高感度辐射变色薄膜电子剂量计

 以聚乙烯醇缩聚物为基质,以类丁二炔化合物为有机染色材料,研制了一种高灵敏度新型辐射变色膜。采用JJ-2型范格拉夫静电加速器对变色薄膜进行剂量范围为15～90 Gy的电子束辐照,结果显示:变色薄膜颜色由粉红渐变为蓝色,并随着辐照剂量的增加而逐渐加深;分光光度计测试其吸收光谱,发现主吸收峰值出现在675 nm附近,且吸收峰处的响应吸光度与电子注量具有较好的线性关系;对变色层厚度为20～80 μm的变色膜,吸收峰处的响应吸光度与其变色层厚度也成线性关系;添加不同比例的协同剂,能提高变色薄膜的响应灵敏度;变色膜辐照后续效应微弱,辐照后可以立即测量,且对测量环境变化不敏感。     

Vibrational Spectra and Adsorption of Trisiloxane Superspreading Surfactant at Air/Water Interface Studied with Sum Frequency Generation Vibrational Spectroscopy

使用界面和频振动光谱(SFG-VS)测量了空气/水界面三甲基硅烷表面活性剂Silwet L-77的C-H伸缩振动光谱．这些光谱峰主要是在2905 cm-1附近属于-Si-CH3基团的对称伸缩(SS)振动,在2957 cm-1的主要是-Si-CH3基团反对称伸缩(AS)振动,以及明显较弱的在2880 cm-1附近的属于-O-CH2-基团的对称伸缩(SS)振动．通过比较低于和高于临界聚集或胶束浓度(CAC)的SFG-VS偏振光谱显示Silwet L-77分子的C-H基团取向在不同的界面密度下变化很小．SFG-VS测量的吸附等温线表明Silwet L-77分子在空气/水界面没有形成所谓的双层结构的迹象．Silwet L-77分子在空气/水界面的Gibbs吸附自由能为-42.2±0.8 kJ/mol,表明该分子具有很强的表面吸附能力．     

Inhibitory Effects of Cucurbitane-Type Triterpenoids from Momordica charantia Fruit on Lipopolysaccharide-Stimulated Pro-Inflammatory Cytokine Production in Bone Marrow-Derived Dendritic Cells

The bitter melon, Momordica charantia L., was once an important food and medicinal herb. Various studies have focused on the potential treatment of stomach disease with M. charantia and on its anti-diabetic properties. However, very little is known about the specific compounds responsible for its anti-inflammatory activities. In addition, the in vitro inhibitory effect of M. charantia on pro-inflammatory cytokine production by lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs) has not been reported. Phytochemical investigation of M. charantia fruit led to the isolation of 15 compounds (1−15). Their chemical structures were elucidated spectroscopically (one- and two-dimensional nuclear magnetic resonance) and with electrospray ionization mass spectrometry. The anti-inflammatory effects of the isolated compounds were evaluated by measuring the production of the pro-inflammatory cytokines interleukin IL-6, IL-12 p40, and tumor necrosis factor α (TNF-α) in LPS-stimulated BMDCs. The cucurbitanes were potent inhibitors of the cytokines TNF-α, IL-6, and IL-12 p40, indicating promising anti-inflammatory effects. Based on these studies and in silico simulations, we determined that the ligand likely docked in the receptors. These results suggest that cucurbitanes from M. charantia are potential candidates for treating inflammatory diseases.     

Purification,Crystallization, and Preliminary Crystallographic Studies of Human As(III) S-Adenosylmethionine Methyltransferase (hAS3MT)

Crystallography Reports - Exposure to environmental arsenic is associated with serious of health issues such as cancer, diabetes and developmental delays in infants and children. In human liver,...     

Enhanced thermal conductivity and mechanical properties of polymeric composites through formation of covalent bonds between boron nitride and rubber chains

Hexagonal boron nitride (BN) platelets, also known as white graphite, are often used to improve the thermal conductivities of polymeric matrices. Due to the poor interfacial compatibility between BN platelets and polymeric matrices, in this study, polyrhodanine (PRd) was used to modify BN platelets and prepared functionalized BN-PRd platelets, thereby enhancing the interfacial interaction between the thermal conductive filler and polymeric matrix. Then, BN-PRd platelets were dispersed into the nitrile butadiene rubber (NBR) matrix to yield high thermally conductive composites. The presence of N? C═S groups in PRd allowed the combination of PRd and NBR chains containing stable covalent bonds via vulcanization reaction. The thermal conductivity of the as-prepared 30 vol% BN-PRd/NBR composite reached 0.40 W/mK, representing an increment of 135% over pure NBR (0.17 W/mK). In addition, the largest tensile strength of NBR composite containing 30 vol% BN-PRd platelets was 880% times of pure NBR. The 30 vol% BN-PRd/NBR composite also displayed a relatively high dielectric constant (9.35 at 100 Hz) and a low dielectric loss tangent value (0.07 at 100 Hz), indicating their usefulness as dielectric flexible materials of microelectronics. In sum, the simplicity and good efficiency of formation of covalent bonds between boron nitride and rubber chains look very promising for large-scale industrial production of high thermally conductive composites.     

全局优化问题的一个新的无参数填充函数

求全局最优化问题的填充函数算法被提出以来，参数的选取和调整一直是制约算法有效性的因素。如何在实际的计算过程中选取合适的参数，直接影响和决定了运算速度和效率。因此，构造不含参数的填充函数就显得极为重要。提出一个新的无参数的填充函数，对其理论性质进行了分析，并给出相应的填充函数算法，数值计算验证了算法的有效性。     

Sections in functional equations: stability and hyperstability

Aequationes mathematicae - The section method provides a technique for solving certain functional equations with the help of their characteristic equations. We prove here that a large class of such...     

FeOOH@Metal–Organic Framework Core–Satellite Nanocomposites for the Serum Metabolic Fingerprinting of Gynecological Cancers

High-throughput metabolic analysis is of significance in diagnostics, while tedious sample pretreatment has largely hindered its clinic application. Herein, we designed FeOOH@ZIF-8 composites with enhanced ionization efficiency and size-exclusion effect for laser desorption/ionization mass spectrometry (LDI-MS)-based metabolic diagnosis of gynecological cancers. The FeOOH@ZIF-8-assisted LDI-MS achieved rapid, sensitive, and selective metabolic fingerprints of the native serum without any enrichment or purification. Further analysis of extracted serum metabolic fingerprints successfully discriminated patients with gynecological cancers (GCs) from healthy controls and also differentiated three major subtypes of GCs. Given the low cost, high-throughput, and easy operation, our approach brings a new dimension to disease analysis and classification.     

Shifted convolution sums of Fourier coefficients with squarefull kernel functions

Lithuanian Mathematical Journal - Let f(z) be a primitive holomorphic cusp form of even integral weight k for the full modular group. Denote its nth normalized Fourier coefficient (Hecke...     

有耗介质层上多导体传输线的电磁耦合时域分析方法

目前,针对空间电磁场作用有耗介质层上传输线的电磁耦合,仍缺乏有效的数值分析方法.因此,本文提出一种高效的时域混合算法,很好地解决了有耗介质层上传输线电磁耦合建模难的问题.首先,对经典传输线方程进行改进,推导了适用于有耗介质层上多导体传输线电磁耦合分析的修正传输线方程.然后,结合时域有限差分方法和相应插值技术,求解修正传输线方程,获得多导线及其端接负载上的电压和电流响应,并实现空间电磁场辐射与多导线瞬态响应的同步计算.最后,通过相应计算实例的数值模拟,与CST软件的仿真结果进行对比,验证了时域混合算法的正确性和高效性.