A Review of the Methods of Identifying and Testing Plant Cold Resistance

Low-tempemture stress is a major abiotic stress influencing plant growth, economic yield and quality worldwide. Precise and reliable identification and test of plant cold resistance is a foundation for exploring low-temperature damages, cold resistance mechanism of plants, cultivating and innovating quality cold-re- sistant germplasm resources, which is rather important for woody plants because their perennial and large-sized characteristics. Generally, most researches on plant cold-resistant physiology focused on identification and utilization of cold resistance worldwide, and a few on test methods of cold resistance, but cold resistance mechanism has been less reported. Therefore, researches on methods of identifying and testing plant resistance have achieved considerable progress, accumulated much experience and formed characteristics gradually in terms of methodology. Current methods of identifying plant cold resistance include open field/outdoor culti- vation evaluation, cold and frost damage investigation, simulated cold weather, and mathematical model forecast. And the methods of testing plant cold resistance include growth condition test, frozen index investigation, electrolyte leakage, bioelectrical impedance mapping and so on. Synthesizing the methods of identifying and testing plant cold resistance should be a key matter in the present and future researches and application of plant cold resistance physiology, improvement and in- novation of the identification and test will be an important direction of the future researches. Identification and test of plant cold resistance based on genomies, meta- bonomics and proteomics should be the new trend of the researches on physiology and ecology of plant cold resistance.

Biological perspectives in geotechnics:Application and monitoring

This paper builds on exploring the applications of biomediated pathways to solve geotechnical challenges.First,the state of the art of biological remediation strategies including microbial remediation and phytoremediation have been introduced and critically reviewed in the context of decontaminating the soils.Next,biopolymerisation,biomineralisation and bioneutralisation processes have been depicted with a special emphasis on the applications including but not limited to soil stabilisation,soil erosion prevention,anti-desertification and pH neutralisation.Each of these methods have their own limitations and bottlenecks while scaling up,and these challenges have been summarised and some possible paths to overcome the challenges have also been discussed.The state of the art of electromagnetic(EM)monitoring methods to capture the effects of biomediation on spatio-temporal soil properties are then highlighted as a non-invasive and rapid pathway to track the progress of biomediated soil processes.Finally,each of the technologies discussed have been evaluated for their maturity level using the principles of technology readiness level(TRL).A majority of the technologies amounting to around 77%are still in the TRL 4e7,i.e.in the valley of death.It is thus evident that development of these technologies needs to be supported with appropriate funding for improving their maturity to a level of industrial deployment.

New Approach to Lightning Strike Risk Assessment of Wind Farm

In the past,lightning strike risk assessment of buildings mainly referred to the Protection against Lightning—Part 2:Risk Management(IEC 62305-2-2010)based on protection angle method.Lightning strike risk assessment of wind farms was conducted according to the Lightning Protection for Wind Energy System(IEC 61400-24-2019),which proposed the method of lightning strike risk assessment for wind turbine.In fact,the basic idea of the two is the same,that is,the source of the lightning strike wind turbine is transformed from the former S1-S4 to the latter N D-N DJ.According to the above method,wind farm was evaluated,and it has been proved that the practice can not achieve good results.After 2018,China has issued the Guide to Evaluation of Lightning Protection Technology in Buildings(T/GZLY 3-2022)and the Technical Specifications for Lightning Interception in Forest Areas(T/LYCY 4062-2024)based on semicircle protection,in which the source of risk defined by lightning point was closer to the reality,highly targeted and effective.Taking offshore wind farm as an example,this paper introduced a new method of establishing six evaluation indicators to determine the risk level according to the principle of compliance and the new protection technology of semi-circular method,which can be used as a reference for technical personnel.

Measuring method for micro-diameter based on structured-light vision technology

Based on structured-light vision measurement technology, we study a measuring method for microdiameter. The measurement principle and mathematical model are described. A novel grayscale barycenter extraction algorithm along the radial direction is proposed, which can precisely gather the image coor- dinates of the ellipse-shaped light-stripe centers. The accuracy of the measurement result shows marked improvement by using the algorithm. The method executes circle fitting to the measured three-dimensional （3D） data using linear least square method, which can acquire the diameter, surface profile, and other information of the object effectively. On the scene, a line-structured light vision system using the presented method is applied to measure the curvature radius of metal blades. Experimental results show that the measurement precision of the system is higher than 2 μm.

A lattice measuring method based on integral imaging technology

Aiming at the problem that the lattice feature exceeds the view field of the scanning electron microscope(SEM)measuring system,a new lattice measuring method is proposed based on integral imaging technology.When the system works,the SEM measuring system is equivalent to an integral image acquisition system.Firstly,a lattice measuring method is researched based on integral imaging theory.Secondly,the system parameters are calibrated by the VLSI lattice standard.Finally,the value of the lattice standard to be tested is determined based on the calibration parameters and the lattice measuring algorithm.The experimental results show that,compared with the traditional electron microscope measurement method,the relative error of the measured value of the algorithm is maintained within 0.2%,with the same level of measurement accuracy,but it expands the field of view of the electron microscope measurement system,which is suitable for the measurement of samples under high magnification.

Spatial diversity and combination technology using amplitude and phase weighting method for phase-coherent underwater acoustic communications

The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propagation, spatial diversity equalization is the main technical means. The paper combines the passive phase conjugation and spatial processing to maximize the output array gain. It uses signal-to-noise-plus-interference to evaluate the quality of signals received at different channels. The amplitude of signal is weighted using Sigmoid function. Second order PLL can trace the phase variation caused by channel, so the signal can be accumulated in the same phase. The signals received at different channels need to be normal- ized. It adopts fractional-decision feedback diversity equalizer （FDFDE） and achieves diversity equalization by using different channel weighted coefficients. The simulation and lake trial data processing results show that, the optimized diversity receiving equalization algorithm can im- prove communication system＇s ability in tracking the change of underwater acoustic channel, offset the impact of multipath and noise and improve the performance of communication system. The performance of the communication receiving system is better than that of the equal gain combination. At the same time, the bit error rate （BER） reduces 1.8%.

本溪衍水斜拉桥主桥塔梁同步平衡法施工技术

以本溪衍水特大桥主桥钢拱塔与钢箱梁同步施工为例,突破常规斜拉桥塔、梁分离异步式施工方法,应用midas civil有限元软件建模分析及三维模拟技术,施工中合理组织安排塔、梁、索施工顺序,并通过仿真计算与现场实测相结合的方法,实时监测结构应力与线型,采用塔梁同步平衡法施工,提高施工作业效率,降低了施工安全风险,确保了工程质量及工期目标的实现。

70-nanometer DRAM Process Technology Employing the CVD Method

随着物质生活水平的提高,人们对手机、个人电脑和家用电器的使用功能要求越来越高。为了满足人们的需求,采用高性能的动态随机存取存储器是提高电子产品性能的关键,因此韩国三星公司利用化学汽相沉淀法开发出70纳米级的动态随机存取存储器加工技术。该技术克服了目前采用物理汽相沉淀法加工存储器所存在的缺陷,如晶片表面沉积物分布不均,同时该技术可节约20％的制造成本。