Diagnosis of indirectly driven double shell targets with point-projection hard x-ray radiography

We present an application of short-pulse laser-generated hard x rays for the diagnosis of indirectly driven double shell targets. Coneinserted double shell targets were imploded through an indirect drive approach on the upgraded SG-II laser facility. Then, based on thepoint-projection hard x-ray radiography technique, time-resolved radiography of the double shell targets, including that of their near-peakcompression, were obtained. The backlighter source was created by the interactions of a high-intensity short pulsed laser with a metalmicrowire target. Images of the target near peak compression were obtained with an Au microwire. In addition, radiation hydrodynamicsimulations were performed, and the target evolution obtained agrees well with the experimental results. Using the radiographic images, arealdensities of the targets were evaluated.

The design of double line five step ship lock of Three Gorges Project

The general design and layout of the double-line five-step ship-lock,the water delivery technique for high head ship-lock,the key technical problems of fully lined ship-lock and the monitoring techniques for large-scale miter gates and hoisting equipment under complicated operation conditions of Three Gorges Project (TGP) are introduced.Since the operation of ship-lock in 2003,the operation practice has proved that the design techniques are advanced,rational and reliable.The design and construction of the fully lined ship-lock promotes the development of design theory and practice of ship-lock projects,which makes the construction technology of ship-lock in the world reach a new level.

Teaching Reform for Mobile Application Development with Industrial Projects,Double Instructors,and Automatic Assessments

Mobile Application Development is a well-known undergraduate specialized course majoring in Computer Science and Software Engineering.Since it is a rapid developing technique and requires extensive project samples to help understand,current teaching mechanism has still limitations in rare real project examples,outdated course contents,and lack of automatic assessment platforms.In order to improve the teaching effects and cultivate students’practical ability,we employ this teaching reform with industrial projects,double instructors,and automatic assessment platform to allow students participating in every course process.We aim to improve students’practical and collaboration ability during conducting the project spontaneously,and cultivate their awareness of self-learning and lifelong learning.Our classroom feedback has demonstrated that this teaching reform is effective on improving students’practical abilities,learning initiatives and comprehensive qualities.

The Double Projecting Neuron of the Cat Spinal Dorsal Horn——A Study with Double Retrograde Fluorescent Tracing Technique

The new double projecting neurons were found in the cat spinal dorsal horn by the double retrograde fluorescent tracing technique.Fast Blue(FB)was injected into unilateral dorsal column nucleus(DCN)of adult cats anesthetized with pentobarbital.Nuclear Yellow(NY)was injected ipsilaterally into the lateral cervical nucleus(LCN)8-9 days later.After an additional 18-30 hrs.

Automatic Assessment of Fabric Smoothness Grade Using Double CCD Grating Projection

Automatically assessing fabric smoothness grade is very important in the evaluation of fabric appearance.A system for objectively evaluating the fabric smoothness grade based on a grating projection unit and double colored CCD(short form of charge coupled device) was constructed in this paper.Two images captured by different CCD compensated each other which reduced the influence of noises.The application of the four-step phase-shifting method enabled the calculation of the exact phase in a point easy and quick.A large amount of 3D points with three coordinates X,Y and Z were obtained precisely making the definition and calculation of fabric smoothness characters easy.Then four parameters which intuitively denoted the fabric smoothness degree were obtained.Finally,a proper neural network was built,which successfully performed the fabric smoothness classification.The experimental results show that the system is applicable for all the fabric whatever pattern or color.The experimental grades provided by this grating projection system are also highly consistent with the subjective results.

Multi-model Projection of July–August Climate Extreme Changes over China under CO_2 Doubling. Part I: Precipitation

Potential changes in precipitation extremes in July–August over China in response to CO 2 doubling are analyzed based on the output of 24 coupled climate models from the Twentieth-Century Climate in Coupled Models （20C3M） experiment and the 1% per year CO 2 increase experiment （to doubling） （1pctto2x） of phase 3 of the Coupled Model Inter-comparison Project （CMIP3）. Evaluation of the models’ performance in simulating the mean state shows that the majority of models fairly reproduce the broad spatial pattern of observed precipitation. However, all the models underestimate extreme precipitation by ～50%. The spread among the models over the Tibetan Plateau is ～2–3 times larger than that over the other areas. Models with higher resolution generally perform better than those with lower resolutions in terms of spatial pattern and precipitation amount. Under the 1pctto2x scenario, the ratio between the absolute value of MME extreme precipitation change and model spread is larger than that of total precipitation, indicating a relatively robust change of extremes. The change of extreme precipitation is more homogeneous than the total precipitation. Analysis on the output of Geophysical Fluid Dynamics Laboratory coupled climate model version 2.1 （GFDL-CM2.1） indicates that the spatially consistent increase of surface temperature and water vapor content contribute to the large increase of extreme precipitation over contiguous China, which follows the Clausius–Clapeyron relationship. Whereas, the meridionally tri-polar pattern of mean precipitation change over eastern China is dominated by the change of water vapor convergence, which is determined by the response of monsoon circulation to global warming.

Multi-Model Projection of July–August Climate Extreme Changes over China under CO_2 Doubling. Part II: Temperature

This is the second part of the authors’ analysis on the output of 24 coupled climate models from the Twentieth-Century Climate in Coupled Models （20C3M） experiment and 1% per year CO 2 increase experiment （to doubling） （1pctto2x） of phase 3 of the Coupled Model Inter-comparison Project （CMIP3）. The study focuses on the potential changes of July–August temperature extremes over China. The pattern correlation coefficients of the simulated temperature with the observations are 0.6–0.9, which are higher than the results for precipitation. However, most models have cold bias compared to observation, with a larger cold bias over western China （5°C） than over eastern China （2°C）. The multi-model ensemble （MME） exhibits a significant increase of temperature under the 1pctto2x scenario. The amplitude of the MME warming shows a northwest–southeast decreasing gradient. The warming spread among the models （～1°C– 2°C） is less than MME warming （～2°C–4°C）, indicating a relatively robust temperature change under CO 2 doubling. Further analysis of Geophysical Fluid Dynamics Laboratory coupled climate model version 2.1 （GFDL-CM2.1） simulations suggests that the warming pattern may be related to heat transport by summer monsoons. The contrast of cloud effects also has contributions. The different vertical structures of warming over northwestern China and southeastern China may be attributed to the different natures of vertical circulations. The deep, moist convection over southeastern China is an effective mechanism for ＂transporting＂ the warming upward, leading to more upper-level warming. In northwestern China, the warming is more surface-orientated, possibly due to the shallow, dry convection.

A Brief Introduction and Recent Progress of the Geospace Double Star Program

The Geospace Double Star Project (DSP) consists of two small satellites operating in the near-earth equatorial and polar regions, respectively. The goals of DSP are: (1) to provide high-resolution field, particle, and wave measurements in some important near-earth active regions which have not been covered by current ISTP missions, such as the near-earth plasma sheet and its boundary layer, the ring current, the radiation belts, the dayside magnetopause boundary layer, and the polar region; (2) to investigate the trigger mechanisms of magnetic storms, magnetospheric substorms, and magnetospheric particle events,as well as the responses of geospace storms to solar activities and interplanetary disturbances; (3) to set up the models describing the spatial and temporal variations of the near-earth space environment.To realize the above goals, the equatorial satellite TC-1 and the polar satellite TC-2 will accommodate, respectively, eight instruments on board. TC-1was launched successfully in December 2003 while the polar satellite (TC-2)will be launched in July 2004. The orbit of the equatorial satellite TC-1 consists of a perigee at 550 km, an apogee at 60 000 km, and an inclination of about 28.5; while the orbit of the polar satellite will have a perigee of 700 km, an apogee of 40 000 km, and an inclination of about 90. The two satellites will take coordinated measurements with Cluster Ⅱ and will first form a "six-point exploration" in geospace.The operational status of TC-1 are introduced in this paper.

A BRIEF INTRODUCTION TO GEOSPACE DOUBLE STAR PROGRAM

The Geospace Double Star Exploration Project (DSP) contains two small satel lites operating in the near-earth equatorial and polar regions respectively. The tasks of DSP are: (1) to provide high-resolution field, particle and wave mea surements in several important near-earth active regions which have not been covered by existing ISTP missions, such as the near-earth plasma sheet and its boundary layer, the ring current, the radiation belts, the dayside magnetopause boundary layer, and the polar region; (2) to investigate he trigger mechanisms of magnetic storms, magnetospheric substorms, and magnetospheric particle storms, as well as the responses of geospace storms to solar activities and in terplanetary disturbances; (3) to set up the models describing the spatial and temporal variations of the near-earth space environment.To complete the mission, there are eight instruments on board the equatorial satellite and the polar satellite, respectively. The orbit of the equatorial satellite is proposed with a perigee at 550km and an apogee at 60 000km, and the inclination is about 28.5°; while the orbit of the polar satellite with a perigee at 700 km and an apogee at 40 000 km, as well as an inclination about 90°. The equatorial and polar satellites are planed to be launched into orbits in June 2003 and December 2003 respectively to take coordinating measurements with Cluster Ⅱ and other missions.

Design Consideration and Reconstruction Method for Double-source Double-multislice Spiral CT

To accelerate the scan speed and improve the image quality, a new type of CT configuration, "double-source double-multislice spiral CT" (DSDMS-CT), which is based on two sets of single-source multislice spiral CT was proposed with a special reconstruction algorithm. Simulation results using the fan-beam filtered backprojection algorithm with a special interpolation method were presented for both single-source multislice spiral CT and DSDMS-CT. The results of new CT model show that it scans faster than the traditional spiral CT and has a better slice sensitivity profile (SSP) with larger pitch value.

面向“双碳”目标人才培养的工业化学课程教学改革探索与实践

为培养“双碳”目标高等教育紧缺专业人才,过程装备与控制工程专业工业化学课程“教”与“学”的模式需要与时俱进,改变以教师为中心的教学模式,建立以学生为中心的教学模式势在必行。该文针对工业化学课程教学过程中存在的“双碳”目标教育内容不足问题,初步探索通过增加绿色工程教育内容、实施项目驱动教学、建设跨学科的工业化学师资队伍和建立与“双碳”目标人才培养相适应的教学评价方法等措施来提高教学质量,并提出“双碳”目标下工业化学课程体系改革建议,为培养“双碳”目标紧缺人才提供参考和应用实践。

能源技术进步与区域专业化——特高压输电工程的视角

基于2003—2020年中国285个地级市数据,以特高压输电工程为切入点,研究能源技术进步对区域专业化的影响及作用机制。结果显示:以特高压输电技术为代表的能源技术进步显著提升了区域专业化水平,具体而言,较没有特高压输电项目城市,配备特高压输电工程城市的专业化水平提升约1.09%,且该效应在中小城市、资源丰富城市和内陆地区更强;在考虑样本选择偏差、基期分工水平、调整指标测度、剔除极端值并进行安慰剂检验和倾向得分匹配后,该结果依然稳健;进一步的机制分析表明,特高压建设所表征的能源技术进步通过激发资源禀赋的比较优势、生产的集聚效应来促进地区专业化。继续扩大特高压输电规模,合理实施区域专业化,互通有无、取长补短,对促进区域协调发展具有重要意义。

“双一流”大学教师国际学术影响力研究——结构、评价指标及影响因素

构建大学教师国际学术影响力的三维评价指标和量表,对中国37所“双一流”大学教师进行了国际学术影响力抽样调查和测评。通过结构方程模型方法,拟合验证了所构建的大学教师国际学术影响力的三维结构,即国际人才培养、国际科学研究和国际社会服务。研究结果表明,大学教师的国际学术影响力平均水平偏低,存在较大的个体差异,同时,还会受到大学教师的学科领域、职称、访学时长、访学次数等因素的显著影响。

楚怡双高校“第二课堂成绩单”课程项目体系的构建

文章从深刻剖析高职院校“第二课堂成绩单”存在的问题入手,以永州职业技术学院为例,将“楚怡”精神融入“第二课堂成绩单”,创新构建具有湖湘职教特色的课程项目体系,并将楚怡双高校“第二课堂成绩单”课程项目体系应用于人才培养中。该体系有助于实施学生综合素质评价、提升学生综合素养、实现德智体美劳“五育融合”,有助于落实立德树人根本任务和“三全育人”综合改革,推进楚怡双高校建设和学校共青团改革发展,服务“人才强省”“三高四新”“富民兴湘”战略。

高职院校工程伦理教育的问题与改革路径

高职院校对于加强理工科学生的工程伦理教育已经基本达成共识。工程伦理教育有助于培养高素质技术技能人才,有助于推动“双高计划”的实施与落地。当前高职院校工程伦理教育还面临教育目标不明、教育资源匮乏、教学模式落后等一系列问题。对此,提出明确工程伦理教育培养目标、构建“本土化”的教育模式、组建跨学科教学团队等一系列改革路径增强学生的人文素养与情怀,提高专业人才培养质量。

NνDEx-100 conceptual design report

Observing nuclear neutrinoless double beta (0vββ) decay would be a revolutionary result in particle physics.Observing such a decay would prove that the neutrinos are their own antiparticles,help to study the absolute mass of neutrinos,explore the origin of their mass,and may explain the matter-antimatter asymmetry in our universe by lepton number violation.We propose developing a time projection chamber (TPC) using high-pressure ^(82)SeF_(6) gas and Topmetal silicon sensors for readout in the China Jinping Underground Laboratory (CJPL) to search for neutrinoless double beta decay of82Se,called the NvDEx experiment.Besides being located at CJPL with the world’s thickest rock shielding,NvDEx combines the advantages of the high Qββ(2.996 MeV) of82Se and the TPC’s ability to distinguish signal and background events using their different topological characteristics.This makes NvDEx unique,with great potential for low-background and high-sensitivity 0 vββsearches.NvDEx-100,a NvDEx experiment phase with 100 kg of SeF_(6)gas,is being built,with plans to complete installation at CJPL by 2025.This report introduces 0 vββ physics,the NvDEx concept and its advantages,and the schematic design of NvDEx-100,its subsystems,and background and sensitivity estimation.

“双一流”背景下科研项目融入本科实验

在“双一流”背景下,结合卓越工程教育要求,探讨一种基于5C理念综合素质的“一生双师”制科研项目融入型本科实验模式。以选修科研项目实验课程的本科生为中心,以项目组教师团队为实验教学主导,以项目组研究生团队为实验教学辅助,将科研项目的资源和技术有机地融入本科实验,可以为我们营造良好的乐学环境,创设卓越的学习平台。实践表明:该实验模式有助于培育具有探索精神、创新意识、科学思维、学术素养、创新能力的卓越型工程人才,对学校本科教育的改革与发展具有一定的参考意义。

国家自然科学基金视角下地理科学学科“双一流”建设成效及优化策略

“双一流”建设工程是我国在高等教育领域开展的重大国家战略,其开展与实施对学科人才队伍建设起到了极大的促进作用,并为抢占学科前沿高地与提高国际话语权提供了强有力的支撑。地理科学是理学门类的重要基础学科,其核心研究内容是人—地关系及其相互作用机理,并在“生态文明建设”“一带一路倡议”“乡村振兴”“全球变化与可持续发展”等国家重大需求中发挥着至关重要的学科作用。国家自然科学基金委员会是地理科学基础研究的主要资助机构,从国家自然科学基金委员会的管理角度审视当前“双一流”建设高校地理科学学科的建设情况,可为学科建设的优化布局提供支撑。

杨氏双缝干涉实验中引入偏振片的教学思考及分析

将偏振片引入杨氏双缝干涉实验,并讨论不同组合时干涉条纹的规律,是一道很有意义的习题,然而,常见的解答——“无固定相位差”,对问题的本质认识不够深入。本文运用马吕斯定律和波的叠加原理,计算了叠加后的衬比度。定量计算表明,在杨氏双缝干涉实验中,引入三个偏振片时,没有干涉条纹的物理实质是存在投影相位差,并且指出,在这一问题中,投影相位差是干涉条纹存在与否的决定性因素。文章物理图像直观,适合在课堂教学中运用,清晰地展示投影相位差的作用,也有助于学生对光源发光机理、干涉、偏振的概念以及偏振光干涉的深入理解与运用。