不同包装方式对苹果-蟠桃纸的感官品质和理化特性的影响

目的 比较聚乙烯普通包装、铝箔密封袋包装、真空袋真空包装3种包装方式对苹果-蟠桃纸在37 ℃温度贮藏42 d期间的组织状态、色泽、口感、风味、菌落总数、色泽、褐变度、总酸、维生素C、总酚含量和抗氧化活性的影响。方法 对苹果-蟠桃纸分别进行PE普通包装、铝箔密封袋包装、真空袋真空包装3种方式的处理,在37 ℃温度下进行货架期加速实验,对不同包装方式处理的苹果-蟠桃纸在42 d贮藏期内的感官评定、菌落总数、色泽、褐变度、总酸、维生素C、总酚含量和抗氧化活性进行分析。结果 随着贮藏时间延长,PE普通包装保存的苹果-蟠桃纸褐变严重（42 d时,褐变度为10.39）,营养价值损失严重（42 d时,维生素C含量为2.19 mg/100 g）,而真空包装保存的苹果-蟠桃纸表面色泽、营养成分、抗氧化活性保留较好。此外,所有样品中的总酚含量在贮藏过程中逐渐下降,真空包装保留了更高的总酚含量（42 d时,总酚含量为3.62 mg GAE/g dw）。结果表明真空包装能更好地保持苹果-蟠桃纸质量;在贮藏过程中,所有包装方式的苹果-蟠桃纸的微生物生长繁殖都在安全期限以内（<2 lg CFU/g）,这表明苹果-蟠桃纸是安全可食用的。结论 这一研究明确了苹果-蟠桃纸的42 d贮藏期的品质变化情况,为确保苹果-蟠桃纸的安全贮藏提供理论支持。     

The Effect of a Perceived Leader's Influence on the Motivation of the Members of Nonwork-Related Virtual Communities

In the plethora of virtual communities (VCs), the importance of nonwork-related VCs is increasing because organizations want to utilize these VCs to improve their performance by means of the social interaction among the members of the nonwork-related VCs. Despite the growing importance of nonwork-related VCs, only limited research has been conducted to examine the factors affecting their members' motivation and organizational commitment. This study investigated the critical role of leaders in motivating the members of nonwork-related VCs. The influence of the members' perceptions of two leadership styles-consideration (relationship-oriented leadership) and initiating structure (task-oriented leadership)-on the members' motivation was examined. We also tested the moderating effects of the members' perceptions of three sources of power to determine how these sources could increase the leader's influence on the members. The results obtained from 92 individuals in various nonwork-related VCs showed the significant influence of the leader's consideration and initiating structure, as perceived by the members, on the members' motivation and organizational commitment. An additional finding indicated that the influence of the leader's initiating structure on the members' motivation and organizational commitment was greater than that of consideration. Furthermore, expert power had a positive moderating effect on the relationship between the leader's consideration and the members' motivation while reward power and legitimate power had negative moderating effects. Finally, we discuss the theoretical and practical implications of these findings.     

离线梗丝分离技术在PROTOS70中的应用

为解决PROTOS70卷接机组仅有一级、二级风选装置,存在梗丝分离不彻底的问题,参照PROTOS-M5卷接机组梗丝分离技术,在PROTOS70卷接机组加装离线梗丝分离装置中,增加了烟梗和烟丝垂直提升的距离,形成“之”字形风选通道,实现梗丝分离.使用离线梗丝分离后,减少了成品烟支丝中含梗缺陷频次,降低了梗中含丝率,单班可节约烟丝10～ 15 kg,该装置梗丝分离彻底,使用效果明显.     

Imperceptible digital watermarking scheme combining 4-level discrete wavelet transform with singular value decomposition

An imperceptible digital watermarking algorithm based on 4-level discrete wavelet transform, discrete cosine transform and singular value decomposition is designed. In this method, the 4-level diagonal sub-band image is obtained by performing the 4-level two-dimensional wavelet transform on the original image, and then a coefficient matrix is produced by applying the discrete cosine transform on the 4-level diagonal sub-band image. A diagonal matrix is constructed by performing the singular value decomposition on the coefficient matrix. The watermark is scrambled by Arnold transform and Logistic map, then the scrambled watermark is processed by the singular value decomposition. Later, the encryption process is completed by embedding the scrambled watermark singular value into the singular value of the coefficient matrix. Simulation results demonstrate that the proposed digital watermarking algorithm could resist JPEG compression attack, Salt and Pepper noise attack, Gaussian noise attack, filter attack, brightness change attack, geometric attack, cut attack, etc.

     

一种基于模糊自动机的目标识别方法

为更好地识别目标,提出一种基于模糊自动机的目标识别系统.该系统先对图像进行处理,然后对目标识别.系统包括图像预处理、特征提取、目标匹配和实验4个部分.与现有的其它方法相比,本文方法利用目标图像的全局特征和局部特征,并运用模糊自动机进行目标识别.仿真结果表明,基于模糊自动机的目标识别效果比现有其它识别方法的识别效果要好,其正确识别率高达94.59%.     

Chromium Supported on Mesocellular Silica Foam (MCF) for Oxidative Dehydrogenation of Propane

A series of chromium-containing mesocellular silica foam (MCF) catalysts have been prepared and characterized in the oxidative dehydrogenation (ODH) of propane between 350 and 600 °C. It is demonstrated that the chromium catalysts supported on MCF exhibit much higher catalytic activity in terms of propane conversion and propylene yield than literature results obtained over chromium-supported mesoporous SBA-15 or MCM-41 catalysts during the ODH of propane. Enhanced catalytic performance of the chromium-containing mesoporous MCF catalysts has been attributed to the unique three-dimensional (3D), continuous, ultralarge mesopore structure of the MCF materials, which allow a much faster internal molecular transport during the ODH of propane.     

无线Ad Hoc网络QoS路由协议研究的进展与展望

无线ad hoc网络是一种无固定通信设备支持、节点可自由移动的多跳全分布式无线网络。无线ad hoc网络的应用环境以及与Internet的互连要求它必须提供一定的服务质量(QoS)保证，而QoS路由协议是无线ad hoc网络支持QoS的一个关键理论和技术，也是目前的一个研究热点。本文回顾了近年来国内外在无线ad hoc网络QoS路由协议研究方面取得的研究成果，对已有的无线ad hoc网络的QoS路由协议进行了分类．并对它们作了较全面的概括。总结和深入的比较分析，系统阐述了在无线ad hoc网络中实现QoS路由协议时需要考虑的因素，指出了亟待解决的问题和今后的研究方向。     

持载下外贴纤维布加固RC梁抗弯性能研究基于物理的实时人体动画

为了考察持续荷载作用下外贴碳纤维布(CFRP)对梁的抗弯性能的影响,进行了16根外贴CFRP加固的钢筋混凝土(RC)梁和2根对比梁的抗弯试验.试验参数为:纵筋配筋率、CFRP加固量、持载点.并对构件的各特征点的荷载、承载力及各受力阶段的刚度进行了详细的分析.试验及分析结果表明,采用CFRP加固的钢筋混凝土梁的刚度较普通钢筋混凝土梁的刚度都有明显提高,纤维布对承受以抗弯为主的构件具有增强刚度、控制挠度的作用;纤维加固时梁所承受的荷载大小,即加固时梁内已存在的弯曲裂缝的宽度对梁的屈服荷载及极限承载力影响不是很大,但对梁的刚度有较大影响,特别是对屈服阶段的刚度影响较大.其试验及分析结果对相应规范的编制及工程应用具有较高的参考价值.     

溶胶-凝胶法制备抗原子氧涂层及性质研究

采用有机无机复合的溶胶-凝胶方法,合成了用于聚合物表面保护层的前驱溶液.采用旋转涂覆方法,将前驱溶液涂覆于聚酰亚胺基片上,制成了表面涂层.将所制得的相应涂层分别进行原子氧暴露试验,其表面形貌的变化通过扫描电镜观测.结果表明,在原子氧辐照下,无保护的聚酰亚胺表面已非常粗糙,与辐照前的光滑表面形成显著的对比.而涂覆有保护层的表面,原子氧辐照前后却没有变化.这表明使用这种有机无机复合的溶液涂层具有很好的抗原子氧能力.     

非淋菌性泌尿生殖道感染患者支原体培养及药敏分析

目的 了解非淋菌性泌尿生殖道感染患者解脲(Uu) 和人型支原体(Mh) 感染及耐药情况, 以指导临床合理用药。 方法 采用支原体培养、鉴定、药敏一体化试剂盒对472 例非淋菌性尿道炎(NGU) 患者进行支原体培养及药敏试验。 结果 472 例中阳性153 例, 感染率为32.42 %。其中Uu 阳性112 例(23.73 %), Mh 阳性11 例(2.33 %), 混合感染30 例(6.36 %), 女性感染率显著高于男性(χ²=4.157, P<0.05)。支原体敏感性最高的是强力霉素、美满霉素(96.1 %、94.8 %), 耐药率最高的是乙酰螺旋霉素、红霉素(69.3 %、60.1 %)。 结论 支原体在体外对多种抗菌药物耐药现象严重, 治疗宜首选强力霉素、美满霉素或交沙霉素。