Synthesis of Novel Benzotriazoloazepine Derivatives

Eight new benzotriazoloazepine derivatives have been synthesized starting from 7‐methoxy‐2,3,4,5‐tetrahydro‐1H‐2‐benzo[c]azepin‐1‐one. The compounds 2a–c have been synthesized by the reaction of 7‐methoxy‐2,3,4,5‐tetrahydro‐1H‐2‐benzo[c]azepin‐1‐thione with various hydrazides. Reaction of 5 with hydrazine hydrate, followed by treatment of the resultant hydrazone with formic acid, gave corresponding 9‐alkoxy‐6,7‐dihydro‐5H‐benzo[c][1,2,4]triazolo[4,3‐a]azepine(6 a , b ). Cyclization of 5 with methyl carbazate gave 9‐alkoxy‐6,7‐dihydro‐2H‐benzo[c][1,2,4]triazolo[4,3‐a]azepin‐3(5H)‐one (7 a–c ). The structures of the compounds were confirmed by their elemental analysis and spectral data. Their anticonvulsant activities have been initially screened.     

叠栅条纹信号细分误差的一种动态补偿方法

缺乏有效的误差补偿方法足制约长光栅测最精度提高的关键原因之一.提出一种动态的误差补偿方法.可以消除由直流漂移、两路信号不等幅和非止交导致的细分误差.其原理是跟踪光栅信号在一个周期上的8个特征值点(正余弦信号的过零点及绝对值交点),从特征值点的幅度值中首先分解出正弦信号的直流漂移误差.对其进行补偿;然后继续跟踪补偿后的信号.从中义能分解出余弦信号的直流漂移误差.再补偿.再跟踪.又能依次分解出不等幅误差和非正交误差.最多只需要3个光栅信号周期,就能对三种误差依次实现补偿.分析了谐波对该方法的影响并提出r改进措施.实验证实了该方法的有效性.     

Solid-phase microextraction of triazine herbicides via cellulose paper coated with a metal-organic framework of type MIL-101(Cr), and their quantitation by HPLC-MS

Microchimica Acta - A nanostructure was prepared from titania nanoparticles and copper oxide (TiO2NP@CuO) and used to modify a carbon paste electrode (CPE). The modified CPE is shown to enable...     

Acetate reduction synthesis of Sr2Si5N8:Eu phosphor and its luminescence properties

A novel synthesis method was developed for the efficient red phosphor, Eu²⁺-activated Sr₂Si₅N₈, by employing the strontium acetate as both the reducing agent and strontium source. The phase purity of final product was strongly dependent on the heating rate of the precursors. Sr₂Si₅N₈:Eu²⁺ (2 at%) phosphor presented a broadband excitation spectrum in the range 300–500 nm, matching well with the blue emission (400/460 nm) of current InGaN light-emitting diodes (LEDs). The red emission peaking at 619 nm gave the relatively high (about 155%) intensity compared with the Y₃Al₅O₁₂ (YAG) (P46-Y3) standard phosphor. In addition, the saturated chromatic coordinates (0.638, 0.359) allowed it a promising candidate as a red phosphor in white LEDs application for illumination or display.     

含5-氟脲嘧啶齐聚物的合成

<正> 5-氟脲嘧啶是用于治疗肺癌、肾癌、乳癌、结肠癌等癌变的药物。虽然5-氟脲嘧啶具有上述疗效,但在临床应用时,尚存在恶心,呕吐,腹泻,白细胞、血小板下降等副作用。更为严重的缺点,是既对肿瘤细胞有活性,同时也作用于正常细胞,为克服此缺点,将抗癌药物与低分子化合物结合,诸如激素、磺胺,这些是已知能集聚在一定组织内药物,但利用此法,迄今也很少获得成效。     

ICP—AES分析的线性回归校准曲线

本文对ICP-AES分析中2种线性回归方法的校准曲线作了比较和讨论。对大多数元素而言,用加权法得到的校准曲线的斜率比不加权校准曲线的斜率略大,减小3校准曲线在低浓度部分的弯曲,曲线明显优于不加权校准曲线。将2种方法得到的校准曲线进行比较时,应将剩余标准偏差(或剩余变差平方和)及曲线截距等加以综合考虑。用含零标的标准系列制作校准曲线可使曲线的截距更接近原点,有利于提高在低浓度部分校准分析的准确性。     

高效液相色谱法检测氟吗啉在土壤中的降解

建立了氟吗啉在土壤中残留分析的高效液相色谱(HPLC)检测方法,在实验室条件下对氟吗啉在我国具有代表性的3种土壤中的降解动态进行了研究。样品通过V(正己烷)∶V(乙酸乙酯)=1∶2混和溶液萃取,经弗罗里硅土SPE柱净化,浓缩后进行HPLC检测。结果表明,药剂土壤添加浓度在0.2和2.0mg/kg时,氟吗啉在不同土壤中回收率为78.8%～97.1%;标准偏差为2.24%～7.48%。氟吗啉在土壤中的降解遵循一级动力学方程;氟吗啉在3种土壤中的降解速率大小依次为黑龙江黑土>江西红土>河南黄土,其降解半衰期分别为99.02、106.64和157.53d,降解速率常数(k)分别为7.0×10-3、6.5×10-3和4.4×10-3。根据国内农药在土壤中的残留划分标准,氟吗啉属于中等降解类农药。比较氟吗啉在非灭菌与灭菌的黑龙江黑土、江西红土和河南黄土中的降解情况表明,药剂在非灭菌土中降解明显快,分析可能是土壤中微生物对氟吗啉的降解具有显著的影响。     

Cosmic duality in quintom Universe

In this Letter we study the duality in two-field quintom models of dark energy. We find that an expanding Universe dominated by quintom-A field is dual to a contracting Universe with quintom-B field.     

The role of short exchange length in the magnetization processes of L10-ordered FePt perpendicular media

A three-dimensional micromagnetic model with non-uniform grain size distribution has been built up to study the magnetization process in FePt L1₀ perpendicular media. A 3D model of a single FePt magnetic grain is also set up for comparison. The high magneto-crystalline anisotropy K_u results in a short exchange length l_ex in FePt nanograins. Therefore a magnetic grain is divided into smaller grids on the order of l_ex. The simulated perpendicular and longitudinal loops are consistent with experiments, and it is explained why the measured perpendicular H_c is relatively smaller compared with the saturation field of the longitudinal loop in the FePt perpendicular medium.