent and descent with varying loads. Fifteen healthy young men (mean age: 22.1 ± 1.6 years) walked while holding four different loads relative to each subject’s body mass (0, 20, 40 and 60% of body mass: BM) on their backs. Stance time, swing time, and double support times were selected as gait parameters. All parameters showed a maximal value during stair ascent and a minimum value during level walking. Stance and double support times increased significan- tly with each load during level walking and during stair ascent and descent. In conclusion, st- air ascent and descent creates more unstable movement than level walking regardless of the weight of the load. The effect of loads on gait increases with the weight of the load and becomes obvious once the load exceeds 60% of BM.

传感器网络拓扑控制-ASCENT算法

ASCENT算法[1]的前提是节点密度足够大,有一个CSMA,MAC协议或TDMA,MAC协议支持。ASCENT算法与STEM算法都属于节点唤醒机制,它们之间也存在着比较大的差别。ASCENT算法偏重于均衡网络中骨干节点的数量,保障数据通路的顺畅。当一个节点接收到数据时,如果存在严重的丢包率,则向该数据源的方向向该相邻节点发送帮助消息;从该相邻节点接收到帮助请求或从该相邻节点检测到丢包率高时,该节点唤醒,它会主动成为一个活动节点来帮助该相邻节点转发数据包。

On the ascent of infinite dimensional Hamiltonian operators

In this paper, the ascent of 2 × 2 infinite dimensional Hamiltonian operators and a class of 4 × 4 infinite dimensional Hamiltonian operators are studied, and the conditions under which the ascent of 2 × 2 infinite dimensional Hamiltonian operator is 1 and the ascent of a class of 4 × 4 infinite dimensional Hamiltonian operators that arises in study of elasticity is2 are obtained. Concrete examples are given to illustrate the effectiveness of criterions.

The ascent of immune checkpoint inhibitors： is the understudy ready for a leading role？

The recent approval of pembrolizumab as second-line treatment for any solid tumor with high-level microsatellite instability or mismatch repair deficiency agnostic of tissue and origin1 has shattered a glass ceiling for immune checkpoint inhibitors.No longer bound to a specific cancer diagnosis but rather a biomarker,pembrolizumab has heightened a burgeoning optimism towards the drug class.Yet how these agents should carve out additional

A Computerized Evaluation of Sensory Memory and Short-term Memory Impairment After Rapid Ascent to 4280 m

To evaluate the effect of acute high-altitude exposure on sensory and short-term memory using interactive software,we transported 30 volunteers in a sport utility vehicle to a 4280 m plateau within3 h.We measured their memory performance on the plain（initial arrival）and 3 h after arrival on the plateau using six measures.

MARTIN LOGAN Ascent静电扬声器

英国城堡声学公司(Castle)生产的音箱做工精湛, 音乐味浓郁,而且价格并不太高,因而深得发烧友 青睐。您现在看到的Castle Conway 3小型落地箱, 与不久前本刊介绍的Richmond 3小型书架箱一样,都是属于城堡公司Classic系列当中的产品。Conway

丹尼尔·利贝斯金德设计的Ascent大厦开放

国外媒体4月16日报道，丹尼尔·利贝斯金德事务所设计的Ascent大厦在美国辛辛那提市开放，这将成为“美国住宅建筑的一个新基准”。大厦坐落在Roebling大桥旁。这座大桥是仿照纽约布鲁克林大桥设计的，因此Ascent大厦也被人看作有着同样的效应。

化解水平井裂缝支撑剂难题的Ascent^(TM)压裂技术

通常情况下,扩大裂缝面积、提高压裂井产量的办法是增加压裂液的用量。这一办法虽然可以使裂缝继续扩展,但是并不能带来与之相对应产量。因为大多数支撑剂会在水平井段的低洼处堆积,即使砂粒能够到达水平段上部的裂缝内也会在裂缝闭合前沉降,支撑剂很难嵌入进水平井眼上方的裂缝内。一旦这些未被支撑剂填充的裂缝闭合,制造的这些裂缝的成本往往就白白浪费了。

温度敏感凝胶推进剂中气泡间相互作用机理研究

为了研究凝胶推进剂除气工艺过程中的气泡两相流问题,采用Carreau-Yasuda模型描述凝胶的剪切稀化特性,并进一步引入了温度敏感性本构描述。数值上,运用流体体积方法研究了剪切和温度敏感耦合的凝胶中浮力驱动气泡的运动特性和气泡间的相互作用机理,关注了气泡的初始排列、气泡个数以及凝胶温度的影响。研究结果表明,主导气泡的尾流以及底部的低粘区会吸引尾随气泡并加速尾随气泡的上升;水平排列的气泡间由于强涡量场会存在一定的横向排斥力;温度上升带来的黏度下降会加速气泡的融合和上升,并且增强了气泡间的相互作用。

火星表面起飞上升热控技术研究与分析

火星表面起飞上升热控技术是火星取样返回探测的关键技术,涉及探测器在火星表面存储控温、火星表面起飞上升控温及火星在轨飞行控温等,具有温度指标要求高、控温维度大、资源紧张的特点。本文对国内外主要火星车及美国航空航天局(NASA)火星上升器的热控方案进行了调研和总结。分析表明火星表面探测器热控技术根据资源分配情况主要采用2种方式:当热控质量受限不明显时,可采用机械泵驱动流体回路技术配合常规热控措施,对大热耗单机进行热量收集和传输,实现废热的再利用;当热控质量受限严重时,需采用轻量化低功耗的控温措施,可采用复合纳米气凝胶隔热技术配合常规热控措施,高效隔绝火星表面低温对流环境,实现低功耗控温。随后提出了火星表面起飞上升的热控关键技术,主要包括纳米气凝胶隔热技术、火星原位资源隔热技术、机械泵驱动两相流体回路技术、气动热防护技术及热试验模拟技术等,可为后续火星探测提供一定的参考。

火星上升器入轨段自适应迭代制导方案设计

针对火星上升器入轨段的制导问题,设计了一种自适应迭代制导策略。为降低初始状态偏差和火星环境不确定性的影响,每个周期内在制导坐标系下迭代计算剩余飞行时间,求解出在上升器推力大小固定情况下满足目标点位置与速度矢量约束的最优控制角,进而实时修正飞行轨迹。仿真结果表明,相较于传统的开环制导方案,提出的方案显著地提升了制导精度,其中高度误差降低3个量级,最大速度误差降低至原开环制导的三分之一,入轨点轨道倾角和偏心率误差均满足基本工程需求,可作为未来火星上升器入轨段制导的一种可靠方案。

火星表面上升轨迹映射伪谱凸优化方法

针对火星表面上升轨迹优化问题,提出了映射Chebyshev伪谱凸优化方法。首先采用无损凸化方法对火星表面上升燃耗最优问题进行凸松弛,然后将凸化后的问题在映射Chebyshev-Gauss-Lobatto点处离散,利用重心有理Lagrange插值技术进行插值,最后使用序列凸优化方法迭代求解,得到数值最优解。仿真对比了本文方法、一般伪谱凸优化方法和经典的序列凸优化方法,证明了本文方法在计算效率方面存在优势,并有效改善了标准Chebyshev微分矩阵的病态特性。

STAR-RIS辅助通信感知一体化系统联合波束成形设计

提出同时将透射和反射可重构智能表面(Simultaneously transmitting and reflecting reconfigurable intelligent surfaces,STAR-RIS)与通信感知一体化(Integrated sensing and communication,ISAC)系统结合,以实现全空间的通信与感知。同时在STAR-RIS上应用一种低成本的传感器实现了在STAR-RIS上进行目标感知,解决了雷达感知的严重路径损耗问题。基于此,本文研究了STAR-RIS辅助位于STAR-RIS两侧的多用户多输入单输出(Multi-usermulti-input single-output,MU-MISO)以及一个位于STAR-RIS透射侧的目标的ISAC系统,旨在联合优化STAR-RIS的被动波束成形矩阵和ISAC基站处的主动波束成形矩阵,以最大化用户的通信和速率,同时满足目标感知的最低信噪比要求。为了解决优化过程中的非凸问题,提出了一种基于分式规划的块坐标上升算法,将优化变量分为几个块变量交替优化。在迭代优化后续波束成形问题上,应用了连续凸逼近和半正定松弛算法。与传统的可重构智能表面相比,仿真结果验证了在ISAC系统中部署STAR-RIS的优点。同时将所提的基于分式规划的算法与基于加权最小均方误差的算法进行了对比并验证了所提算法在提高通信和速率上的优势和有效性。

ON THE USE OF A SYSTEM-SCALE ASCENT/DESCENT DIAGNOSTIC FOR SHORT-TERM FORECASTING OF TROPICAL CYCLONE DEVELOPMENT,INTENSIFICATION AND DECAY

The Brisbane Tropical Cyclone Warning Centre has used two forms of a thermal advection diagnostic to identify relatively large areas of isentropic ascent and descent for many years. When the thermodynamic conditions are favourable the ascent regions are correlated with significant outbreaks of convection that produce heavy rainfall. The diagnostic is based on the relationship between geostrophic winds that turn with height and flow perpendicular to thickness contours. As the relationship is also valid for the more general case of gradient winds, the diagnostic, in theory, should be useful for most heavy-rain-bearing tropical systems. A climatology of rainfall rate with one form of the diagnostic is presented at two Queensland locations(one tropical and one subtropical) that demonstrates a clear relationship between the isentropic ascent wind distribution and heavy to extreme rainfall.The diagnostics applied to numerical weather prediction models are valuable forecast tools as they identify heavy rainfall threat regions within which the extreme rain is likely to fall, whereas the rainfall from the same models is often under predicted or has large location errors. Applied to tropical lows and tropical cyclones the diagnostics have been used successfully to forecast tropical cyclone formation and rapid intensification and decay. Examples of such intensification and decay from around the world are presented, as well as a climatology of the diagnostic applied to intensifying tropical cyclones in the Australian region.

基于黄元御“一气周流、土枢四象”理论探析糖尿病胃轻瘫六期病机与辨治

基于黄元御“一气周流、土枢四象”理论探析糖尿病胃轻瘫(DGP)的病机与辨治。认为DGP病机演变可概括为“中虚-土湿-木郁-金燥-水寒-络瘀”六期,治疗时当以健运斡旋中土为核心,把握木、火、金、水四象的动态变化,根据不同阶段的病机演变,立足扶阳抑阴、疏肝理气、升阳敛肺、清上温下、散瘀通络、敛神静心之法,使气机升降有序,周流不息。

A high dynamics algorithm based on steepest ascent method for GNSS receiver

High dynamic conditions impose critical challenges on Global Navigation Satellite System(GNSS)receivers,leading to large tracking errors or even loss of tracking.Current methods that intend to improve receivers’adaptability for high dynamics require either complicated structures or prior statistical information of noises.This paper proposes a high dynamics algorithm based on steepest ascent method that can circumvent the deficiencies of existing methods.First,the relationship between the error of carrier tracking and the maximum of Fast Fourier Transform(FFT)outputs is established,and a performance function based on the steepest ascent method is designed.It can keep stable in high dynamics.Second,a new carrier-tracking loop is constructed by deploying the performance function.When the variation of GPS receiver acceleration ranges from 10 g to 100 g,compared with the PLL that either loses lock or keeps tracking accuracy less than 33.89 Hz,the experimental results show that the proposed method can not only keep tracking,but also achieve tracking accuracy more than 2.77 Hz.

Performance optimization of dye-sensitized solar cells by gradient-ascent architecture of SiO_2@Au@TiO_2 microspheres embedded with Au nanoparticles

Highly homogeneous, well dispersed SiO_2@Au@TiO_2(SAT) microspheres decorated with Au nanoparticles(AuNPs) were prepared and incorporated into the photoanode with an optimized concentration gradientascent. The effects of SAT microspheres and the gradient-ascent architecture on the light absorption and the photoelectric conversion efficiency(PCE) of the dye-sensitized solar cells(DSSCs) were investigated.Studies indicate that the introduction of SAT microspheres and the gradient-ascent architecture in the photoanode significantly enhance the light scattering and harvesting capability of the photoanode. The DSSC with the optimized SAT gradient-ascent photoanode has the maximum short circuit current density(J_(sc)) of 17.7 mA cm^(-2) and PCE of 7.75%, remarkably higher than those of the conventional DSSC by 23.7%and 28.0%, respectively. This significantly enhancement of the performance of the DSSC can be attributed to the excellent light reflection/scattering of SAT, the localized surface plasma resonance(LSPR) effect of AuNPs within the microspheres, and the gradient-ascent architecture of SAT microspheres inside the photoanode. This study demonstrates that the tri-synergies of the scattering of SAT microspheres, the LSPR of AuNPs and the gradient-ascent architecture can effectively improve the PCE of DSSC.

载人月面上升动力重构方案研究

针对载人月面着陆器上升期间发动机发生故障时航天员应急救生的难题,提出了通过多发动机并联可在部分发动机故障时通过动力重构继续上升入轨的方法。分析了3~5台发动机并联方案的动力重构策略,建立对应的发动机系统可靠性模型进行可靠性评估。基于能量最优的动力上升制导律,对不同故障工况下的动力重构上升轨迹进行仿真分析,得到推进剂消耗、入轨相位等关键参数的变化规律,根据应急入轨条件,设计了3种应急交会对接策略。仿真结果表明,若单台发动机可靠性为0.99,则3~4台发动机并联的动力重构方案可将发动机系统可靠性提升至0.9996,通过调整交会对接策略可在预定时间内完成快速交会对接,实现航天员安全返回。