285/60R18低噪声轮胎的设计与开发

进行了285/60R18低噪声轮胎的设计与开发。结构设计:外直径791 mm,断面宽305 mm,行驶面宽度229.43 mm,行驶面弧度高10.32 mm,胎圈着合直径457.6 mm,胎圈着合宽度254 mm,断面水平轴位置(H_1/H_2)1.035 9,花纹深度8.5 mm,花纹饱和度73.5%,花纹周节数37。施工设计:带束层采用2层2+2×0.30HT钢丝帘线,胎体采用1670dtex/2高模量低收缩聚酯帘线,采用VMI一次法成型机成型,液压硫化机硫化。成品轮胎性能试验结果表明,轮胎的充气外缘尺寸、强度性能、耐久性能、高速性能符合相关标准要求,噪声达到欧盟标签等级的低噪声轮胎水平。     

T125/80R18 T型临时使用轿车子午线轮胎的设计

介绍T125/80R18 T型临时使用轿车子午线轮胎的设计。结构设计:外直径655 mm,断面宽135 mm,行驶面宽度96 mm,行驶面弧度高7.5 mm,胎圈着合直径460.8 mm,胎圈着合宽度127 mm,断面水平轴位置(H_1/H_2)0.97,花纹深度3.2 mm,花纹饱和度75.7%,花纹周节数50。施工设计:胎面采用三方四块结构,带束层采用3×0.38ST钢丝帘线,胎体采用高模量低收缩聚酯浸胶帘线,采用二次法成型机成型、硫化机硫化。成品性能试验结果表明,成品轮胎的外缘尺寸、强度性能、脱圈阻力、耐久性能、高速性能等均达到设计和相关标准要求。     

185/60R14 82H TAXIPLUS出租车专用轮胎的设计

介绍185/60R14 82H TAXIPLUS出租车专用轮胎的设计。结构设计:外直径574 mm,断面宽195 mm,行驶面宽度138 mm,行驶面弧度高6.1 mm,胎圈着合直径350.1 mm,胎圈着合宽度153mm,断面水平轴位置(H_1/H_2) 0.984 3,胎面采用3条花纹沟槽设计,花纹深度8.4 mm,花纹饱和度68.46%,花纹周节数60。施工设计:胎面采用三复合设计,胎侧采用双复合设计,1~#和2~#带束层使用3×0.30HT钢丝帘线,冠带层采用锦纶66帘线,胎体采用高模量低收缩聚酯帘线,采用一次法成型机成型、液压硫化机和氮气硫化工艺硫化。成品性能试验结果表明,轮胎的充气外缘尺寸、强度性能、耐久性能和高速性能均达到相应设计和企业标准要求。     

265/35R22 102Y轿车子午线轮胎的设计

介绍265/35R22 102Y轿车子午线轮胎的设计。结构设计:外直径739 mm,断面宽287 mm,行驶面宽度227.9mm,行驶面弧度高20.9mm,胎圈着合直径559.2mm,胎圈着合宽度262mm,断面水平轴位置(H_1/H_2)1.06,胎面采用TH201花纹并优化花纹节距排列,花纹深度7mm。施工设计:胎面采用三方四块结构,带束层采用2层3×0.30HT钢丝帘线,胎体采用2层1100dtex/2DSP聚酯帘布,采用一次法成型机成型、双模液压硫化机硫化。成品性能试验结果表明,轮胎的外缘尺寸、强度性能、脱圈阻力、耐久和低气压耐久性能及高速性能均达到相应设计和国家标准要求,滚动阻力达到欧盟标签法限值要求。     

285/70R19.5全钢载重子午线轮胎的设计

介绍285/70R19.5全钢载重子午线轮胎的设计。结构设计:外直径892 mm,断面宽282 mm,行驶面宽度224 mm,行驶面弧高度8 mm,胎圈着合直径493.5 mm,胎圈着合宽度222 mm,断面水平轴位置(H_1/H_2)1.028,花纹深度13.5 mm,花纹饱和度76.4%,花纹周节数58。施工设计:胎面采用两方两块设计,1#和2#带束层采用3×0.20+6×0.35HT高强度钢丝帘线,3#带束层采用5×0.30HI高抗冲击钢丝帘线,0°带束层采用3×7×0.20HE高伸长钢丝帘线,胎体采用3+9×0.22+0.15钢丝帘线,采用一次法三鼓成型机成型,热板充氮双模硫化机硫化。成品性能试验结果表明,成品轮胎的外缘尺寸、强度性能和耐久性能均达到国家标准要求。     

385/65R22.5全天候全钢载重子午线轮胎的设计

介绍385/65R22.5全天候全钢载重子午线轮胎的设计。结构设计:外直径1067 mm,断面宽385 mm,行驶面宽度308 mm,行驶面弧度高13 mm,胎圈着合直径570.5 mm,胎圈着合宽度311 mm,断面水平轴位置(H_(1)/H_(2))1.01,胎面采用对称式条形花纹,中心花纹块开设横向细沟槽,花纹深度16.5 mm,花纹周节数55,花纹饱和度70%,胎肩花纹采用封闭式设计。施工设计:胎体采用0.25+6+12×0.225HT钢丝帘线,1#和2#带束层采用3+8×0.33HT钢丝帘线,3#带束层采用1×5×0.30HI钢丝帘线,0°带束层采用3×7×0.20HE钢丝帘线,胎面采用双复合结构,采用一次法成型机成型,采用热板式硫化机硫化。成品性能试验结果表明,成品轮胎的充气外缘尺寸、耐久性能、滚动阻力、噪声、抗湿滑性能、雪地性能均达到相应设计要求。     

315/80R22.5宽行驶面无内胎全钢载重子午线轮胎的设计

介绍315/80R22.5宽行驶面无内胎全钢载重子午线轮胎的设计。结构设计:外直径1 078 mm,断面宽306mm,行驶面宽度255 mm,行驶面弧度高8.8 mm,胎圈着合直径369.5 mm,胎圈着合宽度242 mm,断面水平轴位置(H_1/H_2)0.963,胎面采用纵向直沟花纹,花纹深度17 mm,花纹饱和度76.3%,花纹周节数100。施工设计:胎面采用贯通型结构,胎侧采用三复合结构,胎体采用0.25+(6+12)×0.225HT钢丝帘线,1~#带束层采用0.365+6×0.35BETRU?钢丝帘线,2~#和3~#带束层采用3+8×0.33HT钢丝帘线,4~#带束层采用5×0.35HI钢丝帘线,钢丝圈采用斜六角形结构,采用一次法成型机成型、双模蒸锅式硫化机硫化。成品轮胎的充气外缘尺寸、强度性能、耐久性能和速度性能符合国家标准要求。     

385/65R22.5全钢载重子午线轮胎的研制

介绍385/65R22.5轮胎的设计。结构设计:外直径1 070 mm,断面宽394 mm,行驶面宽度288 mm,行驶面弧度高12.5 mm,胎圈着合直径569.5 mm,胎圈着合宽度324 mm,断面水平轴位置(H_1/H_2)1.059 7,胎面采用纵向花纹变节距设计,花纹深度15 mm,花纹周节数51,花纹饱和度78.5%。施工设计:胎面胶采用三方四块结构,带束层采用3+0°结构,1~#和2~#带束层采用3×0.20+6×0.35HT钢丝帘线,3~#带束层采用5×0.30HI钢丝帘线,0°带束层采用3×7×0.20HE钢丝帘线,胎体采用3+9+15×0.175W钢丝帘线,钢丝圈采用六角形结构,采用一次法成型机成型,双模硫化机氮气硫化。成品性能试验结果表明:轮胎充气外缘尺寸、强度性能和耐久性能均达到国家标准要求。     

265/70R19.5无内胎全钢载重子午线轮胎的设计

介绍265/70R19.5无内胎全钢载重子午线轮胎的设计。结构设计:外直径862 mm,断面宽270 mm,行驶面宽度215 mm,行驶面弧度高6.0 mm,胎圈着合直径493.5 mm,胎圈着合宽度220.5 mm,断面水平轴位置(H_1/H_2)0.82,胎面采用混合型花纹设计,花纹深度17 mm,花纹饱和度72%,花纹周节数60。施工设计:采用双复合挤出胎面,1~#带束层采用3×0.20+6×0.35HT钢丝帘线,2~#和3~#带束层采用3+9+15×0.22+0.15钢丝帘线,4~#带束层采用5×0.30HI钢丝帘线,胎体采用3×0.24+9×0.225+0.15HT钢丝帘线,采用两鼓一次法成型机成型、硫化机硫化。成品性能试验结果表明,成品轮胎充气外缘尺寸、强度性能和耐久性能均符合相关设计和国家标准要求。     

245/70R19.5全钢载重子午线轮胎的设计

介绍245/70R19.5全钢载重子午线轮胎的设计。依据有限元仿真分析结果,确定结构设计参数如下:外直径843 mm,断面宽248 mm,行驶面宽度225 mm,行驶面弧度高10 mm,胎圈着合直径493.5 mm,胎圈着合宽度203 mm,断面水平轴位置(H_1/H_2)0.97,采用横向小块花纹,花纹深度17.5 mm,花纹饱和度74.25%,花纹周节数46。施工设计:胎面采用两方两块设计,胎体采用3×0.24/9×0.225CCHT钢丝帘线,1~#—3~#带束层采用3×0.20+6×0.35HT钢丝帘线,4~#带束层采用5×0.35HI钢丝帘线;采用一次法机械式成型机成型,液压全自动硫化机硫化。成品性能试验结果表明,成品轮胎的充气外缘尺寸、强度性能和耐久性能均达到国家标准要求。     

Preparation and properties of poly(Nε,Nε-dicarboxymethyl-l-lysine)

A new ampholytic homopolypeptide, $\text{poly}\text{(N}{}^{\mathrm{\epsilon }}\text{,N}{}^{\mathrm{\epsilon }}\text{-}\text{dicarboxy-methyl-}\text{l}\text{-lysine}\text{)}$, which has one tertiary amino and two carboxyl groups in the side chain has been derived from a hydrochloride salt of poly(L-lysine). The polymer in aqueous solution seems to be in the coil form with locally extended structure (LES) at neutral pH. In both the acidic and alkaline regions, the molar ellipticity of the polymer changes as a result of change in net charge on the side chain. The conformational changes may be from the coil with LES to other coiled forms. 5–7 M NaClO₄ and 80% aqueous methanol induce the α-helix in the polymer at neutral pH. Divalent cations, Cu²⁺ and Ca²⁺, do not induce any remarkably ordered structures such as α-helix or β-structure in the polymer in aqueous solution at any pH. Ultraviolet absorption studies show an absorption peak of the polymer-Cu²⁺ complex near 240 nm. Dependence of the peak intensity on pH at various q values ($\text{q =}\text{[}\text{Cu}{}^{\mathrm{2+}}\text{]}\text{[}\text{residue}\text{]}$) indicates the two steps of the complex formation. At q less than 0.64, the formation is described only with the first step. An average coordination number for Cu²⁺ at the first step was calculated to be about 2 by the method of Mandel and Leyte. The association constant of Cu²⁺ with the residue at the step was determined from the absorption data to be far smaller than that for the Cu²⁺-EDTA complex. The second step of the formation occurs in the case of large q but the absorption data for the second step cannot be obtained exactly due to precipitation.     

Wet Milling of Fe/Al/Al2O3 and Fe2O3/Al/Al2O3 Powder Mixtures

Wet milling of Al₂O₃-aluminide alloy (3A) precursor powders in acetone has been investigated by milling Fe/Al/Al₂O₃ and Fe₂O₃/Al/Al₂O₃ powder mixtures. The influence of the milling process on the physical and chemical properties of the milled powders has been studied. Particle refinement and homogenization were found not to play a dominant role, whereas plastic deformation of the metal particles leads to the formation of dislocations and a highly disarranged polycrystalline structure. Although no chemical reactions among the powder components in Fe₂O₃/Al/Al₂O₃ powder mixtures were observed, the formation of a nanocrystalline, ordered intermetallic FeAl phase in Fe/Al/Al₂O₃ powder mixtures caused by mechanical alloying was detected. Chemical reactions of Fe and Al particle surfaces with the atmosphere and the milling media lead to the formation of highly porous hydroxides on the particle surfaces. Hence the specific surface area of the powders increases, while the powder density decreases during milling. The fraction of Fe oxidized during milling was determined to be 0.13. The fraction of Al oxidized during milling strongly depends on the metal content of the powder mixture. It ranges between 0.4 and 0.8.     

Participation of lewis base on vinyl chloride polymerization with Al(C2H5)3CCl4 catalyst system

The polymerization of vinyl chloride has been investigated using an $\text{Al}\text{(}\text{C}{}_2\text{H}{}_5\text{)}{}_3\text{CCl}{}_4$ catalyst system in the presence of various Lewis bases. Effective Lewis bases are γ-butyrolactone, diglyme and diethylenetriamine which are multidentate. The rate of polymerization is dependent not only on the basicity of the Lewis base used but also on a coordination number of one. The latter is the predominant factor. For the effect of polymeric amines, a tentative hypothesis is discussed.     

Sintering of Si3N4-Y2O3-Al2O3

Sintering kinetics of the system Si₃N4-Y2O₃-Al₂O3 were determined from measurements of the linear shrinkage of pressed disks sintered isothermally at 1500° to 1700°C. Amorphous and crystalline Si₃N₄ were studied with additions of 4 to 17 wt% Y₂O₃ and 4 wt% A1₂O₃. Sintering occurs by a liquid-phase mechanism in which the kinetics exhibit the three stages predicted by Kingery's model. However, the rates during the second stage of the process are higher for all compositions than predicted by the model. X-ray data show the presence of several transient phases which, with sufficient heating, disappear leaving mixtures of β ' -Si₃N₄ and glass or β '-Si₃N₄, α '-Si₃N₄, and glass. The compositions and amounts of the residual glassy phases are estimated.     

Synthesis and Characterization of Ti0.33Ta0.33Nb0.33C and Ti0.33Ta0.33Nb0.33CxN1-x Whiskers

Ta_0.33Ti_0.33Nb_0.33C and Ta_0.33Ti_0.33Nb_0.33C _x N_{1− x} whiskers were synthesized via a carbothermal vapor-liquid-solid growth mechanism in the temperature range 900°-1450°C in Ar or N₂. The optimum temperature was 1250°C. Whiskers were obtained in a yield of 70-90 vol%. The whiskers were 0.5–1 µm in diameter and 10–30 µm in length. The starting materials that produced the highest whisker yield were: TiO₂, Ta₂O₅, Nb₂O₅, C, Ni, and NaCl. C was added to reduce the oxides, and Ni to catalyze whisker growth. NaCl was used as a source of Cl for vapor-phase transportation of Ta and Nb oxochlorides and Ti chlorides to the catalyst. The catalyst metal was recycled several times during the synthesis and was transported as NiCl₂( g ) according to thermodynamic calculations. The rate of formation and the chemical composition of the whiskers depended on the synthesis temperature, the choice of catalyst, and the atmosphere. At low temperatures, the whiskers were enriched in Nb and Ta, whereas the Ti content increased with increased synthesis temperature.