信息公开与志愿服务参与意愿:基于社会组织评估的实验研究

个体并非缺乏志愿服务动机,但信息不足阻碍了其参与意愿。研究借助社会组织评估场景,采用调查实验的方法,探究有关社会组织评估的政府信息公开是否、以及如何影响个体的志愿服务参与意愿。实验结果发现:与控制组相比,在实验组中提供更加全面的社会组织评估信息有助于提升公众的志愿服务参与意愿和预期频率,该过程通过影响公众感知的组织声誉水平来发挥中介效应;且对于过去参与频率较低的公众而言,信息公开的影响效应更大。研究认为,政府信息公开不仅有利于缓解公众志愿服务参与过程中面临的信息不对称问题、提升志愿服务组织的社会合法性,还具有动员“沉睡”的志愿者的巨大潜力。研究结论直面当前志愿服务实践发展的现实问题,也拓宽了信息公开议题在公共管理学术研究中的解释场景。

The cotton mitochondrial chimeric gene orf610a causes male sterility by disturbing the dynamic balance of ATP synthesis and ROS burst

Plant cytoplasmic male sterility(CMS)is maternally inherited and often manifested as aborted pollen development,but the molecular basis of abortion remains to be identified.To facilitate an investigation of CMS in cotton,the complete sequence of cotton mitochondrial(mt)genome for CMS-D2 line ZBA was determined.The mt genome was assembled as a single circular molecule with 634,036 bp in length.A total of 194 ORFs,36 protein-coding genes,six r RNAs,and 24 t RNAs were identified.Several chimeric genes encoding hypothetical proteins with transmembrane domains were identified.Among them,a previously unknown chimeric gene,orf610a,which is composed of atp1 and a 485-bp downstream sequence of unknown nature,was identified.RT-PCR and q RT-PCR validation indicated that orf610a was expressed specifically in a sterile line.Ectopic expression of orf610a in yeast resulted in excessive accumulation of reactive oxygen species and reduction in ATP content,in addition to inhibition of cellular growth.Transgenic A.thaliana overexpressing orf610a fused with a mitochondrial targeting peptide displayed partial male sterility.Interaction between ORF610a and the nuclear-encoded protein RD22 indicated an association between ORF610a and pollen abortion.Positive feedback during transcriptional regulation between nuclear regulatory factors and the mt CMS gene may account for the male sterility of ZBA.

Recent advances of sorafenib nanoformulations for cancer therapy:Smart nanosystem and combination therapy

Sorafenib,a molecular targeted multi-kinase inhibitor,has received considerable interests in recent years due to its significant profiles of efficacy in cancer therapy.However,poor pharmacokinetic properties such as limited water solubility,rapid elimination and metabolism lead to low bioavailability,restricting its further clinical application.Over the past decade,with substantial progress achieved in the development of nanotechnology,various types of smart sorafenib nanoformulations have been developed to improve the targetability as well as the bioavailability of sorafenib.In this review,we summarize various aspects from the preparation and characterization to the evaluation of antitumor efficacy of numerous stimuli-responsive sorafenib nanodelivery systems,particularly with emphasis on their mechanism of drug release and tumor microenvironment response.In addition,this review makes great effort to summarize the nanosystem-based combination therapy of sorafenib with other antitumor agents,which can provide detailed information for further synergistic cancer therapy.In the final section of this review,we also provide a detailed discussion of future challenges and prospects of designing and developing ideal sorafenib nanoformulations for clinical cancer therapy.

Calibration of Mars Energetic Particle Analyzer (MEPA)

The first Mars exploration mission of China(Tianwen-1)is scheduled to be launched in 2020;a charged particle telescope,the Mars Energetic Particle Analyzer(MEPA),is carried as one of the payloads on the orbiter.The MEPA is designed to measure solar energetic particles(SEPs)and galactic cosmic rays(GCRs)in the near-Mars space and in the transfer orbit from Earth to Mars.Before the launch,the MEPA was calibrated in ground experiments with radioactive sources,electronic pulses,and accelerator beams.The calibration parameters,such as energy conversion constants,threshold values for the triggers,and particle identification criteria,were determined and have been stored for onboard use.The validity of the calibration parameters has been verified with radioactive sources and beams.The calibration results indicate that the MEPA can measure charged particles reliably,as designed,and that it can satisfy the requirements of the Tianwen-1 mission.

Baidu index and predictability of Chinese stock returns

A number of studies have investigated the predictability of Chinese stock returns with economic variables.Given the newly emerged dataset from the Internet,this paper investigates whether the Baidu Index can be employed to predict Chinese stock returns.The empirical results show that 1)the Search Frequency of Baidu Index(SFBI)can predict next day’s price changes;2)the stock prices go up when individual investors pay less attention to the stocks and go down when individual investors pay more attention to the stocks;3)the trading strategy constructed by shorting on the most SFBI and longing on the least SFBI outperforms the corresponding market index returns without consideration of the transaction costs.These results complement the existing literature on the predictability of Chinese stock returns and have potential implications for asset pricing and risk management.

Small-current grounding fault location method based on transient main resonance frequency analysis

The small-current grounding fault in distribution network is hard to be located because of its weak fault features.To accurately locate the faults,the transient process is analyzed in this paper.Through the study we take that the main resonant frequency and its corresponding component is related to the fault distance.Based on this,a fault location method based on double-end wavelet energy ratio at the scale corresponding to the main resonant frequency is proposed.And back propagation neural network(BPNN)is selected to fit the non-linear relationship between the wavelet energy ratio and fault distance.The performance of this proposed method has been verified in different scenarios of a simulation model in PSCAD/EMTDC.

An empirical behavioral order‑driven model with price limit rules

We propose an empirical behavioral order-driven(EBOD)model with price limit rules,which consists of an order placement process and an order cancellation process.All the ingredients of the model are determined based on the empirical microscopic regularities in the order flows of stocks traded on the Shenzhen Stock Exchange.The model can reproduce the main stylized facts in real markets.Computational experiments unveil that asymmetric setting of price limits will cause the stock price to diverge exponentially when the up price limit is higher than the down price limit and to vanish vice versa.We also find that asymmetric price limits have little influence on the correlation structure of the return series and the volatility series,but cause remarkable changes in the average returns and the tail exponents of returns.Our EBOD model provides a suitable computational experiment platform for academics,market participants,and policy makers.

AsOBP1 is required for bioallethrin repellency in the malaria vector mosquito Anopheles sinensis

The use of insecticides,primarily pyrethroids,is a pivotal strategy for mosquito control globally.Bioallethrin,the first commercially available volatile pyrethroid,can elicit spatial(i.e.,noncontact)repellency to mosquitoes through the coactivation of ol-factory receptor neurons and sodium channels.However,the olfactory mechanism of the repellency elicited by bioallethrin in mosquitoes is still unclear.Here,we demonstrated the involvement of AsOBP1 in the bioallethrin repellency in Anopheles sinensis,one of the main vectors of vivax malaria in China and other Southeast Asian countries.The behavioral and electrophysiological analyses in AsOrco-/-mutant found that the spa-tial repellency elicited by bioallethrin depended on the odorant receptor(OR)-mediated olfactory pathway.Furthermore,the repellency was reduced in the AsOBPI-/-mutant and a pyrethroid-resistant strain,in which the expression of AsOBPI was significantly decreased.Moreover,recombinant AsOBP1 protein bound to bioallethrin in an in vitro competition assay.These results indicate that activation of the AsOBP1-mediated olfac-tory pathway is an important component of bioallethrin repellency.Our research lays the foundation for further elucidation into the olfactory mechanism of bioallethrin repellency and the behavioral modifications of pyrethroid-resistant mosquitoes.

High Impedance Fault Detection Based on Attention Mechanism and Object Identification

Detection of high impedance faults(HIFs)has been traditionally a main challenge in the protection of distribution systems,since they do not generate enough current to be reliably detected by conventional over-current relays.Data-based methods are alternative HIF detection methods which avoid threshold settings by training a classification or regression model.However,most of them lack interpretability and are not compatible with various distribution networks.This paper proposes an object detection-based HIF detection method,which has higher visualization and can be easily applied to different scenarios.First,based on the analysis of HIFs,a Butterworth band-pass filter is designed for HIF harmonic feature extraction.Subsequently,based on the synchronized data provided by distribution-level phasor measurement units,global HIF feature gray-scale images are formed through combining the topology information of the distribution network.To further enhance the feature information,a locally excitatory globally inhibitory oscillator region attention mechanism(LEGIO-RAM)is proposed to highlight the critical feature regions and inhibit useless and fake information.Finally,an object detection network based You Only Look Once(YOLO)v2 is established to achieve fast HIF detection and section location.The obtained results from the simulation of the proposed approach on three different distribution networks and one realistic distribution network verify that the proposed method is highly effective in terms of reliability and generalization.

POLAR伽马暴瞬时辐射偏振测量与脉冲星导航试验研究进展

伽马射线暴(简称伽马暴,gamma-ray burst,GRB)从发现至今已超过半个世纪,其观测样本得到了极大提高,理论研究也取得了瞩目的成果.但对伽马暴的研究还有诸多未解之谜,例如伽马暴的分类和起源、爆发过程中的喷流成分、辐射机制和磁场构型等.其中,对于伽马暴的辐射机制,科学家提出了多种理论模型,不同的模型对于伽马暴爆发期间产生的伽马射线偏振状态的预测不同.因此,采用测量偏振的方法,可以对伽马暴的爆发机制进行研究,并且理解产生伽马射线的极端相对论喷流的结构及其磁场的构型等物理问题.然而,测量伽马暴瞬时辐射过程中的偏振具有极高的挑战性.伽马暴偏振探测仪(POLAR)是一台专门用于高精度测量伽马暴瞬时辐射偏振的空间望远镜,2016年9月15日搭载于我国的空间实验室“天宫二号”成功发射.POLAR在轨共探测到55个确认的伽马暴,首批给出了5个伽马暴的高精度偏振测量结果,最终统计性地给出了14个伽马暴的偏振测量结果.同时,POLAR还观测到了Crab脉冲星信号和太阳X射线耀发事件等.本文简要介绍POLAR,并给出其在轨伽马暴偏振测量结果以及利用观测到的脉冲星信号所开展的导航试验研究进展情况.此外,简要介绍POLAR的后续实验项目POLAR-2,对其未来的科学探测能力进行展望.

The E3 ubiquitin ligase CSIT1 regulates critical sterility-inducing temperature by ribosome-associated quality control to safeguard two-line hybrid breeding in rice

Two-line hybrid breeding can fully utilize heterosis in crops.In thermo-sensitive genic male sterile(TGMS)lines,low critical sterility-inducing temperature(CSIT)is vital to safeguard the production of two-line hybrid seeds in rice(Oryza sativa),but the molecular mechanism determining CSIT is unclear.Here,we report the cloning of CSIT1,which encodes an E3 ubiquitin ligase,and show that CSIT1 modulates the CSIT of thermo-sensitive genic male sterility 5(tms5)-based TGMS lines through ribosome-associated quality control(RQC).Biochemical assays demonstrated that CSIT1 binds to the 80S ribosomes and ubiquitinates abnormal nascent polypeptides for degradation in the RQC process.Loss of CSIT1 function inhibits the possible damage of tms5 to the ubiquitination system and protein translation,resulting in enhanced accumulation of anther-related proteins such as catalase to suppress abnormal accumulation of reactive oxygen species and premature programmed cell death in the tapetum,thereby leading to a much higher CSIT in the tms5-based TGMS lines.Taken together,our findings reveal a regulatory mechanism of CSIT,providing new insights into RQC and potential targets for future two-line hybrid breeding.

Interactive information disclosure and non-penalty regulatory review risk

Using monthly data from the Shenzhen Stock Exchange's‘Hudongyi’platform and comment letters from December 2014 to December 2018,this study investigates the influence of interactive information disclosure on non-penalty regulatory review risk.The findings reveal that the richness and activeness of interactive information disclosure are positively associated with regulatory review risk.Moreover,the non-penalty regulatory review is effective as it significantly reduces the probability of receiving a comment letter in the subsequent three periods.The timeliness of interactive information disclosure is negatively associated with regulatory review risks.Additionally,we find that newspaper media coverage partially mediates the relationship between interactive information disclosure and regulatory review risk.For companies with low levels of internal governance,in low-competitive industries,and state-owned companies,the positive relationship between the number of investor questions and regulatory review risk is strengthened.These findings enrich the literature on the determinants of regulatory review risk and the economic consequences of interactive information disclosure in emerging markets.

Symmetry-driven half-integer conductance quantization in Cobalt–fulvalene sandwich nanowire

Precise manipulation and monitoring spin transport in one-dimensional (1D) systems is a long-sought goal in the field of nano-spintronics. Based on first-principles calculations, we report the observation of half-integer conductance quantization in the Cobalt-fulvalene sandwich nanowire. Compared with a pure monatomic Cobalt wire, the introduction of fulvalene molecules leads to threeimportant features: Firstly, the strong coupling between the fulvalene and the Cobalt prevents the contamination of the ambientair, ensuring both chemical and physical stabilities;Secondly, the fulvalene symmetry-selectively filters out most of the d-typeorbitals of the Cobalt while leaving a single d-type orbital to form an open spin channel around the Fermi level, which offers amechanism to achieve the observed half-integer conductance;Thirdly, it maintains a superexchange coupling between adjacent Coatoms to achieve a high Curie temperature. Spin transport calculations show that this half-metallic nanowire can serve as a perfectspin filter or a spin valve device, thus revealing the potential of Cobalt-fulvalene sandwich nanowire as a promising building blockof high-performance spintronics technology.

基于DNA高通量测序分析生料酿醋过程中的真菌多样性

【目的】了解生料酿醋不同阶段的真菌群落结构及其变化规律,为生料酿醋工艺优化提供理论指导。【方法】从山西一家生料酿醋企业采集原料、麸曲、发酵缸醋醅、熏醋样、淋醋样等涉及生料酿醋各阶段的样品共51份,扩增真菌ITS1区序列并利用高通量测序技术分析真菌多样性。【结果】除5份样品未扩增成功外,在剩余46份样品中共检测到489个真菌OTU,以子囊菌为主(占88.3%)。原料、麸曲、发酵缸醋醅、熏醋样、淋醋样等不同组别间在真菌群落结构方面存在显著差异。原料和麸曲中的真菌物种丰富度最低,发酵缸醋醅的真菌物种丰富度最高,熏醋样和淋醋样中的真菌物种丰富度又有所降低。原料和麸曲中的优势真菌分别为酿酒酵母和黑曲霉,是发酵阶段真菌的重要来源,但发酵缸醋醅中也检测到大量可能来源于发酵室环境的真菌。发酵缸醋醅在不同发酵时期间也存在明显的真菌群落结构差异,并可据此划分成发酵前期(包括发酵第2–13天的样品)和发酵后期(包括发酵第17–46天的样品)。酿酒酵母和亮白曲霉的丰度在发酵前期显著高于发酵后期,而黑曲霉、一种小戴卫霉科真菌等的丰度在发酵后期显著高于发酵前期。【结论】生料酿醋的不同阶段和发酵缸醋醅发酵的不同时期,其真菌群落结构都存在明显差异。酿酒酵母和黑曲霉是发酵阶段的优势真菌。本研究为生料酿醋工艺优化提供了理论依据。

球孢白僵菌种内比较线粒体基因组学分析

【目的】明确球孢白僵菌种内线粒体基因组的分化程度。【方法】从GenBank下载已知的球孢白僵菌6个菌株线粒体基因组序列,详细分析基因组的组成结构,比较外显子区、内含子区和基因间区的碱基变异情况,分析菌株间的系统发育关系。【结果】球孢白僵菌不同菌株的线粒体基因组大小为28.8–32.3 kb,都有14个常见的核心蛋白编码基因、2个rRNA基因和25个tRNA基因,具有很强的共线性关系。但是,不同菌株含有的线粒体内含子数目存在差异(2–5个/菌株),在cox1、cox2和nad1基因中表现出内含子插入/缺失多态性,这是导致线粒体基因组大小变化的主要因素。对外显子、内含子和基因间区的碱基变异情况进行分析,发现内含子和基因间区相对变异较大,而外显子区相对变异较小。系统发育分析发现,这些球孢白僵菌菌株以很高的支持度聚在一起,具有相同内含子分布规律的菌株也具有较近的聚类关系。【结论】本研究首次报道球孢白僵菌因内含子数目不同、插入缺失突变和单核苷酸变异等在线粒体基因组上表现出较大程度的遗传分化,为认识真菌种内线粒体基因组分化提供了新的证据。

竖冷设备结构的离散元法模拟优化

针对国内某钢厂竖冷设备,建立了基于离散元方法的模型,研究了竖冷设备中烧结矿石的装料过程。结果表明,由于原装料结构烧结矿石下落高度大,不同粒径烧结矿石下落速度相差明显,因此,在载料车倾料过程中出现小颗粒在下、大颗粒在上的偏析形态,同时缓冲仓内缺少限制颗粒运动的结构,导致排料过程中烧结矿石的偏析不断加剧。针对原设备的问题,首先将单一缓冲仓改为上下两层缓冲仓,上层缓冲仓用于降低颗粒下落高度,减小不同粒径颗粒的速度差;其次在缓冲仓底部引入斜栅栏结构,从而阻碍大颗粒运动,减小其运动距离,且限制了角落处的大颗粒再次进入缓冲仓出料口,避免加剧缓冲仓内的颗粒偏析。模拟结果表明新结构能有效改善竖冷设备内颗粒偏析。

含硅功能化聚烯烃:合成及应用

聚烯烃功能化改性是获得高性价比新材料的有效途径。含硅功能化聚烯烃(SFPO)是聚烯烃分子结构中含有机硅功能基团或有机硅聚合物链段的一类功能化聚烯烃的统称。由于有机硅功能基团及有机硅聚合物特殊的理化性质,SFPO通常具有丰富反应性或优异性能,成为一类有代表性的功能化聚烯烃。SFPO可以作为反应性中间体,用于制备具有复杂拓扑结构的功能化聚烯烃(如星型聚合物、梳型聚合物、接枝共聚物)或聚烯烃共价键接枝改性纳米材料;SFPO还可作为功能性添加剂(如增容剂、加工助剂,表面改性剂),用于开发聚烯烃新材料。近年来,研究人员在含硅功能化聚烯烃研究领域取得了系列进展,本文旨在对相关工作进行系统总结,以期引起同行注意并促进相关研究深入发展。

Advancing application of mesenchymal stem cell-based bone tissue regeneration

Reconstruction of bone defects,especially the critical-sized defects,with mechanical integrity to the skeleton is important for a patient's rehabilitation,however,it still remains challenge.Utilizing biomaterials of human origin bone tissue for therapeutic purposes has provided a facilitated approach that closely mimics the critical aspects of natural bone tissue with regard to its properties.However,not only efficacious and safe but also costeffective and convenient are important for regenerative biomaterials to achieve clinical translation and commercial success.Advances in our understanding of regenerative biomaterials and their roles in new bone formation potentially opened a new frontier in the fast-growing field of regenerative medicine.Taking inspiration from the role and multicomponent construction of native extracellular matrix(ECM)for cell accommodation,the ECM-mimicking biomaterials and the naturally decellularized ECM scaffolds were used to create new tissues for bone restoration.On the other hand,with the going deep in understanding of mesenchymal stem cells(MSCs),they have shown great promise to jumpstart and facilitate bone healing even in diseased microenvironments with pharmacology-based endogenous MSCs rescue/mobilization,systemic/local infusion of MSCs for cytotherapy,biomaterials-based approaches,cell-sheets/-aggregates technology and usage of subcellular vesicles of MSCs to achieve scaffolds-free or cell-free delivery system,all of them have been shown can improve MSCsmediated regeneration in preclinical studies and several clinical trials.Here,following an overview discussed autogenous/allogenic and ECM-based bone biomaterials for reconstructive surgery and applications of MSCsmediated bone healing and tissue engineering to further offer principles and effective strategies to optimize MSCs-based bone regeneration.

Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band(1-250 ke V) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 Me V. It was designed to perform pointing, scanning and gamma-ray burst(GRB)observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed.Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.

The High Energy X-ray telescope (HE) onboard the Insight-HXMT astronomy satellite

The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector plane of HE comprises 18 Na I(Tl)/Cs I(Na) phoswich detectors, where Na I(Tl) is used as the primary detector to measure ~ 20-250 ke V photons incident from the field of view(FOV) defined by collimators, and Cs I(Na) is used as the active shielding detector to Na I(Tl) by pulse shape discrimination. Additionally, Cs I(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV,i.e. 1.1°×5.7°(15 units), 5.7°×5.7°(2 units), and blocked(1 unit). Therefore, the combined FOV of HE is approximately5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 ke V. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the deadtime is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20-250 ke V band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 Me V band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments.