Growth of PbI2 single crystal by the top seed vertical zone melting method

PbI₂ is a type of syntectic compound, and its single crystal is one of the room temperature semiconductor nuclear radiation detector materials. A new method for the growth of the PbI₂ single crystal is proposed in this article, which was named the top seed vertical zone melting method (TSVZMM), directly from the synthesis of polycrystal with analytically pure lead and iodine, by controlling the decomposition and stratification of the melt and the stoichiometry of the PbI₂ crystal. Impurities in the crystal and the coagulating droplets of lead were eliminated during the PbI₂ crystal growth process from the top to bottom by TSVZMM. The PbI₂ single crystal was successfully grown with the size of Φ15 mm×15 mm, an infrared transmittance of more than 40%, a resistivity of 2×10¹² Ω cm magnitude and stoichiometry close to its theoretical value.     

Structural,Pasting, and Thermal Properties of Ultra-high Pressure-treated Lotus Seed Starch

Lotus seed starch(15%, w/w) was subjected to ultra-high pressure(UHP) at 500 MPa for 10~60 min. The effects of UHP on the structural, pasting, and thermal properties of starch were investigated using solid-state 13C CP/MAS NMR, differential scanning calorimetry(DSC), HPSEC-MALLS-RI, and a rapid visco analyzer. The 13C CP/MAS NMR results revealed a reduction in the relative crystallinity and peak intensity of the crystalline state with increasing the UHP time. The molecular weight of native starch was 1.433 × 107 Da, which was higher than that of the UHP-treated starch. Viscograms of UHP-treated starch revealed an increase in paste viscosity, peak time, and pasting temperature and a reduction in breakdown and setback viscosity compared to the native starch. Furthermore, the DSC results showed a reduction in gelatinization temperature and gelatinization enthalpy with increasing the UHP time.     

结构优化的GA算法

本文提出了一种用于结构优化的具有动态种源空间的ＧＡ算法，这种ＧＡ算法可以与其它结构优化方法如齿行法结合起来处理结构优化问题。这种ＧＡ具有很好的鲁棒性和较高的效率，可作为一个黑箱处理相当广泛的结构优化问题。     

Physicochemical characterisation and radical-scavenging activity of Cucurbitaceae seed oils

Oils extracted from Cucurbitaceae seeds were characterised for their fatty acid and tocopherol compositions. In addition, some physicochemical characteristics, total phenolic contents and the radical-scavenging activities were determined. Oil content amounted to 23.9% and 27.1% in melon and watermelon seeds, respectively. Physicochemical characteristics were similar to those of other edible oils and the oils showed significant antioxidant activities. Fatty acid composition showed total unsaturated fatty acid content of 85.2–83.5%, with linoleic acid being the dominant fatty acid (62.4–72.5%), followed by oleic acid (10.8–22.7%) and palmitic acid (9.2–9.8%). The oils, especially watermelon seed oil, showed high total tocopherol and phenolic contents. The γ-tocopherol was the predominant tocopherol in both oils representing 90.9 and 95.6% of the total tocopherols in melon and watermelon seed oils, respectively. The potential utilisation of melon and watermelon seed oils as a raw material for food, chemical and pharmaceutical industries appears to be favourable.     

Formulation and evaluation of quince seeds mucilage – sodium alginate microspheres for sustained delivery of cefixime and its toxicological studies

Quince seed mucilage was used in a combination of sodium alginate to develop sustained-release microspheres of cefixime. Physical characterizations such as FTIR, TGA, DSC, and SEM were performed on the prepared microspheres. The swelling of microspheres was maximum at pH 7.4 and reduced at acidic pH. The average particle size ranged from 679 µm ± 0.21 to 810 µm ± 0.31, while the drug encapsulation efficiency range was found as 73.76 ± 0.24–85.63 ± 0.46. In vitro release profile of QSM-alginate-cefixime microspheres followed Korsmeyer-Peppas model (R² = 0.9732-–0.9946); and release was non-Fickian as we found value of n > 1. This study reveals the benefits of QSM-alginate microspheres for the sustained release of cefixime without any toxicity and it also improved antibacterial properties.     

萃取火焰原子吸收法测定高梁种皮中的硒

本文研究了微量元素硒，用APDC和MIBK萃取，火焰原子吸收法进行测定。通过萃取富集，既克服了硒的原子化效率低而难以测定的缺点，又消除了稳定剂Cu^2 及样品中所含有的其他金属离子对硒测定的干扰，用于高梁种皮中硒的测定，效果良好，方法简单，快速、准确，具有较高的准确度和精密度，相对标准偏差为4.18%，回收率为97.8%。     

种子光与抽运光能量比对布里渊放大的影响

利用瞬态包含抽运抽空的受激布里渊散射理论模型对布里渊放大器进行了数值模拟,给出了布里渊放大器中能量提取效率、种子光放大率、种子光脉宽压缩率和抽运光脉宽压缩率随Stokes种子光与抽运光能量比的变化规律,并用实验进行了验证,理论与实验符合得较好 关键词： 布里渊放大器 提取效率 种子光与抽运光能量比     

浙江龙塘山自然保护区种子植物区系的研究

本文为龙塘山自然保护区种子植物区系的初步研究结果 ,扼要报道了本区系现知的 1356种 (不包括种下等级 113亚种或变种、变型 ) ,分隶 144科 687属;对科、属的性质及分布区类型作了分析 ,表明本区系以温带性成分为主 ,也兼有相当的热带性成分 ,具有亚 热带特性;介绍了本区系世界单种属 38属 ,在中国为单种属的有 39属 ,分布于该地区的中国特有属 19属;珍贵植物 36种及列入中国珍稀保护植物 20种.通过与邻近山地植物区系比较分析 ,表明本区植物区系与西天目山、黄山、庐山的关系最为密切 ,显示出该区具有典型的华东植物区系的特征 .     

用M-C方法计算低能V+注入花生种子的深度-浓度分布

实验表明,低能重离子注入植物种子后的深度-浓度分布曲线是一个非对称高斯分布,直接用LSS理论计算该分布,与实验结果差别甚大.本文根据植物种子的结构特点,对靶材料进行了处理,并对LSS理论进行了修正,用M-C方法计算了初始能量为200keV的V 注入花生种子的深度-浓度分布,得到了与实验结果符合较好的分布曲线.     

Phytochemical screening,total phenolic content and phytotoxic activity of corn (Zea mays) extracts against some indicator species

Allelopathic effects of corn (Zea mays) extracts was studied, against seed germination and seedling growth of Phalaris minor, Helianthus annuus, Triticumaestivum, Sorghum halepense, Z. mays. Bioassay results showed that aqueous extracts of corn root and shoot, markedly affected seed germination, and other parameters compared with related controls. Preliminary phytochemical screening revealed the presence of various phytochemicals such as tannins, phlobatannins, flavonoids, terpenoids and alkaloids in both roots and shoot aqueous extracts. However, saponins were only present in the shoot aqueous extract, while in shoot ethanol extracts, only terpenoids and alkaloids were detected. Additionally, total polyphenolic (TPC) content in aqueous extracts of corn root and shoot, plus ethanol extracts of corn shoot were determined using an Ultraviolet–visible spectroscopy. Results revealed TPC content of the corn shoot aqueous extract showed the highest yield, compared to other extracts. These findings suggest that phytochemicals present in Z. mays extracts may contribute to allelopathy effect.