Vacancy-modified bimetallic FeMoS_(x)/CoNiP_(x) heterostructure array for efficient seawater splitting and Zn-air battery

The development of highly efficient OER catalysts with superior durability for seawater electrolysis and Zn-air battery is important but challenging.Herein,the vacancy-modified heterostructured bimetallic Fe Mo S_(x)/Co Ni P_(x)OER electrocatalyst is exploited.Benefiting from the electron redistribution and reaction kinetics modulation resulting from vacancy introduction and heterojunction formation,it yields ultralow OER overpotentials of 196,276,303 m V in 1 M KOH and 197,318,348 m V in 1 M KOH+seawater at 10,500,1000 m A cm^(-2),respectively,surviving 600 h at 800 m A cm^(-2)without obvious decay.Further,FeMoS_(x)/CoNiP_(x)-based Zn-air battery not only affords the high peak power density of 214.5 m W cm^(-2)but also exhibits the small voltage gap of 0.698 V and long lifetime of 500 h at 10 m A cm^(-2),overmatching overwhelming majority of reported advanced catalysts.It is revealed experimentally that the OER process on rationally designed Fe Mo S_(x)/Co Ni P_(x)follows the adsorbate evolution mechanism and the ratedetermining step shifts from^(*)OOH formation in individual building blocks to^(*)OOH deprotonation process in FeMoS_(x)/CoNiP_(x),providing the directly proof of how the vacancy introduction and heterojunction formation affect the reaction kinetics.

Synergistic Effect and Electrochromic Mechanism of Nanoflake Li-doped NiO in LiOH Electrolyte

Inorganic metal oxide electrochromic materials have good application prospects for energy-saving windows in buildings and smart display applications.Therefore,the development of electrochromic films with good cycling stabilities,fast color-change response times,and high coloring efficiencies has attracted considerable attention.In this study,nanoflake Li-doped NiO electrochromic films were prepared using a hydrothermal method,and the films exhibited superior electrochromic performances in the LiOH electrolyte.Li^(+)ions doping increased the ion transmission rates of the NiO films,and effectively promoted the transportation of ions from the electrolyte into NiO films.Meanwhile,the nanoflake microstructure caused the NiO films to have larger specific surface areas,providing more active sites for electrochemical reactions.It was determined that the NiO-Li20%film exhibited an ultra-fast response in the LiOH electrolyte(coloring and bleaching times reached 3 and 1.5 s,respectively).Additionally,the coloration efficiency was 62.1 cm^(2)C^(−1),and good cycling stability was maintained beyond 1500 cycles.Finally,the simulation calculation results showed that Li doping weakened the adsorption strengths of the NiO films to OH^(−),which reduced the generation and decomposition of NiOOH and helped to improve the cycling stabilities of the films.Therefore,the research presented in this article provides a strategy for designing electrochromic materials in the future.

聚氨酯类锚固剂的合成及对软质聚氯乙烯的改性

使用自制的中低相对分子质量的热塑性聚氨酯(TPU)齐聚物"锚固剂"(AA),可将增塑剂分子"锚固"在聚氯乙烯(PVC)基体上,从而改善PVC的迁移析出性能和低温性能。通过凝胶渗透色谱、红外光谱、差示扫描量热分析和动态力学热分析表征了自制的"锚固剂"(AA)。通过扫描电镜、动态力学热分析、高低温力学性能以及高低温迁移析出性能测试,研究了AA与PVC的相容性以及对软质PVC性能的影响。结果表明,AA与PVC可互容,AA用量至60 phr,-30℃时软质PVC的断裂伸长率保留率提高了280%倍左右,-10℃时温度敏感指数下降了44%,迁移析出率下降了72%。相同增塑剂含量下,DOTP/AA复合体系与纯DOTP相比,-30℃时的温度敏感指数仅为后者的24%,-10℃时的迁移析出率仅为后者的5%左右。

Anionic formulation of electrolyte additive towards stable electrocatalytic oxygen evolution in seawater splitting

Hydrogen generation through seawater electrolysis provides a promising,attractive pathway towards the utilization of sustainable energy.However,the catalytic activity and stability of oxygen evolution anode are severely limited by the chloride-induced corrosion and competitive oxidation reactions.In this work,we demonstrate an anion-assisted performance improvement strategy by quick and universal screening of electrolyte additive via correlating Cl-repellency with the anionic properties.Particularly,the addition of phosphate ions is found to enable highly stable alkaline seawater splitting at industry-level current density(0.5 A cm^(-2))over 500 h using transition metal hydroxides as anodic electrocatalysts.In situ experiments and theoretical simulations further reveal that the dynamic anti-corrosion behaviors of surface-adsorbed phosphate ions are attributed to three factors including repelling Cl-ions without significantly blocking OH-diffusion,preventing transition metal dissolution and acting as a local pH buffer to compensate the fast OH-consumption under high current electrolysis.

High-throughput identification of one-dimensional atomic wires and first principles calculations of their electronic states

Low dimensional materials are suitable candidates applying in next-generation high-performance electronic,optoelectronic,and energy storage devices because of their uniquely physical and chemical properties.In particular,one-dimensional(1D)atomic wires(AWs)exfoliating from 1D van der Waals(vdW)bulks are more promising in next generation nanometer(nm)even sub-nm device applications owing to their width of few-atoms scale and free dandling bonds states.Although several 1D AWs have been experimentally prepared,few 1D AW candidates could be practically applied in devices owing to lack of enough suitable 1D AWs.Herein,367 kinds of 1D AWs have been screened and the corresponding computational database including structures,electronic structures,magnetic states,and stabilities of these 1D AWs has been organized and established.Among these systems,unary and binary 1D AWs with relatively small exfoliation energy are thermodynamically stable and theoretically feasible to be exfoliated.More significantly,rich quantum states emerge,such as 1D semiconductors,1D metals,1D semimetals,and 1D magnetism.This database will offer an ideal platform to further explore exotic quantum states and exploit practical device applications using 1D materials.The database are openly available at http://www.dx.doi.org/10.11922/sciencedb.j00113.00004.

Materials Design on the Origin of Gap States in a High-κ/GaAs Interface

Given the demand for constantly scaling micro- electronic devices to ever smaller dimensions, a SiO2 gate dielectric was substituted with a higher dielectric-constant material, Hf（Zr）O2, in order to minimize current leakage through dielectric thin film. However, upon interfacing with high dielectric constant （high-κ） dielectrics, the electron mobility in the conventional Si channel degrades due to Coulomb scattering, surface-roughness scattering, remotephonon scattering, and dielectric-charge trapping.Ⅲ-Ⅴ and Ge are two promising candidates with superior mobility over Si. Nevertheless, Hf（Zr）O2/Ⅲ-Ⅴ（Ge） has much more complicated interface bonding than Si-based interfaces. Successful fabrication of a high-quality device critically depends on understanding and engineering the bonding configurations at Hf（Zr）O2/Ⅲ-Ⅴ（Ge） interfaces for the optimal design of device interfaces. Thus, an accurate atomic insight into the interface bonding and mechanism of interface gap states formation becomes essential. Here, we utilize first- principle calculations to investigate the interface between HfO2 and GaAs. Our study shows that As--As dimer bonding, Ga partial oxidation （between 3＋ and 1＋） and Ga- dangling bonds constitute the major contributions to gap states. These findings provide insightful guidance for optimum interface passivation.

Hydrogen-assisted activation of N_(2)molecules on atomic steps of ZnSe nanorods

Electrochemical reduction reaction of nitrogen(NRR)offers a promising pathway to produce ammonia(NH_(3))from renewable energy.However,the development of such process has been hindered by the chemical inertness of N_(2).It is recently proposed that hydrogen species formed on the surface of electrocatalysts can greatly enhance NRR.However,there is still a lack of atomiclevel connection between the hydrogenation behavior of electrocatalysts and their NRR performance.Here,we report an atomistic understanding of the hydrogenation behavior of a highly twinned ZnSe(T-ZnSe)nanorod with a large density of surface atomic steps and the activation of N_(2)molecules adsorbed on its surface.Our theoretical calculations and in situ infrared spectroscopic characterizations suggest that the atomic steps are essential for the hydrogenation of T-ZnSe,which greatly reduces its work function and efficiently activates adsorbed N_(2)molecules.Moreover,the liquid-like and free water over T-ZnSe promotes its hydrogenation.As a result,T-ZnSe nanorods exhibit significantly enhanced Faradaic efficiency and NH3 production rate compared with the pristine ZnSe nanorod.This work paves a promising way for engineering electrocatalysts for green and sustainable NH3 production.

Corrigendum to “Drivers of PM_(2.5)-O_(3) co-pollution: from the perspective of reactive nitrogen conversion pathways in atmospheric nitrogen cycling” [Sci. Bull. 67(18) (2022) 1833–1836]

The authors would like to correct Fig.1e,f.Due to our neglect when doing the picture layout of Fig.1,the abscissa in Fig.1e,f is error:the abscissa ranges from
80 to 0 in Fig.1e and ranges from
90 to
20 in Fig.1f.The image has been corrected:the abscissa ranges from
80 to 80 in Fig.1e and ranges from
80 to 80 in Fig.1f[1].We declare that this correction does not change the results or conclusions of this paper.

非传统稳定同位素在大气颗粒物溯源中的应用

大气颗粒物对环境与人体健康都具有显著的负面影响,是当前严重的环境污染问题之一.准确判断大气颗粒物的来源是大气颗粒物污染控制的重要前提.近年来,基于天然稳定同位素的大气颗粒物溯源技术受到了广泛关注.本文综述了大气颗粒物中非传统稳定同位素(主要包括硅、锶、铁、锌、铜、钕、铅、汞、碘)的组成分析方法和溯源应用,总结了大气颗粒物中同位素组成的时空分布特征及各排放源同位素组成的差异性,并对非传统稳定同位素应用于大气颗粒物溯源的未来发展趋势进行了展望.

掺铒氟硫磷酸盐高增益激光光纤

光纤激光器是大功率激光、空间激光通信、引力波探测、地球磁力探测等国家安全与科学前沿领域的迫切和重大需求.稀土离子掺杂的高增益玻璃光纤是光纤激光器的核心工作介质.氟硫磷酸盐(fluoro-sulfo-phosphate,FSP)激光玻璃具有稀土溶解度高、受激发射截面大、光学光谱性质优异等特点,是高增益激光光纤的潜在候选.本文从玻璃形成区、玻璃结构与性质关系、掺稀土玻璃发光与激光角度系统研究了Al F_(3)-R_(2)SO_(4)-RPO_(3)/Zn(PO_(3))_(2)(R=Li、Na、K)系列新型FSP玻璃.结果表明,热力学方法有助于简便快速地确定玻璃形成区,为该类新型激光玻璃设计提供指导.通过固体核磁共振谱、拉曼光谱、差示扫描量热分析、耐久性实验等揭示了Zn(PO_(3))_(2)能够提高FSP玻璃的结构聚合度和阴阳离子相互作用强度,从而增强玻璃的抗析晶稳定性和化学耐久性等,为大尺寸玻璃制备和光纤拉制奠定基础.Er^(3+)/Yb^(3+)共掺FSP激光玻璃典型的Er^(3+):^(4)I_(13/2)→^(4)I_(15/2)跃迁(~1.5μm)的荧光寿命为5.9~7.5 ms,发射截面为8.5×10^(–21)~9.0×10^(–21)cm^(2),光谱品质因子最高为6.4×10^(–23)cm^(2)s,饱和强度最低为1.0×10^(7)W/m^(2),优于部分掺铒磷酸盐、氟磷酸盐激光玻璃.通过组分优化,本文制备了Er^(3+)/Yb^(3+)共掺FSP单模光纤,峰值增益达4.7 d B/cm@1535 nm.基于该光纤实现了阈值约为50 m W、斜率效率为11.3%的光纤激光.

A multijunction of ZnIn2S4 nanosheet/TiO2 film/Si nanowire for significant performance enhancement of water splitting

Photoelectrodes with a specific structure and composition have been proposed for improving the efficiency of solar water splitting. Here, a novel multijunction structure was fabricated, with Si nanowires as cores, ZnIn2S4 nanosheets as branches, and TiO2 films as sandwiched layers. This junction exhibited a superior photoelectrochemical performance with a maximum photoconversion efficiency of 0.51%, which is 795 and 64 times higher than that of a bare Si wafer and nanowires, respectively. The large enhancement was attributed to the effective electron-hole separation and fast excited carrier transport within the multijunctions resulting from their favorable energy band alignments with water redox potentials, and to the enlarged contact area for facilitating the electron transfer at the multijunction/electrolyte interface.

Effect of defects in TiO2 nanoplates with exposed {001} facets on the gas sensing properties

The exposed crystal facet of TiO2 is a crucial factor influencing the gas sensing properties. TiO2 with high-energy{001}crystal facets that have higher surface energy and reactivity is expected to exhibit excellent gas-sensing properties. In this paper, TiO2 nanoplates with defective{001}facets were synthesized by chemical etching via one-step hydrothermal method. We carefully explored the gas-sensing performance of TiO2 nanoplates with defective and complete{001}facets towards acetone. The results show that the sensing response of TiO2 nanoplates with complete{001}facets is 70%higher than that of defective TiO2 nanoplates, which proves that the{001}facets plays a vital role in improving the gas sensing performance of TiO2. It is speculated that the poor gas sensitivity of defective TiO2 can be contributed to fewer adsorption sites and blocked electron transfer. This work presents a more direct evidence for explaining the important role of the complete{001}crystal facets in high sensitivity of TiO2 and also provides a new insight for preparing high sensitivity sensing materials.

High performance of a unique mesoporous polystyrene-based adsorbent for blood purification

A multi-functional polystyrene based adsorbent(NKU-9)with a unique mesoporous and a high surface area was prepared by suspension polymerization for removal of therapeutic toxins in blood purification.The adsorbent produced had an almost equal amount of mesopore distribution in the range from 2 to 50 nm.The adsorption of serum toxins with different molecular weights were examined by in vitro adsorption assays and compared with some clinical currently used adsorbents such as HA-330,Cytosorb and BL-300 which are produced by China,America and Japan,respectively.Test results indicated that the adsorption rate for pentobarbital by NKU-9 was 81.24%which is nearly as high as HA-330(81.44%).The latter adsorbent is currently used for acute detoxification treatment in China.To reach adsorption equilibrium,NKU-9 was faster than HA-330,which implies short treatment time.For the removal of middle molecular toxins such as b2-microglobulin(98.88%),NKU-9 performed better adsorptive selectivity than Cytosorb(92.80%).In addition,NKU-9 showed high performance for the removal of albumin-bound toxins(e.g.,bilirubin),and its adsorption rate for total bilirubin(80.79%)in plasma was 8.4%higher than that of anion exchange resin BL-300 which is currently used to eliminate bilirubin in clinic.Therefore,our results indicate that the newly developed adsorbent with a wide distribution and almost equal amount of mesopores is a multifunctional adsorbent for high efficient removal of serum toxins with different molecular weights which might be an excellent blood purification adsorbent especially to treat diseases that conventional medical methods are low or not efficient.

Drivers of PM2.5-O3 co-pollution:from the perspective of reactive nitrogen conversion pathways in atmospheric nitrogen cycling

Fine particulate matter(PM)and ozone(O),two globally signifcant air pollutants,have exerted substantial adverse impacts on climate and human health[1].From 2013 to 2020,China has achieved a signifcant decline of PMlevels,though O3pollution has deteriorated over time[2].PM-Oco-pollution includes not only both high levels of PMand O,but also high PMor Oeven when the other remain low.Therefore,the coordinated control of PMand Oshould not only focus on reducing high concentrations of PMand Osimultaneously.

Design rules of pseudocapacitive electrode materials:ion adsorption,diffusion,and electron transmission over prototype TiO_(2)

The development of a high-performing pseudocapacitor requires a comprehensive understanding of electrode materials from the aspects of electron transfer and electrolyte ion adsorption and diffusion.Herein,these factors are considered over the prototype TiO_(2),and a high pseudocapacitance is achieved via the introduction of various defects,i.e.,oxygen defect(V_(O))and co-doped defect(V_(O)+N_(O)).The study is based on joint explorations of first-principle calculations and the transfer matrix method.Relative to pristine TiO_(2)(300 F g^(-1)),defective TiO_(2) produces pseudocapacitance as high as 1700 F g^(-1).Moreover,defects induce small barriers for electron transmission caused by surface band bending.The climbing image nudged elastic band diffusion of H ions displays a much higher barrier in TiO_(2)-V_(O) than in TiO_(2)-V_(O)+N_(O).Such a result indicates easy H diffusion in the co-doped system.This work provides insights into the adsorption and diffusion of electrolyte ions and the influence of defects on electron transfer.The results are also significant for the design and optimization of electrode materials for the next generation of supercapacitors.

Guest Editorial: Special Issue on Wireless Sensor Networks, Cyber-Physical Systems, and Internet of Things

Recent convergence of information communications technology and sensing equipment is creating new de- mands and opportunities for wireless sensor networks without technological restrictions, such as cyber- physical systems and internet of things. The fast-growing number of wireless sensor networks, the variety of sensors, the different granularity of time control in cyber-physical systems,

Forced Collision:Detecting Wormhole Attacks with Physical Layer Network Coding

Previous research on security of network coding focused on the protection of data dissemination procedures and the detection of malicious activities such as pollution attacks. The capabilities of network coding to detect other attacks have not been fully explored. In this paper, we propose a new mechanism based on physical layer network coding to detect wormhole attacks. When two signal sequences collide at the receiver, the starting point of the collision is determined by the distances between the receiver and the senders. Therefore, by comparing the starting points of the collisions at two receivers, we can estimate the distance between them and detect fake neighbor connections via wormholes. While the basic idea is clear, we have proposed several schemes at both physical and network layers to transform the idea into a practical approach. Simulations using BPSK modulation at the physical layer show that the wireless nodes can effectively detect fake neighbor connections without the adoption of special hardware or time synchronization.

Informative and diverse emotional conversation generation with variational recurrent pointer-generator

1 Introduction and main contributions The controllable multi-turn emotional response generation task aims to understand the feelings and intentions according to the conversation history between two speakers,and then generate emotionally consistent and empathic responses based on the specific emotion category for smooth human-machine communication[1].The traditional methods[1–3]on this task only focused on enriching the response with desired emotion,which,however,can only generate safe and dull emotional responses.Inspired by the psychology theory on the emotional trigger expressions[4],in this paper,we conjecture that taking the expressions into consideration can refine conversation generation and enhance user satisfaction.Specifically,the emotional trigger expressions can be defined as:the entity-related words and phrases which can provoke and cause the desired emotion of any response.

Atomically Dispersed Ru-Decorated TiO_(2) Nanosheets for Thermally Assisted Solar-Driven Nitrogen Oxidation into Nitric Oxide

Thermally assisted photodriven nitrogen oxidation to nitric oxide(NO)using air as a reactant is a promising way to supersede the traditional NO synthesis industry accompanied by huge energy expenditure and greenhouse gas emission.Meanwhile,breaking the N≡N triple bond(941 kJ·mol^(−1))in nitrogen is still challenging,and the development of more efficient catalysts is necessary.Herein,Ru single atoms decorated TiO_(2) nanosheets(Ru SAs/TiO_(2))were constructed and achieved superior performance for NO photosynthesis with a product rate of 192μmol g^(−1) h^(−1) and a quantum efficiency of 0.77% at 365 nm.Both ^(15)N isotope labeling experiments and in situ near ambient pressure X-ray photoelectron spectroscopy(in situ NAP-XPS)proved the origin of NO from N_(2) photooxidation.A series of in situ characterizations and theoretical calculations unveiled the reaction pathway of nitrogen photooxidation.Breaking the O-O bond to form(N-O)2-Ru intermediates was demonstrated as the rate-determining step.Importantly,a single-atomic structure was proven to inhibit the aggregation and inactivation of Ru,leading to outstanding durability.

A Rational Design of Heterojunction Photocatalyst Cd S Interfacing with One Cycle of ALD Oxide

Photo-corrosion is one of the major obstacles for CdS application in wet chemical fields, and atomic layer deposition （ALD） has been proposed as an effective way to suppress the corrosion. Here, prior to ALD coating, CdS, one facilely corrosive photocatalyst, was synthesized via hydrothermal synthesis to access the fundamental corrosion mechanism and the according corrosive sites. X-ray photoelectron spectros- copy （XPS） and X-ray diffraction （XRD） demonstrated that the failure of catalytic decomposition of methylene blue originated from the formation of soluble CdSO4 by oxidizing S2 of as-prepared CdS. High resolu- tion transmission electron microscopy （HRTEM） further identified the active sites in the V-shaped regions ofCdS nanoparticles, confirmed by the simulated electric field distribution. To rationally coat oxides on CdS, the right candidates and their thicknesses have been considered by our tunneling model with trans- fer matrix method based on quantum mechanism, upon which the thickness of protective layer should be less than 0.5 nm to maintain a high tunneling probability, and thus one cycle of ALD TiO2 or AbO3 was proposed to passivate the CdS powder to balance the carrier transportation and corrosion suppres- sion. Based on HRTEM results, we found that the active V-shaped region was covered by ALD oxides （TiO2 or AbO3）. For each case, no soluble CdSO4 has been found before and after photocatalytic reactions based XPS measurements. Importantly, we noticed that with the passivation of one cycle of ALD, the catalyst＇s lifetime was elongated up to 〉14 times higher than that of the as-prepared CdS.