SAFE-FAIL LINE METHOD—AN ALGORITHM TO REDUCE THE CALCULATION OF COMPLEX CONSTRAINTS IN DESIGN OPTIMIZATION

A rather simple but quite effective algorithm is proposed for reducing the number of calculations of complex constraint functions in optimization problems. A type of monotonicity is used to set up a direct relationship between the design variables and the critical constraints. It can frequently be predicted whether or not the constraints are satisfied at a design point just by checking the variation in the design variables. It can be established in advance that a given constraint function varies with respect to a design variable in one of four ways, and rules can be defined, based on the previous history of function values, whether or not a constraint function need be evaluated. Trial calculations of a sample of problems suggest typical savings of 40-50%. The procedure is illustrated by stress constraints; but the same method can be used in other types.     

THE APPLICATIN OF MSSBAUER EFFECT IN MEASUREMENT OF RETAINED AUSTENITE IN HIGH SPEED STEEL

本文首先应用透射Mssbauer 法测定了一组标准样品中奥氏体的含量,并且从实验上得到了与已知含量相吻合的结果。然后用背散射X 射线M(?)ssbauer 法和X 射线衍射法测量了一组不同热处理制度下M_2高速钢中的残留奥氏体含量,两种方法的测量结果可相互比较.     

A NEW METHOD TO PREDICT THE PRECIPITATION OF σ—PHASE IN NICKEL-BASE SUPERALLOYS——THERMODYNAMICS EQUILIBRIUM CALCULATION

采用热力学平衡计算方法作出Ni-Cr-Mo 三元相图,并据此对实际Ni 基高温合金进行了σ相的析出预测。通过与Inconel_(713)C 合金的试验结果对比,证明此法可以用于不含Co 的Ni 基高温合金的σ相控制。     

STUDIES ON THE MECHANISM OF ELECTROLUMINESCENCE IN ORGANIC THIN FILMS

A high quality multilayer organic thin film electroluminescence (EL) device was prepared by LB film and vacuum evaporation technique. The uniform blue-green emission was observed under the positive DC voltage of less than20V in ambient room light. The mechanism of the EL device was discussed after measuring the Ⅰ—Ⅴcurves, absorption spectrum, fluorescent emitting spectrum and electroluminescent spectrum.     

SPECTACULAR IMAGES OF THE “REFUGEE CRISIS”

The current “refugee crisis” in Europe has generated an abundance of photographs, which have been circulated in print and digital media since 2015. This article focuses on two of the most reproduced of these photographs: that taken in September 2015 of Aylan Kurdi’s dead body near the Turkish coast and a photograph of refugees walking along the Croatian?Slovenian border which was used by the UK Independence Party (UKIP) during the summer of 2016 as part of their pro-Brexit campaign. The article examines the repeated visual tropes which perpetuate stereotypes of refugees as either miserable, helpless victims or threatening subjects. It further questions the ways in which the “individual” and the “collective” have been framed in these photographs, in ways which contribute to dominant and uncontested visual narratives of the “refugee crisis”. The paper contends that the passive acceptance of these reified representations of the refugee experience in these media-saturated times equates to uncritical approval of the sociopolitical conditions from which these photographs are generated. Finally, it argues that only through the rejection of such spectacular images can we hope to open up a serious, critical, public debate about the “refugee crisis”, the necessity of which is becoming increasingly urgent.     

STUDY OF CH ROLE IN THE DIAMOND VAPOR DEPOSITION BY MEANS OF OPTICAL SPECTRUM

We examine the role of CH radical in diamond vapor deposition in mixed gas CH_4-H_2 mainly from the measurement of CH optical emisiop spectrum. Two dynamic parameters, the ratio of Intensity of CH to H spectra, I_(CH)/I_H, and the rat of change of spectra intensity with pressure, |⊿I/⊿P|, are introduced to characterize the plasma. On the basis of these two parameters, the diamond deposition conditions are discussed.     

THE EFFECT OF PHYSICAL AGING ON α-RELAXATION PEAK IN PS

用内耗方法分析了非晶聚合物聚苯乙烯（ＰＳ）的物理老化对动态力学弛豫过程中的主转变内耗峰（α峰）的影响，说明老化过程（时效）和α峰的参数变化之间存在着规律性的联系．从另一方面证明了前人通过热焓分析和微蠕变等静力学参量分析得到的非晶聚合物老化过程的规律，特别是说明了老化过程对在玻璃化转变温度（Ｔｇ）以上的α峰参数的影响原因是存在着一个与α峰相叠加的过程内耗峰（淬火峰）．     

DIFFUSION EFFECT IN THE FORMATION PROCESS OF Cr-NITRIDE UNDER N~ IMPLANTATION

The diffusion of nitrogen atom in Cr thin film is studied. The temperature of the film under ion beam bombarding was measured by a new method and discussed theoretically. The temperature measured by means of thin film resistor gave a same level of volume. On the basis of the conservation of energy in equilibrium state, a semi-theoretical formula has been derived. The factors ion beam assisted diffusion were discussed. The result of AES analysis indicates that the arrangement of N atoms is long and smooth. HREM analysis and dynamic resistance measurement show that the Cr-nitride formed by N~ implantation is in the near surface layers and can not grow very deep. The assemble of N was observed by means of TEM.     

THE THERMODYNAMIC CALCULATION OF α/βPHASE EQUILIBRIUM IN Ti-Al-Nb SYSTEM

用巨势法分析了三元系的相平衡问题．计算了Ti－Al－Nb系中α／β在1150℃和1400℃的相平衡，采用亚正规溶体模型描述了Ti－Al－Nb系α和β相的Gibbs自由能．计算结果与实测相图相符，证明本方法是可行的，使用的相互作用参数值是正确的     

A STUDY ON THE THERMAL STABILITY TO 1000°C OF VARIOUS CARBON ALLOTROPES AND CARBONACEOUS MATTER BOTH UNDER NITROGEN AND IN AIR

ABSTRACT

The thermal behavior of graphite, C₆₀ fullerene, fullerene black (carbon soot containing fullerenes), extracted fullerene black and diamond has been analyzed to 1000°C by TGA–DTA (thermogravimetric analysis and differential thermal analysis) under a nitrogen flow at a heating rate of 20°C/min. Very small weight losses have been recorded in the case of graphite and diamond. Furthermore no diamond graphitization has been observed. The sublimation of pure C₆₀ and the fullerene fraction of fullerene black (both pristine and extracted) has been observed and discussed.

The combustion reaction in air flow of graphite, C₆₀ and C₇₀ fullerenes, fullerene black (both unextracted and extracted), carbon nanotubes and diamond has been studied by TGA–DTA at a heating rate of 20°C/min. C₇₀ fullerene and fullerene black have been found to be the most reactive carbon materials with O₂. The role played by C₇₀ in the degradation of fullerites has been discussed. Among the carbon materials examined, the best resistance to O₂ attack has been shown by diamond and carbon nanotubes. The behavior of graphite is intermediate between diamond and fullerene blacks. The behavior of C₆₀ fullerene appears closer to that of graphite although it appears to be more reactive with O₂. Samples of graphite and carbon blacks N375 and N234 have been studied by TGA–DTA in air flow before and after a radiation treatment with neutrons or γ radiation. The effect of the radiation damage in the combustion reaction of these carbon materials has been discussed.     

THE FORMATION OF DEFORMATION α'-MARTENSITE FOR METASTABLE AUSTENITE IN AN Fe-Mn-Al-Cr SYSTEM

本文以金相、X射线衍射和透射电镜方法研究了Fe-Mn-Al-Cr系亚稳奥氏体中形变α′-马氏体的形成,证实了它产生于ε-马氏体片相交区,且主要通过γ(?)ε(?)α′和ε(?)α′转变形成。通过回归分析方法建立了形变α′-马氏体量与合金成分的经验关系。     

A STUDY ON THE MECHANISM OF HYDROGEN SOFTENING AND HYDROGEN HARDENING IN α-Fe

本文研究了工业纯α-Fe 中晶内同晶界对氢致软化同氢致硬化效应的不同贡献,发现其中仍以晶内贡献为主,并提出了相应的新机制。     

PSEUDO-DENDRITE GROWTH CHARACTERISTICS OF THE γ'' PRECIPITATES IN A SINGLE CRYSTAL NICKEL BASE SUPERALLOY

在镍基单晶温合金中，发现以类树枝晶形态析出的γ＇相。     

RELATIONSHIP BETWEEN HYDROGEN SOFTEN—ING OR HYDROGEN HARDENING AND THE STATE OF HYDROGEN IN α-Fe

<正> 1 引言α-Fe 充氢后既不产生氢化物,也不能在表面形成有效的保护膜,此外很多作者还指出α-Fe 单晶没有不可逆氢脆现象,所有这些都应是讨论α-Fe 中氢时的基本出发点。由于氢能在室温下自由地跑出试样表面,故将氢的状态总地分成室温稳定(RTS)同室温非稳定(RTU)的两部分不无道理。在文献〔5〕中我们又成功地将退火α-Fe同脱C,N α-Fe 的氢致软化(HS)同氢致硬化(HH)现象分成晶内(CL)同晶界(GB)     

AN IN SITU STUDY ON DISLOCATION BEHAVIOR OF THE CRACK TIP IN A SINGLE CRYSTAL Ni-BASE SUPERALLOY——Ⅱ.The Effect of Interface on DFZ

Ni 基高温合金中含有大量的γ′强化相,γ/γ′界面阻碍位错的运动,同时对裂尖无位错区(DFZ)的形成及尺寸都有很大的影响。可用以下表达式来描述两者间的关系:L(DFZ)=0.7X_(ob)~(1.07),其中L(DFZ)为DFZ 长度,X_(ob)为γ/γ′界面到裂尖距离。对实验结果进行了理论推算并同实验结果相吻合。     

THE ORDERING OF THE α-Fe(Si)PHASE IN Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 ANNEALED ALLOY

用ＸＲＤ法研究了退火Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９合金中α－Ｆｅ（Ｓｉ）晶化相的有序化过程，结果表明，Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９非晶合金在４９０℃，１ｈ退火后，α－Ｆｅ（Ｓｉ）晶化相是具有ＤＯ３结构的有序相，有序畴为球形，直径为７．０ｎｍ，它随退炎温度的升颃是长大，在５９０℃退火后达１０．９ｎｍ，与α－Ｆｅ（Ｓｉ）的尺寸相当，此时α－Ｆｅ（Ｓｉ）的有序度为０．８，在８５０℃     

EFFECTS OF HYDROGEN ON THE α_2 /βTRANSUS TEMPERATURE AND LATTICE CONSTANT IN SUPER-α_2 ALLOY

用膨胀仪测定了含氢Ｓｕｐｅｒ－α２／β相变点；用Ｘ射线衍射仪探讨了氢对α２和β相晶格常数的影响。结果表明，随氢含量增加，Ｓｕｐｅｒ－α２的α／β相变点显著降低，β相晶格常数显著增大，α２相的晶格常数α增大，而Ｃ变化不大。     

CARBON CONTENT,MORPHOLOGY AND CONSTRUCTION OF CARBON,IMPURITY CRYSTAL IN BURNED“ALLOY TYPE”MATERIAL

研究了有机-无机烧结“合金型”材料1700℃烧结样品的碳含量、碳和孔的形态,以及结构中的非主晶杂质晶体。测试及观察表明:材料中的碳含量与聚合物的性质关系较大,材料的常温耐压性能与碳含量没有对应关系,而碳的形态对性能影响较大,碳成网状分布有利于提高材料的强度。高聚物对材料中杂质晶体的生成和分布有很重要的影响。