Molecular and Physiological Responses of Citrus sinensis Leaves to Long-Term Low pH Revealed by RNA-Seq Integrated with Targeted Metabolomics

Low pH-induced alterations in gene expression profiles and organic acids (OA) and free amino acid (FAA) abundances were investigated in sweet orange [Citrus sinensis (L.) Osbeck cv. Xuegan] leaves. We identified 503 downregulated and 349 upregulated genes in low pH-treated leaves. Further analysis indicated that low pH impaired light reaction and carbon fixation in photosynthetic organisms, thereby lowering photosynthesis in leaves. Low pH reduced carbon and carbohydrate metabolisms, OA biosynthesis and ATP production in leaves. Low pH downregulated the biosynthesis of nitrogen compounds, proteins, and FAAs in leaves, which might be conducive to maintaining energy homeostasis during ATP deprivation. Low pH-treated leaves displayed some adaptive responses to phosphate starvation, including phosphate recycling, lipid remodeling, and phosphate transport, thus enhancing leaf acid-tolerance. Low pH upregulated the expression of some reactive oxygen species (ROS) and aldehyde detoxifying enzyme (peroxidase and superoxidase) genes and the concentrations of some antioxidants (L-tryptophan, L-proline, nicotinic acid, pantothenic acid, and pyroglutamic acid), but it impaired the pentose phosphate pathway and V_E and secondary metabolite biosynthesis and downregulated the expression of some ROS and aldehyde detoxifying enzyme (ascorbate peroxidase, aldo-keto reductase, and 2-alkenal reductase) genes and the concentrations of some antioxidants (pyridoxine and γ-aminobutyric acid), thus disturbing the balance between production and detoxification of ROS and aldehydes and causing oxidative damage to leaves.     

我国有机食品的现状及发展趋势

介绍了有机食品的特点及对人与自然和谐发展的作用,并概述了我国有机食品的发展现状及趋势.     

Large-scale graphene transistors with enhanced performance and reliability based on interface engineering by phenylsilane self-assembled monolayers

In this letter, we report the dielectric/graphene interface physics and engineering of large-scale, chemical vapor deposited (CVD) graphene transistors by self-assembling a molecular-scale organosilane monolayer onto the dielectric surface. We show that phenyl-alkyl-terminated self-assembled monolayers (SAM) at the dielectric/graphene interface consistently improve the graphene device performance and reliability. The extrinsic field-effect mobility of large-scale CVD graphene transistors on the phenyl-SAM engineered dielectric is currently up to 2500 cm(2)/(V s) at room temperature, considerably higher than the counterparts without the SAM. In addition, significant reduction on the bias stress instability and hysteresis is achieved by the SAM-based interface engineering. Further analysis reveals that charge injection from graphene to the dielectric/graphene interface dominates the observed hysteresis behavior. For both graphene transistors with and without SAMs, the bias stress stability, that is, Dirac point shift under bias stress, is well described by the stretched exponential model with its fitting parameters clearly indicating different interface properties.     

异相膜NIMTE在空气能量回收装置中使用效果试验研究

通过对国产纸膜和日本滤纸膜材料的分析研究,研制出NIMTE异相膜,并在空气能量回收装置使用过程中对风压、空气流量、热流方向与热交换效率、回收能量、能效及安全性的关系进行分析,设计出能够更好发挥异相膜使用效果的传热膜机芯,有效提高空气能量回收装置的综合性能。     

Synthesis and Physical Properties of Mn Doped ZnO Dilute Magnetic Semiconductor Nanostructures

Mn doped ZnO nanostructures have been prepared using low temperature simple, quick, and versatile synthesis approach. The structural, microstructural, and vibrational investigations reveal that as prepared nanostructures with low Mn doping concentration have single hexagonal phase and are grown along the preferred c-axis. The X-rays photoelectron spectroscopy demonstrates that the Mn ions are in mixed oxidation states for high doping concentration of Mn, while are in 2+ oxidation state for low concentration into ZnO lattice. The photoluminescence spectrum (PL) exhibits a significant red-shift of 22 nm in the optical band gap of doped ZnO and shows the improved luminescence properties, which makes it potential for its use in the photocatalyst, optoelectronics and solar cell nanodevices. Furthermore, the magnetic measurement of Mn doped ZnO nanostructures exhibits the ferromagnetism at room temperature.     

基于中间件规范的容侵应用服务器研究与实现

针对现有的容忍入侵应用系统的构建需要针对不同的业务类型进行不同的个性化设计和开发以及系统或部件的可重用性较差的问题,在研究基于规范的容忍入侵中间件方法的基础上,提出了一种基于拦截器的容侵中间件模型,从逻辑上将系统分为容忍入侵服务提供者和容忍入侵服务管理者,可在满足既有规范情况下实现用户应用的业务逻辑与容忍入侵特性所依赖的非功能性服务的分离。对涉及的容忍入侵框架、容忍入侵策略组件、安全群组通信管理器、安全群组通信系统等进行了详细设计,在一个开源的J2EE应用服务器JBoss中实现了对容忍入侵功能的支持,可利用Java类加载机制完成容忍入侵服务的动态加载。     

Annealing process of fine grained co-stabilised (Y,Mg)-PSZ/MgAl2O4 ceramics

Abstract

Co-stabilised (Y,Mg) partially stabilised zirconia (PSZ) ceramics with MgAl₂O₄ spinel additions were produced, with industrial zirconia as the main starting material. Powders were prepared using a mechanical milling–mixing process. The effect of the annealing process on the mechanical properties, phase compositions, and microstructure of fine grained PSZ ceramics was investigated.     

Energy transfer in and fluorescence studies of the Eu-Tb doped BPA-phen system

To enhance the red emission efficiency of Eu³⁺ complexes, [Eu/Tb_x(BPA)₃phen] (BPA?=?bisphenol A, phen?=?1,10-phenanthroline) is designed and synthesized. The complexes are characterized fully and their luminescence properties are evaluated. Co-fluorescence is detected in the Eu/Tb_x(BPA)₃phen complexes, and the existence of Tb³⁺ enhances the luminescence intensity of the central Eu³⁺ because of the intramolecular energy transfer from the ⁵D₄ level of Tb³⁺ to the ⁵D₀ level of Eu³⁺. The luminescence intensity of europium ions at 615?nm is the highest for Eu/Tb₁(BPA)₃phen. To improve the thermal stabilities and mechanical properties of pure complexes, Eu/Tb₁(BPA)₃phen/PAN (PAN?=?polyacrylonitrile) is used to fabricate fibres by electrospinning. Compared with Eu/Tb₁(BPA)₃phen (τ?=?1.1087?ms), the fibres have a longer fluorescence lifetime of 1.533?ms. The fibres also retain a high quantum yield of 47.16%. Thus, the flexible luminescent fibres have potential applications in many fields.     

Improved optical photoluminescence by charge compensation in the phosphor system CaMoO4:Eu

It has been found that charge compensated CaMoO₄:Eu³⁺ phosphors show greatly enhanced red emission under 393 and 467 nm-excitation, compared with CaMoO₄:Eu³⁺ without charge compensation. Two approaches to charge compensation, (a) 2Ca²⁺ → Eu³⁺ + M⁺, where M⁺ is a monovalent cation like Li⁺, Na⁺ and K⁺ acting as a charge compensator; (b) 3Ca²⁺ → 2Eu³⁺ + vacancy, are investigated. The influence of sintering temperature and Eu³⁺ concentration on the luminescent property of phosphor samples is also discussed.     

ZnCl2-assisted Synthesis of ZnSe Polycrystal

A chemical-assisted element direct-reaction method is developed to synthesize ZnSe compound semiconductor material at a relatively low temperature (～1000 C). ZnSe polycrystal was obtained in the closed-tube systems with Zn-Se, Zn-Se-Zn(NH3)2Cl2, Zn-Se-NH4Cl and Zn-Se-ZnCl2. The as-synthesized samples were tested by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and analyzed by thermodynamic numerical method. The results demonstrate that the synthesis efficiency is higher than 99.96% for Zn-Se-ZnCl2 system at around 1000 C for 3 weeks. It also exhibits that not only temperature, but also low apparent ratio of volume and surface area of the source materials and higher ZnCl2 content are required to achieve high synthesis efficiency. A SeCl transporting reaction synthesis process is proposed based on the thermodynamic analysis.