Current Status and Perspectives of Dual-Atom Catalysts Towards Sustainable Energy Utilization

The exploration of sustainable energy utilization requires the imple-mentation of advanced electrochemical devices for efficient energy conversion and storage,which are enabled by the usage of cost-effective,high-performance electro-catalysts.Currently,heterogeneous atomically dispersed catalysts are considered as potential candidates for a wide range of applications.Compared to conventional cata-lysts,atomically dispersed metal atoms in carbon-based catalysts have more unsatu-rated coordination sites,quantum size effect,and strong metal-support interactions,resulting in exceptional catalytic activity.Of these,dual-atomic catalysts(DACs)have attracted extensive attention due to the additional synergistic effect between two adja-cent metal atoms.DACs have the advantages of full active site exposure,high selectiv-ity,theoretical 100%atom utilization,and the ability to break the scaling relationship of adsorption free energy on active sites.In this review,we summarize recent research advancement of DACs,which includes(1)the comprehensive understanding of the synergy between atomic pairs;(2)the synthesis of DACs;(3)characterization meth-ods,especially aberration-corrected scanning transmission electron microscopy and synchrotron spectroscopy;and(4)electrochemical energy-related applications.The last part focuses on great potential for the electrochemical catalysis of energy-related small molecules,such as oxygen reduction reaction,CO_(2) reduction reaction,hydrogen evolution reaction,and N_(2) reduction reaction.The future research challenges and opportunities are also raised in prospective section.

Investigating the impact of dynamic structural changes of Au/rutile catalysts on the catalytic activity of CO oxidation

The surface properties of oxidic supports and their interaction with the supported metals play critical roles in governing the catalytic activities of oxide‐supported metal catalysts.When metals are supported on reducible oxides,dynamic surface reconstruction phenomena,including strong metal–support interaction(SMSI)and oxygen vacancy formation,complicate the determination of the structural–functional relationship at the active sites.Here,we performed a systematic investigation of the dynamic behavior of Au nanocatalysts supported on flame‐synthesized TiO_(2),which takes predominantly a rutile phase,using CO oxidation above room temperature as a probe reaction.Our analysis conclusively elucidated a negative correlation between the catalytic activity of Au/TiO_(2) and the oxygen vacancy at the Au/TiO_(2) interface.Although the reversible formation and retracting of SMSI overlayers have been ubiquitously observed on Au/TiO_(2) samples,the catalytic consequence of SMSI remains inconclusive.Density functional theory suggests that the electron transfer from TiO_(2) to Au is correlated to the presence of the interfacial oxygen vacancies,retarding the catalytic activation of CO oxidation.

Electromagnetic Ion Beam Instability in the Solar Corona

Remote-sensing measurements indicate that heavy ions in the corona undergo an anisotropic and mass-charge dependent energization.A popular explanation to this phenomenon is the damping of the Alfven/ion cyclotron waves.In this paper,we propose that the ion beam instability can be an important source of the Alfven/ion cyclotron waves,and we study the excitation of the ion beam instability in the corona at the heliocentric distance~3R_(⊙)and the corresponding energy transfer process therein ba sed on plasma kinetic theory.The results indicate that the existence of the motionless heavy ions inhibits the ion beam instability.However,the anisotropic beams of heavy ions promote the excitation of the ion beam instability.Besides,the existence ofαbeams can provide a second energy source for exciting beam instability.However,when both the proton beam and the a beam reach the instability excitation threshold,the proton beam driven instability excites preferentially.Moreover,the excitation threshold of the Alfven/ion cyclotron instability driven by ion beam is of the local Alfven speed or even less in the corona.

肝性脊髓病的中医诊治进展

肝性脊髓病是慢性肝病晚期的一种罕见的神经系统并发症,以双下肢缓慢进行性对称性痉挛性瘫痪为特征性表现.其发病机制尚不明确,西医尚无有效的预防和治疗方法.本文结合近年文献,对肝性脊髓病中医病因病机及诊治研究进展作以下概述.

唐氏筛查临界或高风险孕妇羊水染色体核型和基因组拷贝数变异结果分析

目的分析唐氏综合征产前筛查(简称唐氏筛查)临界风险或高风险孕妇羊水染色体核型和基因组拷贝数变异的检出情况,为此类孕妇的产前诊断提供参考。方法收集2019年12月—2021年10月阜阳市人民医院450例唐氏筛查临界风险或高风险孕妇羊水样本,进行染色体核型分析、染色体微阵列分析(CMA)或基因组拷贝数变异测序(CNV-seq)。结果450例孕妇中,染色体核型分析共检出异常核型40例(8.89%),其中18/21-三体综合征29例(6.44%)、非18/21-三体综合征染色体异常11例[2.44%,包括常染色体异常3例(0.67%)、性染色体异常8例(1.78%)]。CMA或CNV-seq共检出染色体异常76例,其中35例与染色体核型分析结果相符、41例不相符[包括染色体平衡易位2例、复杂性染色体结构嵌合2例、致病和疑似致病拷贝数变异(CNV)12例、临床意义不明25例]。染色体核型分析联合基因组检测共检出非18/21-三体的染色体异常23例(5.11%)。结论唐氏筛查临界风险或高风险除提示18/21-三体综合征外,对非18/21-三体的染色体异常也有一定的提示作用。产前诊断时采用羊水染色体核型分析联合CMA或CNV-seq技术可提高染色体异常的检出率。

将In_(2)O_(3)/CdSe-DETA纳米复合材料中的电荷转移从Type-Ⅰ转变为S-Scheme以提高光催化制氢的活性和稳定性

化石能源的问题限制了人类的发展。解决这个问题的有效方法是发展可持续性的清洁能源。近年来,氢气作为一种新型的清洁能源被争相报道。氢气燃烧热很大,且产物只有水,完全符合绿色环保可持续性能源的特点。因此,解决氢能源的生产方法就可以有效地解决能源危机问题。自TiO_(2)在1972年作为光催化剂分解水产生氢气开始,半导体光催化剂分解水产生氢气登上了历史的舞台。然而,单一组分光催化剂的固有缺点限制了它的实际应用,寻找克服单一组分光催化剂缺点的解决方案仍然具有挑战性。相对于单一的光催化剂,复合材料光催化剂可以更有效地分离光生电子和空穴,增加光催化析氢反应的速率。因此,通过选择复合材料异质结处合适的光催化机制(如:S-scheme),可以进一步提升催化剂的光催化析氢活性和稳定性。本文通过改变合成条件获得了一系列具有不同带隙宽度的单一CdSe-DETA光催化剂。光催化实验显示调节CdSe-DETA的带隙(2.31eV)可以获得最佳的光催化产氢活性,但是其稳定性很差。因此,我们将CdSe-DETA纳米花附着在In2O3多孔纳米片表面,构建了In_(2)O_(3)/CdSe-DETA纳米复合材料,以提升光催化析氢活性,稳定性和光电流响应。In_(2)O_(3)/CdSe-DETA纳米复合材料中异质结的类型可随着CdSe-DETA带隙宽度的改变而变化。随着CdSe-DETA带隙宽度的增加,异质结的类型可从Type-I型转变到S-scheme型。相对于单一光催化剂和Type-I型光催化剂,S-scheme型In_(2)O_(3)/CdSe-DETA纳米复合材料具有更高的光催化活性以及良好的稳定性。因此,我们选择S-scheme异质结的In_(2)O_(3)/CdSe-DETA纳米复合材料来获得光催化活性和稳定性的最大收益。此外,我们通过差分电荷密度计算结合实验结果证实了S-scheme异质结的存在。S-scheme异质结In_(2)O_(3)/CdSe-DETA纳米复合材料有效分离了光生电子和空穴,最大程度地利用复合材料的导带和价带,高效且稳定的光催化析氢。本研究展示了一种调制载流子转移机制的策略,可为开发高效的析氢光催化剂提供借鉴。

扩展性无创产前基因检测在产前诊断中的应用

目的探讨扩展性无创产前基因检测(NIPT-plus)在产前诊断中的应用价值。方法选取2020年4月至2021年12月在阜阳市人民医院就诊的159例NIPT-plus结果提示高风险的孕妇,所有孕妇均行羊膜腔穿刺术,同时进行染色体核型分析联合染色体微阵列分析(CMA)或染色体拷贝数变异(CNV)测序(CNV-seq)并进行随访,对所有孕妇的检测结果和妊娠结局进行汇总分析。结果159例NIPT-plus高风险孕妇中,21三体36例、18三体11例、13三体2例、性染色体数目异常58例、其他染色体数目异常30例、CNV 22例。159例孕妇羊水样本通过染色体核型分析联合CMA/CNV-seq检测共检出70例与NIPT-plus结果一致的异常样本和4例非NIPT-plus提示的其他异常。NITP-plus对21三体、18三体、13三体、性染色体数目异常、其他染色体数目异常、CNV的阳性预测值分别为75.0%(27/36)、72.7%(8/11)、0(0/2)、36.2%(21/58)、6.7%(2/30)和54.5%(12/22)。4例非NIPT-plus提示的其他异常的CNV片段大小均小于3 Mb,包括1例致病性变异、3例临床意义未明变异。结论NIPT-plus具有较高的准确度,对常见的染色体非整倍体异常和拷贝数变异具有一定的预测价值,同时建议NIPT-plus提示高风险的孕妇,运用染色体核型分析联合CMA或CNV-seq进行进一步的产前诊断,以确定胎儿是否存在染色体变异。

In-situ detection equipment for radon-in-water:unattended operation and monthly investigations

Radon is recognized as a powerful tracer of certain geophysical processes in marine and aquatic environments.In the past few decades,the instruments and methods for measuring radon concentration in water have been developed to some extent but still lack underwater in-situ measurements.Here we present an in-situ detection equipment for radon-in-water(pulsed ionization chamber(PIC)-radon)to measure dissolved radon in ocean and groundwater settings.The equipment has been successfully deployed in the Jiaozhou Bay in July 2022 and has achieved 14 d of unattended underwater in-situ observation.Then it was successfully placed in a groundwater monitoring well in the Laizhou Bay in November 2022 and monitored radon activities for over 30 d.The results showed that this instrument had a good indication of submarine groundwater discharge.The PIC-radon detector takes advantage of smaller size,lower power consumption,and is barely influenced by humidity,making it particularly suitable for long-term in-situ measurement,especially in harsh environments with limited human care or deployment spaces.

High throughput screening of single atomic catalysts with optimized local structures for the electrochemical oxygen reduction by machine learning

Single atomic catalysts(SACs),especially metal-nitrogen doped carbon(M-NC)catalysts,have been extensively explored for the electrochemical oxygen reduction reaction(ORR),owing to their high activity and atomic utilization efficiency.However,there is still a lack of systematic screening and optimization of local structures surrounding active centers of SACs for ORR as the local coordination has an essential impact on their electronic structures and catalytic performance.Herein,we systematic study the ORR catalytic performance of M-NC SACs with different central metals and environmental atoms in the first and second coordination sphere by using density functional theory(DFT)calculation and machine learning(ML).The geometric and electronic informed overpotential model(GEIOM)based on random forest algorithm showed the highest accuracy,and its R^(2) and root mean square errors(RMSE)were 0.96 and 0.21,respectively.30 potential high-performance catalysts were screened out by GEIOM,and the RMSE of the predicted result was only 0.12 V.This work not only helps us fast screen high-performance catalysts,but also provides a low-cost way to improve the accuracy of ML models.

Measuring^(222)Rn in aquatic environment via Pulsed Ionization Chamber Radon Detector

Radon(Rn)is a naturally occurring radioactive inert gas in nature,and^(222)Rn has been routinely used as a powerful tracer in various aquatic environmental research on timescales of hours to days,such as submarine groundwater discharge.Here we developed a new approach to measure^(222)Rn in discrete water samples with a wide range of^(222)Rn concentrations using a Pulsed Ionization Chamber(PIC)Radon Detector.The sensitivity of the new PIC system is evaluated at 6.06 counts per minute for 1 Bq/L when a 500 mL water sample volume is used.A robust logarithmic correlation between sample volumes,ranging from 250 mL to 5000 mL,and system sensitivity obtained in this study strongly suggests that this approach is suitable for measuring radon concentration levels in various natural waters.Compared to the currently available methods for measuring radon in grab samples,the PIC system is cheaper,easier to operate and does not require extra accessories(e.g.,drying tubes etc.)to maintain stable measurements throughout the counting procedure.

A Compensation Algorithm for Large Element Characterizing the Damage Evolution Process and Its Application to Structure Collisions

When simulating the process from elastic–plastic deformation,damage to failure in a metal structure collision,it is necessary to use the large shell element due to the calculation efficiency,but this would affect the accuracy of damage evolution simulation.The compensation algorithm adjusting failure strain according to element size is usually used in the damage model to deal with the problem.In this paper,a new nonlinear compensation algorithm between failure strain and element size was proposed,which was incorporated in the damage model GISSMO(Generalized incremental stress state dependent damage model)to characterize ductile fracture.And associated material parameters were calibrated based on tensile experiments of aluminum alloy specimens with notches.Simulation and experimental results show that the new compensation algorithm significantly reduces the dependence of element size compared with the constant failure strain model and the damage model with the linear compensation algorithm.During the axial splitting process of a circular tubular structure,the new compensation algorithm keeps the failure prediction errors low over the stress states ranging from shear to biaxial tension,and achieves the objective prediction of the damage evolution process.This study demonstrates how the compensation algorithm resolves the contradiction between large element size and fracture prediction accuracy,and this facilitates the use of the damage model in ductile fracture prediction for engineering structures.

Depolarization of Li-rich Mn-based oxide via electrochemically active Prussian blue interface providing superior rate capability

The high-rate cyclability of Li-rich Mn-based oxide(LMO)is highly limited by the electrochemical polarization resulting from the slow kinetic of the Li2MnO3 phase.Herein,the Prussian blue(PB)coating layer with specific redox potential is introduced as a functionalized interface to overcome the side effect and the escaping of O on the surface of LMO,especially its poor rate capability.In detail,the PB layer can restrict the large polarization of LMO by sharing overloaded current at a high rate due to the synchronous redox of PB and LMO.Consequently,an enhanced high rate performance with capacity retention of 87.8%over 300 cycles is obtained,which is superior to 50.5%of the pristine electrode.Such strategies on the high-rate cyclability of Li-rich Mn-based oxide compatible with good low-rate performances may attract great attention for pursuing durable performances.

Acute neck tendonitis with dyspnea:A case report

BACKGROUND Longus colli tendinitis(LCT)with dyspnea is a relatively less-reported condition in the literature,and physicians should be aware of its existence.Misdiagnosis of this condition may cause unnecessary treatment for dyspnea.CASE SUMMARY Herein,we report the case of a 40-year-old man with acute neck tendonitis.The patient presented to the pneumology department clinic with a complaint of acute neck tendonitis with dyspnea.An emergency cervical magnetic resonance examination was performed,and the preliminary diagnosis was“acute longus cervicalis tendinitis.”After aggressive medical treatment,the symptoms obviously improved.CONCLUSION LCT is a self-limiting disease that usually improves after three to seven days of conservative treatment following a definite diagnosis.However,owing to its insidious onset and complex clinical manifestations,most relevant personnel are not fully understood.The definite diagnosis of LCT is based on a comprehensive understanding of the triad,rare symptoms,and the clear identification of cervical 1 and 2 levels calcification and prevertebral edema by medical imaging examination,especially magnetic resonance imaging and computed tomography.

The Oblique Alfvén Ion Beam Instability in the Earth’s Ion Foreshock

How ions evolve in the Earth’s ion foreshock is a basic problem in the heliosphere community,and the ion beam instability is usually proposed to be one major mechanism affecting the ion dynamics therein.This work will perform comprehensive analyses of the oblique ion beam instability in the Earth’s ion foreshock.We show that in addition to two well-known parallel instabilities (i.e.,the parallel fast-magnetosonic whistler instability and the parallel Alfvén ion cyclotron instability),the oblique Alfvén ion beam (OA/IB) instability can also be triggered by free energy relating to the relative drift d V between the solar wind proton and reflected proton populations.For slow d V (e.g.,d V■2.2V_(A),where VAdenotes the Alfvén speed),it only triggers the OA/IB instability.When d V■2.2V_(A),the growth rate in the OA/IB instability can be about 0.6 times the maximum growth rate in parallel instabilities.Moreover,this work finds the existence of two types of OA/IB instabilities.The first one appears at slow d V and in the small wavenumber region at fast d V,and this instability can be described by the cold fluid model.The second one arises in large wavenumber regions at fast d V,and this instability only appears in warm plasmas.Furthermore,through the energy transfer rate method,we propose that the OA/IB instability is driven by the competition among the Landau and cyclotron wave-particle interactions of beam protons,the cyclotron wave-particle interaction of core protons,and the Landau wave-particle interaction of electrons.Because oblique waves can experience significant damping,the importance of the OA/IB instability may be the effective heating of ions in the Earth’s foreshock.

鸟-胞内分枝杆菌复合群与龟-脓肿分枝杆菌肺病并发支气管扩张的CT征象比较

目的探讨鸟-胞内分枝杆菌复合群(MAC)肺病与龟-脓肿分枝杆菌肺病并发支气管扩张患者CT征象的差异,提高对两种疾病并发支气管扩张的鉴别诊断水平。方法搜集2017年1—12月在广州市胸科医院门诊及住院治疗并经临床确诊的25例并发支气管扩张的鸟-胞内分枝杆菌复合群肺病患者(简称“A组”)和26例并发支气管扩张的龟-脓肿分枝杆菌肺病患者(简称“B组”),两组患者均为初诊或未经抗结核和抗非结核分枝杆菌(NTM)治疗。对两组患者的CT扫描资料进行回顾性分析,主要就两组患者支气管扩张(CT分型、分布)、肺内病灶的形态(微结节、树芽征、结节、实变等)、伴发空洞(类型、分布)的CT征象特点及并发症发生情况进行对比分析。结果B组左肺下叶支气管扩张、左肺下叶微结节、肺体积收缩的比率分别为57.69%(15/26)、84.62%(22/26)、61.54%(16/26),均明显高于A组[分别为28.00%(7/25)、56.00%(14/25)、32.00%(8/25)],差异均有统计学意义(χ^2值分别为4.58、5.03、4.46,P值分别为0.032、0.025、0.035)。A组柱状型支气管扩张占52.00%(13/25),高于B组(15.38%,4/26);B组囊状型支气管扩张占50.00%(13/26),高于A组(16.00%,4/25),差异均有统计学意义(χ^2值分别为7.69、6.63,P值分别为0.006、0.010)。结论龟-脓肿分枝杆菌肺病患者的CT表现中,左肺下叶支气管扩张、左肺下叶微结节、肺体积收缩的发生率高于MAC肺病患者;龟-脓肿分枝杆菌肺病多并发囊状型支气管扩张,而MAC肺病多并发柱状型支气管扩张,以上特征性CT征象有助于两种疾病的鉴别。

Review and Comparison of Classical Entrepreneurial Intention Models

The study of entrepreneurial models carries significance in guiding the development of entrepreneurial activities.On the basis of a literature review,this paper reviews and analyzes six classic and widely influential entrepreneurial models:entrepreneurial event model(EEM),entrepreneurial intention model(EIM),revised EIM,theory of planned behavior(TPB),economic psychological model(EPM),and structural model of entrepreneurial intention(SMEI).This paper aims to discuss the similarities and differences of these entrepreneurial intention models and their applications in different contexts,which carries important theoretical and practical significance for further research on entrepreneurial behavior and intention.

以能力塑造为核心的材料学科实验教学改革研究

针对国防科技大学"以能力塑造为核心"的材料学科人才培养计划,结合学校材料学科实验教学现状和存在的主要问题,通过改革实验教学内容,建立了基于装备材料的基础性实验、综合性实验、实装性实验和创新性实验四位一体实验教学内容体系。通过实验教学改革,夯实了学员基础实验技能,增强了学员综合运用材料知识解决装备材料问题的能力,提高了学员对典型装备材料的认识,培养了学员的实践创新技能及岗位任职能力,达到了"以能力塑造为核心"的材料专业实验教学目标。

虚拟仿真实验教学中心的发展现状探析

虚拟仿真实验是学科专业与信息技术深度融合的产物,虚拟仿真实验教学突破了高校传统的实验教学模式,是当前实验教学的发展方向。本文多角度总结了我国国家级和省级虚拟仿真实验教学中心的建设情况,分析了材料学科虚拟仿真实验教学中心的发展现状,阐明了发展材料学科虚拟仿真实验教学的紧迫性。

Electronic Transport Properties of Phenalenyl Molecular Devices via Gated Modulation

By applying nonequilibrium Green’s functions (NEGF) in combination with the density functional theory (DFT), we investigate the electronic transport properties of gated phenalenyl molecular devices with two different contact geometries. The calculated results show that electronic transport properties of the two different devices can be modulated by external transverse gates. When the molecule contacts the Au electrodes through two second-nearest sites, the current-voltage (I-V) characteristic curves are symmetric and suppressed by the gate electrodes. However, a rectifying behavior will occur when the electrodes connect the molecule on both sides, one second-nearest site and one third-nearest site, respectively. Mechanisms for such phenomena are proposed and these findings suggest a new opportunity for developing molecular devices.

氧化物钙钛矿的光催化研究进展:CO_(2)还原、水裂解、固氮

在寻求可再生能源供应及解决环境问题的迫切需求下,光电、光催化、电催化等领域中多种技术被开发以解决这一迫切问题。其中,光催化技术因其可将清洁太阳能转化为化学燃料的优越能力而备受关注。在层出不穷的光催化材料中,具有阳离子可替代性的钙钛矿氧化物(ABO_3)在电子信息、太阳能电池和光催化等领域具有极大的潜力。由于这类材料具有活性高、成本低、稳定性好、结构易调控等独特性能,钙钛矿氧化物光催化剂在水分解、二氧化碳还原转化、固氮等方面取得了广泛的应用。本文综述了光催化的结构与合成方法,重点介绍了光催化的应用,最后展望了光催化的未来发展前景。