A STUDY ON THE RECONSTRUCTION OF THE EIGHTEENTH CENTURY MEIYU (PLUM RAINS) ACTIVITY OF LOWER CHANGJIANG(YANGTZE) REGION OF CHINA

This study presents a scheme for delimiting the meiyu period in the Lower Changjiang (Yangtze) region. This scheme was applied to the Clear and Rain Records of Nanjing, Suzhou and Hangzhou to reconstruct the 1723-1800 meiyu climate series. The beginning and ending dates, length, precipitation, and the intensity grades of meiyu were determined. The years of early, heavy, light, and empty meiyu were also given. Statistical analyses of the 18th century meiyu series indicate the existence of the quasi-periodicities of 2-3, 4-5, and 9 years. Many basic characteristics of the modern meiyu also existed in the 18th century. Some characteristics of the Northwest Pacific Subtropical High in the 18th century in typical meiyu years were inferred from the historical meiyu series.     

汞电极表面电荷的快速估算

本文报导了用交流示波极谱快速估算电极表面电荷的方法。该方法使用仪器简单,测量快速,操作简便,在吸附研究中很有用处。     

SILURIAN-DEVONIAN COUPLING OF THE NORTH CHINA AND YANGTZE PLATES: EVIDENCE FROM THE GEOCHEMISTRY OF SEDIMENTARY ROCKS

Major and trace element compositions of a large number of Proterozoic-Tertiary finegrained clastic sedimentary rocks from the Qinling Orogenic Belt and its adjacent southern margin of the North China Platform and northern margin of the Yangtze Platform reveal that the North China and Yangtze plates were coupled during the period of Silurian to Devonian.     

NEW TYPES OF COMMON FRAGMENTS IN THE PERTIDE-PROTEIN BIOREGULATORS CONTAINING CYSTINE

Abstract

Our attempts to investigate the basic principles underlying the structural and functional organization of peptide-protein bioregulators had revealed the presence in their amino acid sequences of two types of “common” fragments. Type 1 was Gly/X-COOH-B-Pro/Val-Pro/Val, X being an amino acid with a free carboxylic group and B - a basic amino acid (arginine, lysine) or a dicarboxylic acid amide; as exemplified by the sequences of α-MSH 10←13, wasp kinin 9←12, ACTH 18←20, α-MSH 22→19, angiotensin 1←3, bradykinin 1←3, insulin B 30→28, ranatensin 4→2, etc. Type II was B-Pro/Val-B-Pro/Val, e.g. sequences of the substance P 1←4, fibrinopeptide B 13←16, bradykinin-potentiating peptide B 6←9, snake venom toxins of Naja Nivea 49→46 and Naja Naja oxiana 46→43, etc. The common fragments were found (1) to contain equifunctional amino acid residues (Lys and Arg, Pro and Val, and others); (2) to occur in the structures of biologically active peptides of widely diverse origins and functions; (3) to be situated in the vicinity of specifically active centres of the molecules and lastly; (4) to affect the activity of the “specific” part of the molecule increasing it, on an average, by three orders of magnitude. The foregoing facts indicate the great importance of these fragments in determining the biological activity of the compounds as well as the universal occurence of the phenomenon.     

STEREOSPECIFIC FORMATION OF A 1,2λ3 -AZAPHOSPETANE IN THE THERMOLYSIS OF BIS[BIS(DIISOPROPYLAMINO)PHOSPHANYL] DIAZOMETHANE

Abstract

Heating of bis[bis(diisopropylamino)phosphanyl]diazomethane 7. in refluxing benzene for 48 hours, quantitatively led to the corresponding 1.2λ³-azaphosphetane 9 as only one diastereoisomer. This result is explained in terms of carbene insertion into a methin-CH bond of an isopropyl substituent. The regiospecificity and the stereospecificity of the ring closure is discussed. Treatment of 9 with elemental sulfur afforded the corresponding 1.2.2λ³-azathiophosphetane 10 which has been characterized b X ray crystallo raphy: C₂₅H₅₆N₄P₂S₂, space group P2(l)/n, a = 13.628 (3) Å, 6 = 19.369 (5) Å, c 112.485 (4) Å, V = 3073 (3) ų.     

室温交联型硅丙微胶乳的合成研究II.改性微胶乳的粒径控制及其微观形态表征

采用种子微乳液聚合法和单体预乳化法分别合成了室温交联型有机硅改性聚丙烯酸酯微胶乳,研究了硅烷单体的添加和氨化反应对改性微胶乳粒子大小及分布的影响。结果表明:采用种子微乳液聚合法得到的硅丙微胶乳粒子大小与硅烷单体的种类、用量和添加顺序无关,平均粒径约为40~60nm。TEM照片显示出,采用种子微乳液聚合法合成的硅丙微胶乳粒子由于内部存在交联结构而导致表面形状不规则,有“乳突”现象;而采用预乳化法合成的硅丙微胶乳粒径粗大,呈规则的球形,氨化后粒径从100nm以上减小到80nm左右,粒子表面出现“绒毛”现象,这是由于硅烷组分的水解反应受到抑制而使粒子内部的交联密度降低的缘故。     

A NEW METHOD ON THE CHEMICAL SYNTHESIS OF DOPED POLYPYRROLE INITIATED BY CuCl_2-C_2H_5OH SYSTEM

Our objectives were to develop a new chemical method for the polymerization of pyrrole. CuCl_2 dissolved in C_2H_5OH solvent is primarily used for the initiation polymerization of pyrrole. The polymers with different yield and conductivity were obtained by raring the initial concentration of Cu~(2+). The initial concentrations of Cu~(2+) varied from 1.2 ×10~(-4) mole to 6.48 ×10~(-3) mole Cu~(2+) with 2.16 ×10~(-2) mole pyrrole. The polypyrrole obtained was characterized with elemental analyzer, XPS, IR spectroscopy, Four-point probe and SEM.