噻唑类杀虫剂的研究进展

目前杂环化合物的发展呈现出多元化的趋势,其中噻唑类化合物是近年来发展的一个新亮点。尤其噻唑基团引入到各种不同的化合物结构中,通过结构修饰能产生一系列具有广谱生物活性化合物,使得它在新型超高效农药创制中发挥出越来越重要的作用。本文从杀虫方面对噻唑化合物的生物活性研究进行了综述,重点介绍了该类化合物的一些生物活性研究方面的工作,简述了不同取代基团对噻唑类衍生物生物活性的影响,并对它的发展趋势和应用前景作了展望。     

香豆素及其衍生物的合成与生物活性研究进展

香豆素及其衍生物是重要的合成结构单元,具有良好的生物活性。该类化合物显示了广泛的应用和发展前景。综述了近年来含苯并吡喃酮结构单元化合物的研究进展,重点介绍了该类化合物的结构特征、生物活性及合成方法。     

新的昆虫生长调节剂buprofezin(Applaud~)的研制

笔者等对含硫杂环化合物的合成及其生物活性进行了研究。其间,亦对由有机硫化合物(例如二硫化碳和异硫氰酸酯)衍生的中间体的反应性进行了广泛的研究。为了创制新的生物活性化合物,其有效的方法之一,是对已知生物活性化合物进行化学结构的改进。防治水稻稻瘟病的内吸杀菌剂富士一号(2)对某些植物和害虫都呈现生长调节活性。鉴于富士一号化学结构的新颖性和生物活性的多样性,引起了笔者等人的注意,以它作为新的农药化学结构的先导化合物。     

银杏双黄酮类化合物研究进展

我国有着丰富的银杏叶资源,而银杏叶中双黄酮类化合物具有多种生物活性,本文介绍了银杏叶中双黄酮类化合物的发现过程,综述了双黄酮类化合物的提取纯化方法,并详细介绍了双黄酮类化合物的各种生物活性,展望了双黄酮类化合物的应用前景。     

砜类化合物杀菌活性的研究进展

砜类化合物因具有广谱生物活性而引起人们对它的关注，尤其是将砜基团引入到各种不同的化合物结构中，通过结构修饰能产生一系列具有广谱生物活性的化合物，使得它在新型超高效农药创制中发挥出越来越重要的作用。从杀菌剂方面对砜类化合物的生物活性研究进行了分类综述，重点介绍了该类化合物的一些生物活性研究方面的工作，简述了不同取代基对砜类化合物生物活性的影响，并对它的发展趋势和应用前景作了展望。     

萜类的生物活性

关于萜类化合物的生物活性已经进行了一些研究,本文主要简述精油和单萜化合物的:[1]微生物活性,[2]对植物生长的抑制,昆虫的诱引和驱避。     

查尔酮类衍生物在农药活性方面的研究进展

查尔酮类化合物因具有杀菌、杀虫、除草和抗病毒等生物活性成为研发的热点,通过结构修饰将不同结构的药效团引入查尔酮结构中,设计了合成具有广谱生物活性的化合物,在新农药的研究与开发中发挥重要的作用。笔者对该类化合物在农药生物活性方面进行了分类,综述了查尔酮衍生物在抑菌、杀虫杀螨及抗病毒方面的研究成果,并展望了该类化合物的发展趋势和应用前景。     

酰基硫脲类化合物的生物活性研究进展

酰基硫脲类化合物具有广泛的生物活性,可作为除草剂、杀菌剂及植物生长调节剂等。本文简要综述了近年来该类化合物生物活性的研究近况。     

1,5-二芳基-3-苯甲酰氧基吡唑类化合物的合成及生物活性

[目的]寻找具有较好生物活性的活性分子。[方法]在苯甲酰氯的骨架中引入具有良好生物活性的1,5-二芳基-1H-3-羟基吡唑化合物,设计合成一系列1,5-二芳基-3-苯甲酰氧基吡唑化合物,并进行目标化合物生物活性测试。[结果]所合成目标化合物结构经IR、1H NMR、MS和元素分析确证。生物活性测试结果表明:部分目标化合物对小菜蛾和朱砂叶螨有良好的生物活性。[结论]1,5-二芳基-3-苯甲酰氧基吡唑类化合物具有较好的生物活性,在其结构基础上进行进一步的结构修饰,期望得到具有较高抗病毒活性的有机活性分子。     

香豆素类化合物生物活性研究进展

香豆素是一类重要杂环化合物,具多种生物活性,在医药、食品等领域有重要用途。本文综述了近年来香豆素生物活性研究进展,并简单介绍了含有苯并吡喃酮化合物的合成方法,为香豆素类化合物生物活性的深入研究提供依据。     

DUO-ICP-AES测定精对苯二甲酸中的钴、铬、铁、锰、钼、镍、钛

采用DUO-ICP-AES同时测定精对苯二甲酸中钴、铬、铁、锰、钼、镍、钛,并对仪器的分析线选择、背景校正、入射功率、雾化器压力、辅助气流量、冷却气流量、蠕动泵转速的影响及共存元素的干扰、硝酸铯灰化助剂等因素进行了详细的研究。方法的检测限:钴0.0097 mg/L;铬0.0021 mg/L;铁0.0078 mg/L;锰0.0012 mg/L;钼0.0027 mg/L;镍0.016 mg/L;钛0.0027 mg/L,回收率和精密度分别为93.0%～99.5%和0.37%～3.2%。该方法快速简便,具有良好的精密度和准确度,适用于进出口精对苯二甲酸的日常检验。     

Pd-, Ni-, Fe-, and Co-Catalyzed Cross-Couplings Using Functionalized Zn-, Mg-, Fe-, and In-Organometallics

The development of new methods for preparing polyfunctional organometallics has made a broad range of such reagents available for various transition metal-catalyzed cross-couplings. An overview of the most general preparation methods will be presented. Applications to practical cross-coupling procedures will be covered, emphasizing the functional group compatibility and the reaction scope.     

Preparation, Characterization, and Microwave Properties of RETiNbO6 (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, and Yb) Dielectric Ceramics

Microwave ceramic dielectric resonators (DRs) based on RETiNbO₆ (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, and Yb) have been prepared using the conventional solid-state ceramic route. The DR samples are characterized using XRD and SEM methods. The microwave dielectric properties are measured using resonant methods and a net work analyzer. The ceramics based on Ce, Pr, Nd, and Sm have dielectric constants in the range 32–54 and positive coefficient of thermal variation of resonant frequency (τ_f). The ceramics based on Gd, Tb, Dy, Y, and Yb have dielectric constants in the range 19–22 and negative τ_f.     

Antiferroelectrics: History,fundamentals, crystal chemistry,crystal structures,size effects,and applications

Antiferroelectric (AFE) materials are of great interest owing to their scientific richness and their utility in high-energy density capacitors. Here, the history of AFEs is reviewed, and the characteristics of antiferroelectricity and the phase transition of an AFE material are described. AFEs are energetically close to ferroelectric (FE) phases, and thus both the electric field strength and applied stress (pressure) influence the nature of the transition. With the comparable energetics between the AFE and FE phases, there can be a competition and frustration of these phases, and either incommensurate and/or a glassy (relaxor) structures may be observed. The phase transition in AFEs can also be influenced by the crystal/grain size, particularly at nanometric dimensions, and may be tuned through the formation of solid solutions. There have been extensive studies on the perovskite family of AFE materials, but many other crystal structures host AFE behavior, such as CuBiP₂Se₆. AFE applications include DC-link capacitors for power electronics, defibrillator capacitors, pulse power devices, and electromechanical actuators. The paper concludes with a perspective on the future needs and opportunities with respect to discovery, science, and applications of AFE.     

电感耦合等离子体原子发射光谱法同时测定金属饰品中铅、镉、铬、汞、锑、砷、硒、钡、镍含量

采用电感耦合等离子体原子发射光谱法同时测定金属饰品中铅、镉、铬、汞、锑、砷、硒、钡、镍的含量.用体积比为3∶1的浓硝酸和浓盐酸微波溶解样品,研究了样品的消解方法、消解介质、分析谱线及工作参数等对检测结果的影响.方法的检测限(mg/L):铅0.06、镉0.009、铬0.002、汞0.04、砷0.02、硒0.01、钡0.0...     

THERMOPLASTIC,FLEXIBLE, AND RECYCLABLE COMPOSITES,DESIGN, PREPARATION,AND CHARACTERIZATION

Glass fiber reinforced composites based on thermosets are the traditional materials used for many applications due to their good mechanical properties. The non-recyclability of these materials has led to the necessity to develop thermoplastic composites and industrial processes for their manufacture [1]. The present paper deals with the preparation of thermoplastic pre-pregs unidirectionally reinforced with Twarn® and their mechanical characterization.     

Fatty Acids,Tocopherols, Tocotrienols,Phytosterols, Carotenoids,and Squalene in Seed Oils of Hyptis suaveolens,Leonotis nepetifolia,and Ocimum sanctum

The oil yield and composition of fatty acids, tocopherols, tocotrienols, sterols, carotenoids, and squalene in the seeds of three species—Hyptis suaveolens, Leonotis nepetifolia, Ocimum sanctum—belonging to the Lamiaceae family, are studied. The oil yields are 12.1%, 16.1%, and 29.0% in O. sanctum, H. suaveolens, and L. nepetifolia, respectively. The unsaturated fatty acids are a predominant group (86.8–92.1%) in all three investigated plants; however, the profile for each species is unique. The main fatty acid differs as follows: H. suaveolens—linoleic acid (85.8%), L. nepetifolia—oleic acid (58.3%), and O. sanctum—α‐linolenic (48.6%). γ‐Tocopherol accounts for over 97%, 90%, and 93% of the total tocochromanol content (sum of tocopherols and tocotrienols) in H. suaveolens, L. nepetifolia, and O. sanctum, respectively. Two tocotrienol homologues, α and γ, are detected only in L. nepetifolia. β‐Sitosterol is the main detected sterol (38–59%) in all three species. High levels of campesterol (18–20%), Δ5‐stigmasterol (9–21%), and Δ5‐avenasterol (7–12%) are also detected. Squalene is detected only in O. sanctum (45.8 mg/100 g oil). The content of sterols, tocochromanols, and carotenoids in the investigated Lamiaceae plant seed oils ranges between 279.5–576.3, 54.5–66.7, and 0.3–3.1 mg/100 g oil, respectively. Practical Applications: Lamiaceae plants are of medicinal interest due to the presence of a broad spectrum of bioactive molecules. The present study demonstrates that seeds of the species H. suaveolens, L. nepetifolia, and O. sanctum are rich sources of bioactive compounds of lipophilic nature. There is limited knowledge associated with the composition of tocopherols, tocotrienols, sterols, carotenoids, and squalene. The results of the studied medicinal plants may enhance future targeted applications in various sectors.     

Synthesis of Hexabenzo[a,cd,f,j,lm,o]perylene

Hexabenzo[a,cd,f,j,lm,o]perylene (HBP), an undecacyclic condensed polycyclic aromatic hydrocarbon with two severely crowded fjord regions, was synthesized by Clar's method; the starting material 8H-benzo[fg]-naphthacene-8-one was newly prepared by the glycerol condensation of 5,12-dihydro-naphthacene-5,12-dione. ¹H and ¹³C NMR spectra of HBP were measured and the chemical shifts were completely assigned. Absorption and fluorescence spectra of HBP were also measured and the effects of nonplanarity on its spectroscopic properties was discussed.     

ICP-OES测定大量元素水溶肥料中锌、镁、铜、铁、锰、钼、硼含量

采用ICP-OES对大量元素水溶肥料中微量元素锌、镁、铜、铁、锰、钼、硼进行分析,研究确定了最佳分析条件。加标回收率为96.94%～106.2%,RSD为0.50%～1.40%,检出限为0.001 8～0.218 0 mg/L,方法简便、快速、准确。     

Synthesis of methyl,propyl, butyl,isobutyl, hexyl,cyclohexyl, octyl,and 2-ethylhexyl esters of epoxyoleic acid

A series of esters of 12,13-epoxyoleic acid were prepared by means of alcoholysis of triepoxyolein (trivernolin). The procedure for the alcoholysis, and isolation and purification of the esters are described. Analytical characteristics of the esters are reported. E. Util. Res. Devel. Div., ARS, USDA.