A multilayer recognition model for twitter user geolocation

Wireless Networks - Geolocation is important for many emerging applications such as disaster management and recommendation system. In this paper, we propose a multilayer recognition model (MRM) to...     

Memory effect of reversibly thermoswitchable self-assembly-competent recombinant TMV coat protein with multi-binding moieties with potential applications in nanoparticle purification

Biomolecule-mediated assembly of novel nanoconjugates has been subjected to numerous investigations nowadays, which provides a new insight into the material science and engineering. Via the molecular biology technology, the genetically engineered polypeptide for inorganics (GEPI) can be designed as a molecular binder into the bio-scaffold to assemble hybrid functional nanoarchitectures. In the present work, we constructed a multi-functional virus-like particle (VLP) scaffold based on the Tobacco mosaic virus (TMV) (wild-type strain U1) in a facile way. The S123C site-mutated coat protein (CP) of TMV recombinated with a Ti–GEPI and 6-histidine tag (His tag) was successfully cloned, expressed and purified. The as-produced r-CP products retained both binding affinity for inorganic nanoparticles and self-assembly capability. Analysis of r-CP self-assembly during condensation polymerization was conducted. The r-CP-assembled aggregates including disc-like structures and rod-like VLPs were recovered by preparative size-exclusion chromatography (SEC) and then examined by TEM analysis. Notably, r-CP protein displayed a thermo-triggered reversibly switchable transition between bistable states of transparency and opaqueness. Western blot analysis, Immunogold labelling and TEM analysis were employed to test the existence and binding function of the His tag group in r-CP VLPs. Furthermore, dispersion of TiO₂ NPs in r-CP solution and recyclable application in bio-benefication was introduced. Here we demonstrated the possibilities of combining peptide-mediated immobilization with VLP-based biotemplate bearing multi-binding moieties for prospectful functional applications.     

钢筋混凝土钻孔咬合桩的施工实践及方法介绍

某工程基坑围护结构采用钢筋混凝土钻孔咬合桩,桩径Ф100cm,桩中心距80cm,桩长21-31m,咬合厚度20cm。本文介绍该钻孔咬合桩的施工方法与质量安全措施,并简述施工中出现的问题及采取的措施。     

“中国建筑研究室”初创及研究成果探究

本文以"中国建筑研究室"从1953年4月正式成立到1964年研究室被迫撤销,隶属关系数度变更的历史始末为线索,结合档案文献与人物访谈,特别记述了"中国建筑研究室"初创时期的历史史实。及在刘敦桢的领导下"中国建筑研究室"的调研发现和重要学术研究成果。真实再现了"中国建筑研究室"的历史,阐释其对中国建筑历史理论研究的影响和贡献。     

仙人掌多糖中单糖组成的气相色谱分析

从仙人掌茎中提取多糖,并采用SuperdexTM200、SaphacrylS-100HR、Sephadex G-100凝胶柱层析法分离得到2个多糖组分(OPS Ⅰ和OPSⅡ),它们均为化学均一物质;用气相色谱法分析仙人掌多糖OPS Ⅰ和OPSⅡ的单糖组成,结果表明OPSⅠ主要由鼠李糖、葡萄糖和半乳糖组成;OPSⅡ主要由岩藻糖、木糖和葡萄糖组成.     

基于机器学习的密集烘烤过程烟叶失水率预测模型对比

为准确预测密集烘烤过程烟叶失水率,以精准调控烘烤工艺参数,基于机器学习建立烟叶失水率预测模型。以翠碧一号中部叶为材料,实时采集烘烤过程中烟叶图像和失水率; 利用图像处理技术提取烟叶的10种颜色特征和10种纹理特征,通过变量聚类和皮尔逊相关性分析优选出2种颜色特征(a*/b*、R)和2种纹理特征(梯度熵、梯度分布不均匀性); 将训练集图像的4种优选特征和烟叶失水率作为输入变量,分别对建立的网格式支持向量机(GS-SVM)、遗传算法优化的BP神经网络(GA-BP)、极限学习机(ELM)3种预测模型进行训练。利用3种预测模型对测试集图像进行烟叶失水率预测并与实际失水率比较。结果表明,3种预测模型均能够较为准确地预测密集烘烤过程烟叶失水率(均方根误差RMSE≤0.014 0,决定系数R2≥0.996 1),对变黄期(0~40 h)和定色期(40~100 h)的预测误差小于干筋期(100~140 h)。该技术可为烟叶烘烤智能调控系统的研发提供支持。      

发酵乳清饮品的研究

选用保加利亚乳杆菌和嗜热链球菌,对乳清进行发酵,开发具有生物活性的乳清饮品。通过对乳清蛋白主要成分及理化特性的分析、杆菌球菌比例、稳定剂选择和保质期试验以及正交实验,确定了乳清发酵的优化工艺条件为:GA和CMC混合协同增效的最佳比例为1:3。发酵温度42℃、接种量3%、发酵终点750T,杆菌球菌的最适比例为1～2:1,0～6℃冷藏保质期可达20d以上。     

Theoretical analysis and experimental study on breakaway torque of large-diameter magnetic liquid seal at low temperature

The existing researches of the magnetic liquid rotation seal have been mainly oriented to the seal at normal temperature and the seal with the smaller shaft diameter less than 100 mm. However, the large-diameter magnetic liquid rotation seal at low temperature has not been reported both in theory and in application up to now. A key factor restricting the application of the large-diameter magnetic liquid rotation seal at low temperature is the high breakaway torque. In this paper, the factors that influence the breakaway torque including the number of seal stages, the injected quantity of magnetic liquid and the standing time at normal temperature are studied. Two kinds of magnetic liquid with variable content of large particles are prepared first, and a seal feedthrough with 140 mm shaft diameter is used in the experiments. All experiments are carried out in a low temperature chamber with a temperature range from 200℃ to -100℃. Different numbers of seal stages are tested under the same condition to study the relation between the breakaway torque and the number of seal stages. Variable quantity of magnetic liquid is injected in the seal gap to get the relation curve of the breakaway torque and the injecting quantity of magnetic liquid. In the experiment for studying the relation between the breakaway torque and the standing time at the normal temperature, the seal feedtrough is laid at normal temperature for different period of time before it is put in the low temperature chamber. The experimental results show that the breakaway torque is proportional to the number of seal stages, the injected quantity of magnetic liquid and the standing time at the normal temperature. Meanwhile, the experimental results are analyzed and the torque formula of magnetic liquid rotation seal at low temperature is deduced from the Navier-Stokes equation on the base of the model of magnetic liquid rotation seal. The presented research can make wider application of the magnetic liquid seal in general. And the large-diameter magneti     

琥珀酰亚胺酯基类偶氮染料的制备及其超临界CO2羊毛清洁化染色

以对氨基苯甲酸和4-氨基-2-氯苯甲酸、苯胺和间甲苯胺为原料,采用重氮偶合反应制备染料前驱体,通过在前驱体上引入琥珀酰亚胺酯获得4例活性分散染料Ⅰ～Ⅳ.对染料的紫外-可见吸收光谱、光热稳定性、超临界二氧化碳(scCO2)中羊毛纤维的染色工艺等进行了测试.结果表明,4例染料均具有良好的光热稳定性,染料Ⅰ、Ⅲ和Ⅳ最大吸收波长集中在360～370 nm,染料Ⅱ的最大吸收波长红移到379～452 nm,染料均具备scCO2染色的条件.染料Ⅰ和Ⅲ的最佳染色条件为2 h、80℃和15 MPa,染料Ⅱ的最佳染色条件为1.5 h、80℃和15 MPa,染料Ⅳ的最佳染色条件为2 h、80℃和24 MPa.染色后的羊毛纤维的耐皂洗和耐光色牢度都可达4～5级,固色率最高可达86％,相比于未活化的前驱体,耐皂洗色牢度能提高2～3级,固色率最高能提升63％.SEM和显微镜成像证明4例染料具有良好的透染性,且能均匀附着于纤维的表面和内部.力学性能测试表明,染色后的羊毛纤维能基本保持原有的力学性能.     

峰谷电价体制下原油管道输油方案优化研究

以日东原油管道为例,建立了峰谷分时电价体制下各输油站泵机组优化运行时动力耗电的数学模型,考虑了流态、摩阻、高程及油品黏度对计算结果的影响,在保证日输油计划的情况下,求解了平均输量和分时段调整输量下的最少泵送动力耗电费用,得到最优配泵和输油方案。计算结果表明,当日输量处于某一适中范围时,利用峰谷电价体制调整管道输油方案,具有一定的优化运行降低能耗成本的潜力。同时,因日东线采用在线掺混输送工艺,通过分析对比输送不同掺混比例油品的单位能耗,表明不同掺混黏度的油品节能效果不同,对日东原油管道掺混输送具有一定的理论参考意义。