基于全局响应面算法的Q235B钢的Johnson-Cook模型参数最优

This study investigates the mechanical properties of Q235B steel through quasi-static tests at both room temperature and elevated temperature.The initial values of the Johnson-Cook model parameters are determined using a fitting method.The global response surface algorithm is employed to optimize and calibrate the Johnson-Cook model parameters for Q235B steel under both room temperature and elevated temperature conditions.A simulation model is established at room temperature,and the simulated mechanical performance curves for displacement and stress are monitored.Multiple optimization algorithms are applied to optimize and calibrate the model parameters at room temperature.The global response surface algorithm is identified as the most suitable algorithm for this optimization problem.Sensitivity analysis is conducted to explore the impact of model parameters on the objective function.The analysis indicates that the optimized material model better fits the experimental values,aligning more closely with the actual test results of material strain mechanisms over a wide temperature range.

An option for green and sustainable future: Electrochemical conversion of ammonia into nitrogen

Green and sustainable options are needed to ease the current energy and environmental crisis, and alleviate the greenhouse effect and energy shortage. As an alternative carbon–neutral synthetic fuel, ammonia shows great potential due to its high energy density, non-toxic by-products, and mature related infrastructures. However, related practical applications have been severely hampered on ammoniaoxidation due to the high cost of catalysts and immature energy utilization systems. Here, we comprehensively summarized the efforts which have been made in recent years with the aim of providing a deep sight into the development and deficiencies in this territory and trying to establish a simple framework of basic knowledge for researchers. The exploration of mechanism is discussed first and then the relevant catalysts studied in recent years are summarized. Besides, the progress of direct ammonia fuel cells(DAFCs) is also presented and the challenges as well as perspectives on future developments of electrocatalysts for ammonia electro-oxidation and its practical application are provided at the end.

Iron(Fe,Ni,Co)-based transition metal compounds for lithium-sulfur batteries:Mechanism,progress and prospects

Lithium-sulfur batteries(LSBs)have a high theoretical capacity,which is considered as one of the most promising high-energy-density secondary batteries due to the double electrons reaction of sulfur.However,the shuttle effects of lithium polysulfides(Li PSs)and sluggish redox kinetics lead to their materials capacity loss and cycle stability deterioration,which restrains LSBs commercialization.Metallic compounds as additions can improve the electrochemical performance of the Li-S system,through the trap of Li PSs and accelerate the conversion of the soluble Li PSs.Among of them,the iron group elements(Fe,Ni,Co)-based compounds are the promising materials for the LSBs,due to their unique outer electronic structure and its tunable properties,low cost,abundant in the earth,environmental benignity,controllable and scalable prepared,and so on.In this review,we have made a summary for iron-based compounds to capture Li PSs according to lithium bond,sulfur bond and magnetic force.The type of iron-based compound including oxides,sulfides,nitrides,phosphides,carbides,and so on,and we have investigated the electrocatalytic mechanism of these materials.Besides,some improvement strategies are proposed,such as the engineering of the special micro/nanostructure,defect concentrations,band structures,and heterostructures.We hope to shed an in-depth light on the rationally design and fabrication of robust,commercial and stable materials for high-performance LSBs.

Promoting surface reconstruction of NiFe layered double hydroxides via intercalating[Cr(C_(2)O_(4))_(3)]^(3-)for enhanced oxygen evolution

Rationally manipulating surface reconstruction of catalysts for water oxidation,inducing formation and dynamic accumulation of catalytically active centers still face numerous challenges.Herein,the introduction of[Cr(C_(2)O_(4))_(3)]^(3-)into NiFe LDHs by intercalation engineering to promote surface reconstruction achieves an advanced oxygen evolution reaction(OER)activity.In view of the weak electronegativity of Cr^(3+) in[Cr(C_(2)O_(4))_(3)]^(3-),the intercalation of[Cr(C_(2)O_(4))_(3)]^(3-)is expected to result in an electron-rich structure of Fe sites in NiFe LDHs,and higher valence state of Ni can be formed with the charge transfer between Fe and Ni.The optimized electronic structure of NiFe-[Cr(C_(2)O_(4))_(3)]^(3-)-LDHs with more active Ni^(3+) species and the expedited dynamic generation of Ni^(3+) (Fe)OOH phase during the OER process contributed to its excellent catalytic property,revealed by in situ X-ray absorption spectroscopy,Raman spectroscopy,and quasi-in situ X-ray photoelectron spectroscopy.With the modulated electronic structure of metal sites,NiFe-[Cr(C_(2)O_(4))_(3)]^(3-)-LDHs exhibited promoted OER property with a lower overpotential of 236 mV at the current density of 10 mA cm^(-2).This work illustrates the intercalation of conjugated anion to dynamically construct desired Ni^(3+) sites with the optimal electronic environment for improved OER electrocatalysis.

猪戊型肝炎研究进展

我国为猪戊肝发病率比较高的地区之一,曾发生戊型肝炎的多次爆发或大面积的流行,并可传播给人类,与人的生活密切相关,回顾猪戊肝炎病毒结构特征研究,流行方式、临床症状及病理变化等,为猪戊型肝炎未来的诊断提供参照。文章收集国内外文献资料查询酶联免疫吸附试验(ELISA)、免疫电子显微镜(IEM)、免疫荧光实验(IFA)、荧光定量RT-PCR法对防治猪戊型肝炎进行研究,对其作了分析、比较和汇总。为猪戊型肝炎病毒提供了有效诊断方式以及防御措施。对猪戊型肝炎仍需养殖者认真护理,一旦确诊为动物戊型肝炎,应立即对其进行隔离治疗。

Cobalt‐regulation‐induced dual active sites in Ni_(2)P for hydrazine electrooxidation

Better understanding of electrochemical reaction behaviors of hydrazine electrooxidation at metal phosphides has long been desired and the optimization of reaction kinetics has been proved to be operable.Herein,the dehydrogenation kinetics of hydrazine electrooxidation at Ni_(2)P is adjusted by Co as the(Ni_(0.6)Co_(0.4))_(2)P catalyzes HzOR effectively with onset potential of–45 mV and only 113 mV is needed to drive the current density of 50 mA cm^(‒2),showing over 60 mV lower than Ni_(2)P and Co_(2)P.It also delivers the maximum power density of 263.0 mW cm^(-2) for direct hydrazine fuel cell.Detailed experimental results revealed that Co doping not only decreases the adsorption energy of N_(2)H_(4) on Ni sites,lowering the energy barrier for dehydrogenation,but also acts as the active sites in the optimal reaction coordination to boost the reaction kinetics.This work represents a breakthrough in improving the catalytic performance of non‐precious metal electrocatalysts for hydrazine electrooxidation and highlights an energy‐saving electrochemical hydrogen production method.

Impact of SST Anomaly Events over the Kuroshio-Oyashio Extension on the ＂Summer Prediction Barrier＂

The ＂summer prediction barrier＂ （SPB） of SST anomalies （SSTA） over the Kuroshio--Oyashio Extension （KOE） refers to the phenomenon that prediction errors of KOE-SSTA tend to increase rapidly during boreal summer, resulting in large prediction uncertainties. The fast error growth associated with the SPB occurs in the mature-to-decaying transition phase, which is usually during the August-September-October （ASO） season, of the KOE-SSTA events to be predicted. Thus, the role of KOE-SSTA evolutionary characteristics in the transition phase in inducing the SPB is explored by performing perfect model predictability experiments in a coupled model, indicating that the SSTA events with larger mature-to-decaying transi- tion rates （Category-l） favor a greater possibility of yielding a more significant SPB than those events with smaller transition rates （Category-2）. The KOE-SSTA events in Category-1 tend to have more significant anomalous Ekman pumping in their transition phase, resulting in larger prediction errors of vertical oceanic temperature advection associated with the SSTA events. Consequently, Category-1 events possess faster error growth and larger prediction errors. In addition, the anomalous Ekman upwelling （downwelling） in the ASO season also causes SSTA cooling （warming）, accelerating the transition rates of warm （cold） KOE-SSTA events. Therefore, the SSTA transition rate and error growth rate are both related with the anomalous Ekman pumping of the SSTA events to be predicted in their transition phase. This may explain why the SSTA events transferring more rapidly from the mature to decaying phase tend to have a greater possibility of yielding a more significant SPB.

一例多维整合治疗成人重度强迫症的案例（英文）

概述:强迫症(OCD)是一种慢性、痛苦和进行性损害的神经精神疾病,其特点是存在强迫意念或强迫动作。本文报道的一名44岁成年女性强迫症的病例。之前3年治疗中,患者对数个选择性5-羟色胺再摄取抑制剂(SSRIs)疗效不佳,生活质量受到严重影响。经过6个月的多维整合治疗,包括认知行为治疗(CBT)、舍曲林和低剂量抗精神病药物(阿立哌唑),以及家庭支持和网络支持。每两个月Yale-Brown Obsessive-Compulsive Scale(Y-BOCS)标准化量表评估显示,强迫意念或强迫动作明显减少,其社会功能和生活质量得到明显改善。本病例初步显示OCD多维整合治疗有助于达到最佳治疗疗效较好治疗效果,期待今后更严格的临床试验验证。

The cluster digging behavior of larvae confers trophic benefits to fitness in insects

Collective behaviors efficiently impart benefits to a diversity of species ranging from bacteria to humans.Fly larvae tend to cluster and form coordinated digging groups under crowded conditions,yet understanding the rules governing this behavior is in its infancy.We primarily took advantage of the Drosophila model to investigate cooperative foraging behavior.Here,we report that Drosophila-related species and the black soldier fly have evolved a conserved strategy of cluster digging in food foraging.Subsequently,we investigated relative factors,including larval stage,population density,and food stiffness and quality,that affect the cluster digging behavior.Remarkably,oxygen supply through the posterior breathing spiracles is necessary for the organization of digging clusters.More importantly,we theoretically devise a mathematical model to accurately calculate how the cluster digging behavior expands food resources by diving depth,cross-section area,and food volume.We found that cluster digging behavior approximately increases 2.2 fold depth,1.7-fold cross-section area,and 1.9 fold volume than control groups,respectively.Amplification of food sources significantly facilitates survival,larval development,and reproductive success of Drosophila challenged with competition for limited food resources,thereby conferring trophic benefits to fitness in insects.Overall,our findings highlight that the cluster digging behavior is a pivotal behavior for their adaptation to food scarcity,advancing a better understanding of how this cooperative behavior confers fitness benefits in the animal kingdom.

Green light mediates atypical photomorphogenesis by dual modulation of Arabidopsis phytochromes B and A

Although green light(GL)is located in the middle of the visible light spectrum and regulates a series of plant developmental processes,the mechanism by which it regulates seedling development is largely unknown.In this study,we demonstrated that GL promotes atypical photomorphogenesis in Arabidopsis thaliana via the dual regulations of phytochrome B(phyB)and phyA.Although the Pr-to-Pfr conversion rates of phyB and phyA under GL were lower than those under red light(RL)in a fluence rate-dependent and time-dependent manner,long-term treatment with GL induced high Pfr/Pr ratios of phyB and phyA.Moreover,GL induced the formation of numerous small phyB photobodies in the nucleus,resulting in atypical photomorphogenesis,with smaller cotyledon opening angles and longer hypocotyls in seedlings compared to RL.The abundance of phyA significantly decreased after short-and long-term GL treatments.We determined that four major PHYTOCHROME-INTERACTING FACTORs(PIFs:PIF1,PIF3,PIF4,and PIF5)act downstream of phyB in GL-mediated cotyledon opening.In addition,GL plays opposite roles in regulating different PIFs.For example,under continuous GL,the protein levels of all PIFs decreased,whereas the transcript levels of PIF4 and PIF5 strongly increased compared with dark treatment.Taken together,our work provides a detailed molecular framework for understanding the role of the antagonistic regulations of phyB and phyA in GL-mediated atypical photomorphogenesis.

Sodium Leak Channel in Glutamatergic Neurons of the Lateral Parabrachial Nucleus Helps to Maintain Respiratory Frequency Under Sevoflurane Anesthesia

The lateral parabrachial nucleus(PBL)is implicated in the regulation of respiratory activity.Sodium leak channel(NALCN)mutations disrupt the respiratory rhythm and influence anesthetic sensitivity in both rodents and humans.Here,we investigated whether the NALCN in PBL glutamatergic neurons maintains respiratory function under general anesthesia.Our results showed that chemogenetic activation of PBL glutamatergic neurons increased the respiratory frequency(RF)in mice;whereas chemogenetic inhibition suppressed RF.NALCN knockdown in PBL glutamatergic neurons but not GABAergic neurons significantly reduced RF under physiological conditions and caused more respiratory suppression under sevoflurane anesthesia.NALCN knockdown in PBL glutamatergic neurons did not further exacerbate the respiratory suppression induced by propofol or morphine.Under sevoflurane anesthesia,painful stimuli rapidly increased the RF,which was not affected by NALCN knockdown in PBL glutamatergic neurons.This study suggested that the NALCN is a key ion channel in PBL glutamatergic neurons that maintains respiratory frequency under volatile anesthetic sevoflurane but not intravenous anesthetic propofol.

Highly efficient through-space charge transfer TADF molecule employed in TADF-and TADF-sensitized organic light-emitting diodes

The inception and harnessing of excitons are paramount for the electroluminescence performance of organic light-emitting devices(OLEDs).Through-space charge transfer(TSCT)via intramolecular interaction has proved to be one of the most potent techniques employed to achieve 100% internal quantum efficiency.However,molecular strategies utilized to comprehensively enhance the electroluminescent performance of TSCT emitters regarding improving the photoluminescence quantum yield(PLQY)and elevating the light out-coupling efficiency remain arduous.To surmount this challenge,we deliberately designed and synthesized a proof-of-concept TSCT emitter called CzO-TRZ by incorporating an extra carbazole donor into spiroheterocyclic architecture.The introduction of rigid spiral fragments can immensely boost the horizontal orientation dipole ratio and establish an extra through-bond charge transfer(TBCT)radiative decay channel.As a result,a very high PLQY of 98.7%,fast kRISCof 2.2×10^(5)s^(-1)and high k_(r)^(s) of 2.2×10^(7)s^(-1),and an ultrahigh horizontal dipolar ratio of 90%were concurrently achieved for Cz O-TRZ blended films.Furthermore,corresponding thermally activated delayed fluorescence(TADF)-and TADF-sensitized fluorescence(TSF)-OLEDs based on CzO-TRZ demonstrated external quantum efficiencies(EQEs)of 33.4% and 30.3%,respectively,highlighting its versatile applications as both an emitter and sensitized host.

Silk fibroin-based flexible pressure sensors:processing and application

With the advent of the internet of things and artificial intelligence,flexible and portable pressure sensors have shown great application potential in human-computer interaction,personalized medicine and other fields.By comparison with traditional inorganic materials,flexible polymeric materials conformable to the human body are more suitable for the fabrication of wearable pressure sensors.Given the consumption of a huge amount of flexible wearable electronics in near future,it is necessary to turn their attention to biodegradable polymers for the fabrication of flexible pressure sensors toward the development requirement of green and sustainable electronics.In this paper,the structure and properties of silk fibroin(SF)are introduced,and the source and research progress of the piezoelectric properties of SF are systematically discussed.In addition,this paper summarizes the advance in the studies on SF-based capacitive,resistive,triboelectric,and piezoelectric sensors reported in recent years,and focuses on their fabrication methods and applications.Finally,this paper also puts forward the future development trend of high-efficiency fabrication and corresponding application of SF-based piezoelectric sensors.It offers new insights into the design and fabrication of green and biodegradable bioelectronics for in vitro and in vivo sensing applications.

Structurally ordered high-entropy intermetallic nanoparticles with enhanced C–C bond cleavage for ethanol oxidation

Efficient ethanol oxidation reaction(EOR)is challenging due to the multiple reaction steps required to accomplish full oxidation to CO_(2) in fuel cells.Highentropy materials with the adjustable composition and unique chemical structure provide a large configurational space for designing high-performance electrocatalysts.Herein,a new class of structurally ordered PtRhFeNiCu high-entropy intermetallics(HEIs)is developed as electrocatalyst,which exhibits excellent electrocatalytic activity and CO tolerance for EOR compared to high-entropy alloys(HEAs)comprising of same elements.When the HEIs are used as anode catalysts to be assembled into a high-temperature polybenzimidazole-based direct ethanol fuel cell,the HEIs achieve a high power density of 47.50 mW/cm^(2),which is 2.97 times of Pt/C(16.0mW/cm^(2)).Online gas chromatography measurements show that the developed HEIs have a stronger C–C bond-breaking ability than corresponding HEAs and Pt/C catalysts,which is further verified by density functional theory(DFT)calculations.Moreover,DFT results indicate that HEIs possess higher stability and electrochemical activity for EOR than HEAs.These results demonstrate that the HEIs could provide a new platform to develop highperformance electrocatalysts for broader applications.

缺陷与催化

催化技术在现代工业生产和日常生活中发挥着举足轻重的作用,开发高效的催化剂是催化领域重要的研究方向。近些年来,许多研究发现催化剂的缺陷对其催化活性有着重要的影响,同时各种各样的缺陷催化剂也被开发出来。尽管如此,缺陷与催化活性之间的关系仍有待厘清。本文围绕这一主题,分别介绍了固体缺陷化学的基础、催化剂中缺陷的类型、表征、可控构筑以及在催化中的作用和动态变化,最后进行总结和展望。希望通过本文阐明催化剂缺陷化学研究的起源与发展,强调缺陷对催化的重要性,为今后高效催化剂的进一步开发与机理研究提供指导。

The China Multi-Model Ensemble Prediction System and Its Application to Flood-Season Prediction in 2018

Multi-model ensemble prediction is an effective approach for improving the prediction skill short-term climate prediction and evaluating related uncertainties. Based on a combination of localized operation outputs of Chinese climate models and imported forecast data of some international operational models, the National Climate Center of the China Meteorological Administration has established the China multi-model ensemble prediction system version 1.0 (CMMEv1.0) for monthly-seasonal prediction of primary climate variability modes and climate elements. We verified the real-time forecasts of CMMEv1.0 for the 2018 flood season (June-August) starting from March 2018 and evaluated the 1991-2016 hindcasts of CMMEv1.0. The results show that CMMEv1.0 has a significantly high prediction skill for global sea surface temperature (SST) anomalies, especially for the El Nino-Southern Oscillation (ENSO) in the tropical central-eastern Pacific. Additionally, its prediction skill for the North Atlantic SST triple (NAST) mode is high, but is relatively low for the Indian Ocean Dipole (IOD) mode. Moreover, CMMEv1.0 has high skills in predicting the western Pacific subtropical high (WPSH) and East Asian summer monsoon (EASM) in the June-July-August (JJA) season. The JJA air temperature in the CMMEv1.0 is predicted with a fairly high skill in most regions of China, while the JJA precipitation exhibits some skills only in northwestern and eastern China. For real-time forecasts in March-August 2018, CMMEv1.0 has accurately predicted the ENSO phase transition from cold to neutral in the tropical central-eastern Pacific and captures evolutions of the NAST and IOD indices in general. The system has also captured the main features of the summer WPSH and EASM indices in 2018, except that the predicted EASM is slightly weaker than the observed. Furthermore, CMMEv1.0 has also successfully predicted warmer air temperatures in northern China and captured the primary rainbelt over northern China, except that it predicted much more precipitation in the middle and lower reaches of the Yangtze River than observation.

Prediction of Primary Climate Variability Modes at the Beijing Climate Center

Climate variability modes, usually known as primary climate phenomena, are well recognized as the most impor- tant predictability sources in subseasonal-interarmual climate prediction. This paper begins by reviewing the re- search and development carried out, and the recent progress made, at the Beijing Climate Center （BCC） in predicting some primary climate variability modes. These include the El Nifio-Southern Oscillation （ENSO）, Madden-Julian Oscillation （MJO）, and Arctic Oscillation （AO）, on global scales, as well as the sea surface temperature （SST） modes in the Indian Ocean and North Atlantic, western Pacific subtropical high （WPSH）, and the East Asian winter and summer monsoons （EAWM and EASM, respectively）, on regional scales. Based on its latest climate and statistical models, the BCC has established a climate phenomenon prediction system （CPPS） and completed a hindcast experi- ment for the period 1991-2014. The performance of the CPPS in predicting such climate variability modes is system- atically evaluated. The results show that skillful predictions have been made for ENSO, MJO, the Indian Ocean basin mode, the WPSH, and partly for the EASM, whereas less skillful predictions were made for the Indian Ocean Dipole （IOD） and North Atlantic SST Tripole, and no clear skill at all for the AO, subtropical IOD, and EAWM. Improve- ments in the prediction of these climate variability modes with low skill need to be achieved by improving the BCC＇s climate models, developing physically based statistical models as well as correction methods for model predictions. Some of the monitoring/prediction products of the BCC-CPPS are also introduced in this paper.

Tailoring lattice strain in ultra-fine high-entropy alloys for active and stable methanol oxidation

High-entropy alloys(HEAs)have been widely studied due to their unconventional compositions and unique physicochemical properties for various applications.Herein,for the first time,we propose a surface strain strategy to tune the electrocatalytic activity of HEAs for methanol oxidation reaction(MOR).High-resolution aberration-corrected scanning transmission electron microscopy(STEM)and elemental mapping demonstrate both uniform atomic dispersion and the formation of a face-centered cubic(FCC)crystalline structure in Pt Fe Co Ni Cu HEAs.The HEAs obtained by heat treatment at 700℃(HEA-700)exhibit 0.94%compressive strain compared with that obtained at 400℃(HEA-400).As expected,the specific activity and mass activity of HEA-700 is higher than that of HEA-400 and most of the state-of-the-art catalysts.The enhanced MOR activity can be attributed to a shorter Pt–Pt bond distance in HEA-700 resulting from compressive strain.The nonprecious metal atoms in the core could generate compressive strain and down shift d-band centers via electron transfer to surface Pt layer.This work presents a new perspective for the design of high-performance HEAs electrocatalysts.

Giant magnetic enhancement across a ferroelectricantiferroelectric phase boundary in Bi_(1-x)Y_xFeO_3

The structural,vibrational,and magnetic properties of well prepared Bi 1 x Y x FeO 3(x=0-0.1) powders are investigated by combining the X-ray diffraction,Raman scattering,differential scanning calorimetry,and magnetometry measurements.A structural symmetric breaking from the rhombohedral R3c to orthorhombic Pnma between x=0.07 and 0.1 is identified from the X-ray and Raman measurements,accompanying a ferroelectric-antiferroelectric phase transition.The remnant magnetization of Bi 0.9 Y 0.1 FeO 3 is about 15 times higher in magnitude compared to the pure BiFeO 3.Such a giant enhancement is suggested to result from the destruction of the spin cycloid accompanied with the structured transition.

Silica-facilitated proton transfer for high-temperature proton-exchange membrane fuel cells

High-temperature proton-exchange membrane fuel cells(HT-PEMFCs)have shown a broad prospect of applications due to the enhanced reaction kinetics and simplified supporting system.However,the proton conductor,phosphoric acid,tends to poison the active sites of Pt,resulting in high Pt consumption.Herein,Pt nanoparticles anchored on SiO_(2)-modified carbon nanotubes(CNT@SiO_(2)-Pt)are prepared as high-performance cathode catalysts for HT-PEMFCs.The SiO_(2)in CNT@SiO_(2)-Pt can induce the adsorption of phosphoric acid transferring from Pt active sites in the catalytic layer,avoiding the poisoning of the Pt,and the phosphate fixed by SiO_(2)provide a high-speed proton conduction highway for oxygen reduction reactions.Accordingly,The CNT@SiO_(2)-Pt cathode achieve superior power density of 765 mW cm^(−2)(160℃)and 1,061 mW cm^(−2)(220℃)due to the rapid proton-coupled electron process and outstanding stability in HT-PEMFCs.This result provides a new road to resolve the phosphate poisoning for the commercialization of HT-PEMFCs.