An Exploration of the Effect of the Kleier Model and Carrier-Mediated Theory to Design Phloem-Mobile Pesticides Based on Researching the N-Alkylated Derivatives of Phenazine-1-Carboxylic Acid-Glycine

The Kleier model and Carrier-mediated theory are effective for molecularly designing pesticides with phloem mobility. However, the single Kleier model or Carrier-mediated theory cannot achieve a reliable explanation of the phloem mobility of all exogenous substances. A detailed investigation of the two models and the scope of their applications can provide a more accurate and highly efficient basis for the guidance of the design and development of phloem-mobile pesticides. In the present paper, a strategy using active ingredient-amino acid conjugates as mode compounds is developed based on Carrier-mediated theory. An N-alkylated amino acid is used to improve the pesticide’s physicochemical properties following the Kleier model, thus allowing the conjugates to fall on the predicted and more accessible transportation region of phloem. Moreover, the influence of this movement on phloem is inspected by the Kleier model and Carrier-mediated theory. To verify this strategy, a series of N-alkylated phenazine-1-carboxylic acid-glycine compounds (PCA-Gly) were designed and synthesized. The results related to the castor bean seeds (R. communis L.) indicated that all the target compounds (4a–4f) had phloem mobility. The capacity for phloem mobility shows that N-alkylated glycine containing small substituents can significantly improve PCA phloem mobility, such as 4c(i-C₃H₇-N) > 4a(CH₃-N) ≈ 4b(C₂H₅-N) > 4d (t-C₄H₉-N) > PCA-Gly > 4e(C₆H₅-N) > 4f(CH₂COOH-N), with an oil–water partition coefficient between 1.2~2.5. In particular, compounds 4a(CH₃-N), 4b(C₂H₅-N), and 4c(i-C₃H₇-N) present better phloem mobility, with the average concentrations in phloem sap of 14.62 μΜ, 13.98 μΜ, and 17.63 μΜ in the first 5 h, which are 8 to 10 times higher than PCA-Gly (1.71 μΜ). The results reveal that the Kleier model and Carrier-mediated theory play a guiding role in the design of phloem-mobile pesticides. However, the single Kleier model or Carrier-mediated theory are not entirely accurate. Still, there is a synergism between Carrier-mediated theory and the Kleier model for promoting the phloem transport of exogenous compounds. Therefore, we suggest the introduction of endogenous plant compounds as a promoiety to improve the phloem mobility of pesticides through Carrier-mediated theory. It is necessary to consider the improvement of physicochemical properties according to the Kleier model, which can contribute to a scientific theory for developing phloem-mobile pesticides.     

Quantum Tunneling of Massive Particles from a Garfinkle-Horowitz-Strominger Dilatonic Black Hole

Hawking radiation is viewed as a process of quantum tunneling. The massive particles‘ tunneling from Garfinkle-Horowitz-Strominger black hole is investigated. Using Jingyi Zhang‘s de Broglie wave method, we get the unthermal spectrum, and the result is consistent with the underlying unitary theory.     

某工程地基基坑支护探讨

软土地基中的支护是基础工程的关键,在节约成本的前提下,选择合理的支护结构至关重要．通过对某公司将要开发的2个基坑支护方案的项目进行的相关分析、计算和探讨,总结出了软土地基中的基坑支护方案的选择原则及其相对应的施工措施等．     

Joint Detection of Community and Structural Hole Spanner of Networks in Hyperbolic Space

Community detection and structural hole spanner (the node bridging different communities) identification, revealing the mesoscopic and microscopic structural properties of complex networks, have drawn much attention in recent years. As the determinant of mesoscopic structure, communities and structural hole spanners discover the clustering and hierarchy of networks, which has a key impact on transmission phenomena such as epidemic transmission, information diffusion, etc. However, most existing studies address the two tasks independently, which ignores the structural correlation between mesoscale and microscale and suffers from high computational costs. In this article, we propose an algorithm for simultaneously detecting communities and structural hole spanners via hyperbolic embedding (SDHE). Specifically, we first embed networks into a hyperbolic plane, in which, the angular distribution of the nodes reveals community structures of the embedded network. Then, we analyze the critical gap to detect communities and the angular region where structural hole spanners may exist. Finally, we identify structural hole spanners via two-step connectivity. Experimental results on synthetic networks and real networks demonstrate the effectiveness of our proposed algorithm compared with several state-of-the-art methods.     

Performance of La2O3/InAlN/GaN metal—oxide—semiconductor high electron mobility transistors

We report on the performance of La2O3/InAlN/GaN metal-oxide-semiconductor high electron mobility transistors(MOSHEMTs) and InAlN/GaN high electron mobility transistors(HEMTs).The MOSHEMT presents a maximum drain current of 961 mA/mm at Vgs = 4 V and a maximum transconductance of 130 mS/mm compared with 710 mA/mm at Vgs = 1 V and 131 mS/mm for the HEMT device,while the gate leakage current in the reverse direction could be reduced by four orders of magnitude.Compared with the HEMT device of a similar geometry,MOSHEMT presents a large gate voltage swing and negligible current collapse.     

High‐mobility solution‐processed zinc oxide thin films on silicon nitride

A high effective electron mobility of 33 cm² V^–1 s^–1 was achieved in solution‐processed undoped zinc oxide (ZnO) thin films. The introduction of silicon nitride (Si₃N₄) as growth substrate resulted in a mobility improvement by a factor of 2.5 with respect to the commonly used silicon oxide (SiO₂). The solution‐processed ZnO thin films grown on Si₃N₄, prepared by low‐pressure chemical vapor deposition, revealed bigger grain sizes, lower strain and better crystalline quality in comparison to the films grown on thermal SiO₂. These results show that the nucleation and growth mechanisms of solution‐processed films are substrate dependent and affect the final film structure accordingly. The substantial difference in electron mobilities suggests that, in addition to the grain morphology and crystalline structure effects, defect chemistry is a contributing factor that also depends on the particular substrate. In this respect, interface trap densities measured in high‐κ HfO₂/ZnO MOSCAPs were about ten times lower in those fabricated on Si₃N₄ substrates. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)

     

Majorana zero modes,unconventional real-complex transition,and mobility edges in a one-dimensional non-Hermitian quasi-periodic lattice

A one-dimensional non-Hermitian quasiperiodic p-wave superconductor without PT-symmetry is studied.By analyzing the spectrum,we discovered that there still exists real-complex energy transition even if the inexistence of PT-symmetry breaking.By the inverse participation ratio,we constructed such a correspondence that pure real energies correspond to the extended states and complex energies correspond to the localized states,and this correspondence is precise and effective to detect the mobility edges.After investigating the topological properties,we arrived at a fact that the Majorana zero modes in this system are immune to the non-Hermiticity.     

SiC电子霍耳迁移率的计算

基于对自身能带结构的分析以及各向同性弛豫时间近似法,采用三椭球等能面、抛物线性简化,建立了适于模拟n型6H-SiC电子霍耳迁移率和霍耳散射因子的解析模型,精确描述了不同散射机制对于6H-SiC低场电子输运特性的影响.计算结果与实测值有很好的一致性.     

求解中国农业困局：国际视野中的农业规模经营与农业竞争力

近年来中国粮食生产出现的“高产量、高库存、高进口”现象,是由于农均耕地面积过小引起的规模经营不足。这背后,是户籍制度造成的城市化滞后以及针对外来人口的公共服务不平等。同时,政府大力补贴农业和农村,提高了农民向城市转移的机会成本,导致土地流转率不足,进一步阻碍规模经营。通过国际比较,我们认为规模化农场有利于提高农业竞争力,而小农经济现代化的成本较高。研究还发现,在世界范围内,农业劳动力转移适应农业产出比重下降的国家拥有更大的农均在（可）耕地,它对农均粮食净出口存在显著正效应。反事实分析说明,若中国2011年的农业就业比重能和产出比重相适应（即消除城乡间劳动力流动障碍）,则下一年粮食净输入将下降约89%。     

Breakdown voltage analysis of Al0.25Ga0.75N/GaN high electron mobility transistors with partial silicon doping in the AlGaN layer

In this paper,two-dimensional electron gas（2DEG） regions in AlGaN/GaN high electron mobility transistors（HEMTs） are realized by doping partial silicon into the AlGaN layer for the first time.A new electric field peak is introduced along the interface between the AlGaN and GaN buffer by the electric field modulation effect due to partial silicon positive charge.The high electric field near the gate for the complete silicon doping structure is effectively decreased,which makes the surface electric field uniform.The high electric field peak near the drain results from the potential difference between the surface and the depletion regions.Simulated breakdown curves that are the same as the test results are obtained for the first time by introducing an acceptor-like trap into the N-type GaN buffer.The proposed structure with partial silicon doping is better than the structure with complete silicon doping and conventional structures with the electric field plate near the drain.The breakdown voltage is improved from 296 V for the conventional structure to 400 V for the proposed one resulting from the uniform surface electric field.