Response Mechanism of Plants to Drought Stress

Drought stress is an important factor affecting plant growth and development.It will provide a theoretical basis for cultivating new stress-resistant varieties and improving water utilization rate of plants by studying the regulation mechanism of osmotic adjustment and water transportation under drought stress,and understanding the physiological and biochemical characteristics and stress resistance mechanism.

TWO-STEP MECHANISM IN HETEROGENEOUS CATALYSIS AND DYNAMIC ANALYSIS

Recent development of the dynamic analysis technique has made it possible to measure separately kinetic parameters of a catalytic reaction as well as to study the effect of catalyst preparation parameters. But its application is still limned to first-order reaction. This work is aimed to demonstrate in some detail that,by comparison of the reaction rate expressions with the two-step mechanism used in catalytic kinetics and dynamic analysis, these methods can be extended to non-first-order reaction, and the kinetic parameters measured by dynamic techniques are interpreted for different reaction mechanisms.

Actuation Mechanism of Two-step Reverse Transformation Behavior in TiNi Alloys Deformed at Parent Phase

The actuation mechanism of TiNi shape memory alloy wires, which were deformed at parent phase followed by a cooling process under constant strain constraint, was investigated. The experimental results show that the two-step reverse martensitic transformation behavior occurs during the heating process, and the temperature range of reverse transformation was obviously widened with the increasing of prestrain. The recovery strain vs temperature curves exhibits an actuation characteristic of linear output recovery strain in a wide temperature range.

Cerium oxide inclusion nucleation mechanism based on classical nucleation theory and two-step nucleation

It is challenging to assess the mechanism responsible for the nucleation of inclusions in metals at high temperatures.The present work therefore systematically investigates the nucleation of cerium oxide inclusions according to classical nucleation theory and a two-step nucleation mechanism.The nucleation rates and nucleation radii of these inclusions are obtained,and the results demonstrate a considerable difference between theoretical and experimental values.On the basis of a two-step nucleation mechanism,(CeO_(2))_(n) and(Ce_(2)O_(3))_(n)(n=1-6)clusters were constructed and the thermodynamic properties of both these clusters and of cerium oxide nanoparticles were analyzed.In addition,the entropies and heat capacity changes of cerium oxides were determined using first principles calculations and are found to be consistent with literature data.The present data indicate that the cerium oxide inclusion nucleation pathway can be summarized as[Ce]+[O]→(CeO_(2))n/(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(2)→core(Ce_(2)O_(3)crystal)-shell((Ce_(2)O_(3))_(2) cluster)nanoparticles→(Ce_(2)O_(3))bulk.

Controlling chaos using Takagi-Sugeno fuzzy model and adaptive adjustment

In this paper, an approach to the control of continuous-time chaotic systems is proposed using the Takagi-Sugeno （TS） fuzzy model and adaptive adjustment. Sufficient conditions are derived to guarantee chaos control from Lyapunov stability theory. The proposed approach offers a systematic design procedure for stabilizing a large class of chaotic systems in the literature about chaos research. The simulation results on Rossler＇s system verify the effectiveness of the proposed methods.

An Equivalent Substitute Strategy for Constructing 3D Ordered Porous Carbon Foams and Their Electromagnetic Attenuation Mechanism

Three-dimensional(3D)ordered porous carbon is generally believed to be a promising electromagnetic wave(EMW)absorbing material.However,most research works targeted performance improvement of 3D ordered porous carbon,and the specific attenuation mechanism is still ambiguous.Therefore,in this work,a novel ultra-light egg-derived porous carbon foam(EDCF)structure has been successfully constructed by a simple carbonization combined with the silica microsphere template-etching process.Based on an equivalent substitute strategy,the influence of pore volume and specific surface area on the electromagnetic parameters and EMW absorption properties of the EDCF products was confirmed respectively by adjusting the addition content and diameter of silica microspheres.As a primary attenuation mode,the dielectric loss originates from the comprehensive effect of conduction loss and polarization loss in S-band and C band,and the value is dominated by polarization loss in X band and Ku band,which is obviously greater than that of conduction loss.Furthermore,in all samples,the largest effective absorption bandwidth of EDCF-3 is 7.12 GHz under the thickness of 2.13 mm with the filling content of approximately 5 wt%,covering the whole Ku band.Meanwhile,the EDCF-7 sample with optimized pore volume and specific surface area achieves minimum reflection loss(RL_(min))of−58.08 dB at 16.86 GHz while the thickness is 1.27 mm.The outstanding research results not only provide a novel insight into enhancement of EMW absorption properties but also clarify the dominant dissipation mechanism for the porous carbon-based absorber from the perspective of objective experiments.

Effect of Facet Displacement on Radiation Field and Its Application for Panel Adjustment of Large Reflector Antenna

Large reflector antennas are widely used in radars, satellite communication, radio astronomy, and so on. The rapid developments in these fields have created demands for development of better performance and higher surface accuracy. However, low accuracy and low effi- ciency are the common disadvantages for traditional panel alignment and adjustment. In order to improve the surface accuracy of large reflector antenna, a new method is pre- sented to determinate panel adjustment values from far field pattern. Based on the method of Physical Optics （PO）, the effect of panel facet displacement on radiation field value is derived. Then the linear system is constructed between panel adjustment vector and far field pattern. Using the method of Singular Value Decomposition （SVD）, the adjustment value for all panel adjustors are obtained by solving the linear equations. An experiment is conducted on a 3.7 m reflector antenna with 12 segmented panels. The results of simulation and test are similar, which shows that the presented method is feasible. Moreover, thediscussion about validation shows that the method can be used for many cases of reflector shape. The proposed research provides the instruction to adjust surface panels efficiently and accurately.

Enrichment Mechanism and Prospects of Deep Oil and Gas

With the deepening of oil and gas exploration,the importance of depth is increasingly highlighted.The risk of preservation of storage space in deep reservoirs is greater than that in shallow and medium layers.Deep layers mean older strata,more complex structural evolution and more complex hydrocarbon accumulation processes,and even adjustment and transformation of oil and gas reservoirs.This paper systematically investigates the current status and research progress of deep oil and gas exploration around the world and looks forward to the future research focus of deep oil and gas.In the deep,especially the ultra-deep layers,carbonate reservoirs play a more important role than clastic rocks.Karst,fault-karst and dolomite reservoirs are the main types of deep and ultra-deep reservoirs.The common feature of most deep large and medium-sized oil and gas reservoirs is that they formed in the early with shallow depth.Fault activity and evolution of trap highs are the main ways to cause physical adjustment of oil and gas reservoirs.Crude oil cracking and thermochemical sulfate reduction(TSR)are the main chemical modification effects in the reservoir.Large-scale high-quality dolomite reservoirs is the main direction of deep oil and gas exploration.Accurate identification of oil and gas charging,adjustment and reformation processes is the key to understanding deep oil and gas distribution.High-precision detection technology and high-precision dating technology are an important guarantee for deep oil and gas research.

Enabling dendrite-free charging for lithium batteries based on transport-reaction competition mechanism in CHAIN framework

Worldwide trends in mobile electrification will skyrocket demands for lithium-based battery production,driven by the popularity of electric vehicles.However,both lithium metal batteries and lithium ion batteries face severe safety issues due to dendrite nucleation and growth process.Li deposition is significantly influenced by interfacial factors and charging conditions.In this paper,an electrochemical model considering the internal and external factors is proposed based on Monte Carlo method.The influence of internal solid electrolyte interphase(SEI)porosity,thickness and the external conditions on dendrite growth process is systematically described.The simulation results support that the three factors investigated in this model could synergistically regulate the dendrite growth process.Three competition mechanisms are proposed to tailor lithium deposition for Li-based batteries and numerical solutions for variation pattern of dendrite growth with time are fitted.A three-step process describing kinetic process of lithium deposition is proposed.To achieve dendrite-free charging process,charging strategies and emerging materials design should be considered,including physicochemical materials engineering,artificial SEI,and design for dynamic safety boundary.This work could contribute to the foundation for insights of Li deposition mechanism,which is promising to provide guidelines for next-generation high-energy-density and safe batteries in CHAIN framework.

Kinematic Calibration of Asymmetricly Actuated 6-DOF 3-PPPS Parallel Mechanism

An asymmetric actuated 3-PPPS parallel mechanism was analyzed in its application to an aircraft wing adjustment process.The posture alignment precision at the wing ends was enhanced with a kinematic calibration method.A constraint equation was built based on a constraint condition that distances among spherical joints of the mechanism were constant,and further eight groups of analytic forward solutions of all poses of the mechanism were solved.An inverse equation of the posture alignment displacements of aircraft wing parts was built based on space vector chains,and a mapping equation of the pose and geometric errors of the posture alignment mechanism containing 39 error sources was derived by differentiating the kinematic equation of the mechanism.After kinematic calibration experiments,the maximum position error of the posture alignment platform dropped from 2.67 mm to 0.82 mm,the maximum angle error decreased from 0.481° to 0.167°,and the posture alignment precision of the aircraft wing end was improved.

Which sectors should be covered by the EU Carbon Border Adjustment Mechanism?

The European Union(EU)is developing the Carbon Border Adjustment Mechanism(CBAM)to address carbon leakage in international trade.However,the EU has paid inadequate attention to input-output linkages,specifically those in the steel,aluminum,and fertiliser industries.This study aims to identify priority sectors eligible for initial regulation within the emissions-intensive trade-exposed(EITE)industries based on input-output linkages and compare its impacts with the current CBAM sector coverage.This study constructs a Global Production Network(GPN)and Carbon Flow Network(CFN)to present the input trade and embodied carbon flows for the EITE industries.This study highlights the role of the EITE industries as influential nodes in the production network and how the EITE industries in the EU contribute to carbon emissions.To improve the economy and political acceptability,CABM should cover four priority sectors with low economic impacts but a crucial role in reducing emissions,such as plastics,phosphorus fertiliser,aluminum,and copper industry.

水利工程供水价格常态化调整机制探索

为纠正水利工程供水成本长期大幅偏离价格,激励水利工程单位主动强化成本管理,需要建立水利工程供水价格常态化调整机制。水价调整既要考虑外围价格环境的传导作用引起的成本刚性增长,也要考虑供水服务质量和管理单位成本控制因素,构建水利工程供水价格与生产管理要素价格的联动机制。

无缝内衣机调密机构动力学特性研究

针对现有无缝内衣机中密度电动机输出力矩不稳定、测量困难等问题,研究无缝内衣机调密机构动力学特性。结合无缝内衣机成圈及密度调节工艺,建立调密机构三维模型,得到三角滑块推力与电动机转矩间数学关系,运用SolidWorks Motion模块对调密机构进行动力学仿真。搭建调密机构力学测试平台,将测试推力值代入推力与电动机转矩间数学关系计算。结果表明:测试结果与仿真数据相差3.81%,证明理论及建模仿真正确性,给现有无缝内衣机密度调节控制方案中电动机输出力矩控制提供参考。

自适应调节重心林间运输车设计与仿真

为提高运输车在林间的工作效率,研究设计一款能够远程遥控且能根据自身运动姿态自动调节重心的小型林间履带式运输车。通过理论计算完成整车各部分机构的设计,分析整车在可调节重心机构调控下的通过性,确定可调节重心机构的控制策略,并利用Recurdyn软件对整机进行通过性模拟仿真。仿真结果表明,经过调控重心后,整机的通过性得到有效提升,整机上坡的极限角度提高17.9%,横坡的极限角度提高18.3%,极限越障高度提高18.7%,跨壕极限宽度提高13.9%。

全旋转指向式导向钻井工具结构设计与仿真

为了提高全旋转指向式导向钻井工具的设计效率,缩短研发周期,笔者首先设计了该钻井工具的导向执行机构,简化导向执行机构的空间机构模型,通过自由度的计算,得出了该机构具有确定的运动。再对该钻井工具的结构组成和导向原理进行分析,得到了其导向控制方法是通过控制全旋转指向式导向钻井工具的双偏心环和旋转外套的角位移关系,调节其工具角和工具面角,实现导向钻井。最后利用SolidWorks和ADAMS软件对钻井工具虚拟样机进行三维实体建模及运动仿真,仿真结果表明该钻井工具可以实现工具面角(0~360)°和工具角(0~5)°的无级调节,验证了所设计的全旋转指向式导向钻井工具结构和导向原理的可行性,为原理样机的加工奠定了基础。

欧盟碳边境调节机制对内蒙古的影响及应对措施

为实现应对气候变化国家自主贡献及碳中和目标,欧盟提出实施碳边境调节机制(CBAM)。欧盟是中国最重要的贸易伙伴国之一,实施该机制可能会对我国贸易产生一系列影响,中国对欧出口产品成本可能会有所增加。内蒙古是我国重要的能源和战略资源基地,也是重要的能源保供基地和制造业基地。虽然内蒙古出口欧盟金额在全国占比较小(约0.014%),但欧盟是内蒙古第二大出口目的地,提前研究欧盟碳边境调节机制对内蒙古的影响、机遇和挑战,具有重要意义。本文阐述了碳边境调节机制主要内容,并深入分析了该机制对内蒙古的影响、机遇和挑战,并从五个方面提出了应对措施和建议,以期为内蒙古提前布局、提早应对欧盟碳边境调节机制提供参考。

世界能否在气候变化议题中积聚信任与共识——兼论中美欧气候合作重要性和前景

气候变化是少有的美国、中国和欧盟三大经济体近年来都关切的议题,也是中美两国沟通交流、打破政治和外交僵局的一个重要渠道,肩负着政治和气候双重使命。不过,随着支持积极应对气候变化力量和经济情况发生变化,世界三大经济体建立的信任、达成的共识能否维继将面临考验。气候变化国际谈判历史反复证明,合作与妥协是唯一通向共识之道。中美欧有效合作为推动全球气候议程发挥了重要作用。在全球致力谈判新一轮国家自主贡献承诺时,应通过激励机制鼓励更多参与和行动。展望未来,欧盟需要继续发挥领导作用,与中国一道,敦促并携手美国,积极回应发展中国家的合理关切,维继信任、加强合作、凝聚共识,继续推动全球强化减排承诺,开展有意义的气候行动,确保实现全球气候目标。

城乡居民基本养老保险的制度优化研究

目前,我国城乡居民养老保险制度进入“从有到好”的新阶段,制度的优化成为关键问题。城乡居民养老保险制度作为“保基本”的社会保险制度,当前面临的主要问题表现在:城乡居民养老保险的待遇水平低、农村老龄人口基数大、管理层级低,公平性和可持续性发展问题凸显。为此,从保险待遇、保险结构和经办服务三个方面提出六条优化措施:提高城乡居民参保的最低缴费档次标准;设立城乡居民基本养老保险待遇的增长机制;引入集体补助促进保险缴费结构优化;引导灵活就业人员、失地农民等劳动年龄段城乡居民参加企业职工基本养老保险;探索城乡居民基本养老保险参保者转为企业职工基本养老保险参保者的分流途径和方法;探索提高城乡居民养老保险的管理层级。

一种杆长可调的多功能铰链四杆机构模型的设计

设计出一款多功能铰链四杆机构,可使不同机构类型在同一模型上实现。阐述了设计原理,完成了杆长调节机构、限位装置、杆长锁紧装置、机架、多功能连接装置、铅笔固定滑块机构的设计,通过数字化模型呈现其功能。

欧美碳关税对我国的挑战及对策探究——基于“碳边境调节机制”与“清洁竞争法案”的比较

简要阐述了欧盟“碳边境调节机制”与美国“清洁竞争法案”的发展历程及现状,并对两者进行了比较。欧美碳关税的实施将对我国的贸易体系产生一定的冲击。在“双碳”目标的指引下,我国政府和企业应该积极应对:主动开展国际交流合作、坚决抵制单边贸易保护,发展低碳技术、大力降低碳含量,增加碳排放成本、提升碳减排效率,加强碳足迹管理、构建产品碳排放核算体系,锚定“双碳”目标,坚定不移走绿色低碳的高质量发展道路。