原子、生物和化学(Nuclear Biological and Chemical简称NBC)武器对人类的威胁不可能通过使用任何形式的服装(军服)来完全避免。然而,一种功能性服装能够在人体受到意外攻击后,使威胁降至最低水平,并使这种防护效力在尽可能短的时间内...原子、生物和化学(Nuclear Biological and Chemical简称NBC)武器对人类的威胁不可能通过使用任何形式的服装(军服)来完全避免。然而,一种功能性服装能够在人体受到意外攻击后,使威胁降至最低水平,并使这种防护效力在尽可能短的时间内起作用。这种服装必须是舒适耐用、不影响军事行动和日常工作。它还必须防御放射性尘埃、软β射线、生物和化学药剂通过皮肤吸收对人体的伤害。假如可能,服装的外层还应当具有阻燃性能。使用两种类型的材料可达此目的。(a)非渗透型。非渗透型材料对人体提供一种屏蔽,使人体与外部物质隔离。(b)渗透型。渗透型材料可使空气完全畅通,但阻止各种有害物质的进入。当今,大部分NBC防护服具有抵抗化学威胁的必要性能。现今世界上通用军服还有一些额外优点,即具备有限的防御生物药剂和放射性尘埃的能力。 本文讨论了与防护服有关的化学药剂的特性和防护材料的类型,并着重讨论各种防护材料的防护机理。本文是1994年1月5日、6日在Sasmira举行的“防护纺织品”专题会议上提交的论文。展开更多
Cu–15%NbC (volume fraction) powder was synthesized using the starting powders of Cu, Nb and graphite in a high energy vibratory disc mill for 7 h of milling under argon atmosphere. A composite sample and a C...Cu–15%NbC (volume fraction) powder was synthesized using the starting powders of Cu, Nb and graphite in a high energy vibratory disc mill for 7 h of milling under argon atmosphere. A composite sample and a Cu/NbC functionally graded material (FGM) sample were produced by using the two-step press and sintering at 900 °C for 1 h under vacuum. The microstructure and physical and mechanical properties of the specimens were investigated. The field emission scanning electron microscopy, energy dispersive X-ray and X-ray diffraction analysis confirmed the synthesis of the nanostructure matrix of 18–27 nm with the nanoparticles reinforcement of 42 nm after sintering, verifying the thermal stability of this composite at high temperature. The hardness of Cu–15%NbC was five times greater than that of the pure Cu specimen. The volume reduction of the sample after the wear test decreased in comparison with the pure Cu specimen. The electrical conductivity of the composite specimen decreased to 36.68% IACS. The FGM specimen exhibited high electrical conductivity corresponding to 75.83% IACS with the same hardness and wear properties as those of the composite sample on the composite surface. Thus, Cu/NbC FGM with good mechanical and electrical properties can be a good candidate for electrical contact applications.展开更多
文摘原子、生物和化学(Nuclear Biological and Chemical简称NBC)武器对人类的威胁不可能通过使用任何形式的服装(军服)来完全避免。然而,一种功能性服装能够在人体受到意外攻击后,使威胁降至最低水平,并使这种防护效力在尽可能短的时间内起作用。这种服装必须是舒适耐用、不影响军事行动和日常工作。它还必须防御放射性尘埃、软β射线、生物和化学药剂通过皮肤吸收对人体的伤害。假如可能,服装的外层还应当具有阻燃性能。使用两种类型的材料可达此目的。(a)非渗透型。非渗透型材料对人体提供一种屏蔽,使人体与外部物质隔离。(b)渗透型。渗透型材料可使空气完全畅通,但阻止各种有害物质的进入。当今,大部分NBC防护服具有抵抗化学威胁的必要性能。现今世界上通用军服还有一些额外优点,即具备有限的防御生物药剂和放射性尘埃的能力。 本文讨论了与防护服有关的化学药剂的特性和防护材料的类型,并着重讨论各种防护材料的防护机理。本文是1994年1月5日、6日在Sasmira举行的“防护纺织品”专题会议上提交的论文。
基金Sharif University of Technology for the financial support
文摘Cu–15%NbC (volume fraction) powder was synthesized using the starting powders of Cu, Nb and graphite in a high energy vibratory disc mill for 7 h of milling under argon atmosphere. A composite sample and a Cu/NbC functionally graded material (FGM) sample were produced by using the two-step press and sintering at 900 °C for 1 h under vacuum. The microstructure and physical and mechanical properties of the specimens were investigated. The field emission scanning electron microscopy, energy dispersive X-ray and X-ray diffraction analysis confirmed the synthesis of the nanostructure matrix of 18–27 nm with the nanoparticles reinforcement of 42 nm after sintering, verifying the thermal stability of this composite at high temperature. The hardness of Cu–15%NbC was five times greater than that of the pure Cu specimen. The volume reduction of the sample after the wear test decreased in comparison with the pure Cu specimen. The electrical conductivity of the composite specimen decreased to 36.68% IACS. The FGM specimen exhibited high electrical conductivity corresponding to 75.83% IACS with the same hardness and wear properties as those of the composite sample on the composite surface. Thus, Cu/NbC FGM with good mechanical and electrical properties can be a good candidate for electrical contact applications.
