Control strategy of central pattern generator gait movement under condition of attention selection

As a typical rhythmic movement, human being＇s rhythmic gait movement can be generated by a central pattern generator （CPG） located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by gait frequency and amplitude variances. As an important property of human being＇s motion vision, the attention selection mechanism plays a vital part in the regulation of gait movement. In this paper, the CPG model is amended under the condition of attention selection on the theoretical basis of Matsuoka neural oscillators. Regulation of attention selection signal for the CPG model parameters and structure is studied, which consequentially causes the frequency and amplitude changes of gait movement output. Further, the control strategy of the CPG model gait movement under the condition of attention selection is discussed, showing that the attention selection model can regulate the output model of CPG gait movement in three different ways. The realization of regulation on the gait movement frequency and amplitude shows a variety of regulation on the CPG gait movement made by attention selection and enriches the controllability of CPG gait movement, which demonstrates potential influence in engineering applications.

An Energy-Saving Control Strategy on Central Air-Conditioning System

An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature control systems, and then parameters in the cold load model and in the central air-conditioning system model are estimated. Generalized predictive control (GPC) is used to establish an optimization model to minimize the consumption of energy and the control error of temperature. The simulated annealing (SA) algorithm, combined with quadratic programming, is adopted to solve the optimal problem. Contrasted with the simulation of traditional PID control, the results prove the effectiveness of this proposed strategy.

Research on central village selection in western underdeveloped region:a case study of Lidian Town,Jingning County,Gansu Province,China

Central village selection is the priority of small town construction.Depending on the development potential analysis,classification analysis,and quantitative and qualitative analysis,this article systematically proposes the specific methods of central village selection and also constructs the indicator system used in central village selection in small towns of western underdeveloped region in China.The article also puts forward ideas and methods for selection of central village in the western underdeveloped region through an empirical research on Lidian Town,Jingning County,Gansu Province.In the final part,suggestions and recommendations on how to develop central village for Lidian Town are made.

Energy performance assessment on central air-conditioning system of commercial building: A case study in China

Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipment is necessary. But it is difficult to evaluate it reasonably and comprehensively due to its complexity. A "holistic" approach was discussed to evaluate the energy performance of central air-conditioning system for an extra-large commercial building in a subtropical city. All procedures were described in detail, including field investigation method, field measurement instruments, data processing and data analyzing. The main factors affecting energy consumption of air-conditioning system were analyzed and the annual cooling-energy use intensity of this building was calculated and also compared with other shopping malls and other types of buildings in Guangzhou. And COP(coefficient of performance) of chiller, water transfer factor of chilled water system and cooling water system were taken into consideration. At last, the thermal comfort and indoor air quality issues were addressed. The results show that the chilled water pumps are over-sized and the indoor environmental quality should be improved. The purpose of this work is to provide reference for energy performance assessment method for air-conditioning system.

Symbol Error Probability of Incremental Relaying with Distributed/Centralized Relay Selection

In this paper,we derive the Symbol Error Probability(SEP)of cooperative systems with incremental relaying and Distributed Relay Selection(DRS).The relays remain idle when the Signal to Noise Ratio(SNR)between the source and destination is larger than T.Otherwise,we activate a relay using DRS.Relay nodes transmit only if their SNR is larger than thresholdβ.If the SNRs of more than two relays is larger thanβ,there is a collision and the destination uses only the received signal from the source.If all relays have SNR less thanβ,no relay is chosen.Thresholdβis optimized to yield the lowest SEP at the destination.Our results are compared to centralized relay selection using opportunistic Amplify and Forward(OAF),Partial and Reactive Relay Selection(PRS and RRS).We compare our results to computer simulations for Rayleigh fading channels.

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

In addition to the loss of motor function,~60% of patients develop pain after spinal cord injury.The cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic pain.Sprouting can lead to the formation of new connections triggering abnormal sensory transmission.The excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and excitotoxicity.Our previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator tamoxifen.In this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord injury.We hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant sprouting.Male and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical allodynia.Tamoxifen treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent effect.The expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on astrocytes.Female rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased excitatory amino acid transporter-2 expression compared with female rodents.Analyses of peptidergic(calcitonin gene-related peptide-α)and non-peptidergic(isolectin B4)fibers outgrowth in the dorsal horn after spinal cord injury showed an increased calcitonin gene-related peptide-α/isolectin B4 ratio in comparison with sham,suggesting increased receptive fields in the dorsal horn.Although the behavioral assay shows decreased allodynia in tamoxifen-treated female rats,this was not associated with overexpression of glutamate transporters or alterations in the dorsal horn laminae fibers at 28 days post-injury.Our findings provide new evidence of the sexually dimorphic expression of glutamate transporters in the spinal cord.The dimorphic expression revealed in this study provides a therapeutic opportunity for treating chronic pain,an area with a critical need for treatment.

Planning for selective amygdalohippocampectomy involving less neuronal fiber damage based on brain connectivity using tractography

Temporal lobe resection is an important treatment option for epilepsy that involves removal of potentially essential brain regions. Selective amygdalohippocampectomy is a widely performed temporal lobe surgery. We suggest starting the incision for selective amygdalohippocampectomy at the inferior temporal gyrus based on diffusion magnetic resonance imaging（MRI） tractography. Diffusion MRI data from 20 normal participants were obtained from Parkinson＇s Progression Markers Initiative（PPMI） database（www.ppmi-info.org）. A tractography algorithm was applied to extract neuronal fiber information for the temporal lobe, hippocampus, and amygdala. Fiber information was analyzed in terms of the number of fibers and betweenness centrality. Distances between starting incisions and surgical target regions were also considered to explore the length of the surgical path. Middle temporal and superior temporal gyrus regions have higher connectivity values than the inferior temporal gyrus and thus are not good candidates for starting the incision. The distances between inferior temporal gyrus and surgical target regions were shorter than those between middle temporal gyrus and target regions. Thus, the inferior temporal gyrus is a good candidate for starting the incision. Starting the incision from the inferior temporal gyrus would spare the important（in terms of betweenness centrality values） middle region and shorten the distance to the target regions of the hippocampus and amygdala.

纵向监管、地方选择性供地与产业结构绿色转型

地方政府的有效执行是中国式分权下提升中央发展战略实施绩效的关键,而中央政府对地方政府治理行为的有效监督则是其中至关重要的环节。本文基于2007—2019年中国微观工业用地供应以及中央环保督察的通报结果数据,采用广义双重差分法实证考察中央环保督察对地方政府选择性供地策略的影响及其机制。研究表明,中央环保督察促使地方政府降低污染密集型工业用地供应,增加清洁型工业用地供应,从而推动地区产业结构的绿色转型。机制分析发现,中央环保督察通过地方领导人职业发展激励机制以及产业转型能力机制对不同特征的城市工业土地供应结构策略产生异质性影响。本文结论对高质量发展背景下的央地互动关系与地方利用土地偏向性供给推动产业结构绿色转型具有政策启示。

“双高”电力系统集中式储能选址定容规划策略

为解决“双高”电网储能选址规划问题,提出包括结构性、运行性两项一级指标及功率波动泰尔熵等6项二级指标的集中式储能选址规划指标体系,建立以熵权法、TOPSIS法为单一评价及模糊Borda法为组合评价的指标体系组合评价模型,获得储能最优选址节点。然后提出基于变分模态分解的混合储能容量配置法,对储能控制功率进行模态分解,根据Hilbert边际谱区分高、低频模态并重构,将高、低频信号能量功率值分别分配给功率型及能量型储能。通过某地区算例结果验证了所提规划策略的有效性。

中国在中亚境外经贸合作区建设的国别和产业选择

近年来,中国与中亚五国的贸易合作不断深入,在能源、农业等领域内展现出极强的经济互补性。而境外经贸合作区正是中国“一带一路”倡议的重要平台,也是促进中国与中亚五国进行贸易合作与共同发展的一个关键载体,为中国企业进一步“走出去”提供了更为便利的条件和有力的支撑。以中国与中亚五国的境外经贸合作区为主要研究对象,运用熵权法和“冷热国”对比法等相关实证方法,分析探讨其在建设过程中涉及的国别及产业选择问题,并针对问题提出相应的对策建议。

Evolution of chemistry and selection technology for DNA-encoded library

DNA-encoded chemical library(DEL)links the power of amplifiable genetics and the nonself-replicating chemical phenotypes,generating a diverse chemical world.In analogy with the biological world,the DEL world can evolve by using a chemical central dogma,wherein DNA replicates using the PCR reactions to amplify the genetic codes,DNA sequencing transcripts the genetic information,and DNA-compatible synthesis translates into chemical phenotypes.Importantly,DNA-compatible synthesis is the key to expanding the DEL chemical space.Besides,the evolution-driven selection system pushes the chemicals to evolve under the selective pressure,i.e.,desired selection strategies.In this perspective,we summarized recent advances in expanding DEL synthetic toolbox and panning strategies,which will shed light on the drug discovery harnessing in vitro evolution of chemicals via DEL.

国家集中带量采购中选药品的供应短缺问题研究

目的:分析我国集中带量采购中选药品的供应短缺现状,提出相关建议。方法:收集全国前5批集采药品的采购和供应数据,对药品供应短缺情况进行分析。结果:集采药品在中选后一年内出现供应短缺的占比达82%,东部和中部地区、临床用量大和价格低的集采药品供应短缺情况更为严重。结论:加强中选企业行为的履约监管,建立参与主体的信用评价制度,综合考虑地区、药理类型和价格因素,优化集采招标规则,提升集采中选药品生产供应保障能力。

西部地区相对集中行政许可权改革的路径选择--基于西部X市的实地调研

行政审批制度改革是加快政府职能转变、深化行政体制改革的重要抓手。相对集中行政许可改革作为现阶段行政审批制度改革的主要方式,在实践中存在两种改革模式:“三集中三到位”和“一枚印章管审批”。通过对西部地区X市开展实地调研,从公众满意度和政府职能转变双重视角出发对比两种模式,进而探讨“一枚印章管审批”同西部地区经济社会发展状况的适配性。分析可得“一枚印章管审批”改革模式更适宜在西部地区推广,但需要谋划建立科学机制以实现高效审批和审管联动。

SLM成形钛合金薄壁结构边缘挂渣及中心凹陷研究

目的探讨激光功率和扫描速度对选区激光熔化(Selective Laser Melting,SLM)成形钛合金Ti-6Al-4V薄壁结构边缘挂渣及尺寸精度的影响规律,分析薄壁中心凹陷的主要原因。方法设计两因素三水平试验,对比不同工艺参数下成形薄壁上表面微观形貌及壁厚,提出影响薄壁边缘挂渣和中心凹陷的机理,并得到较优的成形工艺参数。结果挂渣现象对薄壁尺寸精度的影响较大,薄壁的厚度越小,影响越大。当薄壁厚度达到2 mm时,边缘挂渣区域厚度明显减小。相较于扫描速度,激光功率对挂渣区域厚度的影响更大。采用低激光功率、较高扫描速度有助于减小挂渣区域厚度。激光能量密度越大,SLM成形薄壁尺寸误差越大,二者存在三次非线性关系。结论在低激光功率对应的低能量密度下,成形薄壁尺寸误差较小,当能量密度为44.44 J/mm^(3)时,薄壁获得了最小壁厚(529.37μm)。试验获得的成形薄壁结构误差最小的工艺参数为P=200 W,v=900 mm/s,h=50μm。SLM成形过程中的勾边扫描策略及残余应力导致的翘曲变形是造成薄壁中心凹陷的主要原因。

不同方式亚低温疗法联合肠内营养治疗中枢神经系统感染患儿的疗效及安全性分析

目的比较全身亚低温疗法和选择性头部亚低温疗法联合肠内营养治疗中枢神经系统感染患儿的疗效及安全性。方法回顾性分析37例中枢神经系统感染患儿的临床资料,按治疗方式不同分为观察组(19例)和对照组(18例)。两组均给予肠内营养治疗,在此基础上,观察组应用全身亚低温疗法治疗,对照组应用选择性头部亚低温疗法治疗。比较两组患儿退热时间、抽搐消失时间、重症医学科住院时间、不良反应发生情况及治疗前后实验室检查指标、差值。结果观察组退热时间、抽搐消失时间及重症医学科住院时间分别为(9.79±8.46)h、(4.79±4.97)d、(11.53±7.90)d,与对照组的(9.00±6.11)h、(6.61±5.10)d、(12.06±5.44)d比较,差异无统计学意义(P>0.05)。两组患儿治疗3 d后超敏C反应蛋白(hs-CRP)、血糖、血乳酸、脑脊液蛋白及脑脊液葡萄糖水平均低于入院时,差异均具有统计学意义(P<0.05);两组患儿治疗前后超敏C反应蛋白、血糖、血乳酸、脑脊液蛋白及脑脊液葡萄糖水平及其差值组间比较,差异均无统计学意义(P>0.05)。观察组腹泻、腹胀发生率分别为57.89%、63.16%,均高于对照组的22.22%、27.78%,差异具有统计学意义(P<0.05);两组呕吐发生率差异无统计学意义(P>0.05)。结论选择性头部亚低温疗法和全身亚低温疗法联合肠内营养治疗中枢神经系统感染患儿均有显著效果,其退热时间、抽搐消失时间、重症医学科住院时间也无差异,但选择性头部亚低温疗法可降低患儿腹泻、腹胀发生率,安全性优于全身亚低温疗法。

公共健康视角下城市社区绿道空间挖掘与规划选线研究——以苏州市中心城区为例

社区绿道作为基层公共健康单元的重要组成部分,发挥支持人群活动、服务日常生活、促进身心发展的效用。在后疫情背景下,研究聚焦社区绿道选线问题,以苏州市中心城区为案例区,从解读公共健康与社区绿道关系入手,明晰公共健康视角下社区绿道,在集聚人群活动、连接便捷服务、提供舒适环境的效能的基础上,运用热力图叠加分析、POI数据核密度计算、载体空间适建性评价等技术手段,展开社区绿道出行活力度、目的地潜力度、载体适建性的综合评价,以充分挖掘促进“生理—心理—社会”健康综合提升的社区绿道选线及方案,以推进健康中国建设,增进人民健康福祉。

引入度中心性选择攻击节点的对抗攻击算法

图卷积网络(GCN)在图神经网络中应用广泛,在处理图结构数据方面发挥着重要作用。然而,最近的研究表明,GCN容易受到中毒攻击等恶意攻击。在针对GCN的所有可能的对抗性攻击中,有一种特殊的方法是针对图卷积网络的目标通用攻击TUA(target universal attack)。该方法在挑选攻击节点时为了简便采用随机选择策略,该策略忽略了节点邻居对节点的重要性,对攻击成功率有负面影响。针对这个问题,提出了一种基于度中心性的攻击节点选择策略的对抗攻击算法(adversarial attack algorithm based on degree centrality attack node selection strategy,DCANSS)。优化挑选攻击节点的方式,引入度中心性,得到攻击节点。注入假节点并与攻击节点连接。挑选辅助节点并应用图卷积网络的消息传递机制,使节点信息扩散,计算扰动并将扰动特征赋予假节点,完成攻击,达到误分类目标。在三个流行的数据集上的实验表明,当仅使用3个攻击节点和2个假节点时,所提出的攻击对图中任意受害节点的平均攻击成功率达到90%。将DCANSS算法与TUA算法以及其他建立的基线算法进行实验对比,进一步验证了DCANSS算法的攻击能力。

儿童用药视角下国家药品集中采购政策实施效果探析

目的:分析国家药品集采中选儿童可用药品的特点及存在的问题,提出政策优化建议,保障儿童用药安全。方法:采用比较分析法,挖掘分析九个批次集采中选儿童可用药品在品种、剂型、规格、说明书等方面的特点及存在的问题。结果:集采中选儿童可用药品的品种、疾病覆盖、适宜剂型、适宜规格与临床需求存在差距,儿童临床用药供应不平衡;中选药品说明书儿童用药信息存在不合理、不充分情形,影响儿童用药安全。结论:持续优化药品集采策略和规则,逐步将符合条件的儿童用药纳入集采范围,满足儿童用药需求;鼓励和促进企业更新药品使用说明书有关儿童用药事项,确保中选儿童可用药品在临床上的安全、有效、可及。

广州市花都区3家基层医疗机构实施药品集采的情况分析

目的:分析广州市花都区3家基层医疗机构实施药品集采的情况。方法:收集并分析3家基层医疗机构执行第一批、第六批药品集采前后数据,包括中选药品、价格、采购数量。结果:3家基层医疗机构第一批药品集采共同使用的中选药品有8种,药品集采后价格均下降,降幅最高85.14%,最低40.09%,平均57.23%。第六批药品集采共同使用的中选药品有6种,降幅最高66.59%,最低33.43%,平均48.44%。3家基层医疗机构第一批药品集采共同使用的中选药品采购完成率均>100.00%,平均完成率203.90%。第六批药品集采共同使用的中选药品采购完成率≥100.00%,平均完成率322.72%。结论:广州市花都区较好地落实了药品集采政策,药品价格下降,中选药品采购完成率较高。

Online differential pressure reset method with adaptive adjustment algorithm for variable chilled water flow control in central air-conditioning systems

Central air-conditioning systems predominantly operate under partial load conditions.The optimization of a differential pressure setpoint in the chilled water system of a central air-conditioning system leads to a more energy-efficient operation.Determining the differential pressure adjustment value based on the terminal user's real-time demand is one of the critical issues to be addressed during the optimal control process.Furthermore,the online application of the differential pressure setpoint optimization method needs to be considered,along with the stability of the system.This paper proposes a variable differential pressure reset method with an adaptive adjustment algorithm based on the Mamdani fuzzy model.The proposed method was compared with differential pressure reset methods with reference to the chilled water differential temperature,outdoor temperature,and linear model based on the adjustment algorithm.The energy-saving potential,temperature control effect,and avoidance of the most unfavorable thermodynamic loop effects of the four methods were investigated experimentally.The results indicated that,while satisfying the terminal user's energy supply demand and ensuring the avoidance of the most unfavorable thermodynamic loop,the proposed adaptive adjustment algorithm also decreased the differential pressure setpoint value by 25.1%—59.1%and achieved energy savings of 10.6%-45.0%.By monitoring the valve position and supply air temperature of each terminal user,the proposed method exhibited suitable online adaptability and could be flexibly applied to buildings with random load changes.