期刊文献+
共找到26篇文章
< 1 2 >
每页显示 20 50 100
动能定理在活动物体和固定物体的应用
1
作者 戴明扬 《技术物理教学》 2003年第2期46-46,F003,共2页
学生对在运动的参考系中应用动能解题时,总感觉没有把握,不知如何下手,因而常常解错. 如何让学生解决活动坐标系上出现的问题呢? 首先应使学生明白,物体的速度是相对参考系而言的,参考系选取不同,物体的相对速度不同,具有的动能也不同.
关键词 活动物体 固定物体 物理教学 运动参考系 动能定理 解题方法 教学研究 力学
下载PDF
有固定转轴物体平衡条件的教学设计
2
作者 陈世贤 《实验教学与仪器》 1995年第1期12-12,共1页
有固定转轴物体的平衡状态,是指它保持静止或匀速转动状态。有固定转轴物体在什么条件下才能处于平衡状态呢?这就是本节内容要达到的教学目的之一,也是教学的重点。我讲授这节内容时,安排了两个课时,采用“实验研讨法”,取得了较好的教... 有固定转轴物体的平衡状态,是指它保持静止或匀速转动状态。有固定转轴物体在什么条件下才能处于平衡状态呢?这就是本节内容要达到的教学目的之一,也是教学的重点。我讲授这节内容时,安排了两个课时,采用“实验研讨法”,取得了较好的教学效果。现将教学中的一些点滴改进,简述如下:1 演示现象,引出研讨问题 演示复习:把杠杆安装在杠杆架上,调节杠杆两端的螺旋使它静止在水平方向上; 展开更多
关键词 固定转轴物体 平衡条件 教学设计 处于平衡状态 数据处理 正负力矩 教学效果 杠杆平衡条件 教学目的 水平方向
下载PDF
Directional solidification and characterization of NiAl-9Mo eutectic alloy 被引量:1
3
作者 张建飞 沈军 +2 位作者 商昭 王雷 傅恒志 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3499-3507,共9页
Ni-45.5Al-9Mo (mole fraction,%) alloy was directionally solidified with a constant temperature gradient (GL=334 K/cm) and growth rates ranging from 2 to 300 μm/s using a Bridgman type crystal growing facility wit... Ni-45.5Al-9Mo (mole fraction,%) alloy was directionally solidified with a constant temperature gradient (GL=334 K/cm) and growth rates ranging from 2 to 300 μm/s using a Bridgman type crystal growing facility with liquid metal cooling (LMC) technique. The effect of growth rate (v) on the solidified microstructures such as rod spacing (λ), rod size (d) and rod volume fraction was experimentally investigated. Two types of the solidified interfaces, planar and cellular, were identified. On the condition of both planar and cellular eutectic microstructures, the relationships between λ, d and v were given as: λv1/2=5.90 μm·μm1/2·s1/2 and dv1/2=2.18μm·μm1/2·s1/2, respectively. It was observed that the volume fraction of Mo phase could be adjusted in a certain range. The variation of phase volume fraction was attributed to undercooling increase and the growth characteristics of the individual constituent phases during the eutectic growth. 展开更多
关键词 NiAl-9Mo directional solidification INTERMETALLICS crystal growth MICROSTRUCTURE
下载PDF
散射理论中SF和BF间的坐标变换
4
作者 林圣路 柳忠元 李伟 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1993年第S2期197-199,196,共4页
用转动矩阵表示SF和BF间的坐标变换,推导了两种坐标系中矢量的方向及矢量函数的关系式.
关键词 散射 空间固定(SF)坐标系 物体固定(BF)坐标系 转动矩阵
下载PDF
交通事故现场定位 被引量:1
5
作者 宾艺文 《现代交通管理》 1994年第3期32-32,共1页
交通事故现场定位宾艺文交通事故的现场定位,就是处理事故的交警在勘查交通事故现场时,利用距现场最近的固体,将现场的主要物体准确地绘制到现场图上,以便在拆除现场后,在需要恢复现场进行复查时,能迅速恢复现场原貌,这对分析、... 交通事故现场定位宾艺文交通事故的现场定位,就是处理事故的交警在勘查交通事故现场时,利用距现场最近的固体,将现场的主要物体准确地绘制到现场图上,以便在拆除现场后,在需要恢复现场进行复查时,能迅速恢复现场原貌,这对分析、处理好事故起着关键作用。在绘制重大... 展开更多
关键词 交通事故现场 固定物体 基准点 现场图 定位法 现场定 平面直角座标 座标轴线 主要物 线相交
下载PDF
小窍门
6
《内蒙古宣传》 1993年第1期31-31,共1页
关键词 小窍门 玻璃瓶盖 固定物体 紧绳 颜料 向前推动 向错 门把 根结 墨水瓶
下载PDF
如何处理刹车失灵
7
作者 朱孔俊 《道路交通管理》 2001年第6期17-17,共1页
关键词 固定物体 刹车系统 刹车液 路边护栏 刹车压力 刹车片 刹车踏板 发动机 高速行驶 密封性
下载PDF
中班“我有好办法”创新教育活动
8
作者 王戟 吴晨阳 《早期教育(幼教·教育教学)》 2000年第17期32-32,共1页
活动目标 1.让幼儿自己尝试在不同的底板上选择合适的方法(贴、钉、挂等),按类把小物品固定起来。 2.能积极主动地尝试多种方法。 活动准备 1.幼儿在区域活动中制作了一些夏季用品。
关键词 创新教育 幼儿 固定物体 合适的方法 商品位置 多种方法 辅助材料 透明胶带 活动目标 区域活动
下载PDF
睛明技法治青少年近视
9
作者 覃文波 《家庭医学(上半月)》 1996年第5期13-13,共1页
睛明技法汇点穴、按摩、气功及民间手法为一体,简单易学,疗效显著,青少年近视者可以一试。 1、养气 取坐式。两腿分开与肩同宽,大小腿呈90度,小腿自然平踏地面,两肘弯曲,两掌平放大腿上,躯体端正,头微低,舌抵上腭,两眼微闭,内视前方。... 睛明技法汇点穴、按摩、气功及民间手法为一体,简单易学,疗效显著,青少年近视者可以一试。 1、养气 取坐式。两腿分开与肩同宽,大小腿呈90度,小腿自然平踏地面,两肘弯曲,两掌平放大腿上,躯体端正,头微低,舌抵上腭,两眼微闭,内视前方。全身放松,呼吸自然,气沉丹田3分钟,意念由丹田过会阴,沿督脉到命门、大椎,分别至左右肩,沿手臂外侧转内侧到劳宫,意守劳宫3分钟。 2、点穴 “养气”有气感后,依次按揉穴位: 展开更多
关键词 青少年近视 睛明穴 手臂外侧 劳宫穴 “养气” 气沉丹田 太阳穴 按揉穴位 疗效显著 固定物体
下载PDF
Relationship Between 2:1 Mineral Structure and the Fixation and Release of Cations 被引量:9
10
作者 FENG KE, WANG XIAOLI, WANG XIAOZHI and TANG YANAgricultural College, Yangzhou University, Yangzhou 225009 (China) 《Pedosphere》 SCIE CAS CSCD 2003年第1期81-86,共6页
The effects of different structures of 2:1 layer minerals, layer charge location, and changes of structure and charge during the weathering process on the fixation and release of interlayer cations are reviewed. It co... The effects of different structures of 2:1 layer minerals, layer charge location, and changes of structure and charge during the weathering process on the fixation and release of interlayer cations are reviewed. It could be concluded that the fixation capacity is determined by the total amount of interlayer charge originating from both octahedral and tetrahedral sheets. The relationship between interlayer cation fixation and octahedral structure of the secondary minerals may be different from that of the primary minerals. The oxidation and reduction of cations with variable valence can greatly influence the cation-fixation capacity. 展开更多
关键词 cation fixation interlayer charge mineral structure
下载PDF
Oxygen Gasification of Municipal Solid Waste in a Fixed-bed Gasifier 被引量:4
11
作者 牛淼淼 黄亚继 +1 位作者 金保昇 王昕晔 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第9期1021-1026,共6页
Four waste materials, paper, wood, textile and kitchen garbage, in municipal solid waste were gasified separately with oxygen in a fixed bed reactor. The yields of products char. tar and gas, the composition of gas co... Four waste materials, paper, wood, textile and kitchen garbage, in municipal solid waste were gasified separately with oxygen in a fixed bed reactor. The yields of products char. tar and gas, the composition of gas components H2, CO, CO2 and CH4, and the lower heating value (LHV) were examined at temperatures between 700 and 900 ℃ and equivalence ratio (ER) between 0.14 and 0.32. Characteristics of gas evolution during gasification were inves- tigated. Results show that a higher temperature improves the formation of H2 and CO while lowers the yield of CO2 and CH4. The LHV of syngas increases with temperature and varies in the range of 6-10 MJ. m-3 reaching the maximum at 800 ℃ or above. As ER increases, both combustible gas component and LHV of syngas decrease while the yield of CO2 rises linearly. The appropriate ER for obtaining high quality gas is in the range of 0.18-0.23. Temperature and ER have significant effects on the product distribution. Higher temperature and ER are favorable for higher gas yield and lower yield of char and tar in the gasification of textile and kitchen garbage. At 800 ℃, the gas evolution may be divided into two regions. In the first region, the flow rate of gas increases and then de- creases ranidlv, while in the second reuion the flow rate decreases monotonically to lower level. 展开更多
关键词 Municipal solid wasteOxygen gasificationTemperatureEquivalence ratioGas flow rate
下载PDF
移动式磁力定滑轮的妙用
12
作者 赵建荣 《实验教学与仪器》 1995年第9期16-16,共1页
高中物理课本第一册中讲“力的合成的平行四边行法则”时,通常要用一块装有两只定滑轮的示教板来做实验。由于定滑轮的位置不能随时调整,因此,在演示几组合力F与二个分力F<sub>1</sub>,F<sub>2</sub>的大小和... 高中物理课本第一册中讲“力的合成的平行四边行法则”时,通常要用一块装有两只定滑轮的示教板来做实验。由于定滑轮的位置不能随时调整,因此,在演示几组合力F与二个分力F<sub>1</sub>,F<sub>2</sub>的大小和方向的关系时,往往受到限制,给操作(特别是作图)带来不方便。 展开更多
关键词 定滑轮 移动式 力的合成 环形磁铁 固定转轴物体 平行四边 大小和方向 示教板 高中物理课本 组合力
下载PDF
Fixed-bed-column Studies for Methylene Blue Removal and Recovery by Untreated Coffee Residues
13
作者 Odysseas Kopsidas 《Journal of Environmental Science and Engineering(B)》 2016年第9期412-418,共7页
This paper contributes to the Industrial Ecology Concept by using a common urban solid waste, i.e., coffee residues, to clean industrial wastewaters polluted by basic dyes, e.g., Methylene Blue. For the data from the ... This paper contributes to the Industrial Ecology Concept by using a common urban solid waste, i.e., coffee residues, to clean industrial wastewaters polluted by basic dyes, e.g., Methylene Blue. For the data from the continuous fixed-bed column system, two common models, namely (a) Bohart and Adams and (b) Clark were implemented. The Bohart and Adams capacity was up to N = 46,166 mg.L-1 or q0 = 104.5 mg.g-1 for bed-depth 15 cm, initial dye concentration 800 mg.g-1 and flow rate 20 mL.min-1. The results revealed that the Methylene Blue is fairly adsorbed on coffee residues. Consequently, this process can be applied as a low cost technique for cleaning basic dyes from the aquatic environment. 展开更多
关键词 Adsorption DESORPTION COLUMN methylene blue coffee residues.
下载PDF
Performance of an Ultrafiltration Membrane Pilot System for Treatment of Waste Stabilization Lagoon Effluent
14
作者 I.N. Widiasa A.A. Susanto H. Susanto 《Journal of Environmental Science and Engineering》 2011年第8期962-970,共9页
Bali Tourism Development Corporation's lagoon (BTDC lagoon) has been used for treating wastewaters that come from all facilities available in the Nusa Dua Resort tourist area. Reuse of the lagoon effluent is limite... Bali Tourism Development Corporation's lagoon (BTDC lagoon) has been used for treating wastewaters that come from all facilities available in the Nusa Dua Resort tourist area. Reuse of the lagoon effluent is limited for some applications due to salt and suspended solid contents. Application of an integrated membrane system for improving the water quality of the lagoon effluent which is suitable for various uses is under consideration. In this work an ultraflltration (UF) pilot performance for possible pretreatment of Reverse Osmosis (RO) was investigated. The results showed that permeate quality was stable (less than 0.5 NTU), regardless of concentrating and diluting retentate in each cycle and fouling for a long duration of operation. However, the water quality obtained with this membrane was not enough to be directly used. The permeate quality obtained from the UF system fulfils the requirement for the optimal operation of reverse osmosis. Moreover, appropriate intermittent-backwash operation was fairly effective to maintain the fluxes at a reasonable level. 展开更多
关键词 LAGOON ULTRAFILTRATION wastewater treatment water reuse.
下载PDF
谈物理习题中的一题多解
15
作者 刘敬 《技术物理教学》 1996年第2期19-20,共2页
谈物理习题中的一题多解刘敬(贵州省体育运动学校贵阳550002)一题多解,即是对同一研究对象,从不同的角度,采取不同的方法进行处理,而得到相同的结果.这种教学方法对教学任务的完成,对学生认识问题、分析问题、解决问题能... 谈物理习题中的一题多解刘敬(贵州省体育运动学校贵阳550002)一题多解,即是对同一研究对象,从不同的角度,采取不同的方法进行处理,而得到相同的结果.这种教学方法对教学任务的完成,对学生认识问题、分析问题、解决问题能力的培养,对巩固学生的基础知识,提... 展开更多
关键词 物理习题 匀变速运动 固定转轴物体 体育运动学校 运动学和动力学 正交分解法 列车 合外力 贵州省 教学方法
下载PDF
A New Energy Concept 被引量:2
16
作者 Khaled (Moh'd Khalaf) Suleiman Ainobani 《Journal of Energy and Power Engineering》 2016年第2期116-120,共5页
According to the uncertainties in the results and the wide diversity of how to approach the subject, a new concept for energy is proposed: Energy is an exchange between two different concentrations, the concentration... According to the uncertainties in the results and the wide diversity of how to approach the subject, a new concept for energy is proposed: Energy is an exchange between two different concentrations, the concentration of time in space outside what we call matter and the concentrated phase of time in matter space which is the matter itself. The concept of motion for energy is replaced by time-space interactions with time taken as solid matter. Motion enhances the exchange between the mass and its surrounding time in space, annihilation and creation are special forms of this exchange. During the motion of a mass, it increases as a result of this dissolution. Time concentration in Fock space is responsible for the collision phenomena in physics. In this paper, a new mathematical operator (the equal operator) is introduced. 展开更多
关键词 TIME MASS space.
下载PDF
Effect of Mixed Oxide Support for Ni/ZnO in Reactive Adsorption Desulfurization
17
作者 Chen Weicheng Yu Xiaoling +2 位作者 Huang Huan Shi Li Meng Xuan 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2016年第4期11-18,共8页
The effect of mixed oxide support on the performance of Ni/ZnO in the reactive adsorption desulfurization(RADS) reaction was investigated in a fixed bed reactor by using thiophene as the sulfur-containing compound in ... The effect of mixed oxide support on the performance of Ni/ZnO in the reactive adsorption desulfurization(RADS) reaction was investigated in a fixed bed reactor by using thiophene as the sulfur-containing compound in the model gasoline. A series of oxide supports for Ni/ZnO were synthesized by the co-precipitation method and characterized by XRD, N_2-adsorption, TPR and NH_3-TPD techniques. It was found that the desulfurization capacity of Ni/ZnO was enhanced greatly when active components were supported on the proper mixed oxide. Ni/ZnO supported on oxides exhibited much higher desulfurization efficiency and sulfur adsorption capacity than the unsupported Ni/ZnO and the synthesized Ni/ZnO-SA adsorbent exhibited the highest efficiency for thiophene removal. The higher desulfurization activity and sulfur capacity of Ni/ZnO supported on SiO_2-Al_2O_3 with small particle size, high specific surface area and large pore volume could promote the high dispersion of active metal phase and the transfer of sulfur to ZnO with lower mass transfer resistance. γ-Al_2O_3 species could weaken the interaction of active phases and SiO_2 as well as could increase greatly the amount of weak acids. Therefore, these oxides could impose a great influence on the structure and chemical properties of the catalyst. 展开更多
关键词 reactive adsorption desulfurization Ni/ZnO support effect mixed oxide
下载PDF
Identification of Cholera Source in Mariupol City
18
作者 Valeriia Shavkun Alexey Kapustin 《Journal of Environmental Science and Engineering(A)》 2012年第11期1288-1291,共4页
The cases of cholera in Mariupol and adjacent areas which were observed within the period of May-August, 2011 are investigated. Thirty-two diseased and 22 vibriocarriers were found on the territory of the city in the ... The cases of cholera in Mariupol and adjacent areas which were observed within the period of May-August, 2011 are investigated. Thirty-two diseased and 22 vibriocarriers were found on the territory of the city in the course of epidemic. The potential sources of infection are specified. The ways to avoid similar situations in the future are suggested. The analysis of the locations of the cholera contamination sources results in the obvious conclusion that most of them are connected with the place where the river Kalmius meets the Azov Sea. Waste flow from the residential solid waste landfill brings a considerable harm to the river Kalmius and the Azov Sea. 展开更多
关键词 CHOLERA EPIDEMIC residential solid waste landfill Azov Sea.
下载PDF
Fuel Cell Technology for Propulsion and Power Generation of Ships: Feasibility Study on Ocean Research Vessel Sagarnidhi
19
作者 Rajasekhar D Deepak Sankar P. S Ananthakrishna Narendrakumar D. 《Journal of Shipping and Ocean Engineering》 2015年第5期219-228,共10页
Rising fuel prices, increasing emission levels and impending environmental regulations made shipping industry to find an alternate for internal combustion engine in 21st century. Fuel cell is a sustainable, emerging t... Rising fuel prices, increasing emission levels and impending environmental regulations made shipping industry to find an alternate for internal combustion engine in 21st century. Fuel cell is a sustainable, emerging technology with negligible pollution. More significantly for a research ship, emission levels need to be substantially low to have quality measurements. A feasibility study is carried-out First time in the world, to drive an ice class multi-disciplinary ORV (Oceanography Research Vessel) Sagarnidbi, using hydrogen powered fuel cell. Sagamidhi is equipped with special equipments viz., Deep Sea winch, specially designed cranes for Launching and retrieval of ROV (Remotely Operable Vehicle), DSMC (Deep Sea Mining Crawler), Tsunami systems, manned/unmanned submersible and ACS (Autonomous Coring System) and other facilities that support research in Indian, International and Antarctic waters. Beside this, the propulsion system along with DP (Dynamic Positioning), centralized air conditioning and special equipments require enormous electrical power. The combustion of diesel oil in an engine, that coupled with an alternator generates electrical power required, along with NOx (Nitrous Oxides), SOx (Sulphur Oxides) and PM (Particulate Matter) emissions. Shipping industry is the fourth largest contributor to air pollution and carbon emissions, particularly in coastal areas, and the growth rate makes the problem even more critical. Stringent international air pollution regulation and increasing fuel price paves the way for an alternative "green emission technology". Various fuel cells were analyzed with different combination of fuel, electrolyte and electrodes. From the analysis, it has been found that SOFC (Solid Oxide Fuel Cell) is most suitable for the present scenario. A fuel cell designed with hydrogen as fuel, zirconium oxides stabilized with yttrium oxide as electrolyte and zirconium electrodes is used for 1.5 MW power output and 0.5 MW through regenerator. Volume required for storage of hydrogen is in line with volume of fuel and a high standard safety measures were taken using sensors. The present system saves 3000 MT/annum of diesel oil costing 3,000,000 USD approximately. 展开更多
关键词 Hydrogen air pollution SOX fuel cell REGENERATOR particulate matter.
下载PDF
A Comparative Study on the Fixed Bed Pyrolysis of Different Biomass Solid Wastes
20
作者 Mohammad Nurul Islam Mustafizur Rahman Sheikh Mohammad Najmul Hoque 《Journal of Energy and Power Engineering》 2013年第7期1250-1256,共7页
Biomass in the form of nutshell, hay of catkin, wheat straw and linseed residue in particles have been pyrolyzed in laboratory scale fixed bed reactor which yielded liquid oil, solid char and gas. The variation of oil... Biomass in the form of nutshell, hay of catkin, wheat straw and linseed residue in particles have been pyrolyzed in laboratory scale fixed bed reactor which yielded liquid oil, solid char and gas. The variation of oil yield for different biomass feedstock with reactor bed temperature and feed size is presented in this paper. A maximum liquid yield of 55 wt% of dry feedstock is obtained at an optimum temperature of 500℃ for a feed size of 300-600μm with a running time of 55 min for nutshell as the feedstock while the minimum liquid oil yield is found to be 30 wt% of feedstock at an optimum temperature of 400℃ for a feed size of 2.36 mm with a running time of 65 min for linseed residue as the feedstock. A comparison on the product yields is highlighted in this study. The pyrolysis liquid products are characterized and compared for some of the fuel properties like HHV (higher heating value), viscosity, density and specific gravity. 展开更多
关键词 PYROLYSIS BIOMASS renewable energy pyrolysis oil characterization.
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部