Design,synthesis and evaluation of novel cis-p-menthane type Schiff base compounds as effective herbicides

p-Menthane type monoterpene derivatives were identified as bio-based compounds with high herbicidal activities. In order to search novel p-menthane type monoterpene derivatives in good performance, a series of novel cis-p-menthane type Schiff base derivatives were designed and synthesized. All target products were easily available novel compounds and characterized by FT-IR,^1H NMR,^13 C NMR and ESI＋-MS. Their pre-emergence herbicidal activities against annual ryegrass were evaluated. The bioassays indicated that most of the target compounds displayed excellent herbicidal activities in pre-emergence treatment.

Theoretical Studies on Property and Structure of Silacyclohexane-based Liquid Crystal Compounds

SCF-MO-AM1 calculations have been per formed on 10 silacyclohex-ane-based liquid crystal compounds by energy gradient completed optimization. The stable configurations, electronic structures, heats of formation, dipole moments and ionization potentials of titled comPounds are first reported. The calculated results are.discussed relating to the classical organic electronic theory.

Progress in Antimonide Based III-V Compound Semiconductors and Devices

In recent years, the narrow bandgap antimonide based compound semiconductors (ABCS) are widely regarded as the first candidate materials for fabrication of the third generation infrared photon detectors and integrated circuits with ultra-high speed and ultra-low power consumption. Due to their unique bandgap structure and physical properties, it makes a vast space to develop various novel devices, and becomes a hot research area in many developed countries such as USA, Japan, Germany and Israel etc. Research progress in the preparation and application of ABCS materials, existing problems and some latest results are briefly introduced.

Magnetic Field Induced Entropy Change for La-Fe Based NaZn_(13)-Typed Compounds

Magnetic field induced entropy change was investigated for La-Fe based NaZn13-type compounds with magnetic first-order phase transition. In view of magnetic refrigeration at room temperature, the developing of the materials and the understanding of the entropy change were., reviewed. For La-Fe-Si compounds, the entropy change about 29 J·kg^- 1·K^-1 was obtained at 190 K under the magnetic field of 5 T.While a large entropy change of about 15 J·kg^-1·K^-1 near room temperature under 5 T can be obtained by the substitution of Co for Fe in the compounds. It is found that the entropy change is mainly composed of that contributed from magnetic ordering and crystal lattice. The large entropy change consumed by lattice contribution is mainly due to the magnetic ordering one.

STUDIES ON THE PROPERTIES OF SCHIFF BASE TYPE ARYLMERCURY COMPOUNDS Ⅲ TRANSMETALLATION REACTION OF SCHIFF BASE TYPE ARYLMERCURY COMPOUNDS WITH METALLIC TIN

The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phenylazo)phenyl]mercury(Ⅱ) to give dichlorobisaryltin(Ⅳ).The ~1H NMR spectra of the products provide evidence for the presence of N→Sn intramolecular coordination.The formation of dichlorobisaryltin(Ⅳ)as a unique product probably arises from the N→Sn intramolecular coordination which results in the increasing of the stability of the molecule.

STUDIES ON THE PROPERTIES OF SCHIFF BASE TYPE ARYLMERCURY COMPOUNDS.II ^(199)Hg NMR SPECTRA OF MERCURATED DERIVATIVES OF SUBSTITUTED BENZYLIDENEANILINES

^(199)Hg NHR spectra of 18 Schiff base type arylmercury compounds have been studied.It was further confirmed that in the molecule of XC_6H_4CH=NC_6H_3-2-HgC1-4-CH_3 there exists an intramolecular N→Hg coordination via a four-membered ring.For the series of XC_6H_4CH=NC_6H_3-2-HgCl-4-CH_3(X is a para-or mera-substituent),there is a good linear correlation between δ^(199)Hg and Hammett's o constants.The influence of substituents of C-pheny1 ring on the δ ^(199)Hg can be explained in terms of the intramolecular N→Hg coordination.

Synthesis of Tetra-Schiff Base Macrocyclic Compound Containing Benzo-12-crown-4

Tetra-Schiff base macrocyclic compound containing benzo-12-crown-4 was synthesized via condensation of 2, 6-diformyl-4-methyl-phenol with 4, 5- diaminobenzo-12C- 4 promoted by proton. The compound was characterized by MS, IR 1HNMR spectroscopy and elemental analysis.

CHARACTERIZATION OF SOME SCHIFF BASES OF HETEROCYCLIC COMPOUNDS AND THEIR TRANSITION METAL COMPLEXES

Some new Schiff bases were synthesized by the condensation of equimolar quantities of salicylaldehyde and 2-amino-5-phenylazo-pyridine or its derivatives in dry benzene(1):Metal complexes of the type ML_2and M'L_3 where M=Cu^(2+),Co^(2+),Ni^(2+),Mn^(2+)Pd^(2+),M'=Fe^(3+)and L=different newly synthesized monobasic Schiff bases were prepared in absolute ethanolic medium(2)and characterized by elementary analysis,conductance measurements,infrared spectra,electronic spectra,magnetic moments studies.

Synthesis, Structure Characterization, Antibacterial Activity and Fluorescence Studies of a Ni(Ⅱ) Compound with Schiff-base Ligand

We synthesized one novel Schiff-base ligand by modifying the aromatic aldehyde： H2L^1（H2L^1 = N,N？-bis（2-oxy-acetate-3-methoxyl）benzylpropylene（1,3-propane）diamine）. [Ni（C（23）H（24）N2O8）]·6H2O]（1） was prepared by the reaction between H2L^1 and NiCl2·6H2O in C2H5 OH. Compound 1 was structurally characterized by elemental analysis, IR, H NMR and single-crystal X-ray diffraction. 1 crystallizes in monoclinic system, space group P21/n with a = 1.3952（4）, b = 1.3746（9）, c = 1.6121（0） nm, β = 112.66（3）°, V = 2.8533（4） nm^3, Z = 4, Mr = 623.25 and Dc = 1.451 g·cm^（-3）. The Ni（Ⅱ） atom is hexa-coordinated to furnish a slightly distorted octahedral geometry. Lattice water molecules are found in 1, and the H-bonding intersections formed novel water clusters. The IR, antibacterial activity and luminescence of 1 are studied.

As-cast Medium Mn Steel with Nodular Carbide Modified by Y-base Heavy RE Compound

1.IntroductionMedium Mn steel was developed be-cause the wear resistance of Hadfield steel(Mn13)is poor under low or medium im-pact and extrusion abrasion[1-4].In theforegoing investigations[2-4]we found thatwith the increase of C content,theneedle-like and network carbide in mediumMn steel increased(as shown in Fig.1(a)and(c)).Although its wear resistance was largelyimproved,its impact toughness was greatlydecreased.In order to increase toughness,along-term high temperature heat-treatmentwas needed.But the treatment caused cracks

Literature Review of the Use of Zinc and Zinc Compounds in Paper-Based Microfluidic Devices

Zinc and its compounds, alloys and composites play an important role in the modern day world and find application in almost every aspect that can improve the quality of our lives. This ranges from supplements and pharmaceuticals that are meant to improve our health and wellbeing to additives meant to guard or reduce corrosion in metals. However, over the past several years, a new area of technology has been garnering a great deal of attention and has made use of zinc and its compounds. This is with reference to paper-based microfluidic technology that offers several advantages and that keeps expanding in the amount of applications it covers. In this paper, a review is offered for the applications that have used zinc or zinc compounds in paper-based microfluidic devices.

Synthesis, Characterization, Antimicrobial and DNA Binding Studies of a Tetradentate N2O2 Amino Acid Schiff Base and Its Coordination Compounds

Aminoethanoic acid undergoes condensation with 1,4-benzenedicarboxaldehyde to form an O, N, N, O donor Schiff base, N,N'-di(carboxymethylene) terephthalaldehyde, Ligand L. Coordination compounds of this Schiff base using Ni (II), Cu (II), VO (IV) and Co (II) were then obtained in-situ. The Schiff base and the complexes were evaluated for their antimicrobial and DNA binding abilities. Molecular docking studies of the ligand and synthesized compounds were also carried out. Evidence for the formation of the Schiff base coordination compounds and the coordinating atoms was obtained from 1H NMR, infrared and ultraviolet spectral data, EDX, EDTA complexometric titration and magnetic susceptibility measurement. The results obtained are consistent with octahedral geometry for Ni (II) complex, the metal ion coordinating to one molecule of Ligand L and with additional coordination with two oxygen atoms of two molecules of the solvent. A square-planar geometry was suggested for both Co (II), and Cu (II) complexes and a five-coordinate, square pyramidal geometry for the VO (IV) complex. The results further indicated that the carboxylic acid of Ligand L was not deprotonated both in the free base and also the complexes. In addition, the results showed that Compound 2 elicited the best antimicrobial activity potential. Generally, the compounds exhibited considerable good affinity to CT-DNA.

Co-MOFs衍生的钴基化合物催化氧化典型VOCs研究进展

基于催化氧化技术在挥发性有机化合物(VOCs)末端治理方面有极高的效率,以及近年来金属有机骨架(MOFs)衍生的钴基化合物在催化氧化VOCs中的优异表现,文章总结了4种典型的钴基MOFs(ZIF-67,ZSA-1,Co-MOF-71和Co-MOF-74)及其衍生的钴基催化剂的组成与制备方法,并综述了其衍生物催化氧化几种典型VOCs(甲苯、邻二甲苯、甲醛和丙酮)的研究进展。最后归纳了反应过程中空速和湿度等因素对钴基化合物催化氧化VOCs的影响,探讨了MOFs衍生的钴基催化剂的反应机理,并对MOFs衍生的钴基催化剂在VOCs氧化中的研究进行了展望。

5-取代-4-氨基-3-巯基-1,2,4-三唑衍生物的应用进展

5-取代-4-氨基-3-巯基-1,2,4-三唑是一类重要的五元杂环化合物,由于分子中含有巯基和伯胺基两个活性基团,既可以单个基团参与反应生成N-或S-取代产物,又可以同时发生反应生成稠杂环化合物。由其衍生而来的化合物具有广泛的生物活性,在抗菌、抗肿瘤、抗结核、抗炎镇痛、酶抑制剂、荧光探针等方面都表现出优异的性能。综述了近年来5-取代-4-氨基-3-巯基-1,2,4-三唑衍生物在医学、农业及材料领域的应用,为今后进一步研究、开发此类化合物提供参考。

n型Bi_(2-x)Sb_(x)Te_(3-y)Se_(y)基化合物的缺陷结构调控与电热输运性能

Bi_(2)Te_(3)基化合物是目前室温附近性能最好的热电材料,但其存在着大量复杂的缺陷结构,缺陷工程是调控材料热电性能的核心手段,因此理解和有效地调控缺陷形态和浓度是获得高性能Bi_(2)Te_(3)基热电材料的关键.本文系统地研究了四元n型Bi_(2-x)Sb_(x)Te_(3-y)Se_(y)基化合物的缺陷演化过程及其对热电输运性能的影响规律.Sb和Se的固溶引入的带电伴生结构缺陷使得材料的载流子浓度发生了巨大变化,在Bi_(2-x)Sb_(x)Te_(2.994)Cl_(0.006)样品中,Sb的固溶降低了反位缺陷Sb_(Te)_(2)形成能,诱导产生了反位缺陷Sb_(Te)_(2),使得少数载流子空穴浓度从2.09×10^(16)cm^(-3)增加至3.99×10^(17)cm^(-3),严重劣化了电性能.在Bi_(1.8)Sb_(0.2)Te_(2.994-y)Se_(y)Cl_(0.006)样品中,Se的固溶使得Se(Te)_(2)+SbBi的缺陷形成能更低,抑制了反位缺陷Sb_(Te)_(2)的产生,Bi_(1.8)Sb_(0.2)Te_(2.694)Se_(0.30)Cl_(0.006)样品的少数载流子空穴浓度降至1.49×10^(16)cm^(-3),消除了其对材料热电性能的劣化效果,显著地提升了材料的功率因子,室温下达到4.49 mW/(m·K^(2)).结合Sb和Se固溶增强合金化散射降低材料的热导率,Bi_(1.8)Sb_(0.2)Te_(2.844)Se_(0.15)Cl_(0.006)样品在室温下获得最大ZT值为0.98.该研究为调控具有复杂成分的Bi_(2)Te_(3)基材料的点缺陷、载流子浓度和热电性能提供了重要的指导.

地基深空探测雷达研究进展与展望

地基深空探测雷达通过主动发射电磁波,并接收反射信号,实现对深空目标的精确测量,是研究月球、近地小行星、类地行星等深空目标的重要手段。地基深空探测雷达可以高精度测量深空目标的轨道、自转、形貌等特征,具有全天时全天候观测、精确测距、高分辨率成像等优势,对近地小行星防御和行星科学研究具有重要意义。本文介绍了地基深空探测雷达的概念内涵,梳理了地基深空探测雷达系统的国内外发展现状,回顾了地基深空探测雷达过去数十年间取得的重要历史贡献,包括月球表面高分辨率成像与永久阴影区水冰探测、近地小行星精细形貌特征获取、近地小行星轨道与自转等物理特性精确测量、近地小行星撞击防御任务处置效果快速评估、类地行星表面高分辨率成像与地质结构研究等一系列重要研究成果。在此基础上,本文介绍了分布孔径深空探测雷达的创新机理,通过多部雷达单元协同观测,可突破传统集中式体制地基深空探测雷达的口径和发射功率物理极限,形象称之为“中国复眼”雷达。最后,本文介绍了分布孔径深空探测雷达系统研制与观测实验等最新研究进展,展示了分布孔径深空探测雷达对月球二维成像和三维成像的实验结果,并对地基深空探测雷达的未来发展趋势进行了展望。

乌衣红曲黄酒年份特征挥发性物质指纹图谱分析

目的:建立乌衣红曲黄酒基酒挥发性成分指纹图谱,用于年份基酒酒龄的判别。方法:通过顶空固相微萃取-气相色谱联用质谱法(HS-SPME-GC-MS)分析不同陈酿时间的乌衣红曲黄酒中的挥发性成分,结合正交偏最小二乘法-判别分析(OPLS-DA)和Spearman相关性分析确定与年份相关的关键成分,用于构建年份基酒特征指纹图谱。结果:从不同年份的乌衣红曲黄酒中,共检出并定性挥发性成分122种,与陈酿时间显著相关的有20种(|r|>0.5),其中N-苯甲酰甘氨酸乙酯、6-庚烯酸乙酯、乙酸-2-乙基苯酯等8种与陈酿时间呈正相关关系,2-呋喃甲醇、辛酸、庚酸乙酯等12种与陈酿时间呈负相关关系。基于筛选的20种年份特征挥发性物质,构建了乌衣红曲黄酒基酒年份基酒指纹图谱。依据香气成分的OPLS-DA分析和指纹图谱数据信息将2~15年陈乌衣红曲基酒样品区分为青陈酒(2~4年)、中陈酒(5~9年)、老陈酒(10~15年)3个类别,并通过二次取样分析,验证所建图谱的可靠性。结论:GC-MS技术构建的挥发性成分指纹图谱可为乌衣红曲黄酒基酒品质评价及酒龄的识别提供基础数据。

批判性思维在车辆工程专业课程教学中的运用——以汽车电器与电子课程为例

批判性思维是以一种以合理的、反思的、心灵开放的方式进行思考,从而能够清晰准确地表达、逻辑严谨地推理、合理地论证,进而完成思辨精神培养的思维方式。在车辆工程专业新工科人才培养的过程中,培养学生这种思维方式和精神,具有普适性意义,有利于新工科专业教育内涵发展。该文基于批判性思维教学方法的基本理论,结合汽车电器与电子课程教学实践,在教学目标设计、教学内容设计、议题式教学模式和课后辅导等方面,进行批判性思维在车辆工程专业课程教学中运用的探索,以培养具有学习能力的学生,进而满足汽车行业对于复合型人才的需要。

铁基改性樟树叶复合材料的制备及吸波性能

生物炭材料因高的电导率而具有吸收电磁波的潜在优异性能,但其吸收性能的提高受阻抗失配制约.为了解决此问题,通常在生物炭材料中加入磁性材料,以提高吸波性能.通过简单的浸渍和烧结,制备铁基生物炭(樟树叶)复合材料.研究结果表明:相对于其他6种铁基生物炭复合材料,该文制备的铁基生物炭复合材料具有较强的综合吸波性能.

Fe-MOFs衍生碳基吸波材料研究进展

随着社会的快速发展和电子设备的普及,电磁辐射污染问题变得尤为突出,也带来了潜在的危害。因此,开发高效的电磁波吸收材料以解决电磁辐射污染问题迫在眉睫。铁基金属有机框架(Fe-MOFs)具有高度不饱和的铁金属中心离子和多样的结构类型。通过将Fe-MOFs作为前驱体进行碳化,可以制备出铁/铁氧化物/铁碳化物均匀分布的衍生碳基化合物。这些Fe-MOFs衍生碳基化合物表现出较高的介电损耗和磁损耗能力,可有效克服当前吸波材料存在的吸收频带窄、阻抗匹配性差等问题,成为近年来备受关注的一种新型吸波材料。首先简要介绍了电磁波吸收机制,然后综述了近年来关于单金属、双金属、三金属Fe-MOFs以及由Fe-MOFs与其他材料(包括碳材料、导电聚合物、MXene和生物质)复合制备的衍生碳基吸波材料的研究进展,最后对MOFs衍生碳基吸波材料的未来发展方向进行了展望。