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.

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。

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.

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.

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.

恶劣基建环境中BIPV光伏组件安装工艺的研究

面对泥泞地面和大型机械难以进入等复杂条件,恶劣的建设环境对BIPV(光伏建筑一体化)项目构成了巨大挑战。本文旨在探讨在这些特殊条件下的安装实施策略,研究了在恶劣地面条件下BIPV组件的安装过程,介绍了一种适用于泥泞和恶劣地面条件的光伏组件安装工具,总结了在恶劣建设环境下BIPV项目实施的项目实践,为在恶劣建设环境下进行BIPV项目建设提供参考和借鉴。

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

目的:在高温等恶劣工作环境下,燃气轮机有着迫切的温度等工况参数的实时监测需求。声表面波(SAW)技术与微机电系统(MEMS)技术的结合可提供一种很有发展前景的解决方案。本文旨在探讨SAW谐振器的设计与仿真方法,研究高质量c轴择优取向的AlN压电薄膜制备工艺及与MEMS工艺兼容的SAW谐振器制作工艺,并测试其电学性能以验证SAW谐振器设计与制作的正确性与可行性。创新点:1.首次在耐高温材料AlN/4H-SiC上设计、仿真及制作SAW谐振器并测试电学性能;2.在4HSiC上得到了高质量c轴择优取向的Al N压电薄膜并开发了一套与MEMS工艺兼容的SAW谐振器制作工艺。方法:1.通过对SAW谐振器所有结构参数的设计与仿真,得到谐振器的谐振频率与反谐振频率等(图2和3);2.利用磁控溅射方法在4H-SiC衬底上溅射高质量c轴择优取向的AlN压电薄膜,再利用光刻、湿法腐蚀等MEMS工艺制作SAW谐振器(图4);3.通过扫描电镜和X射线衍射等手段,检测AlN压电薄膜质量(图5和6)及器件制作结果(图7);4.利用网络分析仪测试SAW谐振器电学性能并与仿真结果相比较,验证SAW谐振器设计仿真方法和MEMS制作工艺的可行性和有效性(图8)。结论:1.基于耐高温材料AlN/4H-SiC,成功设计并制作出SAW谐振器(尺寸:1107μm×721μm);2.在4H-SiC上得到了高质量c轴择优取向的AlN压电薄膜,衍射峰为36.10°,摇摆曲线半高宽仅1.19°;3.SAW谐振器电学性能测试结果与仿真结果一致,证明其设计仿真方法正确有效、MEMS制作工艺可行。

面向多层级目标的汽车前围声学包优化研究

为了研究汽车声学包设计参数对其多性能目标的影响,首先,改进了传统的深度信念网络(DBNs)方法,并提出SVR-DBNs (support vector regression-deep belief networks)模型,提升了模型映射的准确度;其次,从车辆噪声传递关系与层级目标分解角度出发,提出了一种多层级目标预测与分析方法;最后,将所提方法应用于具体车型的前围声学包性能、重量与成本多目标预测与优化分析.研究结果表明:SVR-DBNs方法对前围声学包性能、重量与成本目标预测准确度均在0.975以上,优于传统的反向传播神经网络(BPNN)、SVR与DBNs模型;基于SVR-DBNs模型的优化结果与实测结果接近,两者加权目标相对误差为1.09%(平均传递损失(MTL)、重量和成本相对误差绝对值分别为1.44%、1.04%与0.71%),优化后的实测结果较前围声学包原始状态性能、重量和成本分别提升了5.51%、9.01%与4.40%.

复杂恶劣环境下水位智能检测方法研究

实现智能化水务管控和洪涝灾害预警,需要实时、准确感知水位信息变化情况。针对现有技术不能满足夜晚、雾天、雨天、漂浮物遮挡、灯光阴影等复杂恶劣环境下的水尺水位的影像水位反演(小目标特征)识别需求,提出一种融合改进YOLOv5与RankSE的水位智能检测方法。首先,采用强化小尺度特征的多层级特征融合方法来改进YOLOv5算法,以强化对小目标的捕捉能力;其次,融入RankSE模块进一步提升对小目标的感知能力;最后,提出一种全新的水位高程解算方案,仅需利用部分水尺锚框信息即可获得准确的水位高程信息,极大提升了检测方法的鲁棒性。研究结果表明,本文所述方法水位检测相对准确度达98.5%,较原算法提高了8.4%;在复杂恶劣环境下可以自动、准确识别出水位高程,最大误差仅为0.11 m。研究结果有效提升了复杂恶劣环境下水位检测的准确性。

基于GAHE-VMD与SVD-SCEC的管道信号联合去噪法

为了更有效分析管道信号,提出一种基于采用在恶劣环境下的遗传算法(Genetic Algorithms in Harsh Environments,GAHE)优化变分模态分解(Variational Mode Decomposition,VMD)联合奇异值分解(Singular Value Decomposition,SVD)与选择性累计能量贡献率(Selective Cumulative Energy Contribution,SCEC)的互补去噪方法。首先,提出用GAHE算法优化VMD算法并结合相对熵对信号中的中高频噪声进行初步消噪,解决VMD参数难以确定和传统遗传算法收敛慢的问题。其次,提出采用SCEC算法结合SVD算法对信号中残留的中低频噪声进行消噪,解决非线性、非平稳信号中大数量级的直流分量影响奇异值选择的问题。最后,通过实验与分析表明:GAHE优化算法收敛速度更快;SCEC奇异值选择法的抗直流能力更强;所提算法的处理效果较优且算法两部分具有互补特性。

考虑海洋环境-船体-螺旋桨-主机之间的动态相互作用的船舶在实海况下的油耗预报

The fuel consumption of a ship has always been an important research topic,but nowadays its importance has even increased as it is directly related to a ship’s greenhouse gas(GHG)emissions,which is now tightly regulated.In this paper,such a dynamic model is presented.The ship’s resistance in calm water and propeller’s performance in open water are required as input.The hull efficiency is estimated empirically.The diesel engine is modelled by a first-order transfer function with a delayed response and its performance is calibrated with the data from the manufacturer’s catalogue.A governor is applied to maintain the pre-set engine’s rotational speed and to control the engine fuel rate.A slope limiter is employed to approximate the actual engine operation during engine transients.The default values can be obtained from the manufacturer engine load acceptance diagram.The developed model is implemented in MATLAB SIMULINK environment.After validation against third-party published results,the influence of using different types of governors on ship speed and fuel consumption is investigated.The model is also applied to simulate the fuel consumption of a ship during a typical acceleration manoeuvre and the scenario of a real ship encountering harsh weather conditions.

粗暴养育对中学生网络欺凌的影响:抑郁与基本心理需求的作用

目的:探讨粗暴养育与中学生网络欺凌的关系以及抑郁的中介作用和基本心理需求的调节作用。方法:采用粗暴养育量表、网络欺负量表、流调中心抑郁量表和基本心理需求量表对1081名中学生进行调查研究。结果:①粗暴养育与中学生网络欺凌呈显著正相关(r=0.19,0.19;P<0.01),与抑郁呈显著正相关(r=0.35,0.37;P<0.01),而与基本心理需求呈显著负相关(r=-0.24,-0.23;P<0.01);②抑郁在粗暴养育与网络欺凌之间起中介作用;③基本心理需求仅在父亲粗暴养育的影响模型中的前半段路径起调节作用。结论:粗暴养育通过抑郁影响网络欺凌,基本心理需求调节了父亲粗暴养育对抑郁的关系。