3-Turns教学法在实践共同体促进深度学习中的应用

在电气工程专业实践教学过程中凝练出由Turn up、Turn away、Turn back等环节组成的3-Turns教学法。经过多轮的实践应用,3-Turns教学法在实践共同体中提供了一个兼具解释性与可操作性的教学样例。研究发现,3-Turns教学法对实践共同体促进工科生深度学习起到了提质增效的作用;3-Turns教学法为工程实践学习情境的强化设计提供了理论依据与经验支持。该研究验证了基于3-Turns教学法的实践共同体促进工科生深度学习的有效性,为助力工科人才培养质量的持续提升做出了积极的探索与实践。

HCB-turn热风干燥器在纸机改造中的应用

由于市场、成本、车速、纸张品质等原因,需要对背面涂布段进行优化改造,这时候加装HCB-turn热风干燥器则是最佳的选择之一,因为它比常规纸幅运行节省1/3的安装空间,且适用于所有纸种,对纸张和涂层能够有高效的干燥和无污染的转向。

Case Retrieval Strategy of Turning Process Based on Grey Relational Analysis

To solve the problem of long response time when users obtain suitable cutting parameters through the Internet based platform,a case-based reasoning framework is proposed.Specifically,a Hamming distance and Euclidean distance combined method is designed to measure the similarity of case features which have both numeric and category properties.In addition,AHP(Analytic Hierarchy Process)and entropy weight method are integrated to provide features weight,where both user preferences and comprehensive impact of the index have been concerned.Grey relation analysis is used to obtain the similarity of a new problem and alternative cases.Finally,a platform is also developed on Visual Studio 2015,and a case study is demonstrated to verify the practicality and efficiency of the proposed method.This method can obtain cutting parameters which is suitable without iterative calculation.Compared with the traditional PSO(Particle swarm optimization algorithm)and GA(Genetic algorithm),it can obtain faster response speed.This method can provide ideas for selecting processing parameters in industrial production.While guaranteeing the characteristic information is similar,this approach can select processing parameters which is the most appropriate for the production process and a lot of time can be saved.

Analysis on the turning point of dynamic in-plane compressive strength for a plain weave composite

Experimental investigations on dynamic in-plane compressive behavior of a plain weave composite were performed using the split Hopkinson pressure bar. A quantitative criterion for calculating the constant strain rate of composites was established. Then the upper limit of strain rate, restricted by stress equilibrium and constant loading rate, was rationally estimated and confirmed by tests. Within the achievable range of 0.001/s-895/s, it was found that the strength increased first and subsequently decreased as the strain rate increased. This feature was also reflected by the turning point(579/s) of the bilinear model for strength prediction. The transition in failure mechanism, from local opening damage to completely splitting destruction, was mainly responsible for such strain rate effects. And three major failure modes were summarized under microscopic observations: fiber fracture, inter-fiber fracture, and interface delamination. Finally, by introducing a nonlinear damage variable, a simplified ZWT model was developed to characterize the dynamic mechanical response. Excellent agreement was shown between the experimental and simulated results.

High-sensitive state perception method for inverter-fed machine turn insulation based on FrFT-Mel

Amidst the swift advancement of new power systems and electric vehicles,inverter-fed machines have progressively materialized as a pivotal apparatus for efficient energy conversion.Stator winding turn insulation failure is the root cause of inverter-fed machine breakdown.The online monitoring of turn insulation health can detect potential safety risks promptly,but faces the challenge of weak characteristics of turn insulation degradation.This study proposes an innovative method to evaluate the turn insulation state of inverter-fed machines by utilizing the fractional Fourier transform with a Mel filter(FrFT-Mel).First,the sensitivity of the high-frequency(HF)switching oscillation current to variations in turn insulation was analyzed within the fractional domain.Subsequently,an improved Mel filter is introduced,and its structure and parameters are specifically designed based on the features intrinsic to the common-mode impedance resonance point of the electrical machine.Finally,an evaluation index was proposed for the turn insulation state of inverter-fed machines.Experimental results on a 3kW permanent magnet synchronous machine(PMSM)demonstrate that the proposed FrFT-Mel method significantly enhances the sensitivity of turn insulation state perception by approximately five times,compared to the traditional Fourier transform method.

DER SPATIAL TURN IN DEN KLASSISCHEN ALTERTUMSWISSENSCHAFTEN(UND SPEZIELL IN DER EPIGRAPHIK)

Since the 1990s the so-called spatial turn has brought back space and topography into the discussion within historical studies,particular ancient studies.This survey reviews current trends and developments within the field and offers some perspectives on possible future developments related to space,material,objects,their agency,and frames.

Numerical Study of a Three-Dimensional Laminar Flow in a Rectangular Channel with a 180-Degree Sharp Turn

This study presents a numerical analysis of three-dimensional steady laminar flow in a rectangular channel with a 180-degree sharp turn. The Navier-Stokes equations are solved by using finite difference method for Re = 900. Three-dimensional streamlines and limiting streamlines on wall surface are used to analyze the three-dimensional flow characteristics. Topological theory is applied to limiting streamlines on inner walls of the channel and two-dimensional streamlines at several cross sections. It is also shown that the flow impinges on the end wall of turn and the secondary flow is induced by the curvature in the sharp turn.

TURNING LIGNIN INTO VALUABLE PRODUCTS

In a study published in Nature Catalysis on May 28,Chinese scientists unveiled a nove l approach to transforming lignin,a major component of woody biomass,into valuable chemical products(doi:10.1038/s41929-024-01165-w).This discovery could pave the way for more sustainable and efficient use of renewable resources.

NC code generation for laser assisted turn-mill of various type of clovers and square section members

Laser assisted turning （LAT） is one of the advanced machining technologies, which uses laser power to heat the surface of a workpiece before the material is removed. It has several advantages of low manufacturing costs, high productivity and high qualities to machine difficult-to-cut materials such as silicon nitride, muUite, zirconia and Ni. A large part of studies on LAT have been focused on a round bar. With increasing demands for high quality products and high performance engineering system, the researches on LAT for clover and square section members are necessary. But, these workpieces are impossible to be machined on conventional CNC lathe and to generate NC code with current CAM softwares. As a basic research for combining LAT with a tilting index table type 5-axis machining center, i.e. laser assisted turn-mill, a new method is suggested to generate NC code that can process various types of clover and square section members through development of C＋＋ program.

Ultra-high voltage 4H-SiC gate turn-off thyristor for low switching time

An ultra-high voltage 4H-silicon carbide(Si C) gate turn-off(GTO) thyristor for low switching time is proposed and analyzed by numerical simulation. It features a double epitaxial p-base in which an extra electrical field is induced to enhance the transportation of the electrons in the thin p-base and reduce recombination. As a result, the turn-on characteristics are improved. What is more, to obtain a low turn-off loss, an alternating p^+/n^+region formed in the backside acts as the anode in the GTO thyristor. Consequently, another path formed by the reverse-biased n^+–p junction accelerates the fast removal of excess electrons during turn-off. This work demonstrates that the turn-on time and turn-off time of the new structure are reduced to 37 ns and 783.1 ns, respectively, under a bus voltage of 8000 V and load current of 100 A/cm^2.

Paradigm Shifts in Translation Studies： Focus on Linguistic, Cultural, Social and Psychological Turns

Translation has been the subject of a variety of research and conflicts among theorists. This fact that gives Thomas Samuel Kuhn＇s paradigm theory is pertinent to the present study. Kuhn is an American philosopher of Science. In his book The Structure of Scientific Revolutions, he proposes his paradigm theory which plays a great role in the development of sociology and philosophy of Science. According to Kuhn （1970）, paradigm originates from one or some famous people＇s achievements, and for these achievements to be considered as paradigms, two major characteristics must be met as will be clarified in this paper. This study is an attempt to outline the scope of the disciplines of Translation Studies （TS）, to give some indication of the kind of work that has been done so far. It is an attempt to demonstrate that TS is a discipline in its own right. It is a vastly complex field with many far-reaching ramifications. This study discusses the relationships between the changing definitions of translation and the turns of translation studies.

Physiological Characterization of Green Turning of Rice Seedlings at Different Temperatures

Using early indica rice Zhongzao 39 and japonica rice Xiushui 134 as the experimental materials, the effects of 4 temperature levels after transplantation on turning green, leaf growth, tillering, dry matter accumulation and nutrition absorption were studied using a greenhouse and an artificial climate chest. We found that （1） tillering did not occur and growth of one new leaf took over 15 days at 16℃. New leaf growth took over 10 days and tillering occurred after 15 days of transplanta- tion at 19 ℃. Tillering appeared 10 days after planting and new leaf growth took 5 days between 22 and 25 ℃. This showed that low temperature impeded the turn- ing green of rice seedlings and the temperature must reach above 19 ℃ to ensure timely appearance of new leaf, tillering and turning green in rice seedlings. （2） When the temperature was 10 increased, both 100-seedling dry weight and nitrogen absorption increased. At temperatures lower 11 than 19 ℃, both dry weight incre- ment and nitrogen absorption were low. Nitrogen absorption of all organs increased obviously between 19 and 22 ℃. Thus, 19 ℃ was found to be an minimum tem- perature for plant organs to absorb nutrients. （3）Tiller of seedling cultivated on dry- land soil and substrate grew quickly and tillering occurred about 7 days after trans- planting. After that, the growth rate was about 0.18 tiller per day. For seedlings cultivated in slurry, tillering occurred 10 days after transplanting and the tillers grew at a rate of 0.16 tiller per day. However, substrate choice during the seedling rais- ing stage had no significant influence on leaf age. （4） Japonica rice exhibited stronger resistance to low temperature than indica rice. Tillering began at about the same time after transplanting in both rice varieties, but japonica rice exhibited higher tillering speed than early indica rice. The speed of leaf growth was higher in japoni- ca rice before transplantation but higher in indica rice after transplantation.

Designing Right-Turn Vehicle Box as a Supplemental Treatment to Eliminate Conflicts with Pedestrians and Bicycles

Field observations illustrated that, right-turn vehicles stopped at various positions when proceeding within the right-turn lanes, while some of them trespassed on the crosswalks with multiple stops. In this case, pedestrians and bikes (ped/bike) are encountered unsmooth and hazardous crossings when right-turn vehicles encroaching their lanes. Meanwhile, this also causes conflicts between right-turn and through vehicles at the crossing street. To better protect ped/bike at crossings with right-turn vehicles, this paper proposes a concept of “right-turn vehicle box” (RTVB) as a supplemental treatment within right-turn lanes. Sight distance, geometric conditions, and behaviors of vehicles and ped/bike are key factors to consider so as to set up the criteria and to design the suitable treatment. A case study was conducted at an intersection pair in Houston, USA to shape the idea of RTVB, together with driving simulator tests under relevant scenarios. The preliminary crosscheck examination shows that the right-turn vehicle box could possibly provide ped/ bike with smoother and safer crossings. In the interim, the safety and efficiency of right-turn operations were also improved. To further validate the effects, implementation studies should be conducted before the RTVB can make its debut in practice. Future works will focus on the complete warrants and design details of this treatment. Moreover, the concept of “vehicle box” could also be transplanted to other places where turning movement(s) needs assistance or improvements.

基于延误的U-turn交通组织可行性分析方法

U-turn组织方案下,交叉口的流量流向会重新分布,在新的流量、流向分布下,交叉口车辆延误将发生变化,依据U-turn组织前后交叉口交通流线特征,将交叉口延误细分为交叉口内信控延误、禁左方向绕行延误、绕行车辆变道交织延误3部分,按照各种车流的时空关系以及车流交织理论,借鉴已有延误分析成果,推导3类延误计算方法,将U-turn组织后,3类延误总合与U-turn前交叉口内信控延误对比,评判U-turn组织效益,实例仿真验证显示所介绍方法能够用于U-turn后交叉口的延误计算和效益评判,能够为交叉口是否可采用U-turn组织提供决策依据。

On the Power Relations in If You Are the One from Turn-taking Organization

The power relations in the TV program called If You Are the One will be explored from the perspective of the turns of different speakers on the different positions,such as the host,male guests,female guests and two commentators.Using both quantitative and qualitative methods,the reversion of the program,updated on June 9,2018 on the internet,is sampled.Then,the analyses on respective turns of different speakers are from two main perspectives of the turn-constructional component and turn-allocation component.The results show that the host has more power than others and the role two commentators play in the program is very important.Analyzing the power relations in these conversations of the program helps readers more positively and effectively understand the operation mechanism of this program after reversion.

A Class of the Singularly Perturbed Boundary Value Problems for Elliptic Equation with a Super Surface of Turning Point in n-dimensional Space

In this paper, we study a class singular perturbed elliptic equation boundary value problem with a super surface of turning point in n-dimensional space by using the method of multiple scales and the comparison theorem. The uniformly valid asymptotic approxmations of solutions for the boundary value problem is constructed.

基于量子点“Turn-off”模式结合化学计量学方法快速检测茶叶中多组分农残

作为一个新兴的检测模型,量子点荧光"Turn-off"模式已经成功应用于许多材料的检测,尤其在农残检测方面。研究了基于低毒性、水溶性ZnCdSe量子点"Turn-off"模式快速检测农残的新方法。通过比较百草枯、甲基硫菌灵两种常用农药对量子点荧光的猝灭程度并结合化学计量学方法,成功地实现了不拘于相同浓度下不同农药的快速分析。该方法灵敏度高、选择性好,使其在不同的茶叶背景(如红茶、英山云雾茶)中均能够对农残进行准确分析。

Novel Evaluation Method of Vehicle Suspension Performance Based on Concept of Wheel Turn Center

The current research of suspension performance evaluation is mixed in the evaluation of vehicle handling and ride comfort. However, it is lack of a direct and independent evaluation method for suspension performance. In this paper, a novel wheel turn center method is proposed to evaluate the suspension performance. This method is based on the concept and application of wheel turn center （WTC） and sprung mass turn center （SPTC）. The vehicle body and each wheel are regarded to be independent rigid bodies and have their own turn centers which reflect respective steering motions and responses. Since the suspension is the link between vehicle body and wheels, the consistence between the sprung mass turn center and the wheel turn center reflects the effect and performance of the suspension system. Firstly, the concept and appropriate calculation method of WTC and SPTC are developed. Then the degree of inconsistence between WTC and SPTC and the time that they achieve consistence, when the vehicle experiences from transient steering to steady steering state, are proposed to evaluate suspension performance. The suspension evaluation tests are conducted under different vehicle velocities and lateral accelerations by using CarSim software. The simulation results show that the inconsistence of steering motion between vehicle body and wheels are mainly at high speeds and low lateral accelerations. Finally, based on the proposed evaluation indexes, the influences of different suspension characteristic parameters on suspension performance and their matches to improve steering coordination are discussed. The proposed wheel turn center method provides a guidance and potential application for suspension evaluation and optimization.

高架道路下匝道衔接交叉口U-turn设计方法

高架道路下匝道地面衔接路段及其衔接交叉口的交通设计是城市快速路交通设计的一个重要组成部分,为解决我国城市高架道路下匝道与地面道路衔接交叉口排队和拥堵日益严重的问题,分析了U-turn设计对交叉口车辆延误和饱和度等运行效益指标的影响,以及U-turn在改善交叉口交通安全性方面的作用。以"变交叉为交织或避免交叉和交织"为目标,分析了高架道路下匝道不同接地类型与不同U-turn形式的最佳结合方法;以交叉口延误与左转交通流路段延误加权最小为目标的最佳U-turn选择模型,给出了高架路下匝道交叉口和路段两种U-turn的设计方法。最后,以上海市某高架道路下匝道及其衔接交叉口为例进行算例分析,实施U-turn设计后,可以显著降低交叉口的饱和度,最大降幅达29%;交叉口的车均延误最大降低60%,交叉口服务水平由D级上升到C级。

Clock-turning gait synthesis for humanoid robots

Turning gait is a basic motion for humanoid robots. This paper presents a method for humanoid tuming, i.e. clock-turning. The objective of clock-turning is to change robot direction at a stationary spot. The clock-turning planning consists of four steps： ankle trajectory generation, hip trajectory generation, knee trajectory generation, and inverse kinematics calculation. Our proposed method is based on a typical humanoid structure with 12 DOFs （degrees of freedom）. The final output of clock-turning planning is 12 reference trajectories, which are used to control a humanoid robot with 12 DOFs. ZMP （zero moment point） is used as stability criterion for the planning. Simulation experiments are conducted to verify the effectiveness of our proposed clock-turuing method.