宝鸡市耕地面积变化及其驱动力分析

本文以宝鸡市耕地面积为研究对象,以宝鸡市2000~2012年耕地面积相关数据为基础,研究宝鸡市耕地面积变化,运用主成分分析法分析影响宝鸡市耕地面积变化的因素. 研究结果表明:宝鸡市耕地面积从2000年的333 840公顷,缩减到2012年的299 600公顷,减少了34 240公顷,减少幅度为10. 26%,呈减少趋势,主要是受到该市人口、经济和农业发展水平的影响,应该认清耕地的现状,提高保护耕地资源的意识.     

滁州市南湖公园园林植物多样性调查研究

应用物种丰富度指数（S）、多样性指数（Shannon －Wiener 指数）、优势度指数（Simpson 指数）和均匀度指数（E）,对滁州市南湖公园绿地的园林植物进行了研究。结果表明：公园内乔木47种,灌木51种,草本37种,竹类2种,藤本2种;物种多样性基本表现为灌木层＞乔木层＞草本层;物种均匀度总体上为灌木层＞乔木层＞草本层;群落类型主要为乔木＋草本（小乔木及灌木＋草本）,乔木＋地被灌木＋草本（乔木＋小乔木及灌木＋草本）,乔木＋小乔木及灌木＋地被灌木＋草本。建议在构建较高物种多样性植物群落的同时,优先选择乡土野生花卉。     

Comparative study on degradation of ethylene-propylene rubber for nuclear cables from gamma and beta irradiation

Considering safety is the priority concern of nuclear power plants, equipment qualification testing of the nuclear components manufactured should be paid special attention to. Thereinto, equivalent conversion (1:1) from the absorbed beta doses to gamma doses is a rule of thumb for irradiation qualification testing of the polymers used as nuclear cables, however whether it is reasonable and applicable to Chinese domestic polymers still requires investigation. In this paper, both gamma and beta irradiation testing with the actual dose rates and total absorbed doses in China Advanced Passive (CAP) series nuclear power plant was performed upon one domestically manufactured ethylene-propylene rubber intended for nuclear cable insulation in China. The mechanical and the electrical properties before and after irradiation were measured to compare the extent and the trend of degradation between the two irradiation types, and related oxidation degradation mechanism especially its attenuation along the thickness was quantitatively addressed.     

基于SBE法的北京城市公园植物景观美学质量评价

在全面踏查北京3个代表性城市公园的基础上,选取公园内36个典型植物群落景观作为研究对象,运用心理物理学派的美景度评价法(SBE法)对其进行美学质量评价,以寻求最佳植物配置模式,并建立美景度与主要景观因子之间的景观评价模型。结果表明：公园36个植物景观美景度值范围为-1.521-1.839,评价值相对较高的为乔灌草复层结构,而其中以乡土树种为主、郁闭度较大、树种组成及色彩数量相对较丰富的植物群落更受群众欢迎;不同群落结构景观美景度体现出乔灌草结构﹥乔草结构﹥灌草结构﹥草坪结构;植物群落景观的郁闭度、生活型构成、树种组成数量对公园景观美学质量影响较大,建立的多元线性评价模型能够较准确的进行公园美景度预测。     

Ionic liquid-based microwave-assisted extraction of rutin from Chinese medicinal plants

An ionic liquid-based microwave-assisted extraction (ILMAE) method has been developed for the effective extraction of rutin from Chinese medicinal plants including Saururus chinensis (Lour.) Bail. (S. chinensis) and Flos Sophorae. A series of 1-butyl-3-methylimidazolium ionic liquids with different anions were investigated. The results indicated that the characteristics of anions have remarkable effects on the extraction efficiency of rutin and among the investigated ionic liquids, 1-butyl-3-methylimidazolium bromide ([bmim]Br) aqueous solution was the best. In addition, the ILMAE procedures for the two kinds of medicinal herbs were also optimized by means of a series of single factor experiments and an L₉ (3⁴) orthogonal design. Compared with the optimal ionic liquid-based heating extraction (ILHE), marinated extraction (ILME), ultrasonic-assisted extraction (ILUAE), the optimized approach of ILMAE gained higher extraction efficiency which is 4.879 mg/g in S. chinensis with RSD 1.33% and 171.82 mg/g in Flos Sophorae with RSD 1.47% within the shortest extraction time. Reversed phase high performance liquid chromatography (RP-HPLC) with ultraviolet detection was employed for the analysis of rutin in Chinese medicinal plants. Under the optimum conditions, the average recoveries of rutin from S. chinensis and Flos Sophorae were 101.23% and 99.62% with RSD lower than 3%, respectively. The developed approach is linear at concentrations from 42 to 252 mg L⁻¹ of rutin solution, with the regression coefficient (r) at 0.99917. Moreover, the extraction mechanism of ILMAE and the microstructures and chemical structures of the two researched samples before and after extraction were also investigated. With the help of LC-MS, it was future demonstrated that the two researched herbs do contain active ingredient of rutin and ionic liquids would not influence the structure of rutin.     

Optimized ultrasound‐assisted extraction procedure for the analysis of opium alkaloids in papaver plants by cyclodextrin‐modified capillary electrophoresis

This study investigated the use of ultrasound‐assisted extraction to improve the extraction efficiency of morphine, codeine and thebaine from the papaver plants. Extraction conditions such as type of solvent, temperature, duration, frequency and power level of ultrasonic were optimized and the influences of different parameters on resolution of alkaloids in CE were studied. The optimized condition for CE separation includes a sodium phosphate buffer (100 mM, pH 3.0) containing 5 mM α‐CD. The optimized extraction conditions for ultrasound‐assisted extraction was an extraction time of 1 h, an ultrasonic frequency of 60 kHz with water–methanol (80:20) at 40°C as the extraction solvent. The LOD for alkaloids was found to be 0.1 μg/mL at a signal‐to‐noise ratio of 3:1. The RSDs for peak areas were in the range of 1.4–4.4%. The amounts of opium alkaloids (mg/100 g dried sample) in four Iranian papaver plants were found to be in the range of 7.8–8.7 (morphine), 5.5–9.5 (codeine) and 1.4–10.4 (thebaine). It should be emphasized that no cleanup of the filtered extract was required; hence, direct determination after extraction drastically simplifies the analytical process.     

脉冲喷洒杀虫剂的植物病害模型的周期解

本文研究脉冲喷洒杀虫剂的植物病害模型.考虑在传染率随时间周期变化和森林树木总数保持不变的条件下,讨论具有垂直传播的一类具有单个种群的脉冲喷洒农药的SIRS模型,根据单值算子和Bohl-Brouaser不动点理论证明了无病周期解存在性,并且利用单值矩阵,Floquet理论得到其基本再生数并且给出了其无病周期解局部渐近稳定的条件.     

Determination of potentially toxic heavy metals in traditionally used medicinal plants for HIV/AIDS opportunistic infections in Ngamiland District in Northern Botswana

The determination of four potentially toxic heavy metals, arsenic, chromium, lead and nickel in twelve plant species used for the treatment of perceived HIV and AIDS-associated opportunistic infections by traditional healers in Ngamiland District in Northern Botswana, a metal mining area, was carried out using atomic absorption spectrometry. The medicinal plants; Dichrostachys cinerea, Maerua angolensis, Mimusops zeyheri, Albizia anthelmintica, Plumbago zeylanica, Combretum imberbe, Indigofera flavicans, Clerodendrum ternatum, Solanum panduriforme, Capparis tomentosa, Terminalia sericea and Maytenus senegalensis contained heavy metals in varying quantities: arsenic 0.19–0.54 μg g⁻¹, chromium 0.15–1.27 μg g⁻¹, lead 0.12–0.23 μg g⁻¹ and nickel 0.09–0.21 μg g⁻¹ of dry weight. Chromium was found to be the most abundant followed by arsenic and lead. Nickel was undetectable in nine plant species. M. senegalensis contained the largest amounts of arsenic, chromium and lead. All metals determined were below the WHO permissive maximum levels. The possible maximum weekly intakes of the heavy metals following treatment regimes were insignificant compared to the provisional tolerable weekly intake levels recommended by WHO and the Joint FAO/WHO Expert Committee on Food Additives. This suggests that heavy metal exposure to patients originating from consumption of traditional medicinal plant preparations is within non health-compromising limits.     

珍稀濒危植物迁地保护与园林应用——以南宁植物园为例

为加强南宁植物园珍稀濒危植物迁地保护及应用工作，通过实地调查和资料搜集，对南宁植物园珍稀濒危植物的种类、组成和多样性进行分析与评估，并对园林应用的可能性进行探索。结果表明，(1)南宁植物园共有珍稀濒危维管植物37科66属234种，均属于国家重点保护野生植物；其中属于《濒危野生动植物种国际贸易公约》(CITES)的有5科17属134种；属于世界自然保护联盟(IUCN)濒危物种红色名录的有33科62属210种；属于极小种群的有10科13属32种；属于广西壮族自治区重点保护植物的有1种。(2)园林应用上可分为生长型(常绿乔木、落叶乔木、常绿灌木、多年生草本)、观赏型(观花、观叶、观形、观果、观茎和芳香植物)和生态型(喜阳、中性、耐阴)3种。(3)兰科(Orchidaceae)、苏铁科(Cycadaceae)和山茶科(Theaceae)种数最高，分别为126种、22种和12种。(4)南宁植物园中珍稀濒危植物花期集中在4-8月，果期集中在9-11月，能较好地应用于景观。总体而言，南宁植物园迁地保护植物偏向于裸子植物和受威胁植物种类。目前突出的问题是珍稀濒危植物数量仍较少，对区域性国家重点保护野生植物种质资源的搜集尚不全面，种类多样性仍有待提高。园中适应性较好和普通的种类达95.30%，在园林应用方面可进一步结合优势作出更为精细的管理。本研究为南宁植物园珍稀濒危植物迁地保护、后期回归与园林应用提供了科学基础和参考。     

河北省盐生植物区系的初步研究

从科、属 2个层次对河北省盐生植物区系进行了统计分析 ,得出如下结论 :(1)盐生植物共计有 2 5科、6 2属、91种 ;(2 )植物区系基本上属于温带性质 ;(3)特有现象无