ISO主席哈坎·莫尔比(Hkan Murby)先生致辞

在中国举办2008年奥运会之际,思考一下体育与标准化的关系不无益处。我们很快就会发现规则对二者而言都至关重要。不言而喻,规则对体育不可或缺。事实上,如果没有规则,如果体育协会、运动员、裁判员和观众不遵守规则,就没有体育,体育就成了人人都能参加的活动。体育规则的改变会影响运动员的参赛策略,会对一些运动员有利而对另一些运动员不利,从而影响谁将获胜。因而,参与制定规则很重要。体育规则经常根据经验和(或)技术进行调整。考虑到竞赛是国际性的,     

噪声的测量和分析(下)

六、噪声信号的时间域分析噪声信号的波形表达了它的时间域特性.不稳定的噪声信号的波形是不断变化的,所以难以观察.如果信号中伴随着干扰就更无法分辨.因此,除了有规则的信号外,波形图说明不了信号的特性,遂使信号时间域分析的应用受到了限制.如果想根据波形图来比较两个噪声的异同,则几乎是不可能的.为了在实际环境中提取噪声信号进行分     

ISO权威人士论坛(二)

3在您看来,协商的自愿性标准和强制性法规的相互关系将会怎样发展?Ｐ.Ｃ.我希望我们能保持甚至促进协商的自愿性标准做为强制性法规的补充这一角色,以便后者能在通用规则中发挥作用。我们不得不由公共部门、工厂和用户及时地出台新的标准。如果我们不这样做,其他的技术规范也许只能成为补充,于是与协商的自愿性标准形成竞争。Ａ.Ｈ.这两套标准系统相互促进。强制性标准应用于对健康、安全和环境的保护,而自愿性标准应用于健康和安全不是关键因素的产品、生产过程和服务,这样解释就不会相互混淆。自愿性标准和强制性法规都要求具有产品和生产…     

论圆柱度(三)

6．4最小区域法圆柱度的计算过程评定准则是解决能否用最小区域法评定圆柱度的问题。如果没有正确的评定准则就可能迷失方向，导致得出错误的结论。不完整的评定准则会出现某些情况能适用，而另一些情况就不适用。特别是对各种优化逼近的算法，如果没有一个正确的评定准则就会停机停在一个错误的位置上。评定方法的计算过程的好坏将影响评定的速度与计算精度。图2是目前计算过程的主要框图。这种方法是将测量点中依次取出六点，按组合分组进行计算与判别、不满足条件就进行置换，再行计算与判别,直至符合要求为止，这种方案其程序较为简单。…     

ISO主席哈坎·莫尔比（Hakan Murby）先生致辞

在中国举办2008年奥运会之际,思考一下体育与标准化的关系不无益处。我们很快就会发现规则对二者而言都至关重要。     

彩色反转加工探讨(二)

上文已讨论了彩色反转片的曲线设计。虽然多数使用者没有曝光仪、密度计,无法测定曲线,但可用灰板代替曝光仪。如果买不到灰板可自制一块,尽管不一定是中性灰,但用几次后,你就能找出冲洗工艺对灰板的响应跟好、坏照片之间的关系。这样,在你的脑海里就有了一条没有画出的曲线。如果能有个密度计把它画出来,当然对你的加工工作就更有指导意义。何为彩色反转加工?概括地说,它是利用首显,也即黑白显影将已曝光部分显成银质负像,使该部位在彩显时不产生染料;然     

中国包装加入 WTO之应对 (二)-主动适应世贸规则

加入WTO,我国包装工业将全面融入到全球化的世界经济体系之中,按世贸规则参与竞争与发展.中国加入WTO首席谈判代表龙永图指出:加入世贸组织对我国的影响是客观存在的,对于入世不能简单归结为"利"和"弊"是什么,我们不能只是应对,而应该主动适应,要主动发展壮大,我们如果适应WTO就是利大于弊,不适应就是弊大于利.因此,中国包装必须认真熟悉世贸规则,运用世贸规则,主动适应世贸规则[1].     

动态处理15例(一)

设想一下，如果没有在黄河上游修建刘家峡等大型水库，华北大平原将会是一个什么样子？在暴雨来临的夏季，河水就要上涨、泛滥，然后淹没掉河南、山东等省的农作物、家畜和房屋。而当干旱来临之时，河床又会干涸，使得两岸土地成为不毛之地。水坝在这里起到了调节的作用，在雨季时关闸蓄水，在旱季时开闸放水，从而保持了下游水量的全年均衡。如果没有这个水坝，那么这个地区的一切就只能由老天做主了。动态处理的作用就有些类似于水坝，衰减大电平的信号，或是提升小电平的信号，如果没有它，混音就会成为动态范围和种种噪声的奴隶。动态处…     

通用仪表计量保障方式探讨

一、问题的提出 现代社会各种产品都是多种设备精密配合下的产物,如果量值不能准确一致,设备就不能充分发挥性能,更不可能实现协同工作.因此,就肩负检测设备性能职责的通用仪表而言,对其进行计量检定不仅影响着该仪表的性能发挥,而且直接关系到该仪表所检测设备的技术性能.可以说,没有现代化的计量,就没有现代化的通用仪表;而没有现代化的通用仪表,就没有现代化的工业设备.     

检查机构认可综述(2)

三、CNAL对检查机构的认可要求和工作流程 1.认可规则 在2002年7月4日举行的CNAL第一届管理委员会第一次会议上,通过了8个认可规则和3个认可政策,分别为:<认可程序规则》(CNAL/AR01)、<专门委员会管理规则》(CNAL/AR02)、<公正性与保密规则》(CNAL/AR03)、<认可标志与认可证书管理规则》(CNAL/AR04)、<申诉、投诉与争议处理规则》(CNAL/AR05)、<认可评审员与技术专家管理规则》(CNAL/AR06)、<能力验证规则》(CNAL/AR07)和<认可收费管理规则》(CNAL/AR08),认可政策为<港澳台及国外机构受理政策》(CNAL/AR09)、<量值溯源政策》(CNAL/AR10)和<测量不确定度政策》,这11个文件构筑了CNAL开展认可工作所必须遵循的基础文件.认可规则的制定依据了国家的法律法规、ISO/IEC导则58、ISO/IEC17010和即将颁布的ISO/IEC17011以及ILAC和APLAC对认可机构的有关要求,围绕"客观公正、科学规范、权威信誉、廉洁高效"的原则,对CNAL的组织机构、委员会的管理、公正性和保密性、认可流程、资源的控制、认可体系的持续改进等做了原则规定,为认可工作的开展提供了充实的文件依据,有力地保证了CNAL认可体系的有效运作.     

La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的储氢性能研究

针对两种新型稀土型储氢合金La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2的储氢特性进行研究分析。实验表明,相同温度下,La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的PCT曲线基本重合,且都具有优良的吸氢动力学性能;相比之下,后者的滞后系数要小于前者,吸氢量较大,吸氢速率也较快,故其储氢性能较优。300次吸放氢循环实验结果表明,La0.5Y0.5Ni4.8Al0.2合金的吸氢动力学性能虽然略有下降,但抗粉化性能较好。     

Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x取向晶体的结构与磁致伸缩

采用Ｃｚｏｃｈｒａｌｓｋｉ方法生长了Ｄｙ０．６Ｔｂ０．３Ｐｒ０．１（Ｆｅ０．９５Ｍｎ０．０５）ｘ（１．８５≤ｘ≤１．９５）取向合金。所有合金主相为立方Ｌａｖｅｓ相结构,择优取向不完整择优取向的方向与Ｘ的大小有关。研究了沿着这些样品的生长方向的磁致伸缩性能以及磁致伸缩性能与压力之间的关系。     

Thermal Stability of Amorphous Hydride Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45)

The thermal stability of amorphous ternary hydrides Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45) and their corre-sponding amorphous binary alloys Mg_(50)Ni_(50) and Mg_(30)Ni_(70) were studied with X-ray diffraction(XRD) and differential scanning calorimetry(DSC). Samples of the amorphous alloys were preparedby mechanical alloying and the amorphous hydrides were obtained by charging the alloys with gas-eous hydrogen at 3.0 MPa and 423 K. It was found that the amorphous hydrides released most oftheir hydrogen before the crystallization of the essentially hydrogen depleted amorphous alloy. Thecrystallization temperature of amorphous Mg_(50)Ni_(50)H_(54) elevated and that of amorphousMg_(30)Ni_(70)H_(45) did not change in relation to the original binary amorphous alloy. This is very excep-tional for amorphous hydrides. The reason for the effects of hydrogen absorption/desorption on thecrystallization of amorphous alloys was discussed.     

Zr65Al7.5Ni10Cu15Co2.5合金的玻璃转变温度

根据Ｚｒ６５Ａｌ７。５Ｎｉ１０Ｃｕ１５Ｃｏ２。５合金的纳米晶，晶体，液体和玻璃比热的测量结果，研究了合金的玻璃转变温度与全金的热力学函数，动力学参数以及加热速度的关系。结果表明，非晶态合金玻璃转变所需转变激活能很小，玻璃转变温度实际上是由于加热速度引起的不同状态的玻璃与液体的热力学平衡温度。     

Acousto-optic interaction in alpha-BaB(2)O(4)and Li(2)B(4)O(7) crystals

Experimental studies and analysis of acousto-optic diffraction in alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are given. Ultrasonic wave velocity, elastic compliance and stiffness coefficients, and piezo-optic and photoelastic coefficients of alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are determined. The acousto-optic figure of merit has been estimated for different possible geometries of acousto-optic interaction. It is shown that the acousto-optic figures of merit for alpha-BaB(2)O(4) crystals reach the value M(2)=(270 +/- 70) x 10(-15) s(3)/kg for the case of interaction with the slowest ultrasonic wave. The directions of propagation and polarization of those acoustic waves are obtained on the basis of construction of acoustic slowness surfaces. The acousto-optic diffraction is experimentally studied for alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals.     

Nanomechanical characterization of one-step combustion-synthesized Al(4)B(2)O(9) and Al(18)B(4)O(33) nanowires

Two kinds of aluminum borate nanowires, Al(4)B(2)O(9) and Al(18)B(4)O(33), were successfully synthesized by a one-step combustion method through control of the Al:B atomic ratio and synthesis temperature. Both nanowires are single crystalline but have distinguishing growth habits. Nanoindentation tests were performed directly on individual nanowires to reveal their mechanical properties. A 70% reduction in elastic modulus was found in Al(18)B(4)O(33) nanowires compared with their bulk counterpart. Al(18)B(4)O(33) nanowires exhibited higher hardness and elastic modulus than Al(4)B(2)O(9) nanowires.     

Natural Passivity of Amorphous Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 Alloys

The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.     

Plasma surface treatments of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)

The surfaces of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were modified by oxygen and nitrogen plasma treatments. The physical and chemical surface characteristics were evaluated by contact angle tests, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The plasma treatments caused an increase in both contact angle and roughening, altered the surface morphology, inserted polar groups, and, consequently, enhanced the hydrophilicity for both PLLA and PHBV polymers.     

An SANS Study of Decomposition Kinetics in Amorphous Cu_(12.5)Ni_(10)Zr_(41)Ti_(14)Be_(22.5)

Phase decomposition in amorphous Cu12.5Ni10Zr411Ti14Be22.5 alloy as annealed in the super-cooled liquid range was studied by applying small angle neutron scattering (SANS). As annealed between 600 K and 700 K, the alloy was observed to decompose into two new amorphous phases,with the second phase precipitates embedded in the matrix of the first. Long time annealing of the alloy results in crystallization in addition to evolution of the decomposed microstructure.The kinetic diagram of the decomposition and crystallization for this alloy is given. The second phase precipitates have several nanometers in size and occupy a quite low volume fraction. The decomposition of the supercooled liquid in overall temperature range exhibits the features of spinodal reaction.