P&T-GC-MS 法对食品接触硅胶奶嘴中 VMSs 的模拟迁移研究

目的建立婴幼儿食品接触喂食奶嘴中9种挥发性甲基硅氧烷(VMS)在食品模拟物中迁移量的测定方法。方法采用蒸馏水、体积分数为3%的乙酸和体积分数为50%的乙醇作为食品模拟物,利用吹扫捕集-气相色谱质谱法(PT-GC-MS)测定喂食奶嘴在40℃浸泡24 h后9种VMS单体的迁移量。结果方法学评价结果表明,该方法灵敏度高、回收率高、选择性好,能满足实际工作的要求。迁移实验结果表明,9种VMSs均被检出,3个品牌的硅胶奶嘴中的VMSs总迁移量在乙醇(50%)中最高,为2.62~11.58μg/m L。结论硅胶喂食奶嘴在使用过程中可能存在一定的VMSs迁移和食入风险,尤其在高脂类食物中风险更高。     

Challenges of land administration and Bolivian colonization: beyond technical cadastral mapping

The paper provides an overview of the dynamic process of concluding land-titling efforts started almost 30 years ago in a colonization area of Bolivia. Through the course of the cadastral mapping effort it was discovered that technological solutions cannot stand alone as the answer to land administration challenges. Findings demonstrated failings that can occur in land information systems attributed largely to an over confidence in standardization and technology as well as a lack of information or attention to detail about local land tenure characteristics, illustrating the adage that land is unique. This paper focuses on the lessons learned through public participation in the parcel mapping of 100 colonies subjected to titling and certification. Mechanisms that strengthen the tenants' role in the cadastral mapping process proved mutually beneficial to both tenants and technicians by streamlining the process. Getting initial input into the process during the information-gathering stage rather than simply submitting the results for criticism after the fact avoided duplication of efforts thus improving the efficiency of the land administration project. Efficiency is increased while empowering those most interested in the work. The lessons learned here may be exported to other cadastral mapping projects.     

游戏思维在包装数字化转型中的应用

目的 为包装数字化转型提供游戏思维设计策略。方法 在数字经济时代背景下应用游戏思维理论来拓展包装功能的边界,基于心理学自我决定论原理将包装商业价值与消费者驱动力的内核层次相结合,使用象限分析法以网络技术与电子技术为数字技术的两极,对28个案例进行分析,得到数字化包装中游戏思维属性分布区域图,建立学习类和社交类2种设计策略流程图。使用雷达图分析法得出2种策略模式与消费者驱动力的匹配关系。结论 游戏思维的数字化包装设计思路以满足用户的心理动机和本质诉求为目的,设计程序以明确的目标为导向,综合调动包装的各个构成组件并与数字技术相结合,从而推动用户行为,通过使人兴奋的目标、限制性的规则和及时的反馈形成闭环路径,有效引导消费者与包装之间的互动流程,消费者在满足个人驱动力的愉悦体验中达成了与企业的价值共创。     

Wall temperature experimental investigation in a thermally driven channel

Direct local wall temperature has been measured, in a steady state, along a vertical air channel asymmetrically heated with uniform fluxes. In the range of high Grashof numbers that was investigated, the flow regime probably remained laminar. A radiative part has been analysed with two extreme values of internal surface emissivity corresponding to unpainted metal and black painted wall. A correlation has been proposed for the calculation of a characteristic channel outlet value of the Nusselt number referred to air spacing. A local Nusselt number over the height has been developed in a power law scheme.     

CMR and related properties of single crystals of cation-deficient LaMnO3

Single crystals of LaMnO₃, La_1−xMnO₃ (x=0, 0.04, 0.1) and LaMn_1−xO₃ (x=0.1) have been grown by the floating-zone melting technique. Electrical and magnetic properties of these crystals have been examined. Only La_0.9MnO₃ crystals exhibit ferromagnetism, (T_c∼250 K), an insulator–metal transition around 250 K and CMR (58% at T_c).     

前端渲染函数调用图工具的设计与实现

针对内核在线分析工具,使用服务器计算函数调用图存在渲染时间长、网络传输数据量大等问题,基于Node.js的前端渲染函数调用图工具FRCG(front-end rendering call graph),使用前后端分离的方式,将数据处理与调用图渲染拆分到前后端分别进行.服务器异步处理请求,返回JSON数据,优化传输数据量...     

论品牌包装创意的价值观

从品牌包装的"幻想"创意观,个性化、时尚化创意观,情感创意观,"绿色包装"创意观等多视角进行了研究,从而证明设计者只有站在消费者的角度上进行"换位思考"才能真正体现品牌包装创意的价值观.     

基于蜂群算法的等压灌装阀阀口流道结构优化

目的为了改善等压灌装阀的灌装性能,分析阀口流道结构参数对液料流场的影响,求解流道内最大压力损失、最大液料流速和最大湍动能均最小化的约束多目标优化问题。方法基于正交试验设计和Fluent流场仿真软件对灌装阀阀口流道流场进行数值模拟,并通过回归分析建立以阀口流道结构参数为自变量的最大压力损失、最大液料流速和最大湍动能的经验方程,进而建立阀口流道结构参数约束多目标优化模型,采用约束多目标人工蜂群算法对优化模型进行求解。结果流道内最大压力损失最小化、最大液料流速最小化和最大湍动能最小化这3个目标之间存在冲突,无法同时达到最优,基于多目标人工蜂群算法获得了阀口流道结构参数的最优Pareto解集。结论约束多目标人工蜂群算法能有效用于等压灌装阀阀口流道结构参数的优化。     

物流中心选址的神经网络集成模型研究

针对在建立物流中心选址模型中,单个人工神经网络模型难以确定参数、容易产生“过拟合”等问题,提出一种神经网络二次集成模型,利用Bootstrap可重复采样技术得到不同的训练集来训练产生不同的个体神经网络,采用粒子群优化算法结合个体输出获得神经网络集成,并在此基础上将集成视为个体再次结合。实验结果表明,该模型易于设计且能够提高泛化能力。