High-pressure study on calcium azide(Ca(N_(3))_(2)):Bending of azide ions stabilizes the structure

The high-pressure structure and elastic properties of calcium azide(Ca(N_(3))_(2))were investigated using in-situ highpressure x-ray diffraction and Raman scattering up to 54 GPa and 19 GPa,respectively.The compressibility of Ca(N_(3))_(2)changed as the pressure increased,and no phase transition occurred within the pressure from ambient pressure up to 54 GPa.The measured zero-pressure bulk modulus of Ca(N_(3))_(2)is higher than that of other alkali metal azides,due to differences in the ionic character of their metal-azide bonds.Using CASTEP,all vibration modes of Ca(N_(3))_(2)were accurately identified in the vibrational spectrum at ambient pressure.In the high-pressure vibration study,several external modes(ext.)and internal bending modes(ν_(2))of azide anions(N_(3)^(-))softened up to~7 GPa and then hardened beyond that pressure.This evidence is consistent with the variation observed in the F_(E)–f_(E)data analyzed from the XRD result,where the slope of the curve changes at 7.1 GPa.The main behaviors under pressure are the alternating compression,rotation,and bending of N_(3)^(-)ions.The bending behavior makes the structure of Ca(N_(3))_(2)more stable under pressure.

健康治理:健康社会与健康中国建设的新范式

健康不仅是一种身体状态,也是一种重要的治理能力。自1844年英国城镇健康协会成立以来,健康的概念不断发展,不仅从生理健康扩展到了精神健康和全面健康,也从传统的人口(或个体)健康逐渐扩展到了区域健康和生态社会系统健康。因此,无论国际还是国内的健康管理和研究都经历了从人口健康、区域健康到生态社会系统健康的发展历程和范式变迁。论文在总结国内外健康管理发展历程、范式变迁以及我国健康管理基本经验的基础上,提出了建设健康社会和健康中国的健康管理新范式——健康治理,强调从生理到社会的全健康内涵、从政治到生态的全健康领域、从个体到国家乃至全球的全健康层次、从政府到公众的全健康主体、从事物和人生全过程到全世代可持续发展的全健康过程的综合性"五全"健康管理;并分析了当前我国健康治理所面临的问题,提出了相应的政策建议。

Clinical Value of Echocardiographic Screening and Dynamic Observations for Ductus Arteriosus Closure in Newborns

Objective:To explore and analyze the clinical value of echocardiography screening and dynamic observation for ductus arteriosus closure in newborns.Methods:The study was conducted from August 2022 to December 2023.500 newborns who were admitted to our hospital were selected as research subjects for this study(Kunming Tongren Hospital).All subjects underwent echocardiography to determine the severity of patent ductus arteriosus(PDA).The inner diameter of the pulmonary artery was measured,and the pulmonary artery pressure was estimated through tricuspid regurgitation.If the patient had high pulmonary artery pressure,elective closure surgery was performed.Results:Among the 500 subjects,448 cases of ductus arteriosus closure and 52 cases of PDA were detected by echocardiography,including 23 cases of simple PDA,15 cases with patent foramen ovale,11 cases with atrial septal defect,1 case with muscular ventricular septal defect,1 case with tricuspid valve prolapse,and 1 case with tricuspid valve chordae tendineae rupture.After symptomatic treatment and intervention,their echocardiogram results were reviewed and no abnormalities were found.All measurement results of children with PDA combined with pulmonary hypertension were better than before treatment(P<0.05).Conclusion:Echocardiography is a fast,accurate,and reliable non-invasive imaging examination technology.It can significantly improve congenital heart disease detection rate in infants and young children.Early intervention based on the examination results can dramatically improve the quality of life of infants and young children with PDA.

熔体流淌条件对橡胶生胶燃烧行为的影响

为探究熔体流淌条件对橡胶生胶燃烧行为的影响,文中选取天然橡胶(NR)、顺丁橡胶(BR)和丁苯橡胶(SBR)为研究对象,在自制熔体流淌火灾试验装置上进行燃烧实验,得到质量损失速率(MLR)、气相温度、池火面积等数据。研究结果表明,流淌燃烧条件下3种橡胶的MLR峰值、气相温度和燃烧速度均高于不流淌燃烧条件的,且燃烧时间缩短为不流淌燃烧时的一半,这与熔体流淌扩大了池火的面积有关。流淌条件下橡胶的MLR与池火面积呈线性关系,达到相同MLR时的池火面积大小顺序为NR>SBR>BR。气相温度峰值大小顺序为BR>NR>SBR,这与橡胶样品的平均有效燃烧热(AEHC)、MLR峰值和池火面积有关。

非洲猪瘟的防控关键技术

非洲猪瘟传入我国以来,给我国养猪业造成了巨大的损失。非洲猪瘟可防可控,文章从消灭传染源、切断传播途径、保护易感猪群方面介绍了构建猪场生物安全体系的防控技术。

环保型增塑聚氯乙烯的热响应形状记忆性能与机理

采用环保型增塑剂乙酰基柠檬酸三丁酯(ATBC)制备了具有较宽玻璃化转变温域的增塑聚氯乙烯(PVC),研究了开关温度(T_(s))的选择对材料形状记忆性能的影响。增塑PVC的形状固定率始终接近100%,与T_(s)大小无关,但当T_(s)从70℃升高到100℃,形状回复率由91.5%降至85.5%,回复速率和回复应力也同时劣化。在低的T_(s)下进行同条件拉伸时,增塑PVC高的储能模量赋予其更强的弹性能贮存能力,可提供更大的回复应力,进而加速回复过程。机理研究表明,增塑PVC的形状记忆效应源于微晶和无定形分子链的协同作用,PVC微晶作为物理交联点,充当固定相,其结构和含量在形状记忆前后不变,无定形分子链基于T_(s)的选定划分为软链和硬链部分,分别充当可逆相和第二固定相。提高T_(s)会增大软链比例,加剧分子链滑移,而硬链的减少弱化了固定相对分子链滑移的抑制作用,最终导致形状回复率的降低。

如何防止转型期公共政策公共性的流失?——基于四种类型划分的案例比较研究

随着中国社会转型的推进和利益的日趋多元化,如何防止公共政策公共性的流失成为重要的现实问题和学术问题。为全面探究转型期公共政策公共性的流失发生原因,论文使用类型学研究方法对公共政策公共性的流失现象进行了类型划分,从“流失阶段”和“动力来源”两个维度,将其划分为“源头自利型”“源头捕获型”“下游自利型”“下游捕获型”四个类型,并根据每个类型的特点,选取了对应的典型性案例。通过比较上述类型及案例,发现防止公共政策公共性的流失要做到:通过有效制衡制约公权力自利性;保障民众和社会组织有效参与政策议程;对行政自由裁量权进行必要束缚;完善腐败治理体系以防止公权力被捕获。

Future 5G-Oriented System for Urban Rail Transit:Opportunities and Challenges

As a development direction of urban rail transit system,the train autonomous circumambulate system(TACS)can operate in a safer,more efficient,and more economical mode.However,most urban rail transit systems transmit signals through industrial,scientific,and medical(ISM)frequency bands or narrow frequency bands,which cannot meet the requirements of TACS.As a promising solution,the 5th generation(5G)mobile communication provides more services for the future urban rail transit systems,and covers the shortages of exiting communication technologies in terms of capacity and reliability.In this paper,we first briefly review the research status of current train control system and introduce its limitations.Next,we propose a novel network architecture,and present new technologies and requirements of the proposed architecture for TACS.Some potential challenges are then discussed to give insights for further research of TACS.

Selective oxidation of glycerol in a base-free aqueous solution: A short review

Catalytic transformation of glycerol to value-added products has attracted the attention of scientists all over the world. Among various transformations, selective oxidation of glycerol with molecular oxygen to dihydroxyacetone, glyceric acid, glyceraldehydes, and tartronic acid is challenging both from the viewpoint of academic research and industrial application. Herein, we review the recent progresses in the selective oxidation of glycerol under base-free conditions. Those catalysts widely reported for the selective oxidation of the terminal hydroxyl and secondary hydroxyl groups in glycerol, such as monometallic Au, Pt, and Pd NPs, and bimetallic Au-Pt, Au-Pd, Pt-Bi, Pt-Sb, and Pt-Cu, were compared and discussed in detail. The reaction mechanism over Pt-based catalysts, possible catalyst deactivation, and the corresponding improvements are presented. Further, the recent progresses in the continuous oxidation of glycerol in fixed bed reactors and its excellent selectivity in the formation of dihydroxyacetone are highlighted.

Environmentally‐friendly carbon nanomaterials for photocatalytic hydrogen production

Currently,the energy crisis is the crucial problem faced by the world,and photocatalytic hydrogen(H_(2))production is recognized with a chance to be a standout amongst those guaranteeing results to this issue.For a long time,photocatalytic H_(2) production has mainly relied on the noble metal cata‐lysts.However,the limitations of noble metals themselves,such as scarcity and high cost,have se‐verely restricted their large‐scale application.Therefore,it is urgent to seek a cheaper,more effi‐cient,and stable catalyst for photocatalytic H_(2) production.Fortunately,the emergence of carbon nanostructured materials(CNMs)has brought dawn.Its excellent structure and semiconductor performance can effectively participate in photocatalytic H_(2) production.CNMs have developed rap‐idly since they appeared in the field of photocatalytic water splitting.Therefore,it is necessary to summarize the latest progress of CNMs promptly for further development.This review introduced the CNMs,including carbon dots,fullerenes,carbon nanotubes,graphene,and graphdiyne,which is a powerful assistant in photocatalytic H_(2) production.CNMs can provide abundant adsorption and active sites,charge separation and transport channels,photocatalysts,co‐catalysts and photosensi‐tizers.Then,this review has introduced the strategy for enhancing CNMs in photocatalytic H_(2) pro‐duction based on recent research.Finally,the challenge faced by CNMs in photocatalytic H_(2) produc‐tion has prospected.

Selective oxidation of glycerol with oxygen in base-free solution over N-doped-carbon-supported Sb@PtSb2 hybrid

Selective oxidation of glycerol with molecular oxygen in base-free aqueous solutions has become a hot topic,as the rapidly increasing production of biodiesel is creating a surplus of glycerol.In this work,an N-doped-carbon-supported core-shell structured Sb@PtSb2 hybrid catalyst was prepared via a facile synthesis route,in which a mixture of glucose,melamine,and SbCl3(Sb-NC)was pyrolyzed,then impregnated with Pt by immersion in an aqueous solution of H2PtCl6,and further treated in hydrogen flow.Characterization of the catalyst products indicated that introducing SbCl3 can increase the surface area of the binary glucose+melamine pyrolyzed support(NC),and Sb@PtSb2 hybrids could be formed on the surface of an Sb-NC support during hydrogen treatment at 700℃.It was found that the Sb@PtSb2/NC catalyst was more active for the selective oxidation of glycerol in a base-free aqueous solution than Sb-free NC-supported Pt(Pt/NC).Further characterization also indicated that the promising performance of Sb@PtSb2/NC might be attributed to its enhanced oxygen activation.

Mobile Edge Computing Servers Deployment with Improved Genetic Algorithm in Cellular Internet of Things

Mobile edge computing(MEC)provides services to devices and reduces latency in cellular internet of things(IoT)networks.However,the challenging problem is how to deploy MEC servers economically and efficiently.This paper investigates the deployment problem of MEC servers of the real-world road network by employing an improved genetic algorithm(GA)scheme.We first use the threshold-based K-means algorithm to form vehicle clusters according to their locations.We then select base stations(BSs)based on clustering center coordinates as the deployment locations set for potential MEC servers.We further select BSs using a combined simulated annealing(SA)algorithm and GA to minimize the deployment cost.The simulation results show that the improved GA deploys MEC servers effectively.In addition,the proposed algorithm outperforms GA and SA algorithms in terms of convergence speed and solution quality.

Tissue Culture Rapid Propagation and Transplantation Techniques of Anoectochilus roxburghii (Wall) Lind.

[Objectives]To screen the tissue culture rapid propagation formula suitable for each tissue culture stage of Anoectochilus roxburghii( Wall) Lind. [Methods] The stem segments of Fujian A. roxburghii were used as explant to study the tissue culture rapid propagation and transplantation techniques. The comparative experiment was carried out to study the effects of different hormone concentrations on the induction of stem segments,proliferation of cluster buds,rooting and seedling hardening of A. roxburghii,and study the effects of transplantation matrix on the transplantation of A. roxburghii. [Results]MS + 0. 5 mg/L NAA + 2 mg/L BA + 20 g/L sucrose + 6 g/L agar was suitable for induction of stem segments of A. roxburghii; MS + 0. 5 mg/L NAA + 2 mg/L BA + 1 mg/L KT + 25 g/L sucrose + 6 g/L agar was most suitable for proliferation of cluster buds of A. roxburghii; MS + 1. 0 mg/L IBA + 1. 0 mg/L NAA + 1 g/L activated carbon + 50 g/L mashed banana + 25 g/L sucrose + 6 g/L agar was most suitable for rooting and seedling hardening of A. roxburghii; using peat soil: fine sand( 3∶ 1) as transplantation matrix,the survival rate was the highest. [Conclusions] The experiment results are expected to provide references for factory production of A. roxburghii.

Decoupled estimation of frequency-dependent IQI and channel for OFDM systems with direct-conversion transceivers

The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the transmission of the communication signal, the impact of IQI is coupled with channel impulse responses (CIR), which makes the traditional channel estimation schemes ineffective. A decoupled estimation scheme is proposed to separately estimate the frequency-dependent IQI and wireless channel. Firstly, the generalized channel model is built to separate the parameters of IQI and wireless channel. Then an iterative estimation scheme of frequency-dependent IQI is designed at the initial stage of communication. Finally, based on the estimation result of IQI, the least square algorithm is utilized to estimate the channel-related parameters at each time of channel variation. Compared with the joint estimation schemes of IQI and channel, the proposed decoupled estimation scheme requires much lower training overhead at each time of channel variation. Simulation results demonstrate the good estimation performance of the proposed scheme.

Imitated Ecological Cultivation Technology of Dendrobium offcinale: A Case Study of Longshitou Village,Longmen County

In order to optimize the planting structure of Longshitou Village in Longmen County and promote the efficient cultivation of Dendrobium offcinale industry,the imitate ecological cultivation technology of D.offcinale is studied from the aspects of site selection,seedling domestication,seedling colonization,and disease and pest control after colonization according to the natural environmental conditions of Longshitou Village.

Contact lens as an emerging platform for ophthalmic drug delivery:A systematic review

The number of people with eye diseases has increased with the use of electronics.However,the bioavailability of eye drops remains low owing to the presence of the ocular barrier and other reasons.Although many drug delivery systems have been developed to overcome these problems,they have certain limitations.In recent years,the development of contact lenses that can deliver drugs for long periods with high bioavailability and without affecting vision has increased the interest in using contact lenses for drug delivery.Hence,a review of the current state of research on drug delivery contact lenses has become crucial.This article reviews the key physical and chemical properties of drug-laden contact lenses,development and classification of contact lenses,and features of the commonly used materials.A review of the methods commonly used in current research to create contact lenses has also been presented.An overview on how drug-laden contact lenses can overcome the problems of high burst and short release duration has been discussed.Overall,the review focuses on drug delivery methods using smart contact lenses,and predicts the future direction of research on contact lenses.

Adsorption-desorption Characteristics and Thermodynamics of Quinclorac on Minerals

Adsorption-desorption characteristics of quinclorac on montmorillonite, attapulgite and goethite were investigated by the batch equilibrium techniques. The sorption mechanisms of minerals were discussed based on sorption thermodynamics. The results showed that the adsorption of quinclorac on the 3 minerals was included in both rapid stage and slow equilibrium stage. The adsorption kinetics consisted with the pseudo-second-order equation, the particle diffusion equation, and elovich equations, and among them, fitting from the pseudo-second-order was the best. In addition, it could be seen from the nonzero constant C in the particle diffusion equation that the rate of particle diffusion was not a sole factor. The isotherm adsorption-desorption of quinclorac on the 3 clay minerals all fitted Linear and Freundlich equation very well. The adsorption capacities of minerals for quinclorac followed the order of goethite〉montmorillonite〉attapulgite, The desorption of quinclorac presented obvious hysteresis phenomenon on minerals. The study on thermodynamic behavior indicated that the sorption processes of quinclorec onto minerals were spontaneous, and the sorption spontaneity was strengthened with the temperature increasing.

Development Situation and Countermeasures of Leisure Agriculture and Rural Tourism in Huizhou

In this paper,the development status,advantages (such as superior natural conditions,rich subtropical agricultural resources,and excellent location conditions) and existing problems (such as insufficient safeguard,homogeneous competition and lack of features) of leisure agriculture and rural tourism in Huizhou City were analyzed,and then some suggestions and countermeasures for the development of leisure agriculture and rural tourism in Huizhou were put forward.

Evaluation of the Impact of Government Policy on the Overuse of Groundwater in the Minqin Basin in China

The existing literature simply concludes that the irrational behaviors of local people and natural factors are the major reasons for overuse of groundwater. Using the OLS and ARIMA (BJ) Statistical Methods and Trend Analyses, this article finds that government policy, as measured by four proxy variables, is a very important factor that strongly influences the overuse of groundwater at the collective level. This means the government is a very important actor in the game of groundwater usage. Although these findings cannot clearly separate government effects from local effects, using a Trend Analysis, they reveal that these significant effects are strictly consistent with variations in government policy. Moreover, they show that government policy effective at the county level strongly impacts the overuse of ground-water by influencing the behavior of the local people and that policy at the operative level impacts four policy domains: population, cultivated land, water assignments and peasant income.

Quantum correlations in a chain-type quantum network

A quantum network concerns several independent entangled resources and can create strong quantum correlations by performing joint measurements on some observers.In this paper,we discuss an n-partite chain network with each of two neighboring observers sharing an arbitrary Bell state and all intermediate observers performing some positive-operator-valued measurements with parameterλ.The expressions of all post-measurement states between any two observers are obtained,and their quantifications of Bell nonlocality,Einstein-Podolsky-Rosen steering and entanglement with different ranges ofλare respectively detected and analyzed.