金属有机框架衍生镍纳米颗粒在宽电位窗口内高效电催化二氧化碳还原

电催化二氧化碳(CO_(2))还原被认为是将CO_(2)转化为可再生能源产品的一种有前途的方法。开发性能优异的电催化剂高效完成这一重要反应是关键。镍基催化剂广泛应用于电催化CO_(2)还原研究,但是,镍纳米颗粒经常表现较差的催化性能。在本文中,通过在氮气气氛中高温热解镍基金属有机骨架(MOF)、尿素和炭黑混合物,获得了镍纳米颗粒负载于多孔碳氮中的催化材料(NiNPs-NC)。有趣的是,NiNPs-NC在H型和流动相电池中都表现出优异的CO_(2)电还原性能。在H型电解池和-0.67–-1.07 V vs.RHE(可逆氢电极)电位窗口内,NiNPs-NC催化CO_(2)还原为CO的法拉第效率大于90%,其中,在-0.87 V vs.RHE时,CO的法拉第效率约为100%。在流动相电解池和-0.50–-0.70 V vs.RHE电位窗口内,NiNPs-NC催化CO_(2)还原为CO的选择性大于95%。电化学阻抗谱图和塔菲尔斜率表征显示,NiNPs-NC的高催化活性归因于其在催化过程中的快速电荷转移。本文提供了一种制备高效CO_(2)电还原催化剂的方法。

Multiple SiGe/Si layers epitaxy and SiGe selective etching for vertically stacked DRAM

Fifteen periods of Si/Si_(0.7)Ge_(0.3)multilayers(MLs)with various Si Ge thicknesses are grown on a 200 mm Si substrate using reduced pressure chemical vapor deposition(RPCVD).Several methods were utilized to characterize and analyze the ML structures.The high resolution transmission electron microscopy(HRTEM)results show that the ML structure with 20 nm Si_(0.7)Ge_(0.3)features the best crystal quality and no defects are observed.Stacked Si_(0.7)Ge_(0.3)ML structures etched by three different methods were carried out and compared,and the results show that they have different selectivities and morphologies.In this work,the fabrication process influences on Si/Si Ge MLs are studied and there are no significant effects on the Si layers,which are the channels in lateral gate all around field effect transistor(L-GAAFET)devices.For vertically-stacked dynamic random access memory(VS-DRAM),it is necessary to consider the dislocation caused by strain accumulation and stress release after the number of stacked layers exceeds the critical thickness.These results pave the way for the manufacture of high-performance multivertical-stacked Si nanowires,nanosheet L-GAAFETs,and DRAM devices.

Sphere-shaped SiGe micro/nanostructures with tunable Ge composition and size formed by laser irradiation

SiGe spheres with different diameters are successfully fabricated on a virtual SiGe template using a laser irradiation method.The results from scanning electron microscopy and micro-Raman spectroscopy reveal that the diameter and Ge composition of the SiGe spheres can be well controlled by adjusting the laser energy density.In addition,the transmission electron microscopy results show that Ge composition inside the SiGe spheres is almost uniform in a well-defined,nearly spherical outline.As a convenient method to prepare sphere-shaped SiGe micro/nanostructures with tunable Ge composition and size,this technique is expected to be useful for SiGe-based material growth and micro/optoelectronic device fabrication.

Comparative Study on Effect of Ethephon Treatment on Growth of Two Grape Varieties Kyoho and Shine-Muscat

[Objectives]This study aimed to study the effect of ethephon treatment on the growth of two main grape varieties Kyoho and Shine-Muscat.[Methods]Two-year-old Kyoho and Shine-Muscat grape plants transplanted in the film-covered steel-framed greenhouse were used as the test materials.They were pruned horizontally and linearly.In the late growth period,the new shoots were sprayed with ethephon(1500×).During the germination period,10 plants were randomly selected for each variety to investigate the germination situation.Before flowering,20 new shoots with uniform growth were randomly selected for each variety to investigate the growth.During the fruit maturity period,10 clusters of fruits were randomly selected for each variety to determine the related indices of fruit quality.[Results]After the treatment with ethephon,the germination,new shoot growth and fruit quality differed between the two varieties.Overall,the thickness of main stem,main vine and new shoot of Shine-Muscat was greater than that of Kyoho,and the length of new shoot of Kyoho was significantly greater than that of Shine-Muscat.[Conclusions]The growth of Shine-Muscat was more robust.There was little difference in the ear weight of natural fruit setting between the two varieties.Shine-Muscat showed high sugar and low acid contents than Kyoho.

Zika virus non-structural protein 4B interacts with DHCR7 to facilitate viral infection

Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to impact innate immune responses in ZIKV infection.However,the vital non-structural protein and mechanisms involved in DHCR7-mediated viral evasion are not well elucidated.In this study,we demonstrated that ZIKV infection facilitated DHCR7 expression.Notably,the upregulated DHCR7 in turn facilitated ZIKV infection and blocking DHCR7 suppressed ZIKV infection.Mechanically,ZIKV non-structural protein 4B(NS4B)interacted with DHCR7 to induce DHCR7 expression.Moreover,DHCR7 inhibited TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)phosphorylation,which resulted in the reduction of interferon-beta(IFN-β)and interferon-stimulated genes(ISGs)productions.Therefore,we propose that ZIKV NS4B binds to DHCR7 to repress TBK1 and IRF3 activation,which in turn inhibits IFN-βand ISGs,and thereby facilitating ZIKV evasion.This study broadens the insights on how viral non-structural proteins antagonize innate immunity to facilitate viral infection via cholesterol metabolic enzymes and intermediates.

Multifunctional magnesium organic framework-based photothermal and pH dual-responsive mouthguard for caries prevention and tooth self-healing promotion

Caries is considered to be the most prevalent non-communicable disease in humans, mainly deriving from acidogenic bacterial biofilm and resulting in the demineralization and decomposition of hard dental tissue. Herein, a composite responsive foam brace loaded with magnesium organic framework (MPC) is designed for caries prevention and tooth remineralization. MPC can intelligently release organic antibacterial molecules (gallic acid) and mineralized ions (Mg2+, Ca2+ and PO43 ) under acidic conditions (pH < 5.5) of biofilm infection, regulating pH and killing bacteria. Additionally, due to the excellent photothermal conversion efficiency, MPC can further enhance the destruction of bacterial biofilm by inhibiting virulence genes and destroying bacterial adhesion under near-infrared light irradiation (808 nm). More importantly, MPC can not only reverse the cariogenic environment at both pH and microbial levels, but also promote self-healing of demineralized teeth in terms of both the micro-structure and mechanical properties.

N-羟乙基-N-芳基丙炔酰胺的无金属硒化螺三环化反应

报道了一种温和的经由N-羟乙基-N-芳基丙炔酰胺的自位环化及选择性邻位捕捉的方法,并高效合成了系列含硒苯并[b]吡咯并[2,1-c][1,4]噁嗪-3-酮化合物.反应无需过渡金属催化,具有较高的效率和较广的底物适应范围.该串联环化过程包含了炔烃的α-加成、ipso-环化和螺环中间体的邻位俘获.

安徽省监狱矫治监区建设的回顾与发展

心理矫治是监狱改造罪犯的有效手段。全国各省监狱心理矫治工作机构各不相同,安徽省监狱设立的新型心理矫治机构——矫治监区,以监区为工作载体、以矫治和帮扶为两大任务,具体履行心理矫治、重点罪犯转化、入监教育、出监教育、危机干预、社会化工作六项主要职能,对罪犯的改造生活进行全方位辅导。矫治监区不但较好地解决了机构编制问题,而且化解了监狱矫治工作解决心理问题同时也要解决现实问题的难题,在全国监狱具有独创性。