人参中锗的分光光度法测定

采用灰化法分解人参样品，用分光光度法测定人参中的有机锗含量，方法简便，快捷，回收率为98．90％－99．78％。     

高效液相色谱法测定竹节参中多种人参皂苷含量

建立了高效液相色谱法(HPLC)测定竹节参中人参皂苷Rg1、Re、Rb1、Rb2、Rg2、Rd含量的方法.运用二极管阵列检测器(DAD)峰纯度和光谱检索功能,结合保留时间定性,外标峰面积法定量.采用C18反相柱,以乙腈-水梯度洗脱测定了同一批竹节参总皂苷中人参皂苷Rg1、Re、Rd的含量分别为0.81%、0.15%、2.99%,回收率为93.46%~94.02%,含量及回收率的RSD均小于5%,该方法简便、灵敏,精密度及准确度在允许范围内,可作为竹节参皂苷提取物中多种人参皂苷的同时测定方法.     

Ultrasonic nebulization extraction coupled with headspace hollow fiber microextraction of pesticides from root of Panax ginseng C.A. Mey

The ultrasonic nebulization extraction coupled with headspace hollow fiber microextraction (UNE-HS-HFME) was applied for the extraction of pesticides from root of Panax ginseng C.A. Mey. Experimental parameters, which affect the performances of ultrasonic nebulization extraction coupled with headspace hollow fiber microextraction, such as the kind of acceptor solvent in the pore of the fiber wall, the sample amount, extraction time, salt concentration in extraction solvent, pH of the acceptor solution, the elution time, and times were studied and optimized. The analytes were determined by high-performance liquid chromatography. The detection limits for simeton, monolinuron, chlortoluron, karmex, and prebane are 20.9, 18.4, 18.2, 12.4, and 22.2 μg/kg, respectively. Besides volatile and semi-volatile compounds, the non-volatile compounds also can be determined by the proposed method. The extraction and enrichment process can be performed simultaneously.     

20(R)和20(S)-人参皂甙Rg_2碳氢NMR信号全指定

20 (R)和 2 0 (S) 人参皂甙 Rg2 属于达玛烷型四环三萜类化合物 .应用 2DNMR技术 :1 H 1 HCOSY、HMQC和HMBC全归属 2 0 (R)和 2 0 (S) 人参皂甙 Rg2 碳和氢质子信号 ,为该类型化合物的结构鉴定提供波谱学依据 .     

人参和五灵脂配伍的无机元素含量测定

采用电感耦合等离子体发射光谱法(ICP-AES)测定了人参和五灵脂配伍的无机元素含量。结果表明，人参和五灵脂及其合煎液中的铝含量均低于人参单煎液，人参和五灵配伍可减少有害元素铝的溶出；配伍合煎液中钙、硒、钼、钴、镁、铜、锰等有益元素的含量均高于人参单煎液。     

基于FTIR-SVM的西洋参与籽播参的分类研究

支持向量机(SVM)是根据统计理论提出的一种新的学习算法。文章以40个西洋参样品为实验材料,通过FTIR-SVM建立了西洋参样品与籽播参识别的模型。对学习训练集中的30个样品模型识别率为100%,对10个预测样品的识别准确率为90%。研究结果表明,FTIR-SVM可以用于中药西洋参与籽播参的区别。     

天山云杉凋落物自毒物质分析与初步鉴定

天山云杉凋落物所含化学物质经淋溶释放后对自身种子萌发和幼苗生长有明显的抑制作用,这种自毒作用已造成其种群自然更新不良.本实验采用水溶解、溶剂极性梯度萃取和硅胶柱层析分离法对天山云杉凋落物中自毒物质进行了初分离,利用气相-质谱联机(GC-MS)与核磁共振(NMR)技术,并结合已知标准物质谱图比对,初步鉴定乙醚、乙酸乙酯和正丁醇萃取相中存在的主要植物次生代谢物质.结果显示,存在自毒作用的3种有机萃取相中含包括酚酸、长链脂肪酸、单宁酸和吲哚类物质在内的17种化学物质,其中乙醚萃取相中存在的2-keto-4a-methyl- 8-methoxy-2,3,4,4a,5,6,11,12-ocahydrochrysene(云杉酮)被确定为一个自毒物质.     

离子液体-非极性溶剂微波提取法在人参化学成分研究中的应用

以离子液体作为微波吸收介质建立了离子液体-非极性溶剂微波提取法,对人参中的化学成分进行了提取,并将该法与固体微波吸收介质-非极性溶剂微波提取法、极性溶剂微波提取法以及混合溶剂微波提取法进行了对比.结果表明,极性溶剂提取的主要化学成分为极性化合物,而固体微波吸收介质-非极性溶剂微波提取法与离子液体-非极性溶剂微波提取法相比,提取所得的化学成分并无明显差别,说明离子液体是一种较好的微波吸收介质和能量传递材料.所建立的方法具有提取时间短、操作简单及绿色环保等优点,且对后期分析无明显影响,是快速提取化学成分的理想方法.     

Between Autonomy and Accommodation:The German Physical Society during the Third Reich

I first sketch the history of the German Physical Society (Deutsche Physikalische Gesellschaft,DPG) from its founding by six young Berlin scientists as the Physical Society of Berlin (Physikalische Gesellschaft zu Berlin) in 1845, through its renaming as the DPG in 1899 and its rise to prominence by the beginning of the 1930s. I then turn to the history of the DPG during the Third Reich, which can be divided into two periods, from the transfer of power in Germany to the Nazis in 1933 to 1940, and from 1941 to 1945. During the first period, Johannes Stark (1874–1957), one of the leaders of the “German Physics” (Deutsche Physik) movement, attempted to gain election as the Chairman of the DPG in September 1933 but was repulsed. A period of relative autonomy of the DPG from Nazi ideology and policies ensued, which gradually was transformed into one of accommodation, until at the end of the 1938, Peter Debye (1884–1966), then Chairman of the DPG, bowed to governmental demands and Nazi activists in the DPG, introduced Nazi principles, and strongly advised the Jewish members of the DPG to withdraw from it. Debye left Germany in early 1940, and after a transitional period in which Jonathan Zenneck (1871–1959) served as Acting Chairman, Carl Ramsauer (1879–1955) was elected Chairman of the DPG in December 1940, thus opening the second period, the Ramsauer era, which lasted from 1941 until the end of the war in 1945. Ramsauer oversaw the self-coordination (Selbstgleichschaltung) of the DPG to the Nazi regime, and as an industrial physicist he led the DPG to establish ever more alliances with powerful figures in the military-industrial complex of Nazi Germany, which worked to the advantage both of Ramsauer and the DPG and to that of the Nazi regime during the course of the war. Finally, as the military defeat of Germany loomed, Ramsauer took steps aimed at insuring the survival of German physics in the postwar period. After the war, he masked the wartime activities of himself and the DPG, thereby contributing to the postwar conspiracy of silence or minimization of the Nazi past in Germany. Dieter Hoffmann is a research scholar at the Max Planck Institute for the History of Science and a professor at Humboldt University in Berlin.     

Ginsenoside-Rg6, a Novel Triterpenoid Saponin from the Stem-Leaves of Panax ginseng C. A. Mey.

A novel dammarane-type triterpene oligoglycoside, named ginsenoside-Rg6 3, was isolated from the stem-leaves of Panax ginseng C.A.Mey., together with two known ones, 20(S)-ginsenoside-Rg2 1 and 20(R)-ginsenoside-Rg2 2.On the basis of chemical and physicochemical evidence , the structure of ginsenoside-Rg6 have been elucidated as 6-O-α-L-rhamnosyl-(1→2)-β-D-glucopyranosyl-dammarane-(E)-20(22), 24-diene-3β, 6α, 12β-triol.