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盐雾试验中的测量不确定度 被引量:2
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作者 陆永丽 孙承君 《安全与电磁兼容》 2013年第3期87-90,共4页
阐述了测量不确定度评估的意义,并以盐雾试验为例,评估测量不确定度分量如配置盐溶液、盐溶液PH值、盐雾沉积量、试验箱温度、样品的放置与恢复条件、试验后的检测等对盐雾试验结果的影响,提出了控制各分量的措施。
关键词 测量不确定度 盐雾试验 不确定度分量
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农户供应不确定下农业企业签约量决策研究
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作者 税文兵 刘茜 《物流工程与管理》 2018年第9期85-88,共4页
订单农业中农业企业与农户的签约量决策是影响企业经营效益和农户收益的重要决策问题。综合考虑农产品生产提前期长、单次生产连续消费、可替代性强的特点,在基本的报童模型框架基础上,分别建立供应数量不确定、供应质量不确定和两者都... 订单农业中农业企业与农户的签约量决策是影响企业经营效益和农户收益的重要决策问题。综合考虑农产品生产提前期长、单次生产连续消费、可替代性强的特点,在基本的报童模型框架基础上,分别建立供应数量不确定、供应质量不确定和两者都不确定下的农业企业签约量决策模型,利用二分法对模型进行数值求解。算例计算结果表明:农户供应数量和质量的不确定对签约量和期望利润都有显著的影响,而且随着所考虑不确定因素的增多,签约量越大;较高质量农产品供应越稳定,签约量越小,期望利润越大;签约量随供应率增大而降低,但降低的程度逐渐减少;在进行签约量决策时,考虑农户供应的不确定有利于提高农业企业的期望利润。 展开更多
关键词 订单农业 农户供应 数量和质量不确定 签约量
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环境监测用空气中二氧化碳标准气体的研制
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作者 刘志娟 许峰 +2 位作者 吕鸿 荀其宁 张文申 《低温与特气》 CAS 2009年第1期22-27,共6页
介绍了环境监测用空气中二氧化碳标准气体的制备方法。该标准气体的均匀性和稳定性通过气相色谱法进行了考察,并用比对误差确认了其称量法配制值的准确性。配制的标准气体的浓度为(10~1000)×10^-6(mol/mol),定值不确定度小... 介绍了环境监测用空气中二氧化碳标准气体的制备方法。该标准气体的均匀性和稳定性通过气相色谱法进行了考察,并用比对误差确认了其称量法配制值的准确性。配制的标准气体的浓度为(10~1000)×10^-6(mol/mol),定值不确定度小于2%。 展开更多
关键词 空气中二氧化碳标准气体 不确定度 称量法
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Principle of limitation of physical quantities and cyclic universe 被引量:1
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作者 HE GuoZhu Department of Physics,Nankai University,Tianjin 300071,China 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2008年第5期451-458,共8页
A close study of Heisenberg uncertainty principles reveals many significant facts,and all four major physical quantities,energy,time,momentum and length,have both lower and upper limits.Now,many questions come up.What... A close study of Heisenberg uncertainty principles reveals many significant facts,and all four major physical quantities,energy,time,momentum and length,have both lower and upper limits.Now,many questions come up.What are these limits?Some answers may lead to the understanding of the development of our universe.What is the shortest limit of time?At the beginning of big bang,there exists a tre-mendously short time,the Planck time.This may be just the shortest time limit in our universe.The longest time limit might be the lifetime of our universe.The longest length might be the final diameter of our expanding universe.All these lead to a finite universe.Two more coupling formulae are formed for the other two pairs of physical quantities,mass and speed,thermal energy and temperature.These four physical quantities must also have limits.We already knew that speed has upper limit and temperature has lower limit.By these two formulae,Planck and Einstein equations are derived directly.Since most other physical quantities are somewhat related to these major physical quantities,it seems that there exists a principle of limitation of physical quantities.A quantitative sketch of big bang is described.It also shows that our universe will contract back to another big bang.The principle of limitation opens up some fields of investigation.It may bring nature back to the harmony and determined world described by classical physics. 展开更多
关键词 principle of LIMITATION of PHYSICAL QUANTITIES limits coupling FORMULAE CYCLIC UNIVERSE extension of conven-tional quantum mechanics no uncertainty for PHYSICAL QUANTITIES quantitative evaluation of big bang
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