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基于物理实验能力培养的高中测定性实验教学思考——以“测量电源的电动势和内阻”实验教学为例 被引量:4
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作者 赖佳颖 《物理教学》 北大核心 2021年第8期37-40,共4页
本文通过"测量电源的电动势和内阻"实验的具体教学案例,从教学目标、教学结构、教学评价三方面围绕实验能力框架,对测定性实验的教学模式进行了探索,以凸显其教育功能。
关键词 测定性实验 实验能力 教学设计
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浅谈高中物理“测电源电动势和内电阻”实验的复习
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作者 刘琴 《教育教学论坛》 2013年第17期266-267,共2页
物理学是一门以实验为基础的学科,物理学中的定律,绝大多数是用实验探索得出来的,也就是通过大量实验进行观察,取得数据,加工整理,再运用精辟的数学工具,将大量的数据上升为规律。实验能力是高考物理要考察的能力之一,本文就新课程背景... 物理学是一门以实验为基础的学科,物理学中的定律,绝大多数是用实验探索得出来的,也就是通过大量实验进行观察,取得数据,加工整理,再运用精辟的数学工具,将大量的数据上升为规律。实验能力是高考物理要考察的能力之一,本文就新课程背景下的物理实验"测电源的电动势和内电阻"的复习进行了详细阐述。 展开更多
关键词 新课程 测定性实验 实验原理 数据处理 误差分析
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漫话“两道测R_x实验题”
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作者 梁兰英 苏福河 刘红梅 《物理通报》 2003年第11期28-30,共3页
随着教学改革的深入发展,设计性实验越来越引起广大师生的高度重视,让考生设计"测密度"、"测电阻"和"测电功率"等创新方案,几乎成为中考实验题的重头戏.
关键词 物理实验 物理教学 电阻值 欧姆定律 滑动变阻器 测定性实验 实验原理 测试电路 教学改革
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Evaluation of mouse bioassay results in an inter-laboratory comparison for paralytic shellfish poisoning toxins 被引量:1
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作者 曹际娟 郑江 +3 位作者 于兵 王秋艳 徐君怡 李爱峰 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第4期912-916,共5页
An inter-laboratory comparison of the AOAC mouse bioassay for paralytic shellfish poisoning (PSP) toxicity in shellfish was carried out among 25 Chinese laboratories to examine the overall performance for PSP testing ... An inter-laboratory comparison of the AOAC mouse bioassay for paralytic shellfish poisoning (PSP) toxicity in shellfish was carried out among 25 Chinese laboratories to examine the overall performance for PSP testing in China, and to analyze the main factors affecting the performance of this method. The toxic scallop Patinopecten yessoensis collected from coast of Bohai Sea, China, was used as a test sample in the comparison study. The results were reported and evaluated using robust statistical methods. The z scores showed that 80%, 8%, and 12% of laboratories reported satisfactory results, unsatisfactory results, and questionable results, respectively. This evaluation demonstrates that the PSP mouse bioassay is an appropriate method for screening and testing PSP toxicity in shellfish. However, it was found that the experience and skill of technicians, as well as the body weight and health status of mice being used significantly affected the accuracy of the method. 展开更多
关键词 paralytic shellfish poisoning (PSP) mouse bioassay inter-laboratory comparison
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Development and Lubricating Properties of Rolling Oil for Stainless Steel Cold Rolling 被引量:4
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作者 Zhang Xu Wang Yizhu +2 位作者 Yao Wenjing Sun Jianlin Wang Shiting 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2011年第2期57-64,共8页
Appropriate base oils and homologous additives such as extreme pressure and anti-wear agents,oiliness agents and antioxidants were selected,and experiments testing the compatibility performance between additive,base o... Appropriate base oils and homologous additives such as extreme pressure and anti-wear agents,oiliness agents and antioxidants were selected,and experiments testing the compatibility performance between additive,base oil and other components were carried out to develop the SK and SD series of rolling oils for cold rolling of stainless steel.The developed oils were used in the stainless steel cold rolling lubrication experiments,and were successfully applied in the actual cold rolling operation of stainless steel.Compared with a foreign product,the tribological properties,the thermal oxidation stability,and the rolling lubrication performance of the developed stainless steel cold rolling oils were studied.Test results showed that the tribological properties of the thereby developed rolling oils and the reference one were almost at the same level,and to some extent the performance of rolling was even better than the foreign product,at the same time the stainless steel sheet could retain its well annealed performance.Meanwhile,within a certain range,the lubrication of the rolling oil became better as its viscosity increased at the same level of saponification value,which could provide a lower friction coefficient,so that a higher maximum reduction ratio of the rolled piece through a constant roll gap and a minimum thickness could be secured.Also,similar phenomena appeared as the saponification value increased at a same viscosity level of the rolling oils. 展开更多
关键词 stainless steel cold rolling oil rolling lubrication FRICTION thermal analysis
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Methods of Testing Seed and Seedling Physiological Traits for the Improvement of Rapeseed Yield Stability
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作者 Ladislav Blaiha Dagmar Janovska Miroslava Vyvadilova 《Journal of Life Sciences》 2014年第2期152-163,共12页
The presented work is based on laboratory testing of seed germination speed, emergence and seedling growth under different stress conditions simulated by subnormal water revel, extreme high and low temperatures. It al... The presented work is based on laboratory testing of seed germination speed, emergence and seedling growth under different stress conditions simulated by subnormal water revel, extreme high and low temperatures. It allows one to eliminate the plant materials (initial breeding materials and cultivars) which do not tolerate extreme temperatures and temperature changes during germination, have low water use efficiency and is intolerant to abiotic stressors all right at the seed level. It was confirmed that these genotypes also have poor t^eld emergence and initial root growth implications for further vegetation periods, mainly for over wintering and spring regeneration which has significant influence on the yield. The method also represents the tool for screening genetic resources with the resistance to the abiotic stressors and this technology process is also acceptable for other crops. The results confirm the importance of the seed and root characteristics for crop production. The deteriorating quality of soil in recent years, increasing variability of weather and long periods of drought directly support the need to intensify activities in this research. Obtained results also show the influence of seed quality characteristics on roots and above ground parts of the plant. A relationship exists also vice versa. 展开更多
关键词 Seed traits root traits PROVENANCE periodicity of germination.
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Special Marking of 3D Networks' Points for the Monitoring of Modern Constructions
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作者 Evangelia Lambrou George Pantazis Konstantinos Nikolitsas 《Journal of Civil Engineering and Architecture》 2011年第7期643-649,共7页
In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncert... In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncertainties in the determination of the x, y, z coordinates of the network's points. In order to assure precise centering for both the instrument and targets, not only for the accessible but also for the inaccessible network's points, a prototype way of marking is being implied. A special semi-permanent portable metallic stand (Photo 1) was manufactured for marking the accessible points. The stand provides forced instrument centering of the order of_+0, lmm. It is light enough to carry, it accelerates and facilitates the centering and leveling of the instrument as well as it eliminates the time needed for the measurements. The applied laboratory checks in order to certify the suitability of its use and the provided accuracy are being described. For the inaccessible points special targets were used. The targets were put in permanent attachments (Photos 7-8), which were also manufactured. Useful conclusions were drawn when these special accessories were used in to a 3D network, which was established for the monitoring of a new football stadium. Two measurement phases were carried out. The first one is with the stadium empty and the second one is when it was crowded (about 32000 people) during a significant football match. 展开更多
关键词 Precise centering point marking geodetic control networks monitoring modern constructions.
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Determination of Bed Void Fraction from Fixed Bed Breakthrough Curve
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作者 Junpei Fujiki Toshiaki Kusaba +1 位作者 Shinji Miyamoto Eiji Furuya 《Journal of Chemistry and Chemical Engineering》 2011年第3期202-206,共5页
Accurate physical and chemical properties of adsorbents are required for the efficient design of fixed bed adsorbers. The bed void and particle void are significant physical properties. One of the experimentally deter... Accurate physical and chemical properties of adsorbents are required for the efficient design of fixed bed adsorbers. The bed void and particle void are significant physical properties. One of the experimentally determination technique for the bed void is a breakthrough curve method. In the present paper, experimental conditions for determining the bed void from breakthrough curve were investigated because complex conditions are required. The values of bed void were determined from theoretical elution curve at the point of c/c0 = 0.5 under the condition of negligible amount adsorbed. The bed void value determined from elution curve was clearly affected by particle void and fluid velocity, and regarded as "apparent" bed void values. For large porosity particles, it was difficult to determine the true bed void value due to the effect of penetration into macro pores. Then, the bed void fraction can be determined safely from breakthrough curve when particles possessing small particle void are used. 展开更多
关键词 Bed void particle void fixed bed breakthrough.
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Experimental Evaluation of Rogowski Coil Performance for Locating PD in Energized Overhead Covered-Conductor Feeder
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作者 Muzamir Isa Nagy Ibrahim Elkalashy +1 位作者 Ghulam Murtaza Hashmi Matti Lehtonen 《Journal of Energy and Power Engineering》 2012年第6期949-959,共11页
An experimental analysis is performed to evaluate Rogowski coil performance for PD (partial discharge) location on overhead CC (covered-conductor) distribution lines. The measuring set-up is arranged in high volta... An experimental analysis is performed to evaluate Rogowski coil performance for PD (partial discharge) location on overhead CC (covered-conductor) distribution lines. The measuring set-up is arranged in high voltage laboratory. A multi-end measuring method is chosen as a technique to locate PD source point on the line. A power transformer is used to energize one end of the CC line by the AC voltage source. The performance of Rogowski-coil is tested in noisy environment. The tests are carried out conceming different measurement conditions such as off-line and on-line PD measuring systems. The results obtained from the laboratory measurements confirm the capability of the Rogowski-coil in order to measure and locate the high frequency PD source on the CC line in consistent with energizing AC source. Chirp detector is used as a signal-processing tool in order to extract the PD signals and then apply the locator algorithm. 展开更多
关键词 Partial discharge Rogowski coil overhead covered-conductor distribution network PD sensors.
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Effective model based fault detection scheme for rudder servo system
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作者 徐巧宁 周华 +2 位作者 喻峰 魏兴乔 杨华勇 《Journal of Central South University》 SCIE EI CAS 2014年第11期4172-4183,共12页
The inherent nonlinearities of the rudder servo system(RSS) and the unknown external disturbances bring great challenges to the practical application of fault detection technology. Modeling of whole rudder system is a... The inherent nonlinearities of the rudder servo system(RSS) and the unknown external disturbances bring great challenges to the practical application of fault detection technology. Modeling of whole rudder system is a challenging and difficult task. Quite often, models are too inaccurate, especially in transient stages. In model based fault detection, these inaccuracies might cause wrong actions. An effective approach, which combines nonlinear unknown input observer(NUIO) with an adaptive threshold, is proposed. NUIO can estimate the states of RSS asymptotically without any knowledge of external disturbance. An adaptive threshold is used for decision making which helps to reduce the influence of model uncertainty. Actuator and sensor faults that occur in RSS are considered both by simulation and experimental tests. The observer performance, robustness and fault detection capability are verified. Simulation and experimental results show that the proposed fault detection scheme is efficient and can be used for on-line fault detection. 展开更多
关键词 rudder servo system fault detection nonlinear unknown input observer adaptive threshold
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Testing the nonlocality of entangled states by a new Bell-like inequality 被引量:3
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作者 QI JianXia ZHA XinWei SUN XinMei 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第11期2236-2238,共3页
We test a new four-qubit entangled state by the former Bell-like inequalities and find that it violates these inequalities,but not maximally.According to this entangled state,we build a new Bell-like inequality,which ... We test a new four-qubit entangled state by the former Bell-like inequalities and find that it violates these inequalities,but not maximally.According to this entangled state,we build a new Bell-like inequality,which is violated by this new state maximally.We also determine the nonlocality of some other four-qubit states by the new inequality.It is found that the new inequality acts as a strong entanglement witness for the new state.This can be used to test new entangled states experimentally. 展开更多
关键词 entangled states entanglement witness Bell inequality
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