Rational Electronic and Structural Designs Advance BiCuSeO Thermoelectrics

In this work, a record high thermoelectric figure-of-merit ZT of 1.6 ± 0.2 at 873 K in p-type polycrystalline Bi_0.94Pb_0.06CuSe_1.01O_0.99 by a synergy of rational band manipulation and novel nanostructural design is reported. First-principles density functional theory calculation results indicate that the density of state at the Fermi level that crosses the valence band can be significantly reduced and the measured optical bandgap can be enlarged from 0.70 to 0.74 eV by simply replacing 1% O with 1% Se, both indicating a potentially reduced carrier concentration and in turn, an improved carrier mobility and a boosted power factor up to 9.0 µW cm⁻¹ K⁻². Meanwhile, comprehensive characterizations reveal that under Se-rich condition, Cu₂Se secondary microphases and significant lattice distortions triggered by Pb-doping and Se-substitution can be simultaneously achieved, contributing to a reduced lattice thermal conductivity of 0.4 W m⁻¹ K⁻¹. Furthermore, a unique shear exfoliation technique enables an effective grain refinement with higher anisotropy of the polycrystalline pellet, leading to a further improved power factor up to 10.9 µW cm⁻¹ K⁻² and a further reduced lattice thermal conductivity of 0.30 W m⁻¹ K⁻¹, which gives rise to record high ZT.     

Multifunctional picoliter droplet manipulation platform and its application in single cell analysis

We developed an automated and multifunctional microfluidic platform based on DropLab to perform flexible generation and complex manipulations of picoliter-scale droplets. Multiple manipulations including precise droplet generation, sequential reagent merging, and multistep solid-phase extraction for picoliter-scale droplets could be achieved in the present platform. The system precision in generating picoliter-scale droplets was significantly improved by minimizing the thermo-induced fluctuation of flow rate. A novel droplet fusion technique based on the difference of droplet interfacial tensions was developed without the need of special microchannel networks or external devices. It enabled sequential addition of reagents to droplets on demand for multistep reactions. We also developed an effective picoliter-scale droplet splitting technique with magnetic actuation. The difficulty in phase separation of magnetic beads from picoliter-scale droplets due to the high interfacial tension was overcome using ferromagnetic particles to carry the magnetic beads to pass through the phase interface. With this technique, multistep solid-phase extraction was achieved among picoliter-scale droplets. The present platform had the ability to perform complex multistep manipulations to picoliter-scale droplets, which is particularly required for single cell analysis. Its utility and potentials in single cell analysis were preliminarily demonstrated in achieving high-efficiency single-cell encapsulation, enzyme activity assay at the single cell level, and especially, single cell DNA purification based on solid-phase extraction.     

Encapsulation of Nanoparticles Using Nitrilotriacetic Acid End‐Functionalized Polystyrenes and Their Application for the Separation of Proteins

The use of nitrilotriacetic acid end‐functionalized polystyrenes (NTA‐PS) as a multifunctional nanocarrier for the aqueous dispersion of CdSe, γ‐Fe₂O₃ and gold nanoparticles (NPs) is described. When the amphiphilic end‐ functionalized polystyrenes and NPs are dissolved together in tetrahydrofuran, the addition of water causes the spontaneous formation of micellar aggregates, resulting in the successful encapsulation and aqueous dispersion of NPs. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy, and vibrating sample magnetometer (VSM) are used to characterize the structure and properties of the NPs‐containing micellar aggregates (nanocarrier). After complexation of Ni²⁺ with NTA on the surface of the nanocarrier containing γ‐Fe₂O₃, specific binding between Ni‐NTA complex and histidine‐tagged (His‐tagged) proteins enables selective separation of His‐tagged proteins using a magnet.     

FCM燃料堆内行为模拟及结构设计研究

本文采用二维特征模型模拟不同无燃料区厚度全陶瓷微封装弥散(FCM)燃料的热力学行为,在保证堆芯装载要求的条件下,研究不同结构FCM燃料SiC基体和包覆燃料颗粒SiC层的应力状态。通过优化无燃料区厚度,调整TRISO颗粒间的间距,保证无燃料区和SiC层同时具有较低的应力水平。分析了无燃料区厚度为100～500μm时基体SiC、无燃料区以及SiC层的应力分布,结果表明,基体SiC和SiC层最大应力随无燃料区厚度增大而增大,而无燃料区的最大应力则随其厚度增大而降低。当无燃料区厚度为400μm时,无燃料区和SiC层均处于较低的应力状态,无燃料区SiC基体应力约为400 MPa,而SiC层的最大环向应力约为200MPa,其失效概率约为2.5×10-4。因此,当无燃料区厚度为400μm时,FCM燃料既能维持芯块结构完整,又能保证SiC层具有较低的失效概率。结构优化为FCM燃料的应用提供了基础。     

快速心肌显像剂^99mTc—TEBO的标记和动物体内分布实验

报道了用＾９９ｍＴｃ标记Ｔｅｂｏｒｏｘｉｍｅ（简称ＴＥＢＯ），并在标记后对其质量进行了鉴定。结果表明，其物理性质、化学性质及生物学性质均符合国家制定的放射性药物的质量标准；动物实验表明，小鼠注射量为成人用量的１００倍、观察１５天后，实验组和对照组无差别；注入量为０．１ｍｌ（２０７．２Ｂｑ／只），２ｍｉｎ后心肌摄取达峰值１７．７５±０．３３％（ｇ ｏｒｇａｎ）＾－１；心肌清除也快，１５ｍｉｎ已清除至     

镭厂退役废物分类与处理处置

由于镭厂退役废物的多样性,多必须适当分类后才能分别进行处理处置。利用现有条件,将含镭低放废物进行废铀矿井处置是合理,安全和经济的。     

A rapid measurement of rutin-degrading enzyme activity in extract of tartary buckwheat seeds

In order to measure rutin-degrading enzyme activity conveniently, we have developed an isoabsorptive spectrophotometric method (ISM) for rapidly monitoring rutin-degrading enzyme (RDE) activity in extract of tartary buckwheat seeds. This technique uses discrepancy in absorbency at 372 nm and 344.5 nm, both of which are isoabsorptive wavelengths of rutin, that allow for calculations of quercetin concentrations, which is the only product of the reaction catalyzed by RDE. With this method, extracts containing RDE from buckwheat seeds were analyzed, and the measured data indicated that the sample contained quercetin concentration of 9.909 μg/ml, 8.04 times and 18.08 times greater than negative control (1.232 μg/ml) and positive control (0.548 μg/ml), respectively. ISM results of measuring rutin-degrading enzyme activity in tartary buckwheat seeds correlate with those of HPLC. However, it is beneficial to HPLC as it presents a more convenient and rapid method.     

滤板施工技术比较

滤板是水处理滤池工艺的重要组成单元,文章对预制滤板和整体现场浇筑滤板的施工技术进行了比较说明,并得出了滤板施工技术选型结论。     

Stabilization of the Single-Chain Fragment Variable by an Interdomain Disulfide Bond and Its Effect on Antibody Affinity

The interdomain instability of single-chain fragment variable (scFv) might result in intermolecular aggregation and loss of function. In the present study, we stabilized H4—an anti-aflatoxin B₁ (AFB₁) scFv—with an interdomain disulfide bond and studied the effect of the disulfide bond on antibody affinity. With homology modeling and molecular docking, we designed a scFv containing an interdomain disulfide bond between the residues H44 and L100. The stability of scFv (H4) increased from a GdnHCl₅₀ of 2.4 M to 4.2 M after addition of the H44-L100 disulfide bond. Size exclusion chromatography revealed that the scFv (H44-L100) mutant existed primarily as a monomer, and no aggregates were detected. An affinity assay indicated that scFv (H4) and the scFv (H44-L100) mutant had similar IC₅₀ values and affinity to AFB₁. Our results indicate that interdomain disulfide bonds could stabilize scFv without affecting affinity.