电催化两电子水氧化制备过氧化氢的研究进展

过氧化氢(H_(2)O_(2))是一种环境友好的化学氧化剂,广泛应用于水处理、医疗消毒、化学合成等工业领域。电催化两电子水氧化反应(2e^(-)WOR)是一种可以在温和条件下直接从水中生产H_(2)O_(2)的方法。然而,受限于反应机理认识和催化材料设计的不足,2e^(-)WOR的催化选择性和活性仍然较低。本文综述了近年来通过2e^(-)WOR反应路径电合成H_(2)O_(2)的研究进展,首先介绍了2e^(-)WOR的催化机理和研究方法,强调了理论计算加速高选择性、高活性和高稳定性催化剂研究的作用,并讨论了电合成H_(2)O_(2)的不同定量方法和原位表征手段;然后详细总结了高性能2e^(-)WOR电催化剂的调控策略,包括缺陷、掺杂、晶面和界面工程,同时指出了反应器创新设计的重要性;最后展望了电合成H_(2)O_(2)的研究挑战和机遇。

The complete reference genome for grapevine (Vitis vinifera L.) genetics and breeding

Grapevine is one of the most economically important crops worldwide.However,the previous versions of the grapevine reference genome tipically consist of thousands of fragments with missing centromeres and telomeres,limiting the accessibility of the repetitive sequences,the centromeric and telomeric regions,and the study of inheritance of important agronomic traits in these regions.Here,we assembled a telomere-to-telomere(T2T)gap-free reference genome for the cultivar PN40024 using PacBio HiFi long reads.The T2T reference genome(PN_T2T)is 69 Mb longer with 9018 more genes identified than the 12X.v0 version.We annotated 67%repetitive sequences,19 centromeres and 36 telomeres,and incorporated gene annotations of previous versions into the PN_T2T assembly.We detected a total of 377 gene clusters,which showed associations with complex traits,such as aroma and disease resistance.Even though PN40024 derives from nine generations of selfing,we still found nine genomic hotspots of heterozygous sites associated with biological processes,such as the oxidation–reduction process and protein phosphorylation.The fully annotated complete reference genome therefore constitutes an important resource for grapevine genetic studies and breeding programs.

Green,Sustainable Architectural Bamboo with High Light Transmission and Excellent Electromagnetic Shielding as a Candidate for Energy-Saving Buildings

Currently,light-transmitting,energy-saving,and electromagnetic shielding materials are essential for reducing indoor energy consumption and improving the electromagnetic environment.Here,we developed a cellulose composite with excellent optical transmittance that retained the natural shape and fiber structure of bamboo.The modified whole bamboo possessed an impressive optical transmittance of approximately 60%at 6.23 mm,illuminance of 1000 luminance(lux),water absorption stability(mass change rate less than 4%),longitudinal tensile strength(46.40 MPa),and surface properties(80.2 HD).These were attributed to not only the retention of the natural circular hollow structure of the bamboo rod on the macro,but also the complete bamboo fiber skeleton template impregnated with UV resin on the micro.Moreover,a multilayered device consisting of translucent whole bamboo,transparent bamboo sheets,and electromagnetic shielding film exhibited remarkable heat insulation and heat preservation performance as well as an electromagnetic shielding performance of 46.3 dB.The impressive optical transmittance,mechanical properties,thermal performance,and electromagnetic shielding abilities combined with the renewable and sustainable nature,as well as the fast and efficient manufacturing process,make this bamboo composite material suitable for effective application in transparent,energy-saving,and electromagnetic shielding buildings.

绿色信贷对环境污染治理的影响机制及异质性研究:基于我国长三角地区的实证检验

在我国“双碳”目标的背景下,绿色信贷对环境污染的治理发挥了重要的作用。长三角地区是中国经济高质量发展的示范区,是推进“双碳”目标实现的重要区域。本文基于2013-2019年我国长三角地区41个城市的面板数据,采用双向固定效应模型考察了该地区绿色信贷对环境污染治理的影响、异质特征及作用机制。实证结果表明:(1)绿色信贷的发展对长三角地区环境污染治理具有显著正效应,通过了内生性检验和多重稳健性检验之后,二者的关系依然显著存在。(2)绿色信贷对环境污染的治理效应具有显著的异质性特征。具体而言,属于长三角城市群的城市、大规模城市、财政失衡程度较低和环境污染程度较高的城市,绿色信贷的环境治理效应更为显著。(3)绿色信贷可以通过推进企业技术创新、产业结构升级以及促进经济增长的机制促进环境污染治理,在地方财政存在较为严重失衡问题的情况下,上述传导机制均会被抑制。基于分析结果,本文从鼓励商业银行开展绿色信贷业务、促进区域协调联动、支持企业进行技术创新及深化财政分权体制改革等方面提出政策建议。

梯级水电站群短期发电调度计划快速生成方法

随着水电系统发展，发电计划制定面临着越来越复杂的需求。为避免求解复杂数学规划模型，本文提出一种快速生成梯级水电短期发电计划的方法。该方法不采用特定的目标函数，而是根据实际调度中普遍接受的降低耗水率、有利于负荷平衡、上下游水库协调等原则，在优化模型中采用的约束条件下制定发电计划。该方法由一系列满足调度期末水位、发电用水量、总电量，以及减少弃水的基本操作构成。根据负荷特性将时段排序，并结合能够满足时段关联约束的负荷分配算法，实现这些调度目标。以南方电网红水河梯级水电站群为背景的实例研究表明该方法能有效制定发电计划，并满足复杂的出力分配规则。

Direct Ink Writing of Highly Conductive MXene Frames for Tunable Electromagnetic Interference Shielding and Electromagnetic Wave-Induced Thermochromism

The highly integrated and miniaturized next-generation electronic products call for high-performance electromagnetic interference(EMI)shielding materials to assure the normal operation of their closely assembled components.However,the most current techniques are not adequate for the fabrication of shielding materials with programmable structure and controllable shielding efficiency.Herein,we demonstrate the direct ink writing of robust and highly conductive Ti3C2Tx MXene frames with customizable structures by using MXene/AlOOH inks for tunable EMI shielding and electromagnetic wave-induced thermochromism applications.The as-printed frames are reinforced by immersing in AlCl_(3)/HCl solution to remove the electrically insulating AlOOH nanoparticles,as well as cross-link the MXene sheets and fuse the filament interfaces with aluminum ions.After freeze-drying,the resultant robust and porous MXene frames exhibit tunable EMI shielding efficiencies in the range of 25-80 dB with the highest electrical conductivity of 5323 S m−1.Furthermore,an electromagnetic wave-induced thermochromic MXene pattern is assembled by coating and curing with thermochromic polydimethylsiloxane on a printed MXene pattern,and its color can be changed from blue to red under the high-intensity electromagnetic irradiation.This work demonstrates a direct ink printing of customizable EMI frames and patterns for tuning EMI shielding efficiency and visualizing electromagnetic waves.

Decentralized Searching of Multiple Unknown and Transient Radio Sources with Paired Robots

In this paper, we develop a decentralized algorithm to coord inate a group of mobile robots to search for unknown and transient radio sources. In addition to limited mobility and ranges of communication and sensing, the robot team has to deal with challenges from signal source anonymity, short transmission duration, and variable transmission power. We propose a two-step approach: First, we decentralize belief functions that robots use to track source locations using checkpoint-based synchronization, and second, we propose a decentralized planning strategy to coordinate robots to ensure the existence of checkpoints. We analyze memory usage, data amount in communication, and searching time for the proposed algorithm. We have implemented the proposed algorithm and compared it with two heuristics. The experimental results show that our algorithm successfully trades a modest amount of memory for the fastest searching time among the three methods.

Multiplexing technology based on SQUID for readout of superconducting transition-edge sensor arrays

Multiplexing technologies based on superconducting quantum interference devices(SQUIDs) are crucial to cryogenic readout of superconducting transition-edge sensor(TES) arrays. Demands for large-scale TES arrays promote the development of multiplexing technologies towards large multiplexing factors and low readout noise. The development of multiplexing technologies also facilitates new applications of TES arrays in a wide range of frequencies. Here we summarize different types of SQUID-based multiplexing technologies including time-division multiplexing, code-division multiplexing, frequency-division multiplexing and microwave SQUID multiplexing. The advances and parameter constraints of each multiplexing technology are also discussed.

Gate-regulated transition temperatures for electron hopping behaviours in silicon junctionless nanowire transistors

We investigate gate-regulated transition temperatures for electron hopping behaviours through discrete ionized dopant atoms in silicon junctionless nanowire transistors.We demonstrate that the localization length of the wave function in the spatial distribution is able to be manipulated by the gate electric field.The transition temperatures regulated as the function of the localization length and the density of states near the Fermi energy level allow us to understand the electron hopping behaviours under the influence of thermal activation energy and Coulomb interaction energy.This is useful for future quantum information processing by single dopant atoms in silicon.

Study on the Preparation and Adsorption Property of Polyvinyl Alcohol/Cellulose Nanocrystal/Graphene Composite Aerogels(PCGAs)

The cellulose nanocrystals/graphene composite aerogel(CGA)and polyvinyl alcohol/cellulose nanocrystals/graphene composite aerogel(PCGA)were prepared by suspension titration,tert-butanol solution replacement and freeze-drying successively.The removal rates of methyl blue(MB)from water by CGA and PCGA were evaluated and the effects of additions,adsorption time,reaction temperature and pH value of CGA and PCGA on MB removal rate were discussed.It was found that the optimal concentrations of both CGA and PCGA were 2 g∙L-1 in the adsorption reaction process and the adsorption equilibrium was reached within 120 min.The higher the initial pH value of MB solution is,the better the removal effect will be.The adsorption kinetics conformed to the pseudo-second-order kinetic model.The langmuir isothermal adsorption equation showed the maximum adsorption capacities of CGA and PCGA were 125 mg∙g-1 and 110.9 mg∙g-1,respectively.Under the conditions of adsorption time of 120 min,reaction temperature of 323 K,and initial MB solution pH value of 11,both CGA and PCGA had higher removal rates of MB,reaching more than 98%.

A Novel Metaheuristic Algorithm: The Team Competition and Cooperation Optimization Algorithm

Metaheuristic algorithm is a generalization of heuristic algorithm that can be applied to almost all optimization problems.For optimization problems,metaheuristic algorithm is one of the methods to find its optimal solution or approximate solution under limited conditions.Most of the existing metaheuristic algorithms are designed for serial systems.Meanwhile,existing algorithms still have a lot of room for improvement in convergence speed,robustness,and performance.To address these issues,this paper proposes an easily parallelizable metaheuristic optimization algorithm called team competition and cooperation optimization(TCCO)inspired by the process of human team cooperation and competition.The proposed algorithm attempts to mathematically model human team cooperation and competition to promote the optimization process and find an approximate solution as close as possible to the optimal solution under limited conditions.In order to evaluate the performance of the proposed algorithm,this paper compares the solution accuracy and convergence speed of the TCCO algorithm with the Grasshopper Optimization Algorithm(GOA),Seagull Optimization Algorithm(SOA),Whale Optimization Algorithm(WOA)and Sparrow Search Algorithm(SSA).Experiment results of 30 test functions commonly used in the optimization field indicate that,compared with these current advanced metaheuristic algorithms,TCCO has strong competitiveness in both solution accuracy and convergence speed.

Highly conductive calcium ion-reinforced MXene/sodium alginate aerogel meshes by direct ink writing for electromagnetic interference shielding and Joule heating

Although MXene sheets possess high electrical conductivity and rich surface chemistry and are well suit-able for fabricating electrically conductive nanocomposites for electromagnetic interference(EMI)shield-ing applications,it remains challenging for MXene nanocomposites to achieve tunable EMI shielding per-formances and customized geometries.Herein,an aqueous MXene/sodium alginate ink is developed to print aerogel meshes with customized geometries using a direct ink writing approach.An ion-enhanced strategy is proposed to reinforce the printed aerogel meshes by multi-level cross-linking.The resultant 3D printed aerogel mesh exhibits an ultrahigh electrical conductivity of 2.85×10^(3)S m^(−1),outstanding mechanical properties,and excellent structural stability in wet environment.More importantly,a wide range of tunable EMI shielding efficiencies from 45 to 100 dB is achieved by the structural design of the 3D printed ion-enhanced MXene/sodium alginate aerogel meshes.As a Joule heater,in addition,the printed aerogel meshes can achieve a wide temperature range of 40-135℃at low driving voltages.This work demonstrates a direct ink writing approach for the fabrication of ion-enhanced MXene/sodium al-ginate aerogel meshes with tunable EMI shielding properties and multi-functionalities for applications in many scenarios.

Highly efficient base editing in rabbit by using near-PAMless engineered CRISPR/Cas9 variants

Dear Editor,Base editors can achieve targeted C-to-T and A-to-G conversion without the generation of DNA double-strand breaks(DSBs)or the requirement of a donor template,showing the potential to generate new mutations or to correct pathogenic mutations(Gaudelli et al.,2018).However,for conventional base editors,efficient base editing requires the presence of an NGG protospacer adjacent motif(PAM)that lies 12–16 nt downstream of the target bases,which generally limits the application of these base editors(Gaudelli et al.,2018).

Promising roles of non-exosomal and exosomal non-coding RNAs in the regulatory mechanism and as diagnostic biomarkers in myocardial infarction

Non-exosomal non-coding RNAs(non-exo-ncRNAs)and exosomal ncRNAs(exo-ncRNAs)have been associated with the pathological development of myocardial infarction(MI).Accordingly,this analytical review provides an overview of current MI studies on the role of plasma non-exo/exo-ncRNAs.We summarize the features and crucial roles of ncRNAs and reveal their novel biological correlations via bioinformatics analysis.The following contributions are made:(1)we comprehensively describe the expression profile,competing endogenous RNA(ceRNA)network,and“pre-necrotic”biomarkers of non-exo/exo-ncRNAs for MI;(2)functional enrichment analysis indicates that the target genes of ncRNAs are enriched in the regulation of apoptotic signaling pathway and cellular response to chemical stress,etc.;(3)we propose an updated and comprehensive view on the mechanisms,pathophysiology,and biomarker roles of non-exo/exo-ncRNAs in MI,thereby providing a theoretical basis for the clinical management of MI.

Editorial for the special issue on wearable robots and intelligent device

Wearable devices have a long history,even though wearable robots as emerging area is relatively new.An early report of wearable device can be found in the book Tian Gong Kai Wu(天工开物),published in 1637 where an ancient mechanism that was mounted on human body for cotton fluffing was documented.This type of wearable cotton fluffing tool can still be found in rural areas of China today.

Lane changing assistance strategy based on an improved probabilistic model of dynamic occupancy grids

Lane changing assistance in autonomous vehicles is a popular research topic. Scene modeling of the driving area is a prerequisite for lane changing decision problems. A road environment representation method based on a dynamic occupancy grid is proposed in this study. The model encapsulates the data such as vehicle speed, obstacles, lane lines, and traffic rules into a form of spatial drivability probability. This information is compiled into a hash table, and the grid map is mapped into a hash map by means of hash function. A vehicle behavior decision cost equation is established with the model to help drivers make accurate vehicle lane changing decisions based on the principle of least cost, while considering influencing factors such as vehicle drivability, safety, and power. The feasibility of the lane changing assistance strategy is verified through vehicle tests, and the results show that the lane changing assistance system based on a probabilistic model of dynamic occupancy grids can provide lane changing assistance to drivers taking into consideration the dynamics and safety.

Multimodal Locomotion and Cargo Transportation of Magnetically Actuated Quadruped Soft Microrobots

Untethered microrobots have attracted extensive attention due to their potential for biomedical applications and micromanipulation at the small scale.Soft microrobots are of great research importance because of their highly deformable ability to achieve not only multiple locomotion mechanisms but also minimal invasion to the environment.However,the existing microrobots are still limited in their ability to locomote and cross obstacles in unstructured environments compared to conventional legged robots.Nature provides much inspiration for developing miniature robots.Here,we propose a bionic quadruped soft thin-film microrobot with a nonmagnetic soft body and 4 magnetic flexible legs.The quadruped soft microrobot can achieve multiple controllable locomotion modes in the external magnetic field.The experiment demonstrated the robot’s excellent obstacle-crossing ability by walking on the surface with steps and moving in the bottom of a stomach model with gullies.In particular,by controlling the conical angle of the external conical magnetic field,microbeads gripping,transportation,and release of the microrobot were demonstrated.In the future,the quadruped microrobot with excellent obstacle-crossing and gripping capabilities will be relevant for biomedical applications and micromanipulation.

Ⅳ期NSCLC原发肿瘤三维放射治疗失败模式分析

目的探讨Ⅳ期NSCLC原发肿瘤三维放疗联合药物一线治疗的失败模式特点及放疗相关因素的影响。方法选择2003年3月至2020年7月708例初诊Ⅳ期NSCLC患者,χ2检验失败模式单因素分析;Kaplan-Meier法并log-rank检验、Cox回归模型多因素生存分析。结果708例首次失败发生率71.2%,≤6个月、>6~12个月、>12~24个月、>24个月的治疗失败发生率分别为22.7%、28.8%、13.3%、6.4%,中位生存期分别为7.2、13.4、22.2、37.6个月,差异有统计学意义(χ2=226.013,P<0.001)。复发失败发生率为21.3%,寡转移和非寡转移的复发失败发生率差异无统计学意义。转移失败发生率为66.3%,从高到低依次为脑>骨>肺>胸膜腔>肝>远处淋巴结>肾上腺>其他部位,约1/2病例发生新增转移器官,约1/3病例发生原转移器官进展。转移状态、治疗失败发生时间、病理类型、性别、综合治疗强度是预后的独立影响因素。结论Ⅳ期NSCLC原发肿瘤放疗的失败模式与一线药物治疗不同,局部失败显著降低,转移失败为主,脑转移发生率最高,治疗失败发生时间越晚,OS期越长。寡转移、女性、非鳞癌、治疗失败发生时间晚、4~6个周期化疗同期放疗剂量≥63 Gy是延长生存的独立预后因子。

Robot-aided fN∙m torque sensing within an ultrawide dynamic range

In situ scanning electron microscope(SEM)characterization have enabled the stretching,compression,and bending of micro/nanomaterials and have greatly expanded our understanding of small-scale phenomena.However,as one of the fundamental approaches for material analytics,torsion tests at a small scale remain a major challenge due to the lack of an ultrahigh precise torque sensor and the delicate sample assembly strategy.Herein,we present a microelectromechanical resonant torque sensor with an ultrahigh resolution of up to 4.78 fN∙m within an ultrawide dynamic range of 123 dB.Moreover,we propose a nanorobotic system to realize the precise assembly of microscale specimens with nanoscale positioning accuracy and to conduct repeatable in situ pure torsion tests for the first time.As a demonstration,we characterized the mechanical properties of Si microbeams through torsion tests and found that these microbeams were five-fold stronger than their bulk counterparts.The proposed torsion characterization system pushes the limit of mechanical torsion tests,overcomes the deficiencies in current in situ characterization techniques,and expands our knowledge regarding the behavior of micro/nanomaterials at various loads,which is expected to have significant implications for the eventual development and implementation of materials science.