用于小麦染色体工程的蓝粒小麦单体系列材料的创制

The American geneticist, E. R. Sears, was the founder of wheat chromosome engineering.He established the monosomic series of common wheat, which greatly facilitated cytogenetic analysis of wheat. However, problems of univalent shift and labor involved in chromosome counting have limited the common usage of these materials. To circumvent these problems, I developed an alternative set of monosomic lines, in which the presence of the univalent chromosome was indicated by the production of blue pigmentation in the aleurone tissue of seeds. The gene(s) responsible for the blue pigmentation were carried on a short chromosomal fragment of Agropyron elongatum. This chromosomal fragment has been transferred to the different chromosomes of common wheat using radiation induced translocation. On the spike derived from a blue grained monosomic wheat (2 n =41, the univalent chromosome carries the gene for the blue pigmentation), four types of seeds are produced. The deep blue seed has 42 chromosomes, the medium blue and light blue seed has 41 chromosomes, and the white seed has 40 chromosomes. The monosomic genotype is easily identified based on the color of the seed, without the use of microscope. So far, blue grained monosomic lines have peoduced 11 of the 21 different wheat chromosomes. In the course of propagating the blue grained monosomics, I found that the fertility of the nullisomic lines (2 n =40, represented by white seeds) could be improved by continued selfing and reselection. Using the resulted self fertile nullisomic lines, I established an efficient procedure for producing alien substitution lines of wheat. The utilization of the blue grained monosomic lines and the self fertile nullisomic lines may facilitate chromosome engineering studies in wheat.

复配单体防水材料应用性能试验研究

为了有效解决工程结构的腐蚀问题、提高工程结构的可靠性,增强结构的耐久性,采用复配单体防水材料,通过不同的水灰比、内掺量、喷涂次数为影响因素研究混凝土结构的防腐蚀性能,从两方面进行试验,研究复配单体防水材料对混凝土抗渗强度、吸水率的影响。结果表明:混凝土采用复配单体材料后,降低了混凝土的吸水率,降低幅度约为85%;有效地改善了混凝土的防腐蚀性能,提高了混凝土的耐久性,解决了防水材料同时作用互相排斥的问题,混凝土试件第二次抗渗强度与第一次相比的降低了8%~16%,提高了二次抗渗强度。对混凝土结构的可靠性和耐久性具有重要价值。

小麦-多枝赖草单体异附加材料减数分裂期外源染色体的行为研究

通过细胞学观察和基因组原位杂交技术分析了小麦-多枝赖草单体异附加材料减数分裂期外源染色体的遗传行为,研究结果表明:在减数分裂中期,附加的多枝赖草染色体在一定程度上干扰小麦同源染色体的正常配对,出现了未配对的小麦染色体;在减数分裂后期,30.2％～35.6％的外源染色体随机走向一极,19.5％～20.9％的外源染色体提早分裂,多枝赖草染色体落后和断裂的频率分别为19.8％～21.1％和7.9％～10.5％,同时有少量小麦染色体也发生了不规则分裂现象,表明附加的多枝赖草染色体也影响了小麦染色体后期的正常分离,这为小麦与多枝赖草染色体间产生易位提供了条件。

热电材料的研究和发展方向

讨论了热电材料研究与发展的最新方向,阐述了单体和梯度热电材料的基本理论和正在进行的研究热点及其所遵循的基本原则。

Experimental and numerical investigations on acoustic damping of monoclinic crystalline wideband sound absorbing structures

In order to overcome the limitations of traditional microperforated plate with narrow sound absorption bandwidth and a single structure,two multi-cavity composite sound-absorbing materials were designed based on the shape of monoclinic crystals:uniaxial oblique structure(UOS)and biaxial oblique structure(BOS).Through finite element simulation and experimental research,the theoretical models of UOS and BOS were verified,and their sound absorption mechanisms were revealed.At the same time,the influence of multi-cavity composites on sound absorption performance was analyzed based on the theoretical model,and the influence of structural parameters on sound absorption performance was discussed.The research results show that,in the range of 100-2000 Hz,UOS has three sound absorption peaks and BOS has five sound absorption peaks.The frequency range of the half-absorption bandwidth(α>0.5)of UOS and BOS increases by 242% and 229%,respectively.Compared with traditional microperforated sound-absorbing structures,the series and parallel hybrid methods significantly increase the sound-absorbing bandwidth of the sound-absorbing structure.This research has guiding significance for noise control and has broad application prospects in the fields of transportation,construction,and mechanical design.

液晶中聚合物网络的形貌研究

研究了混合到液晶材料中的双官能丙烯单体材料,在紫外光作用下发生交连聚合形成的聚合物网络的织构。采用二甲基丙烯酸乙二醇酯为预聚物单体,选择E70A向列液晶材料,混合以后注入两片经过平行取向的玻璃基板之间,在紫外光下聚合,形成了与液晶取向方向一致的聚合物网络。介绍了样品的制备过程,以及偏光显微照片和扫描电镜照片,并对结果进行了分析。

脲醛树脂的改性

本文介绍了加入单体或聚合物材料以提高脲醛树脂各种性能的试验。

复合防渗技术在混凝土中的应用研究

采用正交试验方法,在单一防渗透材料应用研究的基础上,充分考虑存在一级交互反应的情况下,以内掺有机硅掺量及外涂佳固士水性无机渗透结晶防水材料喷涂时间为因素,考虑工艺方面存在的有效性影响,研究了水灰比为0.89时混凝土的吸水性能和抗渗性能及其影响规律。结果表明,同时内掺2%有机硅和第7d喷涂佳固士水性无机渗透结晶防水材料时混凝土的吸水率最小,抗渗性能最好。

合成生物技术制备脂肪族二元胺的研究进展

合成生物学作为发展迅速的一门交叉学科,为构建高效的微生物细胞工厂、促进生物基产品的产业化制备提供了强有力的工具。二元胺作为一种重要的聚合单体,广泛应用于聚酯、聚氨酯、聚酰胺等高分子材料的合成中。本文针对C3~C5脂肪族二元胺(1,5-戊二胺、1,3-丙二胺、1,4-丁二胺)的生物合成,从途径设计与构建、关键结构元件的设计和改造、调控元件的挖掘与优化、辅因子合成和转运调控等模块的优化和系统集成等方面,综述了利用合成生物学策略改造大肠杆菌和谷氨酸棒状杆菌合成二元胺的现状,并从非粮生物质的利用和生物合成过程中CO2的再循环利用两个方面阐述了提高二元胺合成过程中原子经济性的研究概况,展望了如何利用合成生物技术进一步优化二元胺合成细胞的性能,以促进生物基二元胺的产业化生产。

Study on Haploid Induction Rates in Different Maize Inducers

[Objective] The aim was to analyze the differences in haploid induction rates of different inducers. [Method] Six maize inducers with purple spot and purple color were selected as the male parents to pollinate six inbred lines. [Result] The mean haploid induction rates were significantly different among the inducers: KMS-3 >WY-1 >PR-2 >YP-13 >KMS-2 >KMS-1. The haploid induction rates of the different hybrid materials were significantly different: K410 >105A >103A >104A >107A >D271 >106A>L73>N21>KZ58. [Conclusion] The haploid inducer line PR-2, which had high haploid induction rate and low variation coefficient, was an elite haploid inducer.

Al_xGa_(1-x)As/GaAs Solar Cell Grown by Multi-substrate Liquid Phase Epitaxy

A novel horizontal push-pull multi-substrate epitaxy boat with three separate cells is introduced in this article, with which multi-substrate LPE processing is feasible in horizontal LPE furnace. The processes of LPE AlxGa1-x)As/ GaAs solar cells are studied and the efficiency of the solar cells achieved 19.8% （AMO, 25℃, 120 mW/cm2）.

X-37B轻质低成本可重复使用防热系统简析

概述了X-37B空间机动飞行器所用的材料,重点分析了美国国家航空航天局艾姆斯研究中心研制的新型轻质低成本可重复使用防热系统(韧化单体纤维增强抗氧化复合材料)的基本构型、结构、材料组成与制备过程,并总结了该防热系统的特点和作用。

Conjugated polymers containing B←N unit as electron acceptors for all-polymer solar cells

Polymer electron acceptors are the key materials in all-polymer solar cells(all-PSCs).In this review,we focused on introducing the principle of boron-nitrogen coordination bond(B←N),and summarizing our recent research on polymer electron acceptors containing B←N unit for efficient all-PSC devices.Two approaches have been reported to design polymer electron acceptors using B←N unit.One is to replace a C-C unit by a B←N unit in conjugated polymers to transform a polymer electron donor to a polymer electron acceptor.The other approach is to construct novel electron-deficient building block based on B←N unit for polymer electron acceptors.The polymer electron acceptors containing B←N unit showed tunable lowest unoccupied molecular orbital(LUMO) energy levels and exhibited excellent all-PSC device performance with power conversion efficiency of exceeding6%.These results indicate that organic boron chemistry is a new toolbox to develop functional polymer materials for optoelectronic device applications.

Conjugated microporous polymers for near-infrared photothermal control of shape change

Herein,a facile and highly efficient synthetic method to prepare organic photothermal materials with high photo-stability and outstanding photothermal performance is reported.Through direct polymerization of commercial aromatic monomers in the presence of anhydrous aluminium chloride and dichloromethane,four kinds of conjugated microporous polymers(CMPs)were obtained.Detailed structural analysis confirmed that the resultant CMPs possessed abundant micropores with an extendedπ-conjugated skeleton.Under near-infrared(NIR)light irradiation(808 nm,1.0 W cm−2),all the CMPs showed fast heating-up behavior with their maximum temperatures higher than 150℃.Moreover,the efficiency of photothermal conversion(η)of the CMPs was found to increase linearly with the increase in the number of conjugated benzene rings within the monomer.Poly-TPE from tetraphenylethylene(TPE)and Poly-TP from o-terphenyl(TP)showed highηvalues of over 47%.Poly-TPE was additionally used as a photothermal filler to remotely and spatially control the shape recovery of thermal-sensitive shape memory polymers(SMPs),while its introduction(1 wt%)had little influence on the thermal and mechanical properties of the polymer matrixes.Owing to their excellent NIR photothermal performance as well as a one-step synthetic preparation,these CMPs may be promising photothermal materials for practical applications.

One pot synthesis, crystal structures and properties of two new MOFs with imidazole-containing tripodal ligand

Two new different Cu(Ⅱ) MOFs with the same 1,3,5-tris(1-imidazolyl) benzene(tib) ligand {[Cu(tib)2]·(H2O)2·Br2}n(1) and {[Cu2(tib)·Br·Cl]·2Br}n(2) were obtained by one pot synthesized of tib with CuBr in the presences of HCl and water. X-ray single crystal diffraction analyses indicate that both complexes 1 and 2 have two dimensional frameworks containing different building blocks. Each Cu(Ⅱ) atom in complex 1 is coordinated by four N atoms from different tib ligands. However, there are two different cryptographic Cu(Ⅱ) atoms in complex 2, one is four coordinated by two bromine atoms and two N atoms from different tib ligands, the other is six coordinated by two chloride atoms and four N atoms from different tib ligands. The thermal gravimetric analysis of complexes 1 and 2 are depicted in the paper.