Boosting lithium batteries under harsh operating conditions by a resilient ionogel with liquid-like ionic conductivity

New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh operating conditions. Here we report on the synthesis of a unique ionogel electrolyte for abuse-tolerant lithium batteries. A hierarchically architected silica/polymer scaffold is designed and fabricated through a facile soft chemistry route, which is competent to confine ionic liquids with superior uptake ability (92.4 wt%). The monolithic ionogel exhibits high conductivity and thermal/mechanical stability, featuring high-temperature elastic modulus and dendrite-free lithium cycling. The Li/LiFePO_(4) pouch cells achieve outstanding cyclability at different temperatures up to 150 ℃, and can sustain cutting, crumpling, and even coupled thermal–mechanical abuses. Moreover, the solid-state lithium batteries with LiNi_(0.60)Co_(0.20)Mn_(0.20)O_(2), LiNi_(0.80)Co_(0.15)Al_(0.05)O_(2), and Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) cathodes demonstrate excellent cycle performances at 60 ℃. These results indicate that the resilient and high-conductivity ionogel electrolyte is promising to realize high-performance lithium batteries with high energy density and safety.

Smart Manipulation of Gas Bubbles in Harsh Environments Via a Fluorinert-Infused Shape-Gradient Slippery Surface

Fundamental research and practical applications have examined the manipulation of gas bubbles on open surfaces in lowsurface-tension,high-pressure,and high-acidity,-alkalinity,or-salinity environments.However,to the best of our knowledge,effi cient and general approaches to achieve the smart manipulation of gas bubbles in these harsh environments are limited.Herein,a Fluorinert-infused shape-gradient slippery surface(FSSS)that could eff ectively regulate the behavior of gas bubbles in harsh environments was successfully fabricated.The unique capability of FSSS was mainly attributed to the properties of Fluorinert,which include chemical inertness and incompressibility.The shape-gradient morphology of FSSS could induce asymmetric driving forces to move gas bubbles directionally on open surfaces.Factors infl uencing gas bubble transport on FSSS,such as the apex angle of the slippery surface and the surface tension of the aqueous environment,were carefully investigated,and large apex angles were found to result in large initial transport velocities and short transport distances.Lowering the surface tension of the aqueous environment is unfavorable to bubble transport.Nevertheless,FSSS could transport gas bubbles in aqueous environments with surface tensions as low as 28.5±0.1 mN/m,which is lower than that of many organic solvents(e.g.,formamide,ethylene glycol,and dimethylformamide).In addition,FSSS could also realize the facile manipulation of gas bubbles in various aqueous environments,e.g.,high pressure(~6.8 atm),high acidity(1 mol/L H 2 SO 4),high alkalinity(1 mol/L NaOH),and high salinity(1 mol/L NaCl).The current fi ndings provide a source of knowledge and inspiration for studies on bubble-related interfacial phenomena and contribute to scientifi c and technological developments for controllable bubble manipulation in harsh environments.

Seismic Evaluation of Reinforced Concrete Frames in the Harsh Environment Using Pushover Analysis

The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and the displacement at different stages of earthquake loading. Typical 5, 15, 20 and 30-storey reinforced concrete frames have been designed for seismicity according to the recently adopted seismic code in Abu Dhabi, ACI 318-08/IBC 2009 code. A pushover analysis has been performed to these four buildings by using SAP 2000. Twenty-four models have been created (6 models for each building) by decreasing the concrete strength gradually from 4000 psi (281 kg/cm2) to 1500 psi (105 kg/cm2). This is to simulate the effect of harsh environment on the strength of concrete in existing buildings.

Should the Harsh Penalties on Drunk Driving Be loosened?

Recently,reform on charges against dangerous driving has stirred up debate among the public.A new stipulation by China’s Supreme People’s court which took effect on May 1 granted judges the discretion to decide whether someone caught driving under the influence of alcohol should be held criminal responsible by taking into account how drunk the person is,road conditions and the seriousness of damages.

Eutectogel-based self-powered wearable sensor for health monitoring in harsh environments

Triboelectric nanogenerators(TENG)have emerged as a highly promising energy harvesting technology,attracting significant attention in recent years for their broad applications.Gel-based TENGs,with superior stretchability and sensitivity,have been widely reported as wearable sensors.However,the traditional hydrogel-based TENGs suffer from freezing at low temperatures and drying at high temperatures,resulting in malfunctions.In this study,we introduce an anti-freezing eutectogel,which uses a deep eutectic solvent(DES),to improve the stability and electrical conductivity of TENGs in harsh environmental conditions.The eutectogel-based TENG(E-TENG)produces an open-circuit voltage of 776 V,a short-circuit current of 1.54μA,and a maximum peak power of 1.1 mW.Moreover,the E-TENG exhibits exceptional mechanical properties with an elongation at a break of 476%under tension.Importantly,it maintains impressive performances across a wide temperature range from−18 to 60℃,with conductivities of 2.15 S/m at−10℃and 1.75 S/m at−18℃.Based on the excellent weight stability of the E-TENG sensor,motion sensing can be achieved in the air,and even underwater.Finally,the versatility of the E-TENG can serve as a wearable sensor,by integrating it with Bluetooth technology.The self-powered E-TENG can monitor various human motion signals in real-time and send the health signals directly to mobile phones.This research paves a new road for the applications of TENGs in harsh environments,offering wireless flexible sensors with real-time health signal monitoring capabilities.

Efficient piezo-catalytic dye degradation using piezoelectric 6H-SiC under harsh conditions

The development of novel piezoelectric catalysts against harsh conditions is indeed crucial for improving the piezo-catalytic degradation efficiency of colored organic dyes in wastewater.In this work,6H-SiC nanoparticles(NPs)are utilized to piezo-catalytic degrade rhodamine B(RhB)and methylene blue(MB)under ultrasonic vibration for the first time.The degradation efficiency of RhB and MB reaches 98.8%and 98.7%within 80 min.The piezoelectricity of 6H-SiC is comprehensively analyzed by the piezoresponse force microscope(PFM)and finite element method(FEM).The strong oxidizing active free radicals generated by the continuous piezoelectric polarized electric field of 6H-SiC,i.e.,·O_(2)^(-)and·OH,induce the decomposition reactions of colored organic dyes in solution.And the dyes are proven to degrade to harmless or less-harmful products gradually during the piezo-catalysis process by high-performance liquid chromatography tandem mass spectrometry(HPLC-MS).Moreover,RhB is also decomposed efficiently by 6HSiC NPs under acidic and alkaline conditions.These results prove the feasibility of 6H-SiC for decomposing common water pollutants under harsh conditions and provide a new perspective for water purification.

Cascade Optimization Control of Unmanned Vehicle Path Tracking Under Harsh Driving Conditions

Under ultra-high-speed and harsh conditions,conventional control methods struggle to ensure the path tracking accuracy and driving stability of unmanned vehicles during the turning process.Therefore,this study proposes a cascade control to solve this problem.Based on the new vehicle error model that considers vehicle tire sideslip and road curvature,the feedforward-parametric adaptive linear quadratic regulator(LQR)and proportional integral control-based speed-keeping controllers are used to compose the path-tracking cascade optimization controller for unmanned vehicles.To improve the adaptability of the unmanned vehicle path-tracking control under harsh driving conditions,the LQR controller parameters are automatically adjusted using a back-propagation neural network,in which the initial weights and thresholds are optimized using the improved grey wolf optimization algorithm according to the driving conditions.The speed-keeping controller reduces the impact on the curve-tracking accuracy under nonlinear vehicle speed variations.Finally,a joint model of MATLAB/Simulink and CarSim was established,and simulations show that the proposed control method can achieve stable entry and exit curves at ultra-high speeds for unmanned vehicles.Under strong wind and ice road conditions,the method exhibits a higher tracking accuracy and is more adaptive and robust to external interference in driving and variable curvature roads than methods such as the feedforward-LQR,preview and pure pursuit controls.

消极情绪对学前儿童问题行为的影响:父母严厉管教的中介作用

本研究以358名学步儿为被试,探讨儿童早期不同消极情绪表现是否会通过父母严厉管教影响学前期的问题行为。结果显示:(1)母亲严厉管教在受限后沮丧和学前儿童外化问题行为之间起部分中介作用,即受限后沮丧不仅直接正向预测外化问题行为,还会通过母亲严厉管教影响外化问题行为。(2)恐惧对学前儿童内化问题行为的直接作用显著,但父母严厉管教在其中的中介作用不显著。研究结果揭示了早期受限后沮丧和恐惧对学前期问题行为的作用机制存在差异。

Pumping Relief Chinese-built water project is a game-changer for local communities in Tanzanian town

When Monica Jiwani relocated to Arusha,the third-largest city in Tanzania,she was dreaming of a happy life in a scenic area.Instead,she was immediately confronted with a harsh and painful reality-scarcity of clean water.The thought of using contaminated water became a constant source of headache.

西藏交通警察道路执法工作的风险与防范

西藏自治区自然、地理与气候环境复杂且特殊,道路交通环境相对恶劣,这导致当地交通警察道路执法工作面临诸多风险,包括警员人身安全和执法效能等风险。对此,文章对西藏交通警察道路执法工作风险进行了调查分析,从地区环境、警员安全意识与技能、执法装备、社会宣传和教育等角度探讨了相关风险的成因,针对性相关风险成因,提出从优化警力配置与道路信息推送、加强警员培训、完善警务装备、加强法治化宣传教育等工作来消除相关风险,以期保障警员安全并改善西藏交通环境。

基于哈里斯鹰优化算法的引信装定系统参数优化方法

为了满足坦克炮弹药作战实时性的需求,开展引信快速准确接收武器平台传输的敌方距离、方位等信息的研究,对提高作战毁伤效能十分重要。针对引信在武器平台实际环境约束下能量和信息无法快速可靠接收的问题,建立引信共击发通道装定系统能量信息同步传输的数学模型,形成目标函数为通过优化系统设计参数使装定时间最小、约束条件为平台恶劣信道环境下能量信息可靠接收的优化模型,采用哈里斯鹰优化(Harris Hawk Optimization,HHO)算法求解装定系统设计参数的最优值。仿真结果表明,基于HHO算法的系统参数优化方法可以得到最优的系统设计参数,与参数未优化的系统对比,不同信道参数下,能量信息同步传输的时间平均减少了26.4%,信息的可靠接收比平均提高了40.4%,特别是在信道电容大于5 nF的恶劣信道环境下仍能保证信息可靠接收,能量信息接收的快速性和可靠性都大幅提高,作战效能得到优化,通过实验室实验验证该方法的有效性。

严厉管教的代际传递:父母的互倚及子女性别的调节作用

基于家庭系统理论和互倚理论探讨严厉管教的代际传递在父母间的互倚与子女性别的调节作用,使用问卷法对388对小学生父母进行调查。主客体互倚模型分析的结果显示:(1)父母的主体效应显著,即父亲和母亲的儿时受严厉管教经历均正向预测自己对子女的严厉管教;(2)仅父亲的客体效应显著,即母亲儿时受严厉管教经历正向预测父亲对子女的严厉管教;(3)父母的组合效应显著,即父母亲儿时受严厉管教经历均强化对方代际传递的主体效应;(4)上述部分关系受子女的性别调节,母亲的主体效应在子女是男孩时强于子女是女孩时,仅当子女是女孩时,母亲的组合效应显著。研究发现严厉管教代际传递在父母间呈现非独立互倚模式,且这种代际传递受到子女性别的调节。

电动助力转向系统NVH特性数据采集与性能评价

针对汽车电动助力转向系统NVH特性数据存在多点位异步采样误差较大,且选取性能评价依据单一的问题,设计一种二十四通道NVH特性数据同步采集与多角度特性分析系统;采用多个数据采集模块联结、同步动态随机存储器读写、高速串行计算机扩展总线融合的方式,实现二十四通道NVH特性数据的同步精确采集与快速传输;从机械性能与声振特性方面对电动助力转向系统NVH特性进行多角度分析与评价。结果表明,与传统测试方法相比,所提方法可实现多点位同步高精度采样与多角度信号时频域分析,每个通道数据采集速率可达200 kHz/s,时频域分析依据更丰富、更全面。

Alloyed Au-Ag nanorods with desired plasmonic properties and stability in harsh environments

Bio-chemical molecular detection in the nanoscale, based on alloyed nanorods(NRs) with tunable surface plasmon resonance(SPR) properties and high chemical stability, has attracted particular interest. In this work,alloyed Au-Ag NRs with tunable aspect ratios were achieved by annealing Au nanobipyramid-directed Au@Ag core-shell NRs. The core-shell NRs were encapsulated within mesoporous silica outer shells to avoid fusion or aggregation. The structural stability of fully alloyed Au-Ag NRs, including chemical and thermal stability, is remarkably improved compared with that of Au@Ag core-shell NRs. The alloyed NRs would maintain the rod-like structure after being incubated in etchant solution, while Au@Ag core-shell NRs would decay into nanobipyramids.Additionally, fully alloyed NRs present stable morphology under annealing at high temperatures of up to 600℃ in air. Benefiting from excellent structural and chemical stabilities, the surface-enhanced Raman scattering effect based on alloyed NRs is stable in harsh environments. Taking advantage of tunable SPR properties(600–1800 nm) and excellent stability, the obtained nanostructures can serve as drug carriers. The perfect photo-thermal effect induced by the particular SPR of alloyed NRs can improve the release efficiency of drugs.

基于恶劣环境的通信产品可靠性研究

文中介绍了一种信息通信产品如何在复杂多变的应用环境下,实现机动便携、快速开通、稳定使用的方案,并详细阐述了方案设计,开展了模拟仿真试验。

强风化长雨季条件下矿山GNSS与合成孔径雷达技术的适用性研究

中国南部地区特别容易发生滑坡事故,主要由于表土风化和强降雨引发,对矿业生产带来不良影响。因此,急需采取有效监测和预警措施。近年来,合成孔径雷达技术迅速发展,并已应用于替代GNSS对矿山边坡进行表面位移监测。本研究以珠江水泥石灰石矿山为例,验证了在强风化长雨季条件下,GNSS与合成孔径雷达技术在矿山边坡监测方面的适用性。对比分析结果显示:两者记录的边坡位移变形趋势一致,为滑坡演化提供了关键信息;然而,GNSS需要更密集的本地观测网络以提供更准确的位移评估和滑坡风险控制;合成孔径雷达技术在特殊气象和地理环境下的应用需要特定的处理工具进行一定程度的校正。

Precision in harsh environments

Microsystems are increasingly being applied in harsh and/or inaccessible environments,but many markets expect the same level of functionality for long periods of time.Harsh environments cover areas that can be subjected to high temperature,(bio)-chemical and mechanical disturbances,electromagnetic noise,radiation,or high vacuum.In the field of actuators,the devices must maintain stringent accuracy specifications for displacement,force,and response times,among others.These new requirements present additional challenges in the compensation for or elimination of cross-sensitivities.Many state-of-the-art precision devices lose their precision and reliability when exposed to harsh environments.It is also important that advanced sensor and actuator systems maintain maximum autonomy such that the devices can operate independently with low maintenance.The next-generation microsystems will be deployed in remote and/or inaccessible and harsh environments that present many challenges to sensor design,materials,device functionality,and packaging.All of these aspects of integrated sensors and actuator microsystems require a multidisciplinary approach to overcome these challenges.The main areas of importance are in the fields of materials science,micro/nano-fabrication technology,device design,circuitry and systems,(first-level)packaging,and measurement strategy.This study examines the challenges presented by harsh environments and investigates the required approaches.Examples of successful devices are also given.

Offshore system safety and operational challenges in harsh Arctic operations

Offshore oil and gas drilling operations are going to remote and harsh arctic environments with demands forheightened safety and resilience of operational facilities. The remote and harsh environment is characterized byextreme waves, wind, storms, currents, ice, and fog that hinder drilling operations and cause structural failuresof critical offshore infrastructures. The risk, safety, reliability, and integrity challenges in harsh environment operations are critically high, and a comprehensive understanding of these factors will aid operations and protectthe investment. The dynamics, environmental constraints, and the associated risk of the critical offshore infrastructures for safe design, installation, and operations are reviewed to identify the current state of knowledge.This paper introduces a systematic review of harsh environment characterization by exploring the metoceanphenomena prevalent in harsh environments and their effects on the floating offshore structures performanceand supporting systems. The dynamics of the floating systems are described by their six degrees of freedom andtheir associated risk scenarios. The systematic methodology further explores the qualitative, quantitative, andconsequences modeling techniques for risk analysis of floating offshore systems in a harsh environment. Whilepresenting the current state of knowledge, the study also emphasizes a way forward for sustainable offshore operations. The study shows that the current state of knowledge is inexhaustive and will require further researchto develop a design that minimizes interruption during remote harsh offshore operations. Resilient innovation,IoT and digitalization provide opportunities to fill some of the challenges of remote Arctic offshore operations.

Design and fabrication of an surface acoustic wave resonator based on AlN/4H-SiC material for harsh environments

Surface acoustic wave （SAW） sensors and micro-electromechanical system （MEMS） technology provide a promising solution for measurement in harsh environments such as gas turbines. In this paper, a SAW resonator （size： 1107μm× 721 μm） based on the AlN/4H-SiC multilayer structure is designed and simulated. A MEMS-compatible fabrication process is employed to fabricate the resonator. The results show that highly c-axis-oriented AlN thin films deposited on the 4H-SiC substrate are obtained, with that the diffraction peak of AlN is 36.10° and the lowest full width at half maximum （FWHM） value is only 1.19°. The test results of the network analyzer are consistent with the simulation curve, which is very encouraging and indicates that our work is a significant attempt to solve the measurement problems mainly including high temperature stability of sensitive structures and the heat transmission of leads in harsh environments. It is essential to get the best performance of SAW resonator, optimize and characterize the behaviors in high temperatures in future research.

Fiber optic sensing technologies potentially applicable for hypersonic wind tunnel harsh environments

Advanced sensing techniques are in big demand for applications in hypersonic wind tunnel harsh environments,such as aero(thermo)dynamics measurements,thermal protection of aircraft structures,air-breathing propulsion,light-weighted and highstrength materials,etc.In comparison with traditional electromechanical or electronic sensors,the fiber optic sensors have relatively high potential to work in hypersonic wind tunnel,due to the capability of responding to a wide variety of parameters,high resolution,miniature size,high resistant to electromagnetic and radio frequency interferences,and multiplexing,and so on.This article has classified and summarized the research status and the representative achievement on the fiber optic sensing technologies,giving special attention to the summary of research status on the popular Fabry-Perot interferometric,fiber Bragg gratings and(quasi)distributed fiber optic sensors working in hypersonic wind tunnel environment,and discussed the current problems in special optical fiber sensing technologies.This article would be regarded as reference for the researchers in hypersonic wind tunnel experiment field.