期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
人类世与环境史研究——《大加速》导读 被引量:7
1
作者 包茂红 《学术研究》 CSSCI 北大核心 2020年第2期110-116,共7页
人类世是一个在科学界和大众传媒中广泛使用但尚未得到相关命名机构正式批准的一个术语。但是,这个概念的流行反映了在导致地球环境变化的诸因素中人类活动已经超过自然营力发挥了主导作用的现实。本文以《大加速:1945年以来的人类世的... 人类世是一个在科学界和大众传媒中广泛使用但尚未得到相关命名机构正式批准的一个术语。但是,这个概念的流行反映了在导致地球环境变化的诸因素中人类活动已经超过自然营力发挥了主导作用的现实。本文以《大加速:1945年以来的人类世的环境史》为蓝本,探讨人类世概念及其判定标准的演变,分析该书的学术特点和未来需要进一步研究的问题,指出人类世与环境史研究仍是一个开放的、发展中的研究领域,而《大加速》这部建立在新概念基础上的、视野宏大、采用跨学科研究方法的、富有启发性的探索性著作将会成为探索这个新领域或新史学的坚实起点。 展开更多
关键词 人类世 大加速 地球环境 人类活动 环境史研究
下载PDF
锥形超强激光场对电子的加速效应
2
作者 鄢让 郝东山 《河南大学学报(自然科学版)》 CAS 北大核心 2005年第1期23-26,共4页
提出了用锥形超强激光场对电子加速的方法,研究了该位形光场对电子的加速效应,得出了电子在该光场里无群聚现象,并能被光场俘获的结论.
关键词 锥形超强激光场 大加速能量 电子群聚
下载PDF
“大加速”:社会生态转型的分析性挑战
3
作者 克里斯托夫·戈尔格 安德烈亚斯·迈尔 +5 位作者 梅勒妮·皮希勒 克里斯蒂娜·普兰克 安克·沙法茨克 多米尼克·维登赫费尔 弗里多林·克劳斯曼 李思齐 《国外理论动态》 CSSCI 北大核心 2019年第9期73-82,共10页
本文采用物质流分析和调节理论相结合的方法,在不忽视全球资本主义、世界市场和全球劳动分工的结构性特征以及所关涉的权力关系的前提下,为分析不同历史阶段和不同国家的具体增长体制提供了一个综合性的方法论框架。社会生态转型所面临... 本文采用物质流分析和调节理论相结合的方法,在不忽视全球资本主义、世界市场和全球劳动分工的结构性特征以及所关涉的权力关系的前提下,为分析不同历史阶段和不同国家的具体增长体制提供了一个综合性的方法论框架。社会生态转型所面临的分析性挑战,不仅在于资源利用速度的增加,更在于现实经济增长体制得到了特定构型下的权力关系的庇护,即调节理论中的所谓调节模式。与此同时,我们还应该注意到,全球资本主义体系本身并非是稳定和不可替代的。事实上,这一体系自身是充满矛盾的,并且其基本规则已经遭到挑战。发现这些冲突是探寻可替代方案并进行现实重塑的重要开始。 展开更多
关键词 社会生态转型 大加速 可持续发展 物质流分析 调节理论
原文传递
《大加速》《狱中书简》
4
作者 张晗 《作文与考试(高中版)》 2019年第33期23-25,共3页
罗伯特·科尔维尔《大加速》罗伯特·科尔维尔(Robert Colvile)是一位政治评论员、作家、资深互联网媒体人。目前担任《CapX》的总编辑。作品简介二十一世纪是一个"以快代慢"的大加速时代。网络从业者讲求自我颠覆,... 罗伯特·科尔维尔《大加速》罗伯特·科尔维尔(Robert Colvile)是一位政治评论员、作家、资深互联网媒体人。目前担任《CapX》的总编辑。作品简介二十一世纪是一个"以快代慢"的大加速时代。网络从业者讲求自我颠覆,否则就会被颠覆。他们担心更快的事物随时出现,夺走他们的用户;担心自己的步伐还不够快,快不过大众的喜新厌旧。 展开更多
关键词 朋霍费尔 狱中书简 大加速
原文传递
An Accelerated Simulation Method for ELDRS of Bipolar Operational Amplifiers Using a Dose-Rate Switching Experiment
5
作者 陆妩 任迪远 +2 位作者 郑玉展 郭旗 余学峰 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第7期1286-1291,共6页
Through different dose-rate switching evaluation methods,the radiation-response rules of operational amplifiers are studied when the irradiation dose rate is switched from high to low under different radiation tempera... Through different dose-rate switching evaluation methods,the radiation-response rules of operational amplifiers are studied when the irradiation dose rate is switched from high to low under different radiation temperatures and total doses. The experimental results indicate that the response characteristics could be affected by the switching total doses, irradiation temperatures,and dose rates individually or together. Accelerated evaluation on the ELDRS can be realized by adopting a proper dose-rate switching method. Meanwhile, the irradiation time can also be reduced. Finally, the mechanisms of the difference between various radiation responses are analyzed. 展开更多
关键词 bipolar OP-amps ^60Co γ radiation switching dose rates accelerated evaluation
下载PDF
Quantitative evaluation of soil erosion of land subsided by coal mining using RUSLE 被引量:13
6
作者 Meng Lei Feng Qiyan +1 位作者 Wu Kan Meng Qingjun 《International Journal of Mining Science and Technology》 2012年第1期7-11,共5页
Based on a RUSLE model, we identified the key factors of the impact on soil erosion induced by coal min- ing subsidence. We designed a method for predicting/.S factors of a mining subsidence basin, using ana- lytical ... Based on a RUSLE model, we identified the key factors of the impact on soil erosion induced by coal min- ing subsidence. We designed a method for predicting/.S factors of a mining subsidence basin, using ana- lytical GIS spatial technology. Using the Huainan mining area as an example, we calculated the modulus of erosion, its volume and classified the grade of soil erosion for both the original area and the subsidence basin. The results show that the maximum modulus of erosion and the volume of erosion of the subsi- dence basin without water logging would increase by 78% and 23% respectively compared with the ori- ginal situation. The edge of the subsidence basin, where the land subsidence was uneven, is subject to the greatest acceleration in soil erosion. In the situation of water logging after subsidence, the maximum modulus of erosion would decrease if the accumulated slope length were reduced. This maximum mod- ulus around the water logged area within the subsidence basin is equal to that without water logging, while the total volume of erosion decreases. Therefore, mining subsidence aggravates soil erosion espe- cially at the edge of basins where water and soil conservation measures should be taken. 展开更多
关键词 RUSLE Coal mining subsidence Soil erosion Quantitative evaluation
下载PDF
MEMS sensor technology 被引量:4
7
作者 Jiang Zhuangde 《Engineering Sciences》 EI 2012年第5期16-25,共10页
Since 1992 the author has led research group in Xi'an Jiaotong University to investigate and develop micro-electro mechanical systems(MEMS) sensors,including pressure sensor,acceleration sensor,gas sensor,viscosit... Since 1992 the author has led research group in Xi'an Jiaotong University to investigate and develop micro-electro mechanical systems(MEMS) sensors,including pressure sensor,acceleration sensor,gas sensor,viscosity & density sensor,polymerase chain reaction(PCR) chip and integrated sensor etc.This paper introduces the technologies and research results related to MEMS sensors we achieved in the last 20 years. 展开更多
关键词 MEMS SENSOR CHIP
下载PDF
Distribution of acceleration and empirical formula for calculating maximum acceleration of rockfill dams
8
作者 周晖 李俊杰 康飞 《Journal of Central South University》 SCIE EI CAS 2010年第3期642-647,共6页
To find the distribution patterns of dynamic amplification coefficients for dams subjected to earthquake, 3D seismic responses of concrete-faced rockfill dams with different heights and different shapes of river valle... To find the distribution patterns of dynamic amplification coefficients for dams subjected to earthquake, 3D seismic responses of concrete-faced rockfill dams with different heights and different shapes of river valley were analyzed by using the equivalent-linear model. Statistical analysis was also made to the seismic coefficient, and an empirical formula for calculating the maximum acceleration was provided. The results indicate that under the condition of the same dam height and the same base acceleration excitations, with the increase of the river valley width, the position of the maximum acceleration on the axis of the top of the dam moves from the center to the riversides symmetrically. For the narrow valleys, the maximum acceleration occurs in the middle of the axis at the top of the dam; for wide valleys the maximum acceleration appears near the riversides. The result negates the application of 2D dynamical computation for wide valleys, and shows that for the seismic response of high concrete-faced rockfill dams, the seismic coefficient along the axis should be given, except for that along the dam height. Seismic stability analysis of rockfill dams using pseudo-static method can be modified according to the formula. 展开更多
关键词 concrete-faced rockfill dam 3D dynamical response analysis equivalent-linear method ACCELERATION seismic coefficient statistical analysis
下载PDF
Analysis and Improvement of Standing-Up Action for Elderly People from a Chair Using a Cushion-Type Support Tool
9
作者 Masakazu Takahashi Reiji Nanba 《Computer Technology and Application》 2012年第11期713-722,共10页
This paper reports the problems that elderly people have when they stand up from a chair, and proposes an adequate standing-up procedure that solves these problems. The important points for an adequate standing-up pro... This paper reports the problems that elderly people have when they stand up from a chair, and proposes an adequate standing-up procedure that solves these problems. The important points for an adequate standing-up procedure are "leaning the upper body forward" and "pulling the legs to the side". Furthermore, this paper proposes a standing-up support tool. The characteristics of the support tool are a cushion-type shape with an adjustable flange and an air-pressure-driven mechanism. When the proposed standing-up procedure and support tool are applied to elderly people, the measured values related to standing-up, such as maximum acceleration, arm force, standing-up time, heel position and forward-bending angle, are improved. Furthermore, elderly people felt that it made the standing-up action easy. We could confirm the effectiveness of the proposed standing-up procedure and support tool. 展开更多
关键词 Elderly people standing-up procedure standing-up support tool cushion-type shape air-pressure-driven mechanism.
下载PDF
Solving Severely Ill⁃Posed Linear Systems with Time Discretization Based Iterative Regularization Methods 被引量:1
10
作者 GONG Rongfang HUANG Qin 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第6期979-994,共16页
Recently,inverse problems have attracted more and more attention in computational mathematics and become increasingly important in engineering applications.After the discretization,many of inverse problems are reduced... Recently,inverse problems have attracted more and more attention in computational mathematics and become increasingly important in engineering applications.After the discretization,many of inverse problems are reduced to linear systems.Due to the typical ill-posedness of inverse problems,the reduced linear systems are often illposed,especially when their scales are large.This brings great computational difficulty.Particularly,a small perturbation in the right side of an ill-posed linear system may cause a dramatical change in the solution.Therefore,regularization methods should be adopted for stable solutions.In this paper,a new class of accelerated iterative regularization methods is applied to solve this kind of large-scale ill-posed linear systems.An iterative scheme becomes a regularization method only when the iteration is early terminated.And a Morozov’s discrepancy principle is applied for the stop criterion.Compared with the conventional Landweber iteration,the new methods have acceleration effect,and can be compared to the well-known acceleratedν-method and Nesterov method.From the numerical results,it is observed that using appropriate discretization schemes,the proposed methods even have better behavior when comparing withν-method and Nesterov method. 展开更多
关键词 linear system ILL-POSEDNESS LARGE-SCALE iterative regularization methods ACCELERATION
下载PDF
Multiple dependent reliability estimation of large range MEMS accelerometers in high temperature environment
11
作者 QIN Li HE Cheng +2 位作者 YU Li-xia WANG Wei QIN Li-jun 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第1期9-15,共7页
In the past,only one performance parameter was considered in the reliability estimation of micro-electro-mechanical system (MEMS) accelerometers,resulting in a one-sided reliability evaluation. Aiming at the failure c... In the past,only one performance parameter was considered in the reliability estimation of micro-electro-mechanical system (MEMS) accelerometers,resulting in a one-sided reliability evaluation. Aiming at the failure condition of large range MEMS accelerometers in high temperature environment,the corresponding accelerated degradation test is designed. According to the degradation condition of zero bias and scale factor,multiple dependent reliability estimation of large range MEMS accelerometers is carried out. The results show that the multiple dependent reliability estimation of the large range MEMS accelerometers can improve the accuracy of the estimation and get more accurate results. 展开更多
关键词 large range MEMS accelerometers zero bias scale factor multiple dependent reliability estimation accelerated degradation test
下载PDF
Experimental study of traffic-induced vibration of the new CCTV headquarters building
12
作者 ZHANG Nan XIA He +2 位作者 ZHAN Jia-wang YAN Hui-chun XU You-lin 《Journal of Civil Engineering and Architecture》 2009年第3期31-38,共8页
The traffic-induced vibrations of the new CCTV Headquarters building are studied stages. In the first stage when the through experiments in two 30th floor of the northwest tower and the 38th floor of the southeast tow... The traffic-induced vibrations of the new CCTV Headquarters building are studied stages. In the first stage when the through experiments in two 30th floor of the northwest tower and the 38th floor of the southeast tower were finished, the traffic flows on the roads surrounding the building were investigated, and 27 setups of accelerations were measured at the roadside, on the pile cap and on the 9th floor. In the second stage when the whole steel structure was completed, l 5 setups of accelerations were measured at the roadside, on the pile cap and on the 37th and the 48th floors. The accelerations of the building under different traffic flows, in different positions are analyzed in both time domain and frequency domain. The damping ratios are estimated by the upgraded half-power bandwidth method. 展开更多
关键词 dynamic experiment traffic-induced vibration power spectrum half-power bandwidth method
下载PDF
From Sequential to Parallel Growth of Cities: Theory and Evidence from Canada
13
作者 SHENG Kerong FAN Jie +1 位作者 SUN Wei MA Hailong 《Chinese Geographical Science》 SCIE CSCD 2016年第3期377-388,共12页
This paper examines city growth patterns and the corresponding city size distribution evolution over long periods of time using a simple New Economic Geography(NEG) model and urban population data from Canada. The mai... This paper examines city growth patterns and the corresponding city size distribution evolution over long periods of time using a simple New Economic Geography(NEG) model and urban population data from Canada. The main findings are twofold. First, there is a transition from sequential to parallel growth of cities over long periods of time: city growth shows a sequential mode in the stage of rapid urbanization, i.e., the cities with the best development conditions will take the lead in growth, after which the cities with higher ranks will become the fastest-growing cities; in the late stage of urbanization, city growth converges according to Gibrat′s law, and exhibits a parallel growth pattern. Second, city size distribution is found to have persistent structural characteristics: the city system is self-organized into multiple discrete size groups; city growth shows club convergence characteristics, and the cities with similar development conditions eventually converge to a similar size. The results will not only enhance our understanding of urbanization process, but will also provide a timely and clear policy reference for promoting the healthy urbanization of developing countries. 展开更多
关键词 sequential city growth Gibrta′s law finite mixture model convergence club Canada
下载PDF
Neutron imaging at Peking University
14
作者 Zou Yubin Guo Zhiyu Tang Guoyou Mo Dawei 《Engineering Sciences》 EI 2009年第4期83-85,共3页
Neutron imaging techniques were investigated at Peking University based on a 4.5 MV Van de Graaff accelerator.The thermal neutron radiography,fast neutron radiography and fast neutron resonance radiography were tested... Neutron imaging techniques were investigated at Peking University based on a 4.5 MV Van de Graaff accelerator.The thermal neutron radiography,fast neutron radiography and fast neutron resonance radiography were tested.The low neutron flux limits the image quality.A new radio frequency quadrupole (RFQ) accelerator based on neutron source with a yield of 1 012 n/s is being set up. 展开更多
关键词 neutron imaging thermal neutron radiography fast neutron radiography fast neutron resonance radiography
下载PDF
Resultant linear acceleration of an instrumented head form does not differ between junior and collegiate taekwondo athletes' kicks
15
作者 David O'Sullivan Gabriel P.Fife +2 位作者 Willy Pieter Taehee Limd Insik Shin 《Journal of Sport and Health Science》 SCIE 2016年第2期226-230,共5页
Objective: The purpose of this study was to compare the effects of various taekwondo kicks and age (school level) in absolute terms and relative body mass on the resultant linear acceleration (RLA) of an instrume... Objective: The purpose of this study was to compare the effects of various taekwondo kicks and age (school level) in absolute terms and relative body mass on the resultant linear acceleration (RLA) of an instrumented head form. Methods: Forty-eight male (middle school: 16; high school: 16; university: 16) taekwondo athletes were recruited for this study. Subjects performed 10 turning, 10 jump spinning hook, and 10 jump back kicks on a Hybrid II head mounted on a height-adjustable frame. Results: A 2-way (School x Kick) MANOVA was used to determine the differences in RLA between schools (age groups) by type of kick. There was no univariate School main effect for absolute RLA (η2 = 0.06) and RLA relative to body mass (η2 = 0.06). No univariate Kick main effects were found for absolute (η2 = 0.06) and relative RLA (η2 = 0.06). Conclusion: It is of concern that RLA did not significantly differ between school levels, implying that young taekwondo athletes generate similar forces to their adult counterparts, possibly exposing young athletes to an increased risk for head ir^iuries. 展开更多
关键词 BIOMECHANICS CONCUSSION Injury Martial arts TAEKWONDO
下载PDF
GOCE kinematic orbit adjustment for EGM validation and accelerometer calibration
16
作者 徐天河 孙张振 +2 位作者 江楠 陈康康 李敏 《Journal of Central South University》 SCIE EI CAS 2014年第6期2397-2403,共7页
The main principle and mathematical model of GOCE kinematic orbit adjustment for Earth gravity field model (EGM) validation and accelerometer calibration are presented. Based on 60 days GOCE kinematic orbits with 1-... The main principle and mathematical model of GOCE kinematic orbit adjustment for Earth gravity field model (EGM) validation and accelerometer calibration are presented. Based on 60 days GOCE kinematic orbits with 1-2 cm accuracy and accelerometer data from 2009-11-02 to 2009-12-31, the RMS-of-fit (ROF) of them using EGM2008, EIGEN-SC, ITG- GRACE2010S and GOCO01S up to 120, 150 and 180 degree and order (d/o) are evaluated and compared. The scale factors and biases of GOCE accelerometer data are calibrated and the energy balance method (EBM) is performed to test the accuracy of accelerometer calibration. The results show that GOCE orbits are also sensitive to EGM from 120 to 150 d/o. The ROFs of EGMs with 150 and 180 d/o are obviously better than those of EGMs with 120 d/o. The ROFs of GOCO01S and ITG-GRACE2010S are almost the same up to 120 and 150 d/o, which are about 3.3 cm and 1.8 cm, respectively. They are far better than those of EGM2008 and EIGEN-SC with the same d/o. The ROF of GOCO01S with 180 d/o is about 1.6 em, which is the best one among those EGMs. The accelerometer calibration accuracies (ACAs) of ITG-GRACE2010S and GOCO01S are obviously higher that those of EGM2008 and EIGEN-SC. The ACA of GOCO01S with 180 d/o is far higher than that of EGMs with 120 d/o, and a little higher than that of ITG-GRACE2010S with 150 d/o. I t is suggested that the newest released EGM such as GOCO01S or GOCO02S till at least 150 d/o should be chosen in GOCE precise orbit determination (POD) and accelerometer calibration. 展开更多
关键词 GOCE orbit adjustment Earth gravity field model kinematic orbit accelerometer calibration
下载PDF
Development of High Power Irradiating Accelerator 被引量:1
17
作者 郑曙昕 唐传祥 +9 位作者 林郁正 陈怀璧 童德春 施嘉儒 徐刚 刘耀红 刘晋升 何宇 管伟强 李国华 《Chinese Physics C》 SCIE CAS CSCD 北大核心 2008年第z1期226-228,共3页
The design of 10MeV/20kW high power irradiating accelerator is presented.The Backward-Traveling-Wave (BTW)accelerating structure is adopted.This structure combines the advantage of traveling-wave accelerator structure... The design of 10MeV/20kW high power irradiating accelerator is presented.The Backward-Traveling-Wave (BTW)accelerating structure is adopted.This structure combines the advantage of traveling-wave accelerator structure with low power reflection and high stability and standing-wave accelerator structure with high shunt impedance.The work frequency of this accelerator is 2856MHz.Designed by Code AccDesign which is coded by ourselves,the output electron beam with final energy 10MeV and peak current 300mA was reached.The length of the accelerating tube is 1.5m,and the power efficiency from microwave to electron beam is 66%.The temperature and stress distribution were simulated.And the frequency shift by microwave loss was calculated. 展开更多
关键词 high power irradiating accelerator backward-traveling-wave traveling wave
原文传递
BEPCⅡ Linac Beam Commissioning and Operation
18
作者 王书鸿 裴国玺 +13 位作者 池云龙 陈延伟 曹建社 孔祥成 赵风利 侯汨 陈志比 刘渭滨 邓秉林 耿哲峤 裴士伦 沈莉 乐琪 叶强 《Chinese Physics C》 SCIE CAS CSCD 北大核心 2008年第z1期215-217,共3页
The BEPCⅡ injector linac upgrade goal aims at higher beam energy with smaller beam emittance and energy spread to meet the colliding luminosity upgrade by two orders of magnitude.This paper describes the beam commiss... The BEPCⅡ injector linac upgrade goal aims at higher beam energy with smaller beam emittance and energy spread to meet the colliding luminosity upgrade by two orders of magnitude.This paper describes the beam commissioning and operation.The beam energy,energy spread,current,transmission and emittance have met the design goal.The beam orbit and energy instabilities have been studied and a steady beam operation has been realized. 展开更多
关键词 BEPCⅡ-linac UPGRADE beam commissioning operation
原文传递
Microstructural evolution and mechanism of grain growth in magnesia ceramics prepared by high pressure and temperature with ultra-high heating rate 被引量:3
19
作者 LIU JiangHao FU ZhengYi +5 位作者 WANG WeiMin ZHANG JinYong WANG Hao WANG YuCheng LEE SooWohn NIIHARA Koichi 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第6期1085-1092,共8页
The fast densification method of combustion reaction plus quick pressing was adopted to prepare nanocrystalline ceramics.The densification process of magnesia compact with a particle size of 100 nm was investigated,un... The fast densification method of combustion reaction plus quick pressing was adopted to prepare nanocrystalline ceramics.The densification process of magnesia compact with a particle size of 100 nm was investigated,under the applied pressure of up to 170 MPa,and the temperature range of 1740–2080 K with ultra-high heating rate(above 1700 K/min).High-purity magnesia ceramics with a relative density of 98.8%and an average grain size of 120 nm was obtained at 1740 K,and the grain growth during the densification process was effectively restrained.The characteristic morphology of evaporation-condensation was observed in the compact prepared at 2080 K,which revealed the actual process of mass transfer by gas diffusion.Moreover,the investigation on the microstructure evolution and mechanism of grain growth was carried out,on the basis of as-preserved nanocrystalline ceramics.The result indicated that the grain growth of the nanocrystalline MgO was controlled by the mechanism of evaporation-condensation rather than surface diffusion.Furthermore,the pressure had an influence of restraining the grain growth based on solid diffusion and strengthening the effect of gas diffusion with the increasing temperature.Under the particular conditions,there existed an appropriate temperature for the densification of nanocrystalline magnesia,while the excessive temperature would exaggerate grain growth and impede densification. 展开更多
关键词 grain growth DENSIFICATION heating rate evaporation-condensation surface diffusion nanocrystalline ceramics
原文传递
Investigate the nonuniformity of low-energy electron beam with large cross-sections 被引量:1
20
作者 REN Jie HUANG JianMing +2 位作者 ZHANG YuTian LI DeMing ZHU NanKang 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第4期997-1000,共4页
Over the past decades, low-energy electron accelerators have been used worldwide for surface curing and sterilization. The beam nonuniformity is an important parameter of the low-energy electron beam with large cross-... Over the past decades, low-energy electron accelerators have been used worldwide for surface curing and sterilization. The beam nonuniformity is an important parameter of the low-energy electron beam with large cross-sections. A simple and accurate measurement system of nonuniformity for the low-energy electron beam with large cross-sections was developed. The main concept consists in the measurement of nonuniformity, which is realized by using a linear actuator to drive two scanning wires through the beam's cross-sections at a fixed speed. The beam distribution can be obtained by sending/collecting the current signals to/from the Data Acquisition (DAQ) software on a laptop by a USB DAQ card. This device is very convenient for the performance testing of a new accelerator at the manufacturer's site. The distribution of the homemade low voltage electron accelerator EBS-300-50 was measured and evaluated. 展开更多
关键词 low-energy electron beam large cross-sections electron beam industry accelerator beam nonuniformity measurement
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部