振动压路机振动轮的随机压振力研究

讨论了振动压路机系统的动力学问题，应用一般随机摄动方法对含有随机土参数的振动压路机振动轮的随机压振力进行了研究，且获理了理想的数值分析结果。     

计算机辅助工艺设计任务分派与管理

提出工艺设计任务的指派和抢选分派方式,基于任务分派方式定义工艺设计任务和子任务,建立工艺设计任务模型,介绍计算机辅助工艺任务分派与管理方法。提出的理论与方法在Web CAPP系统中得到实现。     

寒地大学校园环境要素与冬季体力活动相关性

为探究促进冬季体力活动的寒地大学校园环境设计依据,基于循证设计理论和社会生态学模型在中国东北地区9座大学校园年内进行了问卷调查,用实证方法探究了寒地大学校园的建成、气候及感知环境要素对学生冬季体力活动频率和水平的影响.通过描述性统计横向对比了学生冬季与非冬季月份的体力活动模式及各个校园的主观评价得分;并通过多重线性回归分析探求了校园环境要素对冬季体力活动的影响.统计结果表明:学生在冬季月份进行体力活动的频率和总量低于非冬季月份;校园冬季环境质量低于非冬季月份,且设施防寒、步行可达性、交通安全性、冬季活动安全性得分较低;在冬季,目的地多样性、公共交通选择多样性、道路交通网络连通性、步行道路环境品质、辅助设施存在性、犯罪安全性与交通性体力活动正相关,冰雪危害和空气污染与交通性体力活动负相关;校园环境与冬季休闲性活动无相关关系.利用上述数据可以初步推测促进体力活动的寒地大学校园环境设计倾向并对各个环境要素的重要程度进行评级,重要程度较高的要素是校内目的地、步行道路、犯罪安全性、步行辅助设施和校园公共交通服务.     

Influences of copolymers (Copovidone,Eudragit RL PO and Kollicoat MAE 30 DP) on stability and bioactivity of spray-dried and freeze-dried lysozyme

Protein stability is the most crucial factor in protein pharmaceutical preparations. Various techniques were applied for producing stable protein formulations such as spray-drying and freeze-drying. However, heating and freezing stresses are disadvantages for proteins using these methods, respectively. Accordingly, excipients have been used to preserve therapeutic effects of proteins during processing and for long period of time. Therefore, influences of Copovidone, Eudragit^® RL-PO and Kollicoat^® MAE-30 DP (as excipients) on stability and integrity of lysozyme (as a model protein) in spray-dried and freeze-dried forms were investigated. Protein formulations in both dried forms were prepared without and with the addition of mentioned excipients at different concentrations. Protein formulations were characterized for yield determination, morphology using scanning electron microscopic (SEM), thermal analysis by Differential Scanning Calorimetry (DSC), secondary structure stability using Fourier transform infrared (FT-IR) spectroscopy and biological activity. All protein formulations were subjected to a stability study as solid protein formulations for 3 weeks at 24?°C/76% relative humidity and aqueous protein samples were stored at 50?°C for 30?min in a water bath. Results showed that Copovidone successfully preserved integrity and biological activity of lysozyme before and after storage in both spray-dried and freeze-dried forms with more advantage for using higher concentration of the same excipient. Smooth spheres of spray-dried lysozyme formulations with Copovidone were smaller than spray-dried lysozyme without and with Kollicoat^® MAE-30 DP, which affected %yield produced. Copovidone has demonstrated valuable protection ability for lysozyme.     

Demonstrating the Minimal Impact of Cultivation Conditions on Antioxidants in Fruits and Vegetables by Differential Pulse Voltammetry

Conventionally, organically, and locally grown varieties of carrot, tomato, rhubarb, raspberry, strawberry, and bell peppers were analyzed by differential pulse voltammetry to determine the impact of cultivation conditions on produce antioxidant content. The potential (indicating antioxidant activity) and area (indicating antioxidant capacity) of the primary peaks were evaluated. Overall, no consistent trends were observed across cultivation conditions, suggesting that cultivation conditions have minimal impact on antioxidant content. This study revealed differential pulse voltammetry to be a sensitive and rapid method for antioxidant determination, with a detection and quantitation limit of 8.38 × 10^?5 and 2.79 × 10^?4 mol/L, respectively.     

基坑围护中参数选择与静探试验关系的探讨

介绍了工程中剪切强度指标的选择原则,通过静探试验,对原位测试指标和剪切强度指标进行了相关性研究,发现原位测试指标可以为基坑围护设计时的参数选择提供依据。     

浅谈季节性冻土桥梁桩基础特性及其静载试验

多年冻土地区桥梁工程往往由于地基的冻融作用,不良冻土地区冻融的影响,会产生各种工程病害,从而影响工程使用。文章通过对季节性冻土桩基静载试验来分析验证桩基的承载力能否满足设计使用要求。     

Associated computational plasticity schemes for nonassociated frictional materials

A new methodology for computational plasticity of nonassociated frictional materials is presented. The new approach is inspired by the micromechanical origins of friction and results in a set of governing equations similar to those of standard associated plasticity. As such, procedures previously developed for associated plasticity are applicable with minor modification. This is illustrated by adaptation of the standard implicit scheme. Moreover, the governing equations can be cast in terms of a variational principle, which after discretization is solved by means of a newly developed second‐order cone programming algorithm. The effects of nonassociativity are discussed with reference to localization of deformations and illustrated by means of a comprehensive set of examples. Copyright © 2012 John Wiley & Sons, Ltd.     

污泥炭田间老化对土壤重金属及养分的影响

污泥基生物炭内源重金属和养分含量因污泥来源的不同而差异较大。为探索污泥基生物炭“还田”后，其内源重金属变化和养分的去向问题，采用干湿交替对污泥基生物炭模拟老化处理，分析老化前后污泥基生物炭的Cu、Zn金属形态及TCLP浸出毒性的变化；研究污泥基生物炭BC1和BC2（分别以磷酸二氢钾、磷酸二氢钙与污泥混合后热解制备的生物炭）以5%和10%的质量分数与鲜土混合老化后对污泥基生物炭内源重金属稳定性及土壤有机碳和有效磷含量变化的影响。结果表明：两种污泥基生物炭与土壤混合老化后会使土壤中SiO2含量增加，但不会改变土壤的吸附类型；污泥基生物炭的添加会增加土壤的比表面积，其中BC2增幅较大，为36.17 m2/g；施加两种污泥基生物炭土壤中Cu、Zn生物有效性均有不同程度的降低。TCLP浸出毒性量相比老化前降低（BC1约降低37.5%）。此外，BC1对土壤有效磷的提升效果优于BC2（BC1 70 mg/kg，BC2 30 mg/kg）；BC2对土壤有机碳的提升效果优于BC1（BC2 2.2%，BC1 1.15%）。BC2还田更有利于Cu、Zn的固定以及土壤有机碳和有效磷的提升。     

Enhancing Online Community Activity: Development and validation of the CA framework

Factors contributing to development of active communities are identified and combined into the Community Activity framework, which is useful in setting up new, or revitalizing inactive, communities. Found factors include: notifying members of new messages by e-mail, having a news section, and ability to add pictures to member profiles. During application of the framework to an inactive community, changes have been made to privacy options, polls, activity notifications, and other areas. Significant positive effects have been found in the number of visits, volume of posted messages, and number of topics. Interest of community members in both user profiles and the message board increased significantly. We conclude that the Community Activity framework is able to contribute in developing active online communities.