600 MPa级汽车车轮用钢的工业试制

针对高强度车轮钢高成形性和高疲劳寿命的要求,在C、Mn成分基础上采用Cr等合金化的成分设计,采取分段冷却和中温卷取工艺,济钢开发出高延伸凸缘性能的汽车车轮用钢,其微观组织为铁素体、贝氏体及少量马氏体,抗拉强度在600 MPa以上,延伸率≥24%,扩孔率≥70%,制成的车轮较原普通低合金高强度车轮减重10%以上,车轮弯曲疲劳寿命达到60万次以上。     

700 MPa级高强集装箱用钢的研制

介绍了屈服强度700 MPa级集装箱用高强钢的成分设计思路和主要的轧制工艺参数,并分析了产品的性能、组织和析出相。试制结果表明:通卷钢板的力学性能均匀,组织由位错密度很高的块状铁素体和少量贝氏体组成,析出相主要为不同形态的铌、钛的碳氮化物,在铁素体中析出的细小的TiC第二相粒子沉淀强化作用更大。     

唐山矿业分公司选煤厂浮选系统改造可行性分析

 针对开滦集团唐山矿业分公司选煤厂浮选系统存在的问题,结合煤泥分步释放浮选试验,对浮选系统改造的可行性进行了分析,并介绍了XJM-(K)S型浮选机的特点。     

Cities,Natures and the Political Imaginary

Despite the seeming accumulation of natural and manmade disasters over the last decade, and increasing urban intensification across the world, there seems to be little or no actual progress in solving urban ecological problems. In exploring a way forward, Maria Kaika and Erik Swyngedouw highlight three potential approaches to urban socio-ecological research and how these might provide a conduit for re-politicising urban nature.     

嗜酸乳杆菌La28对丙戊酸暴露引起的子代大鼠外周炎症和肝损伤的缓解作用

为评价嗜酸乳杆菌La28对丙戊酸(valproic acid,VPA)暴露引起的子代大鼠外周炎症和肝损伤的作用,同时明确其对VPA大鼠肠道菌群的调节作用。在大鼠孕期12. 5 d腹腔注射VPA和生理盐水,断奶后,随机选取雄性子代分成对照组、VPA组、La28组和利培酮(MED)组(n=5),La28组每天灌胃菌液(109CFU/m L),对照、VPA和MED组灌胃等量生理盐水和药物,干预期28 d。干预结束后,评价外周炎症、肝功能和肠道菌群的改善情况。与VPA组大鼠相比,嗜酸乳杆菌La28干预能显著地改善VPA大鼠的外周炎症和肝功能,其中对IL-6、TNF-α、ALT和GGT的作用效果更为显著。此外,嗜酸乳杆菌La28可能通过上调Allobaculumhe和Mucispirillum的相对丰度,增加厚壁菌门丰度,降低拟杆菌门丰度从而改善VPA暴露引起子代大鼠的神经炎症和肝功能。     

408UL仪器与KZ-28震源配套助理软件的设计编程和应用

在实际生产中,经常需要408 UL仪器与KZ-28可控震源ADVⅢ箱体配合施工,但由于这两种设备不兼容,导致了408 UL仪器记录系统产生的单炮文件号与KZ-28震源ADVⅢ箱体系统产生的该炮记录相应的振动编号匹配不上,影响了对单炮记录激发因素指标的分析,不利于后期施工方案的设计。本文介绍的软件可以准确地把单炮记录的文件号、炮点桩号等数据与震源激发产生该记录相应的振动编号、坐标等数据对应起来,最后生成Ex-cel表。该软件具有操作简单、实用性强、结果准确、便于统计等特点,文中主要对该软件的设计思路和编程原理进行了介绍。     

Synthesis and photovoltaic properties of an alternating phenylenevinylene copolymer with substituted-triphenylamine units along the backbone for bulk heterojunction and dye-sensitized solar cells

We have fabricated bulk heterojunction (BHJ) photovoltaic devices based on the as cast and thermally annealed P:[6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) blends and found that these devices gave power conversion efficiency (PCE) of about 1.15 and 1.60% respectively. P is a novel alternating phenylenevinylene copolymer which contains 2-cyano-3-(4-(diphenylamino)phenyl)acrylic acid units along the backbone and was synthesized by Heck coupling. This copolymer was soluble in common organic solvents and showed long-wavelength absorption maximum at 390-420 nm with optical band gap of 1.94 eV. The improvement of PCE after thermal annealing of the device based on the P:PCBM blend was attributed to the increase in hole mobility due to the enhanced crystallinity of P induced by thermal treatment. In addition, we have fabricated BHJ photovoltaic devices based on the as cast and thermally annealed PB:P:PCBM ternary blend. PB is a low band gap alternating phenylenevinylene copolymer with BF₂-azopyrrole complex units, which has been previously synthesized in our laboratory. We found that the device based on this ternary blend exhibited higher PCE (2.56%) as compared to either P:PCBM (1.15%) or PB:PCBM (1.57%) blend. This feature was associated with the well energy level alignment of P, PB and PCBM, the higher donor-acceptor interfaces for the exciton dissociation and the improved light harvesting property of the ternary blend. The further increase in the PCE with thermally annealed ternary blend (3.48%) has been correlated with the increase in the crystallinity of both P and PB. Finally, we used copolymer P as sensitizer for quasi solid state dye-sensitized solar cell and we achieved PCE of approximately 3.78%.     

Limonene encapsulation in freeze-drying of gum Arabic-sucrose-gelatin systems

Encapsulation of limonene in freeze-drying of various matrices consisting of gum Arabic, sucrose and gelatin was studied. Retention of limonene in freeze-drying was observed by measuring absorbance at 252 nm using a spectrophotometer. Two different levels of limonene, in the weight ratios (w/w) of 9:1 and 8.5:1.5 (total solids (TS):limonene) were studied. Highest amount of limonene (75.3±0.3% of initially added amount) in the emulsions homogenised at 25 MPa (4 MPa in second stage) followed by freeze-drying, was retained in a matrix consisting of gum Arabic, in the ratio of 9:1 (w/w). A mixture consisting of gelatin-sucrose-gum Arabic in the w/w ratio of 0.66:0.17:0.17 retained highest amount (71.8±0.1% of initially added amount) of limonene in the ratio (w/w) of 8.5:1.5 (TS:limonene). A matrix consisting of gum Arabic-sucrose-gelatin (1:1:1 w/w/w) with added limonene at a ratio (w/w) of 9:1 (TS:limonene), was used to study the effects of ultra high-pressure homogenisation (50-250 MPa) on limonene encapsulation in freeze-drying. Highest amount (84% of initially added amount) of limonene was retained in the emulsions homogenised at a pressure of 100 MPa. Electron micrograph of freeze-dried matrix of gum Arabic-sucrose-gelatin in the weight ratio of 1:1:1 suggested that it possessed a flake like structure, which was free of dents and shrinkage. A mixture consisting of gum Arabic-sucrose-gelatin is an efficient encapsulant for limonene encapsulation by freeze-drying.     

乙醇胺与胜坨油田坨28 区块原油活性组分 相互作用对动态界面张力的影响

为明确胜坨油田坨28区块原油中活性组分与有机碱乙醇胺间的相互作用对动态界面张力的影响,采用SARA四组分分离方法对坨28区块原油进行分离,获得饱和分、芳香分、胶质和沥青质等组分;利用醇碱萃取法获得酸性组分;通过旋转滴界面张力仪测定了乙醇胺与坨28区块原油活性组分模拟油间的动态界面张力。研究结果表明:酸性组分是原油的主要活性组分,其质量分数及结构对有机碱与原油间界面张力的行为具有关键性影响,体系动态界面张力的最低值可达10-2m N/m数量级;酸性组分质量分数越大,低界面张力维持时间越长。对于坨28区块原油,与乙醇胺作用的难易顺序为:酸性组分最强,胶质次之,沥青质、饱和分和芳香分与之作用比较微弱。     

Effects of different force fields and temperatures on the structural character of abeta (12-28) Peptide in aqueous solution

The aim of this work is to investigate the effects of different force fields and temperatures on the structural character of Aβ (12-28) peptide in aqueous solution. Moreover, the structural character of Aβ (12-28) peptide is compared with other amyloid peptides (such as H1 and α-syn12 peptide). The two independent temperature replica exchange molecular dynamics (T-REMD) simulations were completed by using two different models (OPLS-AA/TIP4P and GROMOS 43A1/SPC). We compared the models by analyzing the distributions of backbone dihedral angles, the secondary structure propensity, the free energy surface and the formation of β-hairpin. The results show that the mostly populated conformation state is random coil for both models. The population of β-hairpin is below 8 percent for both models. However, the peptide modeled by GROMOS 43A1 form β-hairpin with turn located at residues F19-E22, while the peptide modeled by OPLS-AA form β-hairpin with turn located at residues L17-F20.