Preface to the special issue: Macrocyclic and supramolecular chemistry

The 14th Conference of Macrocyclic Chemistry and the 6th Conference of Supramolecular Chemistry was held in Northwest Normal University in Lanzhou, Gansu     

PREFACE

The 6~(th)International Symposium on Polymer Physics was held in Dali,China,from June 1-5,2004.Thissymposium was orzanized bv The State Kev Laboratorv of Polvmer Physics and Chemistry,China,TheUniversity of Akron,USA,The Tohoku University,Japan,and The Institute Of Charles Sadron,France.It wassponsored by the National Natural Science Foundation of China,The Chinese Academy of Sciences(CAS),TheInstitute of Chemistry,CAS,The Changchun Institute of Applied Chemistry,CAS,and The Polymer Division,Chinese Chemical Society     

Investigation on Gas Storage in Methane Hydrate

The effect of additives (anionic surfactant sodium dodecyl sulfate (SDS), nonionic surfactantalkyl polysaccharide glycoside (APG), and liquid hydrocarbon cyclopentane (CP)) on hydrate inductiontime and formation rate, and storage capacity was studied in this work. Micelle surfactant solutions werefound to reduce hydrate induction time, increase methane hydrate formation rate and improve methanestorage capacity in hydrates. In the presence of surfactant, hydrate could form quickly in a quiescentsystem and the energy costs of hydrate formation were reduced. The critical micelle concentrations of SDS and APG water solutions were found to be 300x 10-6 and 500x 10-6 for methane hydrate formation systemrespectively. The effect of anionic surfactant (SDS) on methane storage in hydrates is more pronounced compared to a nonionic surfactant (APG). CP also reduced hydrate induction time and improved hydrateformation rate, but could not improve methane storage in hydrates.     

15th Chinese International Peptide Symposium

正As one of the most important and influential peptide conferences in the world,Chinese International Peptide Symposium(CPS)was founded in 1990 and has been held every two years for14 consecutive sessions.From July 4~(th)to 6~(th),2018,the 15th CPS will be held in Shenzhen and hosted by Tsinghua University.This conference will focus on the topics of"Peptide:Technological Innovation and a Better Life",covering the synthesis,structure and function of peptides and proteins,peptide-based drug discovery,     

IN MEMORY OF PROFESSOR REN-YUAN QIAN

1917-2003Professor Ren-yuan Qian, Member of the Chinese Academy of Sciences, associateeditor-in-chief of this journal, passed away on December 6th, 2003 in Beijing.He was born on September 19th, 1917 in Changshu, Jiangsu Province and graduatedfrom the Chemistry Department of Zhejiang University in 1939. In the year of 1943,he went to the United States to undert postgraduate studies mainly at the University ofWisconsin.In 1948, he returned to China and worked for Xiamen University and …     

PREFACE

The 8~(th) International Symposium on Polymer Physics was held in Xiamen,China,in the period of June 8-12, 2008.This symposium was organized by The State Key Laboratory of Polymer Physics and Chemistry,China, MPI for Polymer Research,Germany,The University of Massachusetts,USA,and The Hokkaido University, Japan.It was sponsored by the National Natural Science Foundation of China,The Chinese Academy of Sciences (CAS),Institute of Chemistry,CAS,Changchun Institute of Applied Chemistry,CAS,Polymer Division,...     

International Conference on Liquid Crystal Polymers

Under the sponsorship of the International Union of Pure and Applied Chemistry (IUPAC)and Chinese Chemical Society, the International Conference on Liquid Crystal Polymers was heldat the Twenty-First Century Hotel, Beijing China, in 6-9 September 1994. The conference Chair-man and Secretary general were Professors Q. F. Zhou of Peking University and X. J. Wang of     

Preface

<正>The Ninth Sino-US Chemistry Professors Conference:Frontiers and Challenges in the Rapid Development of Chemistry The Ninth Sino-US Chemistry Professors Conference was successfully held in Chengdu,China from July 12th to July 14th,2013.This conference was co-organized by College of Chemistry of Sichuan University and the Chinese-American ChemistryChemical Biology Professors Association(CAPA)in USA,chaired by Professors Xiaoqi Yu and Xiaoming Feng at Sichuan University,and co-chaired by Professors Zucai Suo,Zhen Huang,and Lin Pu from CAPA.     

Use of HPHT Autoclave to Determine Corrosion Inhibition Effect of Poly（methyl methacrylate-co-N-vinyl-2-pyrrolidone） on Carbon Steels in 3.5% NaCl Solution Saturated with CO2

The influence of poly(methylmethacrylate-co-N-vinyl-2-pyrrolidone), P(MMA-co-VP), on corrosion of carbon steels(J55, N80, P110 SS and C110 steels) in 3.5 wt% NaCl solution saturated with CO2 was evaluated using static high pressure and high temperature(HPHT) autoclave. The surface was further evaluated by X-ray diffraction(XRD), scanning electron microscopy(SEM) and contact angle measurements. Quantum chemical calculations have been used to evaluate the structural, electronic and reactivity parameters of the inhibitor on the steels surface. SEM, XRD and contact angle measurement studies reveal that the surface of metals are quite unaffected after use of inhibitor in 3.5% NaCl solution saturated with CO2.     

PREFACE

The 10th Intemational Symposium on Polymer Physics was held in Chengdu,China,from June 4th to 8th,2012.This symposium was organized by The State Key Laboratory of Polymer Physics and Chemistry,China,MPI for Polymer Research,Germany,The University of Massachusetts,USA,and The HokkaidoUniversity,Japan.It was sponsored by the National Natural Science Foundation of China,Beijing NationalLaboratory for Molecular Sciences,The Chinese Academy of Sciences (CAS),Institute of Chemistry,CAS,Changchun Institute of Applied Chemistry,CAS,Polymer Division,Chinese Chemical Society,andSichuan University.     

A journey through the pre-Budapest-2013 k 0 Users Workshops

A short survey is given of the five meetings preceding the 6th International k ₀ Users Workshop that was held from 22 to 27 September in Budapest/Hungary. These predecessors were the Workshops in: Gent/Belgium (1992), Ljubljana/Slovenia (1996), Bruges/Belgium (2001), Funchal-Madeira/Portugal (2005) and Belo Horizonte/Brazil (2009).     

21世纪毛细管电泳技术及应用发展趋势

在21世纪，毛细管电泳技术面临着新的挑战和机遇，在其检测手段，仪器的小型化和集成化，以及分离模式上都存在着极大的发展空间，文中针对这三方面的发展趋势和毛细管电泳的应用进行了讨论。     

Preface

The 5th Russian Conference on the Scientific Foundations of Catalyst Preparation and Technology and the 4th Russian Conference on Problems of Catalyst Deactivation (Omsk, September 6–9, 2004)

Preface     

Determination of Flavonoids Compounds of Three Species and Different Harvesting Periods in Crataegi folium Based on LC-MS/MS

Crataegi folium have been used as medicinal and food materials worldwide due to its pharmacological activities. Although the leaves of Crataegus songorica (CS), Crataegus altaica (CA) and Crataegus kansuensis (CK) have rich resources in Xinjiang, China, they can not provide insights into edible and medicinal aspects. Few reports are available on the qualitative and quantitative analysis of flavonoids compounds of their leaves. Therefore, it is necessary to develop efficient methods to determine qualitative and quantitative flavonoids compounds in leaves of CS, CA and CK. In the study, 28 unique compounds were identified in CS versus CK by qualitative analysis. The validated quantitative method was employed to determine the content of eight flavonoids of the leaves of CS, CA and CK within 6 min. The total content of eight flavonoids was 7.8–15.1 mg/g, 0.1–9.1 mg/g and 4.8–10.7 mg/g in the leaves of CS, CA and CK respectively. Besides, the best harvesting periods of the three species were from 17th to 26th September for CS, from 30th September to 15th October for CA and CK. The validated and time-saving method was successfully implemented for the analysis of the content of eight flavonoids compounds in CS, CA and CK for the first time.     

Fluorescent high-performance liquid chromatography of folic acid and its derivatives using permanganate as a fluorogenic reagent

Summary A fluorescent high-performance liquid chromatography (HPLC) analysis of folic acid (pteroylglutamic acid) and its derivatives using permanganate as a fluorogenic reagent has been developed. In the present work, the various analytical conditions in which the fluorogenic reaction with permanganate could be applied to the HPLC of folic acid in human serum, have been studied. The present method may be employed for the rapid clinical analysis of small amounts of folic acid (150 ppb), without interference from coexisting natural fluorophors; the precision of the present method for folic acid was 6.6% (n=6) (coefficient of variation).Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthdayA part of this paper was presented at the 12th International Symposium on Microchemical Techniques, Cordoba (Spain), September 1992     

The measurement of neutron-induced radionuclides from Chinese nuclear weapons tests

The concentrations of neutron-induced radionuclides have been measured in ground level air during the period between 1976 and 1981 at Nagoya (35° N, 137° E), Japan. Six Chinese atmospheric nuclear weapons tests were conducted by the government of China at Lop Nor (40° N, 90° E) during the period 1976–1981. The Chinese nuclear tests of November 17, 1976 (the 21st test) and October 16, 1980 (the 26th test), high-yield devices, produced⁵⁴Mn,⁵⁵Fe and⁸⁸Y whose production reactions are⁵⁴Fe(n, p),⁵⁶Fe(n, 2n) and⁸⁹Y(n, 2n), respectively. The tests of September 26, 1976 (the 19th test), September 17, 1977 (the 22nd test) and March 15, 1978 (the 23rd test), low-yield devices, produced⁵⁴Mn,⁵⁷Co and⁵⁸Co whose production reactions are⁵⁴Fe(n, p),⁵⁸Ni(n, pn) and⁵⁸Ni(n, p) respectively. No neutron activation product from the 24th test (December 14, 1978) was observed.     

Doping profile techniques for Si epitaxial layers

Various methods (e.g. spreading resistance and C-V measurements, neutron activation analysis, SIMS) have been used to determine concentration distributions of antimony dopant and charge carriers in single and double epitaxial silicon layers. Comparing the results obtained by the methods, an increased dopant diffusion process could be observed in the epitaxial layer during neutron irradiation of the sample, which arose as a systematic error in the NAA method. The origin of the deviations is discussed. 6th Colloquium on Microwawe Communication, Budapest, 29th August-1st September 1978.     

Synthesis of 5-and 7-fluoroquinazolin-4(1<Emphasis Type="Italic">H</Emphasis>)-ones

5-Fluoroquinazoline-2,4-diones and their 2-thio analogs were obtained from 6-fluoroanthranilic acid. Two convenient routes to 5-fluoroquinazolin-4-ones involved cyclocondensation of 6-fluoroanthranilamide with acid chlorides (anhydrides) or with aromatic (heterocyclic) aldehydes. A method for the synthesis of 7-fluoroquinazolin-4-one from 2,4-difluorobenzoic acid was proposed. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1758–1764, September, 2007.     

Substitution of the halogen atoms in α-halogenonitro compounds of the aliphatic series. 5. Use of the MNDO method to explain the behavior of the chlorine atom in the substitution reactions of chloronitroacetic acid derivatives

The geometric parameters, bond orders, and charge distributions in the molecules of ethyl nitroacetate (I), ethyl chloronitroacetate (II), chloronitroacetamide (III), ethyl chloroacetate (IV), and the anions of ethyl chloronitroacetate (V) and chloronitroacetamide (VI) were calculated by the MNDO method. On the basis of the calculated data and their comparison with the data from x-ray crystallographic analysis (XCA) it was concluded that the nitro group in (II) and (III) is substituted relatively easily, that the order of the C-N bond in (V) and (VI) is close to first, that the charges in the anions alternate, and that there is no conjugation in the C-Cl bond in the.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2012–2017, September, 1990.     

Square Planar (SP-4) and Octahedral (OC-6) Complexes of Platinum(II) and -(IV) with Predetermined Chirality at the Metal Center

cis-Bis-homoleptic platinum(II) complexes, with predetermined helical chirality at the metal center, can be obtained by using strongly sterically interacting ligands. With this aim, two new ligands, (8R,10R)-2-(2'-thienyl)-4,5-pinenopyridine, th4,5ppy (2), and (8R,10R)-2-(2'-thienyl)-5,6-pinenopyridine, th5,6ppy (4), were synthesized and coordinated to platinum. The structures of the resulting complexes, Pt(th4,5ppy)(2) (5) and Pt(th5,6ppy)(2) (6), were determined by X-ray diffraction, and it was found that they both crystallize with a Delta-cis configuration. Thermal oxidative additions (TOA) of alkyl halides were performed with both complexes leading, in the case of 5, to a mixture of isomers and, in the case of 6, to isomerically pure products. The predetermination of chirality at the metal center is therefore preserved in the octahedral (OC-6) platinum(IV) complexes. Crystals of Pt(th4,5ppy)(2) (5) are orthorhombic, of space group P2(1)2(1)2(1), with a = 12.973(1) ?, b = 13.619(2) ?, c = 17.665(2) ?, alpha = beta = gamma = 90 degrees, and Z = 4. Final R = 0.0268 and R(w) = 0.0424 for 3101 observed reflections. Crystals of Pt(th5,6ppy)(2) (6) are hexagonal, of space group P6(1), with a = 11.5465(4) ?, b = 11.5465(4) ?, c = 35.356(3) ?, alpha = beta = 90 degrees, gamma = 120 degrees, and Z = 6. Final R = 0.0424 and R(w) = 0.0845 for 2660 observed reflections. Neither molecule possesses a crystallographic C(2) symmetry.