检定电子汽车衡的1000kg(组合)专用砝码——关于对搬运砝码机械化解决方案的探讨

本文通过对1000kg(组合)专用砝码质量值测量结果不确定度的评定,认证了使用1000kg(组合)专用砝码的理论依据,论证了用叉车叉运1000kg(组合)专用砝码,实现检定电子汽车衡搬运砝码机械化的可行性。     

2kg标准砝码示值误差不确定度分析

本文介绍了用F2等级标准砝码对M1等级标准砝码,采用单次替代称量测量法,建立了数学模型,分析了输入量示值误差不确定度的来源,首先从F2等级标准砝码2kg的最大允许误差、标准砝码及被测砝码示值误差的分析,对2kg标准砝码示值误差测量不确定度进行了分析及评估,得出合成不确定度和扩展不确定度.     

基于伺服控制系统的砝码自动加载装置的设计

本文基于伺服控制系统对电子秤砝码加载装置进行设计,实现电子秤检定过程中砝码的自动加载过程。该装置依据JJG539-2016《数字指示秤检定规程》对30kg的电子秤利用机械手对放置在砝码支架上最大20kg的砝码进行上、下、左、右、前、后六个方位的自动移动,实现砝码在电子秤的任意位置加载,同时伺服控制系统可以按照检定点依次组合砝码自动加载检定。该装置的研制在电子秤检定过程中无需手动加载相对比较重的砝码,可以大大减轻检定人员劳动强度,解放劳动力,具有较强的可操作性和实用性。     

马鞍山计量所加大投入力度做好衡器检定工作

正马鞍山市计量测试研究所是马鞍山市质量技术监督局依法设置的市级法定计量检定机构。该所十分重视计量技术基础建设,在引进高素质人才的同时,加大了配置标准仪器设备的投入力度。截止2014年3月,仅衡器室就有M12等级砝码近百吨;M1等级、20kg/个的砝码五吨;M1等级、1mg~10kg组合砝码叁组;F2等级、1mg~5kg组合砝码壹组并     

搬运砝码机械化的解决方案——关于用"标准砝码箱"检定电子汽车衡可行性的探讨

用M1级20kg砝码检定电子汽车衡,用人力搬运砝码的传统方式,劳动量大、劳动强度高,给被检单位带来很大负担.由于受人力的影响和制约,影响了检定质量和工作效率.本文提出用叉车叉运标准砝码箱,实现搬运砝码机械化的解决方案,不再用人力搬运砝码,保证了检定质量,提高了工作效率;对标准砝码箱质量值、标准砝码箱箱体质量值的准确度进行了论述,同时对用标准砝码箱检定电子汽车衡的可行性进行了探讨.     

基于声学原理的砝码体积测量方法研究

质量标准量值传递过程中,砝码的体积值需要准确测量,以便进行砝码质量值的浮力修正.声学法是一种快速高效的非接触式体积测量方法.为实现砝码体积的高精度快速测量,设计实现了一套声学法砝码体积测量装置,对1 g～20 kgOIML( international organization for legal metrology)形状砝码体积进行测量,并对其测量不确定度进行了评估.经实验测定50 g ～20 kg的OIML形状砝码的测量不确定度小于8×10-1,1～20 g的OIML形状砝码的体积测量值满足E1等级砝码的要求,验证了声学法应用于高精度砝码体积测量的可行性.     

大质量比较仪偏载误差对砝码检定的影响

大质量比较仪因其机械结构,易产生偏载误差。通过500kg F1等级砝码对1T大质量比较仪不同位置的偏载误差进行测试,分析测试数据,得到大质量比较仪偏载误差对砝码检定的影响。     

非接触式不同材质砝码体积测量研究

质量标准量值传递过程中,砝码的体积需要准确测量,为精确测砝码的质量,由砝码体积带来的空气浮力修正是必要的。声学法是一种快速高效的非接触式体积测量方法,与液体静力称重法不同,该方法不需要考虑液体受污染而引起的密度变化。为实现不同形状和材料砝码体积的高精度快速测量,设计实现了一套非接触式固体材料体积测量装置,对5kg~20kg不同材料砝码体积进行测量,并对其测量不确定度进行了评估,其测量不确定度小于6×10~(-4),验证了声学非接触式测量法应用于不同材料高精度砝码体积测量的可行性。     

沟通信息 分享技术——马鞍山所举办衡器免砝码校准标定交流会

正近日,马鞍山举办了衡器免砝码校准标定工作交流会。首先选定一台到检定周期的汽车衡(Max=100t、e=d=20kg、8只SLC820-50t数字称传感器、IND880称重仪表),做免砝码校准标定的效果测试验证。在对汽车衡例行维保后,实施     

山东省计量科学研究院引进的砝码自动检定装置已完成初步调试

<正>3月9日至3月13日,赛多利斯德国总部技术人员到山东省计量院进行砝码自动检定装置(机器人)的安装、调试,该装置可以完成测量范围为1mg~1kg的砝码自动检测,目前机器人已完成初步调试工作。初步调试工作结束后,山东省计量院召开了与德国赛多利斯技术人员的技术交流会议。在技     

Errors due to magnetic effects in 1 kg primary mass comparators

A revised draft of OIML Recommendation 111 has been approved recently. Among the many notable changes to the previous edition are specific requirements for both the magnetic susceptibility and residual magnetization of weights used in legal metrology. The highest class of such weights is E₁, for which a 1 kg weight has a manufacturing tolerance of ±0.5 mg. It therefore follows that better magnetic properties might be needed for weights having mass uncertainties substantially better than E₁ tolerances. The work presented below shows how this problem was approached at the BIPM and supports our conclusion that alloys meeting the new Class E₁ specifications for 1 kg weights have magnetic properties sufficient for the needs of the BIPM.     

A new method to assess the power performance during a lifting task in young adults

This study designs and verifies a new test for evaluating performance during a lifting task. 32 young men performed deadlift to high pull with increasing weights, and deadlift and upright row with a previously established weight of 70% 6RM, either using a Smith machine or free weights. Peak and mean power were significantly higher during deadlift to high pull with free weights than on the Smith machine, however only at ⩾50 kg. Their maximal values were achieved at about 80% and 70% 1RM. The deadlift to high pull with free weights is a reliable test with ICC > 0.80 and SEM < 10% for mean power. It is also a sensitive test for distinguishing lifting performance among healthy young individuals. It may be applied in functional performance testing of college graduate students and office workers with a prevalently sedentary lifestyle as well as construction workers with job demands based on lifting tasks.     

最近邻实例检索相似度分析

针对最近邻实例检索中实例属性相似度和权重的计算问题,给出了区间值属性相似度的计算模型,并将各种属性类型的相似度计算方法加以统一,提出了基于相似度离差信息的客观赋权方法,并以组合权重计算实例相似度.该方法已应用于基于实例推理的导弹概念设计之中,结果表明,所提出的权重计算方法更有利于实例的检索.     

下肢外骨骼负载携行控制方法研究

对人自然行走的步态运动规律进行了5个步态相位划分,并通过人体动作捕获试验获得行走过程中下肢髋关节和膝关节角度变化规律。结合髋关节与膝关节姿态运动规律建立膝关节外骨骼运动数学模型,从理论上分析负载携行系统的运动特性,给出位姿随动控制时的液压缸动态负载参考值。利用伺服阀对液压缸位移进行伺服控制,设计液压缸位移反馈PID控制律,实现携行系统在不同负重、不同位姿变化条件下人机耦合助力随动控制需求。通过重载携行试验表明:外骨骼能够实现50 kg以上人机重载携行,试穿员具有明显的省力效果。     

F_2级大砝码标准装置测量不确定度评定

采用单次替代法,通过标准天平确定标准砝码与被检砝码的质量信息,输出标准砝码与被检砝码的质量量值,然后进行比较。本文比较全面、详细地介绍了F2级大砝码的不确定度的分析具体方法和步骤。     

Henry's constants for ethanol,iso‐octane and gasoline absorption in engine lubricants

Henry's constants for hydrous ethanol, iso‐octane and gasoline absorption in engine lubricants were determined using gas chromatography. Samples of synthetic SAE 5 W30, synthetic SAE 5 W40, semi‐synthetic SAE 15 W40, mineral SAE 15 W40 and mineral SAE 25 W60 oil were used in the experiments. For all lubricants tested, typical molecular weights were considered, ranging from 500 to 5000 kg/kmol. The results show that, for any lubricant, Henry's constant for hydrous ethanol is about 2.2 times higher than that of gasoline, and about 4.3 times higher than that of iso‐octane. Decreasing Henry's constant was observed with increasing lubricant molecular weight, regardless of the fuel type. Copyright © 2014 John Wiley & Sons, Ltd.     

机械运动方案评价中评价因素权重确定的模糊层次分析法

设计方案的评价是概念设计中的重要任务之一，而评价因素权重的确定是影响评价结果的关键环节。根据机构及机构系统设计的主要性能要求，兼顾机械设计专家的咨询意见以及客户的个性化要求，建立了机械运动方案的评价体系。综合运用层次分析法和模糊集理论，以三角模糊数代替常规层次分析法中的标度，提出了一种确定权重的模糊层次分析方法来确定评价体系中各级评价因素的权重，为得到客观、真实的评价结果提供了科学依据。     

F2级砝码组折算质量测量结果的不确定度评定

采用双次替代法,通过标准天平确定标准砝码与被测砝码的质量信息,输出标准砝码与被测砝码的质量值,以1mg和200g砝码为例详细介绍了F<,2>级砝码组折算质量测量结果的不确定度评定的具体方法和步骤.     

Aged garlic extract ameliorates the oxidative stress,histomorphological, and ultrastructural changes of cisplatin‐induced nephrotoxicity in adult male rats

Aim: Aged garlic extract (AGE) is a natural dietary substance having different antioxidant free‐radical‐scavenger compounds that ameliorates the toxicity of the oxidative stress. This study aimed to investigate the effect of AGE on cisplatin (CP)‐induced nephrotoxicity in rats. Materials and Methods: Twenty‐four, adult male Wistar albino rats were randomly divided into four groups namely control, AGE‐treated (a single oral dose of 250 mg/kg/day for 21 days), CP‐treated (a single intraperitoneal dose of 7.5 mg/kg on Day 16), and AGE + CP‐treated (AGE at a dose of 250 mg/kg/once daily for 21 days and a single dose of CP of 7.5 mg/kg intraperitoneally on Day 16). Body weight and absolute and relative kidney weights of each rat were calculated. Serum creatinine, uric acid, and urea levels were determined. Level of malondialdehyde and reduced glutathione and activity of superoxide dismutase and catalase of renal tissues were measured. Renal specimens from each rat were prepared for both light and electron microscopic examinations. Results: Interstitial cell infiltration, hemorrhage, glomerular atrophy, necrosis, and tubular degeneration were observed after CP treatment. Superoxide dismutase and catalase activities and glutathione level were significantly decreased and malondialdehyde level was significantly increased in CP‐treated rats compared with AGE + CP‐treated animals. A remarkable improvement in the histopathological and ultrastructural changes induced by CP in renal tissues was observed in AGE + CP‐treated rats. Conclusion: AGE exhibited antioxidant effect that could ameliorate the nephrotoxic effects of CP. Microsc. Res. Tech. 78:452–461, 2015. © 2015 Wiley Periodicals, Inc.     

均匀设计的神经网络

一个具有足够神经元的多层BP网络就可逼近任何函数。但是，在运用BP网络时难以找到最佳的权值，此外，隐含层神经元的个数、学习的速率、训练时初始权值以及收敛的方法均影响学习的权值。这里采用均匀设计方法构造神经网络模型，并将其应用于生化过程的氧转化系数的预估模型上。实验表明，应用均匀设计法能简化网络设计，避免其陷入局部最小、缩短训练时间、加快收敛速度。