Achieving Narrowed Bandgaps and Blue-Light Excitability in Zero-Dimensional Hybrid Metal Halide Phosphors via Introducing Cation-Cation Bonding

Zero-dimensional(0D)hybrid metal halides,which consist of organic cations and isolated inorganic metal halide anions,have emerged as phosphors with efficient broadband emissions.However,these materials generally have too wide bandgaps and thus cannot be excited by blue light,which hinders their applications for efficient white light-emitting diodes(WLEDs).The key to achieving a blue-light-excitable 0D hybrid metal halide phosphor is to reduce the fundamental bandgap by rational chemical design.In this work,we report two designed hybrid copper(I)iodides,(Ph_(3)MeP)_(2)Cu_(4)I_(6)and(Cy_(3)MeP)_(2)Cu_(4)I_(6),as blue-light-excitable yellow phosphors with ultrabroadband emission.In these compounds,the[Cu_(4)I_(6)]^(2-)anion forms an I6 octahedron centered on a cationic Cu_(4)tetrahedron.The strong cation-cation bonding within the unique cationic Cu_(4)tetrahedra enables significantly lowered conduction band minimums and thus narrowed bandgaps,as compared to other reported hybrid copper(I)iodides.The ultrabroadband emission is attributed to the coexistence of free and self-trapped excitons.The WLED using the[Cu_(4)I_(6)]^(2-)anion-based single phosphor shows warm white light emission,with a high luminous efficiency of 65 Im W^(-1)and a high color rendering index of 88.This work provides strategies to design narrow-bandgap 0D hybrid metal halides and presents two first examples of blue-light-excitable 0D hybrid metal halide phosphors for efficient WLEDs.

Ultrasensitive and stable X-ray detection using zero-dimensional lead-free perovskites

Sensitive and reliable X-ray detectors are essential for medical radiography,industrial inspection and security screening.Lowering the radiation dose allows reduced health risks and increased frequency and fidelity of diagnostic technologies for earlier detection of disease and its recurrence.Three-dimensional(3 D)organic-inorganic hybrid lead halide perovskites are promising for direct X-ray detection-they show improved sensitivity compared to conventional X-ray detectors.However,their high and unstable dark current,caused by ion migration and high dark carrier concentration in the 3 D hybrid perovskites,limits their performance and long-term operation stability.Here we report ultrasensitive,stable X-ray detectors made using zero-dimensional(0 D)methylammonium bismuth iodide perovskite(MA3Bi2I9)single crystals.The 0 D crystal structure leads to a high activation energy(Ea)for ion migration(0.46 e V)and is also accompanied by a low dark carrier concentration(~10^6 cm^-3).The X-ray detectors exhibit sensitivity of 10,620μC Gy-1 air cm-2,a limit of detection(Lo D)of 0.62 nG yairs-1,and stable operation even under high applied biases;no deterioration in detection performance was observed following sensing of an integrated X-ray irradiation dose of^23,800 m Gyair,equivalent to>200,000 times the dose required for a single commercial X-ray chest radiograph.Regulating the ion migration channels and decreasing the dark carrier concentration in perovskites provide routes for stable and ultrasensitive X-ray detectors.

Synthesis and transformation of zero-dimensional Cs3BiX6(X=Cl,Br)perovskite-analogue nanocrystals

The unique structure of zero-dimensional(0D)perovskite-analogues has attracted a great amount of research interest in recent years.To date,the current compositional library of 0D perovskites is largely limited to the lead-based Cs4PbX6(X=Cl,Br,and I)systems.In this work,we report a new synthesis of lead-free 0D Cs3BiX6(X=Cl,Br)perovskite-analogue nanocrystals(NCs)with a uniform cubic shape.We observe a broad photoluminescence peak centered at 390 nm for the 0D Cs3BiCl6 NCs at low temperatures.This feature originates from a self-trapped exciton mechanism.In situ thermal stability studies show that Cs3BiX6 NCs remain stable upon heating up to 200°C without crystal structural degradation.Moreover,we demonstrate that the Cs3BiX6 NCs can transform into other bismuth-based perovskite-analogues via facile anion exchange or metal ion insertion reactions.Our study presented here offers the opportunity for further understanding of the structure-property relationship of 0D perovskite-analogue materials,leading toward their future optoelectronic applications.

Computing polynomial univariate representations of zero-dimensional ideals by Grbner basis

Rational Univariate Representation （RUR） of zero-dimensional ideals is used to describe the zeros of zero-dimensional ideals and RUR has been studied extensively. In 1999, Roullier proposed an efficient algorithm to compute RUR of zero-dimensional ideals. In this paper, we will present a new algorithm to compute Polynomial Univariate Representation （PUR） of zero-dimensional ideals. The new algorithm is based on some interesting properties of Grobner basis. The new algorithm also provides a method for testing separating elements.

Dietary zero-dimensional fullerene supplementation improves the meat quality,lipid metabolism,muscle fiber characteristics,and antioxidative status in finishing pigs

With the increasing demand for high-quality pork,more nutritional substances have been studied for the regulation of meat quality.Zero-dimensional fullerenes(C60)can modulate the biological behavior of a variety of cell lines and animals.In this study,we report the biological effects of C60 on finishing pigs at different concentrations.A total of 24 barrows(Duroc×Large White×Landrace),with an average body weight of 21.01±0.98 kg,were divided into 3 groups and each treated daily with C60(100 or 200 mg per kg feed)or a control diet until the end of the experiment.Our results showed that dietary C60 supplementation improved flesh color,marbling scores,and flavor amino acid contents of longissimus dorsi(LD)of growing-finishing pigs(P<0.05).C60 improved meat quality by regulating lipid metabolism and muscle fiber morphology by mediating the expression of genes,L-lactic dehydrogenase(LDH),myosin heavy chain(MyHC)IIa,MyHCIIb,peroxisome proliferator-activated receptor γ(PPARγ),and fatty acid transport protein 1(FATP1)(P<0.05).Moreover,C60 substantially promoted the mRNA expression of antioxidant enzyme genes(P<0.05),which also contributed to improving meat quality.These findings have important implications for the application of C60 in the livestock industry,especially for improving the meat quality of fattening pigs.

Strongly Zero-Dimensional Locales

New kinds of strongly zero-dimensional locales are introduced and characterized, which are different from Johnstone's, and almost all the topological properties for strongly zero-dimensional spaces have the pointloss localic forms. Particularly. the Stone-Cech compactification of a strongly zero-diluensional locale is stongly zero-dimensional.

Highly luminescent zero-dimensional lead-free manganese halides forβ-ray scintillation

Because of their moderate penetration power,β-rays(high-energy electrons)are a useful signal for evaluating the surface contamination of nuclear radiation.However,the development ofβ-ray scintillators,which convert the absorbed high-energy electrons into visible photons,is hindered by the limitations of materials selection.Herein,we report two highly luminescent zerodimensional(0D)organic-inorganic lead-free metal halide hybrids,(C_(13)H_(30)N)_(2)MnBr_(4)and(C_(19)H_(34)N)_(2)MnBr_(4),as scintillators exhibiting efficientβ-ray scintillation.These hybrid scintillators combine the superior properties of organic and inorganic components.For example,organic components that contain light elements C,H,and N enhance the capturing efficiency ofβparticles;isolated inorganic[MnBr_(4)]2−tetrahedrons serve as highly localized emitting centers to emit intense radioluminescence(RL)underβ-ray excitation.Both hybrids show a narrow-band green emission peaked at 518 nm with photoluminescence quantum efficiencies(PLQEs)of 81.3%for(C_(13)H_(30)N)_(2)MnBr_(4)and 86.4%for(C_(19)H_(34)N)_(2)MnBr_(4),respectively.To enable the solution processing of this promising metal halide hybrid,we successfully synthesized(C_(13)H_(30)N)_(2)MnBr_(4)colloidal nanocrystals for the first time.Being excited byβ-rays,(C_(13)H_(30)N)_(2)MnBr_(4)scintillators show a linear response toβ-ray dose rate over a broad range from 400 to 2,800 Gy·s^(−1),and also display robust radiation resistance that 80%of the initial RL intensity can be maintained after an ultrahigh accumulated radiation dose of 240 kGy.This work will open up a new route for the development ofβ-ray scintillators.

Square-Free Pure Triangular Decomposition of Zero-Dimensional Polynomial Systems

Triangular decomposition with different properties has been used for various types of problem solving.In this paper,the concepts of pure chains and square-free pure triangular decomposition(SFPTD)of zero-dimensional polynomial systems are defined.Because of its good properties,SFPTD may be a key way to many problems related to zero-dimensional polynomial systems.Inspired by the work of Wang(2016)and of Dong and Mou(2019),the authors propose an algorithm for computing SFPTD based on Gr¨obner bases computation.The novelty of the algorithm is that the authors make use of saturated ideals and separant to ensure that the zero sets of any two pure chains are disjoint and every pure chain is square-free,respectively.On one hand,the authors prove the arithmetic complexity of the new algorithm can be single exponential in the square of the number of variables,which seems to be among the rare complexity analysis results for triangular-decomposition methods.On the other hand,the authors show experimentally that,on a large number of examples in the literature,the new algorithm is far more efficient than a popular triangular-decomposition method based on pseudodivision,and the methods based on SFPTD for real solution isolation and for computing radicals of zero-dimensional ideals are very efficient.

零维纳米碳基靶向药物递送系统在肿瘤治疗中的研究进展(综述)

【目的】零维纳米碳基靶向药物递送系统是以具有良好稳定性和生物相容性的纳米碳材料作为药物载体,担载药物、基因以及靶向组分构建的药物递送复合体,在肿瘤治疗领域具有重要的应用价值。【方法】对零维纳米碳基药物载体的结构、靶向药物递送系统的构建及其在化学治疗、基因治疗和诊疗一体化中的应用进行综述。首先,对零维纳米碳材料进行分类。其次,从靶向修饰和药物担载两个方面总结纳米碳基靶向药物递送系统的构建策略。最后,对零维纳米碳基靶向药物递送系统的应用进展进行综述,进而给出其目前在肿瘤治疗中所面临的问题。【结论】为零维纳米碳基靶间药物递送系统在生物医学领域的广泛应用提供可借鉴的理论和实践经验。

三维变形管MVR蒸发器用于纤维素生产末端废水零排放项目

蒸发器的换热性能对机械蒸汽再压缩(MVR)系统投资及运行均有着重要影响。MVR蒸发器的管内传热与压降性能在基于三维变形管和直圆管的情况下存在明显差异。建立了考虑盐水浓度修正的三维变形管MVR蒸发器性能准则关联式,设计一套用于纤维素生产末端废水零排放项目的新型蒸发器。应用实践表明,相对于传统直圆管的MVR蒸发器,基于三维变形管的新型MVR蒸发器节材节能效果显著,其在节省29%换热面积的情形下仍能完全满足工程实际需要。在现场调研期间MVR系统处理每吨废水的压缩机耗电量在18.81~23.78 kW∙h之间,体现出新型蒸发器高能效的技术特性,极具应用推广价值。

零维预测燃烧模型建模方法

为了解决神经网络建立的柴油机零维燃烧模型对稳态和动态工况预测能力不稳定问题,本文采用遗传算法对神经网络的初始权值、阈值进行综合优化,提出了遗传算法-神经网络算法。基于TBD620型柴油机,通过稳态和瞬态试验获得运行参数和缸压数据,通过代数分析法结合遗传算法获得对应燃烧参数,最后分别利用遗传算法-神经网络算法和神经网络算法对燃烧模型进行构建并对比辨识结果。结果表明:与神经网络算法相比,遗传算法-神经网络算法构建的零维燃烧模型对应φ_(50)和IMEP预测值平均误差分别降低了43.84%和42.73%,遗传算法具有高效的权值、阈值寻优能力,模型具有更高的预测精度,泛化性更好,适用于柴油机零维燃烧模型研究。

金属卤化物零维钙钛矿材料及其应用研究进展

金属卤化物零维钙钛矿因其大激子结合能、出色的稳定性、高发光效率以及大Stokes位移等优点,受到广泛的关注。首先,探讨了金属卤化物零维钙钛矿的电子结构与发光机理。其次,分析了离子掺杂对金属卤化物零维钙钛矿光学特性的影响。在此基础上,阐述了金属卤化物零维钙钛矿的合成方法,并详细介绍了金属卤化物零维钙钛矿在发光二极管、防伪、X射线成像和传感等领域的应用。最后,对目前金属卤化物零维钙钛矿面对的挑战和潜在解决方案进行了总结与展望。

Cs3Cu2I5单晶生长与发光性质研究

近年来发光材料已广泛应用于照明、显示和医学影像等领域。铜(Ⅰ)基卤化物因其优异的发光特性和稳定性受到广泛关注。本文报道了生长Cs_(3)Cu_(2)I_(5)单晶的方法,使用有机溶剂(DMF)以溶剂挥发法生长出3×2.4×1 mm的单晶。Cs_(3)Cu_(2)I_(5)是一种具有零维结构的全无机铜(Ⅰ)基卤化物发光材料,晶体结构属于正交晶系Pnma空间群。Cs_(3)Cu_(2)I_(5)单晶在254 nm紫外光激发下表现出明亮的蓝色发光,光致发光峰在445 nm左右,光致发光量子产率为56.65%。此晶体光致发光具有大的斯托克斯位移(117 nm)和984.89 ns的光致发光寿命。Cs_(3)Cu_(2)I_(5)在蓝光LED方面具有应用潜力。

零知识证明在新型电力系统中的应用分析及展望

新型电力系统数据资产价值日益受到重视,但信息安全领域的隐私性、完整性和可用性组成的“不可能三角”对数据资产的有效应用提出挑战。零知识证明技术在保证新型电力系统数据质量方面具有显著优势,然而,其技术的多样性和差异性导致电力系统中的应用呈现分散化和孤岛化。针对于此,该文详细介绍零知识证明技术的基本概念,并通过从属性(条件证明和范围证明)、主体(发电、用电和电网)和功能(身份认证、数据计量、市场交易和调度协调)3个维度对目前零知识证明在电力系统中的应用进行全面分析。在此基础上,通过3个典型应用场景展示零知识证明在未来新型电力系统中的应用潜力。最后,对零知识证明在电力系统中的大规模应用面临的挑战进行分析和总结。

碳点缓蚀剂的研究进展

碳纳米材料因其独特的物理化学性质,如高比表面积、优异的电子传输性能及丰富的表面官能团,成为多个领域的研究热点。特别是碳点(Carbon Dots,CDs),作为一种零维纳米材料,具有优异的光学性能、环境友好性、生物相容性和易改性,在生物传感、新能源和医药等领域展现出广泛的应用潜力。碳点在金属防腐蚀领域的应用逐渐受到关注,其作为缓蚀剂的研究已成为当前科学研究的新方向。简述了碳点的制备方法,并系统综述了近年来碳点在金属防腐蚀领域的应用研究进展。阐述了碳点缓蚀剂在金属防腐蚀中的优势,包括其环境友好性、高稳定性及优异的缓蚀效率。碳点在碳钢和铝合金等多种金属材料的防腐蚀研究中显示出优异的应用潜力。还着重讨论了碳点缓蚀剂的缓蚀机理,包括等温吸附模型和吸附类型。最后,指出了当前碳点缓蚀剂研究中存在的挑战,包括对缓蚀机理的深入理解、大规模合成方法的开发以及在复杂腐蚀环境中的稳定性和长效性,并对碳点缓蚀剂在金属防腐蚀领域的前景进行了展望。尽管目前对碳点作为金属防腐蚀缓蚀剂的研究仍处于初步阶段,但其在腐蚀防护领域的应用前景非常广阔,有望在未来实现其在低碳环保和金属防腐领域的广泛应用。

信息时空:解构信息、语言与交付的多维度与未来趋势

本文旨在探讨信息、语言在交付上的低维、高维、降维、升维演变,以及对人类、AI沟通交付的展望。对零维对动物信息交付沟通、一维对人类信息交付沟通、二维对目前的AI信息交付沟通、三维对更高层级AI的信息交付处理,以及四维在各个维度基础上加时、空维度后产生升维后的信息和语言交付进行研究,分析各个维度的特点,以期为未来信息、语言与交付的研究提供新的视角和启示,从信息、语言的角度预测未来AI的发展轨迹。

实验室网络防火墙零日漏洞入侵检测方法仿真

由于零日漏洞的未知性,导致其缺乏准确的漏洞特征信息。攻击者在利用这些漏洞进行针对性攻击时,使其在网络流量中难以被精准检测到。为了提高实验室网络的安全防御能力,并及时检测防火墙零日漏洞的不同攻击,保障实验室网络的安全稳定运行,提出了面向实验室网络的防火墙零日漏洞入侵检测。采用基于随机森林和主成分分析(Principal Component Analysis,PCA)的融合方法,对实验室网络防火墙数据特征实施特征重要度计算以及特征降维处理;利用模糊聚类算法对该特征展开聚类分析,获取与零日漏洞入侵特征相关的特征集合;将其作为训练样本输入到自适应谐振理论2(Adaptive Resonance Theory 2,ART2)神经网络中,通过网络的训练学习实现实验室网络防火墙零日漏洞不同入侵类型的精确检测。实验结果表明,所提方法的丢包率低,且平均准确率为98.03%,表明该方法能够有效提高实验室网络的安全性和稳定性。

基于NDE-FLNN与零极点配置法的六维加速度传感器动态性能补偿

六维加速度传感器可广泛应用于类人机器人领域的动态全息检测,从而保障机器人运动柔顺性与稳定性。现有六维加速度传感器存在响应速度慢、响应范围窄等动态特性差的问题,限制了传感器对测量载体实时动态位姿信息的敏锐、宽范围响应。针对这一问题,开展六维加速度传感器时频域动态性能补偿研究。利用差分方程建立传感器的动态模型,提出一种基于NDE-FLNN的高精度动态模型参数辨识算法,并进一步推导动态补偿模型补偿传感器的响应速度,提升传感器的时域动态性能。之后,基于零极点配置法设计传感器各通道动态补偿器,消除原极点并引入新极点,拓展传感器响应范围,改善传感器频域动态性能。实验结果表明,相比于DE-FLNN算法,改进后的NDE-FLNN算法能够更高精度地辨识传感器动态模型参数,传感器补偿后各分量的调节时间减少至原先一半左右,均在150 ms以内,工作带宽由22 Hz拓展至84 Hz,传感器时频域动态性能得到显著提升。

一维伊辛模型中是否存在零温相变?

自伊辛模型(IM)被提出的一个世纪以来,它被认为是物理学中最重要的微观模型之一.目前,基于自发磁化结果,一般认为一维IM(1D-IM)存在零温相变.首先给出了1D-IM的内能、比热和熵的结果,并依据Ehrenfest相变分类法得出1D-IM中不存在零温相变;后依据热力学第三定律,对1D-IM不存在零温相变进行了深入分析讨论.

纳米改性沥青研究进展

介绍了聚合物改性沥青的概况,总结了纳米改性沥青的国内外研究现状及存在的问题,从一种新的角度开展了零维纳米材料改性沥青的探索,初步研究结果表明,零维纳米材料改性沥青可使沥青性能大幅度提高,并且在工艺和经济上是可行的,最后提出了改性沥青纳米复合材料今后研究的几个方向。