双瓦楞纸板蠕变特性力学模型分析

基于双瓦楞纸板蠕变-时间曲线的分段式经验公式及其特征系数,运用粘弹性理论,建立了双瓦楞纸板蠕变特性的两种力学模型,并验证了模型的有效性.结果表明,这两种力学模型都能反映双瓦楞纸板的蠕变特性,第2种力学模型相对第1种简洁、方便,而第1种力学模型比第2种更能接近蠕变试验结果.     

预压对瓦楞纸板蠕变特性的影响

目的通过一系列的实验,研究预压对瓦楞纸板蠕变特性的影响,从而得到瓦楞纸板的蠕变曲线。方法通过对瓦楞纸板进行3种恒定载荷、4种不同预压处理条件下的蠕变特性研究实验,得出其蠕变曲线,并分别进行比较,分析预压对瓦楞纸板蠕变特性的影响。结果预压对瓦楞纸板的蠕变都有显著的影响,在不同的预压下,A瓦楞纸板和BC型双瓦楞纸板的蠕变量都是有所不同的。结论瓦楞纸板的蠕变会随着预压的增加而增大。     

湿度对瓦楞纸板蠕变特性的影响

目的通过一系列试验来研究湿度对瓦楞纸板蠕变特性的影响,从而得出瓦楞纸板的蠕变曲线。方法通过对瓦楞纸板进行3种恒定载荷,3种不同湿度处理条件下的蠕变特性研究试验,得出其蠕变曲线,并分别进行研究比较,分析湿度对瓦楞纸板蠕变特性的影响。结果湿度对瓦楞纸板的蠕变都有显著影响。结论瓦楞纸板的蠕变会随着湿度的增加而增大。     

跌落次数对瓦楞纸板蠕变特性的影响

目的研究不同跌落次数处理对瓦楞纸板蠕变特性的影响,从而得出其蠕变曲线。方法通过对瓦楞纸板进行3种恒定载荷和3种跌落次数处理条件下的蠕变特性研究实验,得出其蠕变曲线,并分别进行比较,分析多次跌落对其蠕变特性的影响。结果多次跌落对瓦楞纸板的蠕变有显著影响,跌落次数为1,3,5次时,蠕变量分别为0.29,0.33,0.37 mm。结论瓦楞纸板的蠕变会随着跌落次数的增加而增大。     

折叠型双瓦楞纸板衬垫动态缓冲特性的试验研究

试验研究了3种折叠型双瓦楞纸板衬垫结构在跌落高度分别为30cm、60cm、90cm 3种条件下的动态缓冲特性,采用3次多项式曲线拟合法获得了峰值加速度-静应力曲线的经验公式和特征系数.这些研究工作对折叠型双瓦楞纸板衬垫在运输包装中的应用具有良好的参考价值.     

双瓦楞纸板衬垫结构的动态缓冲特性分析

对比分析了0966型、0940型、0941型、0946型4种双瓦楞纸板衬垫结构在跌落高度为30、60和90cm 3种条件下动态缓冲特性曲线,以及衬垫类型、跌落高度对动态缓冲特性的影响,总结了双瓦楞纸板衬垫结构的动态缓冲特性.     

瓦楞纸板和纸箱蠕变关系的研究

通过运用马基公式和瓦楞纸板和纸箱的蠕变模型,分析得到瓦楞纸板和纸箱蠕变可持续时间之间是一种线性关系,并用实验对这一结论进行了验证。为瓦楞纸板和纸箱蠕变时间关系建立提供了一种新的方式。     

X-PLY超强瓦楞纸板振动传递特性研究分析

研究了两种X-PLY超强瓦楞纸板的防振性能,获得了X-PLY超强瓦楞纸板振动传递率曲线、峰值频率、振动传递率和阻尼比.试验结果表明.X-PLY超强瓦楞纸板的振动传递特性具有多模态性,有主次之分,而且静应力值对振动传递特性有明显影响.     

X-PLY超强瓦楞纸板动态缓冲特性的试验研究

基于跌落冲击试验,研究X-PLY(A)、X-PLY(B)两种超强瓦楞纸板的动态缓冲性能,获得了动态缓冲特性曲线的经验公式及其特征系数,为X-PLY超强瓦楞纸板在缓冲包装中的推广应用提供了基本数据.结果表明,X-PLY超强瓦楞纸板的动态缓冲特性曲线呈凹谷状,开口向上,只有一个极小值点,冲击加速度波形近似于半正弦波,具有优良的动态缓冲特性,而且X-PLY(A)超强瓦楞纸板的动态缓冲性能比X-PLY(B)超强瓦楞纸板更好.     

弹力型双瓦楞纸板衬垫动态缓冲性能的试验研究

试验研究弹力型双瓦楞纸板衬垫的动态缓冲性能,得到弹力型双瓦楞纸板衬垫在跌落高度分别为30、60、90cm 3种条件下的最大加速度-静应力曲线,并采用最小二乘法和多项式曲线拟合,获得曲线的经验公式.这些结果为弹力型双瓦楞纸板衬垫在缓冲包装中的应用提供了基本数据和重要公式.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.