A highly alkaline-stable metal oxide@metal–organic framework composite for high-performance electrochemical energy storage

Most metal–organic frameworks (MOFs) hardly maintain their physical and chemical properties after exposure to alkaline aqueous solutions, thus precluding their use as potential electrode materials for electrochemical energy storage devices. Here, we present the design and synthesis of a highly alkaline-stable metal oxide@MOF composite, Co₃O₄ nanocube@Co-MOF (Co₃O₄@Co-MOF), via a controllable and facile one-pot hydrothermal method under highly alkaline conditions. The obtained composite possesses exceptional alkaline stability, retaining its original structure in 3.0 M KOH for at least 15 days. Benefitting from the exceptional alkaline stability, unique structure, and larger surface area, the Co₃O₄@Co-MOF composite shows a specific capacitance as high as 1020 F g⁻¹ at 0.5 A  g⁻¹ and a high cycling stability with only 3.3% decay after 5000 cycles at 5 A g⁻¹. The as-constructed solid-state flexible device exhibits a maximum energy density of 21.6 mWh cm⁻³.     

经典物理中不同参考系对称性与守恒定律前提等价性的讨论

从牛顿力学、分析力学和量子力学三个不同参考体系推导出的对称性与守恒间的关系,其前提条件虽不同,但其本质都是一致的。     

联合图书馆发展的探讨

结合当前联合图书馆发展的趋势,先阐明了联合图书馆的指导思想、体制结构和联合图书馆的作用;然后介绍了目前国外联合图书馆和国内联合图书馆的发展状况;最后提出了联合图书馆建设的三点可行性措施:即必须要注重观念更新,加强联合馆的合作,抓好人才培养。     

土司体育文化在永顺县中小学推广现状的调查与分析——以土家族摆手舞为例

为促进土司体育文化更好的开展,扩展土家摆手舞的开展范围和提高摆手舞的质量,促进土司体育的发展,提高学生身体素质和文化修养。本文采用文献资料法、问卷调查法、座谈访问法、逻辑分析法,对永顺县中小学土家摆手舞开展的现状进行调查与分析。结果认为,永顺县中小学摆手舞存在学生学习兴趣不高、对摆手舞认知不足的现象,学校也因为资金受限,体育教学场地存在教学用面积不足及地面不平整状况,多数老师靠自学和其他老师所教学习的摆手舞,体育教师认为师资分配不合理现象存在,并且多数学生认为体育教师教学动作不够规范,直接影响了摆手舞在中小学的发展。     

新闻发现的思维模式辨析

本文通过对记者编辑在发现新闻过程中常用的思维模式的反思,展示这些思维模式在具体操作过程中的优势特征,并重点剖析了两种思维模式容易出现的实践偏差。它限制了记者编辑发现新闻时的创造性,也容易导致不合理的新闻实践。     

新时期中国体育外交政策探析

2018年朝鲜成功开展一次体育外交行动参加韩国平昌冬奥会,向韩国政府表达出善意的政策倾向,朝鲜半岛的紧张局势也因此得到缓解,体育外交的政治收益又一次得到验证。以新时期体育外交为研究对象,采用文献资料法、逻辑分析法研究新时期开展体育外交活动的政治诉求,如何推动中国的外交事务和体育行业的发展。研究认为：体育外交能够以相抵柔和的方式表达政治意见或者政治态度;中国优秀传统文化、中国传统体育项目需要传承和发扬光大,需要适合根据国际文化变化做出调整,更需要加强对外交流;国家领导人或者体育明星在体育外交中塑造国家形象的功能不容小觑;积极培养能够在国际体育组织任职的人员、积极参与国际体育事物能够缓解中国在体育界话语权薄弱的问题。     

Injectable hybrid inorganic nanoscaffold as rapid stem cell assembly template for cartilage repair

Cartilage injuries are often devastating and most cannot be cured because of the intrinsically low regenerative capacity of cartilage tissues. Although stem-cell therapy has shown enormous potential for cartilage repair, the therapeutic outcome has been restricted by low survival rates and poor chondrocyte differentiation in vivo. Here, we report an injectable hybrid inorganic (IHI) nanoscaffold that facilitates fast assembly, enhances survival and regulates chondrogenic differentiation of stem cells. IHI nanoscaffolds that strongly bind to extracellular matrix (ECM) proteins assemble stem cells through synergistic 3D cell–cell and cell–matrix interactions, creating a favorable physical microenvironment for stem-cell survival and differentiation in vitro and in vivo. Additionally, chondrogenic factors can be loaded into nanoscaffolds with a high capacity, which allows deep, homogenous drug delivery into assembled 3D stem-cell-derived tissues for effective control over the soluble microenvironment of stem cells. The developed IHI nanoscaffolds that assemble with stem cells are injectable. They also scavenge reactive oxygen species and timely biodegrade for proper integration into injured cartilage tissues. Implantation of stem-cell-assembled IHI nanoscaffolds into injured cartilage results in accelerated tissue regeneration and functional recovery. By establishing our IHI nanoscaffold-templated 3D stem-cell assembly method, we provide a promising approach to better overcoming the inhibitory microenvironment associated with cartilage injuries and to advance current stem-cell-based tissue engineering.     

闽台孙姓

孙姓起源源头很多,其中最主要的源头有三:一出自姬姓.周文王第八子卫康叔之后有惠孙,惠孙的孙子武仲,以惠孙的孙作为自己的姓,是为孙姓,武仲为孙姓始祖.二出自芈姓.楚国王室为芈姓.春秋时楚王室后裔孙叔敖因有大功,其子孙便以他的字--孙为姓,所以这支孙姓出自芈姓.三出自妫姓.西周初周武王封舜后裔妫满于陈(今河南准阳),谥陈胡公,陈胡公后裔陈完逃到齐国,改姓田,齐景公赐田完后裔田书孙姓,这支孙姓实出于妫姓.     

不确定收益下公路BOT项目特许期决策方法研究

特许期作为BOT项目特许经营协议中的一项重要条款,一直是学术界和实务界共同关注的焦点.通过对特许期影响因素和决策方法相关文献的回顾,归纳出建设期、建设成本、交通量、收费价格、运营和维护成本等关键风险因素,采用符合项目实践运作规律的概率分布函数进行拟合,构建了项目收入函数和成本函数,根据对建设期、建设成本和运营期内收益净现值进行Monte Carlo模拟的结果,求解出在给定投资回报水平下的特许期区间,并结合一个实际案例对特许期模拟求解流程进行验证,为不确定收益下公路BOT项目特许期决策提供了一种可借鉴方法.     

基于纠缠相干性的量子投票方案

提出了一个基于3粒子态纠缠相干性的量子投票方案,利用量子力学的物理特性来实现投票、计票和即时监督.此外,方案还采用了量子密钥分配和一次一密算法,克服了传统电子投票协议中普遍存在的计算安全性的局限,具有无条件安全性.