Atomically Substitutional Engineering of Transition Metal Dichalcogenide Layers for Enhancing Tailored Properties and Superior Applications

Transition metal dichalcogenides(TMDs)are a promising class of layered materials in the post-graphene era,with extensive research attention due to their diverse alternative elements and fascinating semiconductor behavior.Binary MX2 layers with different metal and/or chalcogen elements have similar structural parameters but varied optoelectronic properties,providing opportunities for atomically substitutional engineering via partial alteration of metal or/and chalcogenide atoms to produce ternary or quaternary TMDs.The resulting multinary TMD layers still maintain structural integrity and homogeneity while achieving tunable(opto)electronic properties across a full range of composition with arbitrary ratios of introduced metal or chalcogen to original counterparts(0–100%).Atomic substitution in TMD layers offers new adjustable degrees of freedom for tailoring crystal phase,band alignment/structure,carrier density,and surface reactive activity,enabling novel and promising applications.This review comprehensively elaborates on atomically substitutional engineering in TMD layers,including theoretical foundations,synthetic strategies,tailored properties,and superior applications.The emerging type of ternary TMDs,Janus TMDs,is presented specifically to highlight their typical compounds,fabrication methods,and potential applications.Finally,opportunities and challenges for further development of multinary TMDs are envisioned to expedite the evolution of this pivotal field.

Ostensibly perpetual optical data storage in glass with ultra-high stability and tailored photoluminescence

Long-term optical data storage(ODS)technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data.Here,ODS with an ultralong lifetime of 2×10^(7)years is attained with single ultrafast laser pulse induced reduction of Eu^(3+)ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses.We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm^(2).Furthermore,the active ions of Eu^(2+)exhibit strong and broadband emission with the full width at half maximum reaching 190 nm,and the photoluminescence(PL)is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses.The developed technology and materials will be of great significance in photonic applications such as long-term ODS.

Multidimensional defects tailoring local electron and Mg^(2+) diffusion channels for boosting magnesium storage performance of WO_(3)/MoO_(2)

Defect engineering presents great promise in addressing lower specific capacity,sluggish diffusion kinetics and poor cycling life issues in energy storage devices.Herein,multidimensional(0D/2D/3D) structural defects are constructed in WO_(3)/MoO_(2) simultaneously via competing for and sharing with O atoms during simple hydrothermal process.OD and 2D defects tailor local electron,activating more sites and generating built-in electric fields to yield ion reservoir,meanwhile,3D defect owning lower anisotropic property tailors Mg^(2+) diffusion channels to fully exploit Mg^(2+) adsorbed sites induced by OD and 2D defects,enhance the kinetics and maintain structural stability.Benefitted from synergistic effect of 0D/2D/3D structural defects,the designed WO_(3)/MoO_(2) shows the higher specific capacity(112.8 mA h g^(-1) at 50 mA g^(-1) with average attenuation rate per cycle of 0.068%),superior rate capability and excellent cycling stability(specific capacity retention of 80% after 1500 cycles at 1000 mA g^(-1)).This strategy provides design ideas of introducing multidimensional structural defects for tailoring local electron and microstructure to improve energy storage property.

Tailoring of thermal expansion and phase transition temperature of ZrW_(2)O_8 with phosphorus and enhancement of negative thermal expansion of ZrW_(1.5)P_(0.5)O_(7.75)

ZrW_(2)O_(8)is a typical isotropic negative thermal expansion material with cubic structure.However,quenching preparation,pressure phase transition and metastable structure influence its practical applications.Adopting P to part-substitute W for ZrW_(2-x)P_(x)O_(8-0.5x)has decreased the sintering temperature and avoided the quenching process.When x=0.1,ZrW_(1.9)P_(0.1)O_(7.95)with a stable cubic structure can be obtained at 1150℃.The thermal expansion coefficient is tailored with the P content,and phase transition temperature is lowered.When x=0.5,thermal expansion coefficient attains-13.6×10^(-6)℃^(-1),ZrW_(1.5)P_(0.5)O_(7.75)exhibits enhance negative thermal expansion property.The difference of electronegativity leads to the decrease of phase transition temperature with the increase of P content.The different radii of ions lead to new structure of materials when P substitutes more.The results suggest that the P atom plays the stabilization role in the crystal structure of ZrW_(2-x)P_(x)O_(8-0.5x).

Long-term efficacy of a computer-tailored physical activity intervention for prostate and colorectal cancer patients and survivors:A randomized controlled trial

Background Physical activity(PA)can improve the physical and psychological health of prostate and colorectal cancer survivors,but PA behavior change maintenance is necessary for long-term health benefits.OncoActive is a print-and web-based intervention in which prostate and colorectal cancer patients and survivors receive automatically generated,personalized feedback aimed at integrating PA into daily life to increase and maintain PA.We evaluated the long-term outcomes of OncoActive by examining the 12-month follow-up differences between OncoActive and a control group,and we explored whether PA was maintained during a 6-month non-intervention follow-up period.Methods Prostate or colorectal cancer patients were randomly assigned to an OncoActive(n=249)or a usual care waitlist control group(n=229).OncoActive participants received PA advice and a pedometer.PA outcomes(i.e.,ActiGraph and self-report moderate-to-vigorous intensity PA(MVPA)min/week and days with≥30 min PA)and health-related outcomes(i.e.,fatigue,depression,physical functioning)were assessed at baseline,6 months,and 12 months.Differences between groups and changes over time were assessed with multilevel linear regressions for the primary outcome(ActiGraph MVPA min/week)and all additional outcomes.Results At 12 months,OncoActive participants did not perform better than control group participants at ActiGraph MVPA min/week,self-report MVPA min/week,or ActiGraph days with PA.Only self-report days with PA were significantly higher in OncoActive compared to the control group.For health-related outcomes only long-term fatigue was significantly lower in OncoActive.When exploratively examining PA within OncoActive,the previously found PA effects at the end of the intervention(6 months follow-up)were maintained at 12 months.Furthermore,all PA outcomes improved significantly from baseline to 12 months.The control group showed small but non-significant improvements from 6 months to 12 months(and from baseline to 12 months),resulting in a decline of differences between groups.Conclusion The majority of previously reported significant between-group differences at 6 months follow-up were no longer present at long-term follow-up,possibly because of natural improvement in the control group.At long-term follow-up,fatigue was significantly lower in OncoActive compared to control group participants.Computer-tailored PA advice may give participants an early start toward recovery and potentially contributes to improving long-term health.

Superior electrocatalytic negative electrode with tailored nitrogen functional group for vanadium redox flow battery

Development of electrodes with high electrocatalytic activity and stability is essential for solving problems that still restrict the extensive application of vanadium redox flow batteries(VRFBs).Here,we designed a novel negative electrode with superior electrocatalytic activity by tailoring nitrogen functional groups,such as newly formed nitro and pyridinic-N transformed to pyridonic-N,from the prenitrogen-doped electrode.It was experimentally confirmed that an electrode with pyridonic-N and nitro fuctional groups(tailored nitrogen-doped graphite felt,TNGF) has superior electrocatalytic acivity with enhanced electron and mass transfer.Density functional theory calulations demonstrated the pyridonic-N and nitro functional groups promoted the adsorption,charge transfer,and bond formation with the vanadium species,which is consistent with expermental results.In addition,the V2+/V3+redox reaction mechanism on pyridonic-N and nitro functional groups was estabilised based on density functional theory(DFT) results.When TNGF was applied to a VRFB,it enabled enhanced-electrolyte utilization and energy efficiencies(EE) of 57.9% and 64.6%,respectively,at a current density of 250 mA cm^(-2).These results are 18.6% and 8.9% higher than those of VRFB with electrode containing graphitic-N and pyridinicN groups.Interestingly,TNGF-based VRFB still operated with an EE of 59% at a high current density of300 mA cm^(-2).The TNGF-based VRFB exhibited stable cycling performance without noticeable decay of EE over 450 charge-discharge cycles at a current density of 250 mA cm^(-2).The results of this study suggest that introducing pyridonic-N and nitro groups on the electrode is effective for improving the electrochemical performance of VRFBs.

中国式现代化背景下超老龄农村的乡村振兴

中国式现代化是人口规模巨大的现代化,也是全体人民共同富裕的现代化,适应人口变化趋势是中国式现代化与乡村振兴的应然选择和必然之路。当前人口老龄化程度持续加深,叠加长期存在的“城乡倒置”现象,使得农村地区已有近1/4的区域率先进入超老龄社会,其共同面临劳动力与人才老化、乡村发展能力弱化以及养老服务需求增加的现实挑战。为应对挑战,超老龄农村依靠尚存的人口机会窗口与内生的资源禀赋维系发展。在此基础上,乡村振兴战略通过外部资源输入的方式支持乡村发展,以解决农村发展不充分的矛盾、弥合区域发展不平衡的差距。然而,内生资源形塑的区域差异与乡村振兴推进过程中“整齐划一”的发展模式导致的匹配“错位”现象屡见不鲜。因此,为促进区域协同发展、实现超老龄农村的乡村振兴并最终达成共同富裕与中国式现代化,本研究从保障基本、深入发展和城乡融合三个阶段契合超老龄农村不同的发展基础,探索适合超老龄农村的乡村振兴道路。

数智化时代背景下服装立体裁剪课程的创新性探索与实践

针对传统教学模式存在的痛点,以服装专业核心课程“立体裁剪”为例,基于数智化时代信息化、数字化的主要特征进行课程的创新性探索与改革实践。秉承“自主学习、夯实基础、培养能力、注重创新”的教学理念,融合自建在线资源微课程和智慧教学环境,以现代化信息技术为依托,结合社会发展、行业需求及专业目标、课程教学内容实际,重构课程教学内容,革新课程教学模式和考核方式,不断深化课程教学改革,明确教学的新范式、新方法、实施路径,以及多元化评价机制的教学成效,提高立体裁剪课程教学的实施效果,培养高专业水平人才。

面料性能对男士西服门襟造型的影响

西服门襟位于整件服装的视觉中心,是西服结构和造型的重要组成部分。除版型设计外,面料性能也会影响西服门襟的造型。以门襟倾斜度、重叠量作为门襟造型的客观评价指标,并以美观度、平整度作为门襟造型的主观评价指标,通过面料性能测试及门襟造型主客观评价实验,根据SPSS数据分析结果探究面料性能对西服门襟造型的影响,通过回归分析分别建立了门襟倾斜度、重叠量、美观度、平整度与面料性能关系的回归方程。研究表明:克重、厚度、悬垂系数、抗弯刚度、断裂强度和伸长率等面料性能指标会对门襟造型产生影响,主观评价指标与客观评价指标间存在较大的相关性,门襟的倾斜度小,重叠量大,门襟的美观度和平整度较好。

GJB 438C—2021解析及应用研究

软件文档作为软件产品的重要组成部分,文档的质量直接影响软件的研发、应用和维护。GJB 438经过数十年的讨论与修订,其最新版GJB 438C于2022年3月1日起开始实施。基于新发布实施的GJB 438C标准,归纳总结了该标准与其上一版标准GJB 438B之间的主要差异,并简要地分析了标准变化的影响及意义,在此基础上梳理了GJB 438C与GJB 2786A、GJB 5000B之间的关联关系,基于软件工程化管理现状并结合项目实际情况,提出对于新标准在贯彻实施过程中的剪裁思路,为后续新标准实施应用提供了参考。

石墨烯纳米带的制备技术及应用研究现状

石墨烯具有优异的力学、电学、光学、热学等物理性质,是当前新型材料的研究热点之一,被广泛应用在导电薄膜、储能元件、药物载体以及锂电池等领域。然而,石墨烯无带隙的特点限制其更广泛的应用,因此,通过技术手段打开石墨烯带隙成为学者们亟待解决的新问题。将石墨烯制成石墨烯纳米带(Graphene nanoribbons,GNRs)是打开其带隙的可行办法。因此,本文梳理了制备GNRs的不同方法,综述了其制备原理和研究进展,并对比了其优点和不足,提出了将不同方法的优点相互结合的复合制备方法,以实现可控、高效、高质量制备GNRs,最后介绍了GNRs在高性能传感器、场效应晶体管和光电探测器领域应用的研究进展和未来发展趋势。这对GNRs进一步应用在纳米器件中有一定的指导意义。

基于定制纤维铺放工艺的电加热织物制备及其半球成型性能

为开发既具有电热性能又满足对三维表面具有一定适应性的电加热织物,采用定制纤维铺放(TFP)工艺设计制备直线形、正弦波形、锯齿形和尖角形4种镍铬合金丝排布方式的电加热织物,研究电加热织物的电热性能和半球成型性能。结果表明:10 V直流电压下通电30 s,4种电加热织物表面最高平衡温度分别达到159.5、92.8、66.7和31.5℃,温度分布均匀;反作用力与镍铬合金丝排布方式密切相关;半球成型最终状态下,直线形电加热织物成型反作用力最小,表面褶皱和细观缺陷最少,且最大面内剪切角为32.26°;与未引入镍铬合金丝玻璃纤维基底织物相近,即直线形电加热织物半球成型性优于正弦波形、锯齿形和尖角形电加热织物。

SJM Tailor环三尖瓣成形术治疗三尖瓣关闭不全

目的探讨使用SJM Tailor环行三尖瓣成形术治疗风湿性瓣膜病合并功能性三尖瓣关闭不全的疗效。方法从2007年6月到2011年4月共使用SJM Tailor环行三尖瓣成形术治疗27例风湿性瓣膜病合并的三尖瓣关闭不全的患者，对其进行回顾性分析。结果全组患者围手术期无死亡，术后恢复顺利，三尖瓣返流程度明显减轻，术后心功能分级较术前提高Ⅰ～Ⅱ级。结论SJM Tailor环行三尖瓣成形术治疗风湿性瓣膜病合并的功能性三尖瓣关闭不全，安全有效，近中期效果满意。

铜绿假单胞菌适配体的获得及应用

铜绿假单胞菌是一种专性需氧的革兰氏阴性菌,是引起人类机会性感染的最主要的微生物,对人类造成多种健康威胁。因此,快速、灵敏、特异的检测对预防及治疗铜绿假单胞菌感染十分关键。目前常规的检测方法仍存在耗时久、成本高、操作难度大等问题,因此需要更加高效经济的检测方法。适配体是一种从随机文库中筛选出来的寡核苷酸,能够形成多种复杂的二级结构,近年来,由于其易于合成和修饰,并且具有高亲和力和强特异性而受到了广泛的关注,也涌现出了大量基于适配体的铜绿假单胞菌检测和防治的研究。本文总结了目前铜绿假单胞菌适配体的筛选和裁剪方面的研究进展,并从铜绿假单胞菌的检测和防治两个方面对其适配体的应用进行了介绍,以期为铜绿假单胞菌适配体的开发和应用提供参考。

CR340轧制差厚板纵梁成形性能研究

目的研究复杂应力状态下轧制差厚板塑性变形行为和韧性损伤机理,获得轧制差厚板成形性能规律,促进轧制差厚板在汽车工业轻量化中的应用。方法应用细观损伤理论,采用有限元逆向法构建轧制差厚板GTN细观损伤模型,进一步结合有限元数值模拟技术研究轧制差厚板塑性变形行为和韧性损伤机理,对比分析差厚板与等厚板塑性变形特点,研究CR340轧制差厚板纵梁成形性能规律。结果将有限元逆向法和实验相结合,获得了损伤参数值,建立了描述轧制差厚板韧性损伤行为的GTN细观损伤模型,结合有限元分析可知,孔洞体积分数在过渡区变形最大的区域增加最为明显,孔洞最先在此处聚集发展;相比于等厚板,轧制差厚板成形纵梁时,在和厚区交界处的过渡区产生了显著的应力集中,引起过渡区应变急剧增大,使应力和应变整体分布的不均匀性增加。结论应用细观损伤理论和有限元数值模拟分析了轧制差厚板成形纵梁时韧性损伤最先产生的区域,结合应力和应变分布特点可知,与薄区相邻的过渡区在最大应变处最易出现成形缺陷。

基于差分隐私的分段裁剪联邦学习算法

为解决现有的差分隐私联邦学习算法中使用固定的裁剪阈值和噪声尺度进行训练,从而导致数据隐私泄露、模型精度较低的问题,提出了一种基于差分隐私的分段裁剪联邦学习算法。首先,根据客户端的隐私需求分为隐私需求高和低。对于高隐私需求用户使用自适应裁剪来动态裁剪梯度,而低隐私需求用户则采用比例裁剪。其次根据裁剪后阈值大小自适应地添加噪声尺度。通过实验分析可得,该算法可以更好地保护隐私数据,同时通信代价也低于ADP-FL和DP-FL算法,并且与ADP-FL和DP-FL相比,模型准确率分别提高了2.25%和4.41%。

调控Cu/CeO_(2)催化剂形貌增强低温CO氧化的耐水性

合成了管状、棒状和颗粒状的Cu/CeO_(2)的催化剂,探讨了其在潮湿条件下氧化CO的结构-性能相关性.结果表明,管状催化剂(CuCe-NT)具有优异的低温活性和抗H_(2)O稳定性.根据表征,CuCe-NT与纳米棒状(CuCe-NR)和纳米颗粒状(CuCe-NP)催化剂相比,结晶度更低、表面积更大且结构缺陷更多,从而增强了CuO_(x)与CeO_(2)间的相互作用,加强了Ce^(4+)/Ce^(3+)和Cu^(2+)/Cu^(+)的氧化还原循环,使表面富集大量Ce^(3+)和Cu^(+),进一步促进了CO的吸附和氧化.此外,中空结构的CuCe-NT具有较大的孔径,可有效抑制H_(2)O的缔合吸附,从而抑制氧空位上惰性OH的生成,在潮湿条件下保持较高的氧化性.In-situ DRIFTS表明,相比于CuCe-NP,中空结构的CuCe-NT可以缓解H_(2)O与CO的竞争性吸附,抑制桥式碳酸盐的形成,确保在潮湿环境下氧化CO.本研究从吸附H_(2)O的类型和反应机理方面证明了催化剂结构对耐H_(2)O性的影响,为设计耐H_(2)O性CO氧化催化剂提供了一种策略.

3C-SiC纳米线的化学气相沉积法制备及超声裁剪研究

3C-SiC又称β-SiC,有着优异的耐高温、耐腐蚀、耐辐照性能,是反应堆这类复杂环境中的理想材料。近年来,一维碳化硅纳米线材料成为碳化硅材料研究领域的热门研究方向,同时也面临加工手段匮乏、加工难度大的问题。我们通过化学气相沉积法成功制备了含有高密度堆叠层错的3C-SiC纳米线,并采用扫描电子显微镜(Scanning Electron Microscope,SEM)、透射电子显微镜(Transmission Electron Microscope,TEM)、X射线衍射(X-Ray Diffraction,XRD)以及拉曼光谱(Raman spectrum)等多种手段对制备出来的碳化硅纳米线进行了微观结构表征,揭示了其独特的微观形态和晶体结构特征;进一步研究了超声裁剪碳化硅纳米线,利用“气泡-射流”模型结合碳化硅纳米线的形态解释了碳化硅纳米线的超声裁剪过程,探索了碳化硅纳米线的直径、强度、缺陷等对其在超声过程中断裂行为的影响。本研究为碳化硅纳米线的超声裁剪加工和纳米线的强度研究提供了新的视角,对于未来碳化硅纳米线在核能领域的应用具有重要的意义。

基于Tailor基数的B样条曲线节点插入快速生成算法

通过对Tailor级数展开的分析,给出了一种三次均匀B样条曲线节点插入的生成算法.与Oslo算法的递推过程相比,本算法大大简化了运算过程,有效地提高了算法的生成效率.

退火工艺下轧制差厚板非均匀温度场研究

轧制差厚钢板具有连续变化的厚度特性,因此在退火工艺下不同厚度区域的温度变化路径存在显著差异。这种差异改变了轧制差厚钢板的微观组织及力学性能,进而直接影响其后续成形及服役性能。为掌握退火工艺下轧制差厚钢板具有的性能差异化特性及产生内因,需要对轧制差厚钢板热处理过程中的温度分布及规律进行系统研究。研究所用轧制差厚钢板的几何特征为:薄区、过渡区及厚区纵向长度均为50 mm;薄区厚度1 mm,厚区为1.5 mm,差厚比1.5,过渡区厚度连续变化且无突变。建立了同步考虑轧制差厚钢板厚度连续变化特性及综合传热形式的温度场非稳态理论模型,并通过实验方法验证理论模型准确性。结果表明,在预设退火温度780℃的升温历程中,以薄区达到临界温度的时间(75 s)为测温终点,各厚区最高温度为779.3℃;最高温差135.1℃,整体呈现先增后减的趋势;最大升温速率为21.9℃/s,之后各区域升温速率逐步递减且在到达37 s时各厚区升温速率的高低顺序发生转变。研究通过分析轧制差厚钢板随时间变化的温度分布态势与其内在规律,以期为轧制差厚钢板热处理后的性能差异化预测提供理论基础及有效方法。