Characteristics of pigments,modification, and their functionalities

Novel treatments of pigments with inorganic materials have tremendous industrial and commercial prospects. Specific treatment of pigment has a marked effect on its behavior during application. The treatment allows a broad modification of the surface characteristics of pigment particles which leads to improved functionalities. Surface modification of pigments is achieved via coating, polymerization with modifying reagent, treatment with derivatives or polymers, which alter either the optical, conductivity or dispersibility during processing and application. These and many other distinguishing factors that affect the characteristics of pigments such as the class, crystal structure, particle morphology, particle size, hiding power, pigment volume concentration, surface character, and surface treatment have been reviewed. Various organic pigments such as those from fungus and bacteria, and the various families of pigment types such as metallic pigment, light interference, and diffractive pigments which presents decorative quality such as leafing, nonleafing, pearlscent, and Fabry‐Perot effects on substrates have also been reviewed in addition to those from inorganic sources with emphasis on the structure and physiochemical modifications using metal and nonmetal Ions.     

α径迹法用于分辨高浓铀和Pu微粒的方法研究

擦拭样品微粒分析技术是核保障环境样品分析的一种主要手段，从大量灰尘颗粒中识别并定位含高浓铀（HEU）或含Pu微粒是微粒分析首先需要解决的问题。本文以HEU和Pu微粒为研究对象，建立了用于微粒α径迹测量的样品制备方法，采用CR-39固体径迹探测器为α径迹探测器，测量了不同蚀刻时间2种微粒产生的α径迹星的径迹参数。结果表明：可通过测量径迹短轴与曲率直径并作图来分辨HEU和Pu微粒，该方法对于蚀刻时间大于10 h的微粒径迹星，均能明显分辨，对于径迹非常密集的径迹星，也能准确分辨。     

Precisely Controlled Microsphere Design via Visible‐Light Cross‐Linking of Functional Prepolymers

A new strategy for particle synthesis is enabled by utilizing modern synthetic, polymer, and photochemical techniques to facilitate the synthesis of highly narrow–disperse multifunctional microspheres from visible‐light induced crosslinking of prepolymers in both a single and dual polymer system. The approach requires no stabilizers, bases, or initiators, and proceeds at ambient temperature to yield microspheres with a tunable size range (0.25–5 µm) in less than 4 h, depending largely on solvent composition, but also polymer concentration (2–10 mg mL^?1), ratio, and irradiation intensity (3–20 W). Critically, the visible‐light induced dimerization reaction exploited herein enables simple functional particle syntheses via a single polymer system. Underpinned by an in‐depth kinetic analysis of the particle formation as well as a detailed small molecule study, the mechanism for particle formation is also elucidated. Importantly, inherent advantages of the system are exploited for surface functionalization of residual acrylate and hydroxyl groups (generating inherently fluorescent particles).     

石英砂粒径大小对甲烷水合物形成及分布的影响

为了研究不同粒径多孔介质体系中甲烷水合物的形成，本文采用粒径分别为0.075~0.5mm、0.5~1mm、1~2mm和2~3mm的石英砂作为多孔介质，在初始压力7.0MPa、温度0.5℃条件下进行水合物形成实验并进行取样观察、分层分解，得出不同粒径大小石英砂中甲烷水合物形成及分布的特征。结果表明：随着石英砂粒径的增大，石英砂砂体中的水合物形成量和初始水合物形成速率在逐渐减小；在粒径为0.075~0.5mm、1~2mm和2~3mm石英砂中，充气过程中水合物便开始形成，且并未出现明显的水合物大量形成阶段，而在粒径为0.5~1mm石英砂体系中出现了水合物大量形成的阶段；通过计算发现，0.5~1mm石英砂体系的气体消耗量最大，为0.47mol，2~3mm石英砂体系的气体消耗量最小，仅为0.05mol；在这4种粒径的石英砂体表面的甲烷水合物主要以分散状均匀分布于颗粒之间或胶结成块，但这一观察结果与通过分解的方法所得到的石英砂上部水合物形成量大于下部的结果存在差异；重复实验也发现，仅在粒径为0.5~1mm石英砂顶部出现了水合物大量富集的现象，因此推断认为在一定粒径的介质体系同时上部存在较大空隙时，水合物有可能会在空隙中大量富集存在。这一实验结果对自然环境中水合物的赋存区域及形态的预测具有一定的参考价值。     

尘埃粒子计数器校准结果及其应用探讨

本文对尘埃粒子计数器粒子浓度示值误差校准结果的计算进行了讨论,并以制药行业中尘埃粒子计数器的使用为例对尘埃粒子计数器校准结果的应用进行了探讨。     

Silica-supported carboxylated cellulose nanofibers for effective lysozyme adsorption: Effect of macropore size

Engineering hierarchical macro/mesoporous structures that offer an abundance of accessible binding sites are highly desirable in protein adsorption processes. However, numerous significant challenges remain. Herein, cellulose nanofiber (CNF)-loaded macroporous silica (CNF-MPS) particles were successfully synthesized with a high degree of accessible binding sites by tuning the macropore size of the silica particles and loading a highly carboxylated CNF via smart and rational design. The as-prepared CNF-MPS particles exhibited a high negative charge (~−59 mV) and excellent protein adsorption ability (>1000 mg/g) in <5 min. Furthermore, tuning the macropore size influenced the CNF deposition either to the external surface or penetrating within the pores. As a result, the optimum macropore successfully enhances the adsorption capability to >1500 mg/g as a result of improved interconnectivity between the channels. Here exposed macropores of >100 nm allows ingress of protein to the interior structure that houses an abundance of binding sites comprising the dispersed CNF. Additionally, the adsorption kinetics, thermodynamics, and isothermal parameters were studied to analyze the mechanism of lysozyme adsorption. The adsorption process is confirmed to occur spontaneously at any temperature with a pseudo-second-order model describing the kinetic model, and CNF deposition affecting the heterogeneity of the binding sites.     

HVOF喷涂WC-12Co粒子沉积行为分析

目的 研究不同超音速火焰喷涂条件下WC-12Co粒子在45^#碳钢基体上的沉积变形行为。方法 基于Johnson-Cook塑性材料模型与Thermal-Isotropy-Phase-Change热材料模型，采用LS-DYNA进行建模分析。结果 不同喷涂参数下，WC-12Co粒子在45^#碳钢基体上的沉积行为存在明显差异。沉积过程中，粒子等效塑性应变幅度高于基体;粒子边缘位置等效塑性应变幅度高于粒子中心轴线位置;粒子初始速度与初始温度的增加有助于提升结合界面温度与粒子扁平化程度;粒子初始温度与粒子初始速度对接触界面能量变化影响程度基本一致，单位粒子初始速度与温度提升的能量贡献比 分别为0.78以及0.76，二者的能量贡献比近似相同;适度的基体预热( =500 K)可以促进粒子变形，加深沉积坑深度，增大粒子与基体的结合面积，有助于提升粒子与基体之间的结合强度。基体过冷( =300 K)将导致粒子“翘曲”，降低粒子与基体之间的结合面积，基体过热( =600 K)将导致二者结合处于不稳定状态，易引起粒子剥落，二者均不利于粒子与基体的有效结合。结论 一定范围内提升粒子初始速度、温度与基体初始温度，可以提高粒子扁平化程度，增大粒子与基体结合面积，提升粒子与基体的结合性能，进一步提高涂层质量。     

有砟轨道路基翻浆冒泥模型试验系统的研发与应用

为研究既有线有砟轨道路基的翻浆冒泥机理，自主研发了一套能够模拟循环荷载–湿化耦合作用的模型试验系统。模型试样直径500 mm，由厚度分别为350 mm的路基土和200 mm的道砟组成，整个试样在高强度透明有机玻璃模型筒中制备完成。模型试验系统配备有监测荷载、位移、体积含水率和孔隙水压力的4种传感器，并通过高清相机对颗粒迁移过程进行图像捕捉。基于所研发的试验系统，针对辛泰铁路典型翻浆冒泥病害路段土样，开展翻浆冒泥模型试验。试验结果表明：动孔隙水压力是导致翻浆冒泥病害产生的关键因素。随着体积含水率的增加，动孔隙水压力引起的颗粒迁移量逐渐增加；在饱和状态下，会引起大量颗粒迁移，翻浆冒泥现象显著。试验结束时，道砟污染指数达到25%，在实际工程中已严重影响铁路的正常运营，有必要对污染道砟进行换填。