Application of Discrete Lumped Kinetic Modeling on Vacuum Gas Oil Hydrocracking

The kinetic model of vacuum gas oil (VGO) hydrocracking based on discrete lumped approach was investigated, and some improvement was put forward at the same time in this article. A parallel reaction scheme to describe the conversion of VGO into products (gases, gasoline, and diesel) proposed by Orochko was used. The different experimental data were analyzed statistically and then the product distribution and kinetic parameters were simulated by available data. Furthermore, the kinetic parameters were correlated based on the feed property, reaction temperature, and catalyst activity. An optimization code in Matlab 2011b was written to fine-tune these parameters. The model had a favorable ability to predict the product distribution and there was a good agreement between the model predictions and experiment data. Hence, the kinetic parameters indeed had something to do with feed properties, reaction temperature and catalyst activity.     

液压缸有限元应力分析

提出了一种液压缸液压模型。通过计算和实验应力测试表明，该模型有限元分析方法是正确可行的。     

雪山里的独立制表师

每一门手艺大概都有这样一种人,他们视自己的手艺为一种涉及灵魂的东西。在钟表制造业,这个人就是菲利普·杜佛。他一年只做十几只表,却是世界上最好的纯手工机械表。     

石油企业安全管理的思考

随着石油企业的快速发展,加强企业的安全管理显得越来越重要了,虽然企业的安全管理水平在不断地提高,但是任然存在很多的问题。所以加强对石油企业安全管理的研究是很有必要的,它可以提高企业的运营安全,并取得更大的经济效益。本研究综述了企业安全管理概述、石油企业管理现状及问题、加强石油企业安全管理的有效措施等内容。     

Direct nanoimprint lithography of Al₂O₃ using a chelated monomer-based precursor

Nanostructuring of Al?O? is predominantly achieved by the anodization of aluminum film and is limited to obtaining porous anodized aluminum oxide (AAO). One of the main restrictions in developing approaches for direct fabrication of various types of Al?O? patterns, such as lines, pillars, holes, etc, is the lack of a processable aluminum-containing resist. In this paper, we demonstrate a stable precursor prepared by reacting aluminum tri-sec-butoxide with 2-(methacryloyloxy)ethyl acetoacetate, a chelating monomer, which can be used for large area direct nanoimprint lithography of Al?O?. Chelation in the precursor makes it stable against hydrolysis whilst the presence of a reactive methacrylate group renders it polymerizable. The precursor was mixed with a cross-linker and their in situ thermal free-radical co-polymerization during nanoimprinting rigidly shaped the patterns, trapped the metal atoms, reduced the surface energy and strengthened the structures, thereby giving a ~100% yield after demolding. The imprinted structures were heat-treated, leading to the loss of organics and their subsequent shrinkage. Amorphous Al?O? patterns with line-widths as small as 17 nm were obtained. Our process utilizes the advantages of sol-gel and methacrylate routes for imprinting and at the same time alleviates the disadvantages associated with both these methods. With these benefits, the chelating monomer route may be the harbinger of the universal scheme for direct nanoimprinting of metal oxides.     

A novel antibacterial resin composite for improved dental restoratives

A novel furanone-containing antibacterial resin composite has been prepared and evaluated. compressive strength (CS) and Streptococcus mutans viability were used to evaluate the mechanical strength and antibacterial activity of the composites. The modified resin composites showed a significant antibacterial activity without substantially decreasing the mechanical strengths. With 5-30 % addition of the furanone derivative, the composite kept its original CS unchanged but showed a significant antibacterial activity with a 16-68 % reduction in the S. mutans viability. Further, the antibacterial function of the new composite was not affected by human saliva. The aging study indicates that the composite may have a long-lasting antibacterial function. Within the limitations of this study, it appears that the experimental antibacterial resin composite may potentially be developed into a clinically attractive dental restorative due to its high mechanical strength and antibacterial function.     

具有形状记忆功能的自修复电缆护套材料研究

以环糊精修饰的氧化铝纳米粒子(CD-Al₂O₃ NPs)为主体分子，以含金刚烷的丙烯酸酯为客体分子，通过主、客体相互识别自组装生成包合物后与2-羟基乙基-甲基丙烯酸酯(HEMA)、丙烯酸丁酯(BA)和聚乙烯吡咯烷酮(PVP)进行自由基共聚得到了一种新型的PVP/p(HEMA-co-BA)半互穿网络材料，对其微观形貌和性能进行表征和检测。结果表明：通过主客体包合作用赋与了材料自修复性能；同时，由于引入了主客体包合和氢键两种可逆的非共价相互作用，材料具有优异的形状记忆功能。材料具备的形状记忆功能和自修复性能可在裂纹的两个断面距离较大时实现自修复，恢复材料的原有性能。此外，PVP/p(HEMA-co-BA)还具有较好的热稳定性，耐受温度达到200℃，能够在较高温度环境中使用。     

基于lur-g＋的2G／3G网络融合方案

文章对TD—SCDMA／GSM无线网络控制器的lur—g＋融合技术进行了介绍，说明了其基本原理、切换流程，并介绍了lur—g＋技术的外场测试情况，对lur—g＋的测试效果及后续的现网应用做了阐述说明。     

Computer aided design and fabrication of models for in vitro studies of vascular fluid dynamics

An integrated computer aided design/computer aided manufacture system has been used to model the complex geometry of blood vessel anastomoses. Computer models are first constructed with key dimensions derived from radiological images of bypass grafts, and from casts of actual blood vessel anastomoses. Physical models are then fabricated in one of two ways: the surface geometry data can be used to control the movement of a three-axis milling machine; alternatively, the same data can be exported in a form that can be interpreted by a stereolithography apparatus. Both methods produce geometrically defined solid investments that can be used in a multistep casting process that yields high-quality physical models for vascular fluid dynamic studies. This technique is useful for parametric studies.     

Diffusion-activated high performance ZnSnO/Yb2O3 thin film transistors and application in low-voltage-operated logic circuits

The flourishing metal-oxide high-k dielectric materials have been regarded as the vital components of low voltage operated flexible transparent electronic devices.We herein report that ytterbium oxide(Yb2O3)and ZnSnO(ZTO)thin films were firstly integrated into ZTO-based thin film transistors(TFTs)with superior performance.Results have indicated that the 500℃-annealed ZTO/Yb2O3 TFTs possess the large saturation mobility of 9.1 cm2 V-1 S-1 and the high on/off current ratio of 2.15×107,which even surpass those of reported In-based TFTs.The deteriorative electrical properties in the aging process can be attributed to the carrier capture mechanism.However,the 460℃-processed TFTs demonstrate a tenfold increase in saturated mobility and an increase in on/off current ratio after 10 days aging.The inspiring electrical properties are attributed to the diffusion-activated carrier enhancement mechanism and electrons donor role of water molecular,which introduces a facile method to boost the device per-formance at lower processing temperatures.The neglected threshold voltage variations of 0.06 V and-0.2 V have been detected after bias stability experiments.The superior bias stability can be attributed to the charge delay effect induced by the continuous electric field.Meanwhile,the ultrahigh on/off cur-rent ratio of 1.1 x 107 and the recoverable transferring performance have verified the aging-activated mechanism.To confirm its potential application in digital circuits,a resistor-loaded inverter with gain of 5.6 has been constructed and good dynamic response behavior have been detected at a low voltage of 2 V.As a result,it can be concluded that the high temperature annealing TFTs need immediate encapsula-tion,while the performance of the lower temperature processing samples can be optimized after aging treatment,indicating the potential prospect in low power consumption large-scale flexible transparent devices.