TWO NEW ANTIEPILEPSY COMPOUNDS——OTOPHYLLOSIDES A AND B

Two new C_(21) steroidal constituents, named otophylloside A(Ⅳ) and otophylloside B(Ⅴ), have been isolated from the roots of Cynanchum otophyllum Schneid, whose structures have been analysed in this paper by using X-ray crystallography and spectrometric data (UV, IR, ~1H- and ~(13)C-NMR, MS) and chemical reaction. They were found to be active against epilepsy, Ⅳ and Ⅴ can protect rats from a udlogenic seizures(AS) and its ED_(50)=10.20mg/kg.     

PHOTOPHYSICS STUDIES OF ORGANIC COMPOUNDS——NANOSECOND LASER PHOTOLYSIS AND TRANSIENT ABSORPTION SPECTRA STUDIES OF PYRENE-AROMATIC AMINES

Nanosecond time-resolved transient absorption spectra of pyrene-triphenylamine, pyrenediphenylamine, pyrene-N, N-dibenzylaniline systems in various solvents have been investigated. In nonpolar solvent, pyrene-triphenylamine exciplex and pyrene-N, N-dibenzylaniline exciplex were observed directly. In acetonitrile, the pyrene anion radical, triphenylamine and diphenylamine cation radicals were detected. On the basis of the present experimental facts, the mechanism of fluorescence quenching processes of pyrene in polar and nonpolar solvents has been established.     

SEPARATION AND ACCUMULATION OF Mn, Fe AND THE FORMATION OF Mn NODULES

The sediment samples (including various layers) obtained from 12 stations, 35 Mn nodule samples from 16 stations and water body samples were collected during Mn nodule investigation made in the Pacific Ocean in summer, 1983. The coexisting, separating and accumulating regularities and their relation concerning the formation of Mn nodules are approached through the distribution and partition characteristics of Mn and Fe combined with the data from nearshore area in the East China Sea continental shelf.     

THE FORMATION AND CRYSTAL STRUCTURE OF DIHYDRONITIDINE AND DISCUSSION OF ANTICANCER MECHANISM OF NITIDINE CATION

The paper reports the formation and crystal structure of dihydronitidine, expounds thereasons and conditions of easily formed oxynitidine, and discusses anticancer mechanism ofnitidine (cation). The crystallographic parameters of dihydronitidine are: space group P2_(1/n),a= 12.54(1), b = 9. 148(5), c = 14.748(8)A, β= 92. 12(6)°,Z =4. 4108 independent reflec-tions were collected within the range of 3°≤2θ≤54°, of which 2137 intensity data with I≥3σ(I) were used in the structural determination. The crystal structure has been refined byfull matrix least-square method to a final R of 0.050.     

REACTIONS BETWEEN BORIC ACID AND POLYHYDROXY COMPOUNDS AND THE DEVELOPMENTS OF BORON—SELECTIVE RESINS

A Review with 56 references on the reaction between boric acid and polyhydroxy compounds,and the developments of boron-selective resins.     

SYNTHESIS OF A SERIES OF NOVEL ORGANIC COMPOUNDS WITH TWO-PHOTON ABSORPTION AND TWO-PHOTON PUMPED LASING

Two-photon absorption (TPA) occurs through the simultaneous absorption of two photons via virtual states in a medium. Materials with large TPA cross section are gaining increasing attention recently due to their potential applications in optical data storage, two-photon up-converted lasing, two-photon-laser scanning fluorescence microscopy, optical power limiting and photodynamic therapy1-3. Numerous organic compounds have been investigated both experimentally and theoretically in order to u…     

THE FORMATION OF ALTERNATING TRIADS AND THE FORMATION OF CIS LINKAGE CONFIGURATION BY A PARTICIPATION OF THE ELECTRON DONOR-ACCEPTOR COMPLEX OF THE MONOMERS IN THE COPOLYMERIZATION OF N-PHENYLMALEIMIDE AND 2-CHLOROETHYL VINYL ETHER†

The ¹³C NMR technique of distortionless enhancement by polarization transfer and quaternary ¹³C NMR are used to quantitatively determine the proportion of alternating triad and the proportion of cis/trans linkage configurations at the cyclic N-phenylmaleimide (PMI) monomer units in the copolymers of PMI and 2-chloroethyl vinyl ether (CEVE), which are prepared by a radical initiator in chloroform solvent at 50°C.

The amount of the cis linkage configuration at PMI units is found to be proportional to the amount of alternating CEVE-PMI-CEVE triads in the copolymers; i.e., a relation, (% of cis linkages at PMI units) = (48 ± 5.0%) (mol fraction of CEVE-PMI-CEVE triads), is found in the PMI-CEVE copolymers. It is concluded that the cis linkage configuration is formed predominantly in the process of the formation of the alternating CEVE-PMI-CEVE triads in this copolymerization, and that, according to the Olson-Butler mechanism of a complex participation, 48 ± 5.0% of all the reactions which give CEVE-PMI-CEVE triads is the attack by growing CEVE radicals on the PMI component of an electron donor-acceptor (EDA) complex of the comonomers from the syn direction relative to the CEVE component of the complex. The equilibrium constant K of the 1:1 EDA complexation in chloroform at 25°C is determined to be 0.260 L mol^?1 by ¹H NMR spectroscopy.     

DETERMINATION OF PHOSPHORUS AND FLUORINE IN POLYMERS AND ORGANIC COMPOUNDS WITH Nd~(3+)

Percentages of P or/and F in polymers and organic compounds are found by using Nd~(3+) as pre-cipitant and subsequent titration of excess Nd~(3+) with EDTA after decomposing sample in oxygenflask. The errors of determination are for P<±0.20% and F<±0.30% except fully fluorinatedcompounds.     

MECHANICAL ANALYSIS OF THE FORMATION AND PROPAGATION PROCESS OF FRACTURE SYSTEMS AND ITS APPLICATION

In this paper, the mechanical mechanism and propagation process of crustal fracture system are studied by using the principle and method of fracture mechanics. The trendings of two pairs of the X-shaped shearing fracture networks existing widely on the crust are calculated and the main causes to form them from the earth's rotation and thermal activity are considered. After the formation of X-shaped shearing fracture system, parts of them became a closed one but parts of them became more active and propagated further or interacted on each other since the stress field changed in the whole or regionally. Based on the propagating processes of single fracture and fracture systems, the formation process of the zigzag fractures of shear-tension and shear-compression are studied. Some examples showing that the propagating processes of fracture system can be applied to the research of earthquake prediction, are also indicated in this paper.     

PHOTOOXIDATION OF SOME ORGANIC COMPOUNDS CATALYZED BY DECATUNGSTATES

ＰＨＯＴＯＯＸＩＤＡＴＩＯＮ ＯＦ ＳＯＭＥ ＯＲＧＡＮＩＣ ＣＯＭＰＯＵＮＤＳ ＣＡＴＡＬＹＺＥＤ ＢＹ ＤＥＣＡＴＵＮＧＳＴＡＴＥＳ￥ＢｉｎＹＵＥ；ＳｉＳａｎＺＨＵ；ＧａｏＹａｎｇＸＩＥ；ＹｉＤｏｎｇＧＵ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒ...     

SHOCK TUBE AND MODELING STUDY OF THE IGNITION CHEMISTRY OF SMALL HYDROCARBONS

HEAT-release profiles for the ignition of near-stoichiometric andlean hydrocarbon-oxygen mixtures in incident shock waves weremeasured by the laser schlieren method for methane,ethane,ethy-lene and acetylene.Computer modeling showed that the data canbe accounted for at the molecular level by a reaction mechanismin accord with the results of a wide variety of other experiments.The results support recent proposals that the combustion of C_1and C_2 hydrocarbons can be described well by a single unifiedreaction mechanism.New or revised rate constant expressions forseveral of the key induction zone reactions are derived and dis-cussed.     

~(11)B NMR AND QUANTUM CHEMISTRY STUDIES OF BORATRANE COMPOUNDS

The ~(11)B chemical shifts of boratrane compounds were measured. Quantum chemistry calculations of some of the compounds wore carried out using the CNDO/2 method. Both experimental and calculated results confirmed the existence of the B←N dative bonds in boratranes. The exporimental results indicate that the ~(11)B chemical shifts are influenced by the size of the rings, the characteristics of substituents and steric factors. The calculated results indicate that the strengths of the B←N dative bonds in boratranes are about half of that of a purely "covalent two-electron bond" and therefore, the dative bonds B←N are stronger than those of Si←N in the analogous silatranes, and the boratranes are more stable than silatranes.     

FORMATION AND DYNAMIC CHANGE OF INTERMEDIATES DURING THE SYNTHESIS OF LOWER ALCOHOLS

By means of the in silu IR spectroscopy fast response technique for apulse of gas,the formation and dynamic change of the intermediates on the cat-alyst surface during the synthesis of lower alcohols from CO+H_2 have beenstudied.The intermediates,such as HCOM(1715cm~(-1)),(1670cm~(-1)),HCOOM(1590,1382cm~(-1)),CH_3COM(1730cm~(-1))andCH_3COOM(1563,1434cm~(-1))were detected by IR.It was found that HCOMis the initial intermediate and can be transformed into,the growthof carbon chain is realized by the reaction of HCOM or HCOwith theadsorbed CO and H.HCOOM and CH_3COOM are not the main intermediates inthis expermental conditions.     

THE EFFECT OF INCLUSION COMPOUNDS ON THE PHOTOPHYSICS AND PHOTOCHEMISTRY OF SCHIFF’s BASES

通过形成希夫碱分子与环糊精或脱氧胆酸的包合化合物的方法,不仅可以使一些固态时具有热致变色性质的希夫碱表现出光致变色的性质,延长光产物的寿命,而且也可以在室温下检测到具有光致变色性质的包合化合物的荧光。     

THE STUDY OF PHOTOELECTROCHEHICAL CELLS BASED ON CHLOROPHYLL AND ORGANIC DYES

Tetraiodofluorescein(TIF)and safranine T(ST)had great effects on the photovoltaicparameters of the cells.The Voc of the cells was about 3-5 times higher than that of thecells without TIK and ST,Isc increased 1 to 2 orders of magnitude.The Voc and Isc couldbe increased greatly only when Voc and Isc of the cell with Pt as WE properly combinedwith the Voc and Isc produced by chla in the original cell.According to absorption spectraand output characters,the results were elucidated.     

CHEMISTRY OF DENUDATINE I. THE REACTIONS OF DENUDATINE AND DIACETYLDENUDATINE WITH NBS-HOAc

The reactions of denudatine 1 and diacetyldenudatine 2 with NBS-50% HOAc soln. afforded 4 and 6, respectively, in high yields.Treatment of 6 with (Ac)_2CO-Pyr. gives 7. The structures of 3,6 and 7 were deduced on the basis of spectral and chemical methods.     

THE FORMATION, EVOLUTION AND CAUSE OF THE Mu Us DESERT IN CHINA

Comprehensive correlation and analysis on the stratigraphic structure of the Quaternaryeolian sand in the Mu Us Desert comfirm that the Desert has been in existenceintermittently since the initial stage of the Quaternary at latest. The Desert is asteppe type sandy desert characterized by mosaic distribution of shifting, semi-shifting, semi-fixed and fixed dune and areas of loess grass land. It did not evolve toward uniform shift-ing sand, but underwent a series of normal and reverse development processes from the occur-rence of shifting sand to the spread, fixation and reduction of the sandy desert to grassland.Climatic fluctuation since the Quaternary is the primary factor for the formation and evolutionof the Desert, while neotectonics and human activities are the secondary factors.     

A STUDY ON THE ACTIVITY OF Mo-Fe-S CLUSTER COMPOUNDS FOR CATALYTIC REDUCTION OF C_2H_2 AND ITS RELATION TO THE COMPOSITION AND STRUCTURE OF SUCH COMPOUNDS

Activity on catalytic reduction of C_2H_2 for seven Mo-Fe-S cluster compounds (I. (Et_4N_4)_4[Mo_2Fe_2S_(10)]·2CH_3OH, Ⅱ. Mo_2Fe_2S_4(S_2CNEt_2)_5·CH_3CN, Ⅲ. (Bu_4N)_3 [Mo_2FeS_8O]·Ⅳ·(Et_4N)_3[Mo_2FeS_8O_2], V. (Et_4N)_2[MoFeS_4(SCN)_2(OCH_3)_2]·3CH_3OH, Ⅵ. (Et_4N)_3[Mo_2FeS_8O(OCH_3)_2], Ⅶ. (Et_4N)_4Mo_2Fe_7S_(12)(SPh)_6·6CH_3OH), three Fe-S cluster compounds (Ⅷ.(Et_4N)_2[Fe_4S_4(S_2CNEt_2)_4], Ⅸ. (Bu_4N)_2[Fe_4S_3(SC(CH_3)_3)_4], Ⅹ. (Bu_4N)[Fe_2S_3(SCH_2Ph)_2]) and combination systems of related compounds, has been determined under anaerobic conditions at 25℃ and with KBH_4 as the reductant. In addition, at 15℃, under otherwise the same conditions, activity on catalytic reduction of C_2H_2 for different constituent systems from (NH_4)_2MoS_4 and FeCl_3 has also been determined.     

AGE OF THE LONGYIN FORMATION IN SOUTHWEST GUIZHOU PROVINCE——A DISCUSSION ABOUT THE CORRELATION OF THE LOWER PERMIAN BETWEEN SOUTH CHINA AND THE URAL OF USSR

The Permian Artinskian age of the Longyin Formation is indicated by the appearanceof the ammonoid Popanoceras fauna at its lowermost part. The upper Maping Formationin South China should include all the Sakmarin deposit at least.     

FORMATION OF THE CRYSTALLINE INCLUSION COMPLEX BETWEEN β-CYCLODEXTRIN AND POLYPROPYLENE

PP can be included in the cavities of cyclodextrin (CD). The crystalline inclusion complex between β-CD and lowmolecular weight polypropylene (PP) was obtained and investigated. α-CD and γ-CD did not form crystalline inclusioncomplexes with PP. The FTIR spectra, TGA, X-ray diffraction spectra were studied, ~1H-NMR spectra and ~(13)C CP/MAS NMR spectra were used to characterize the crystalline inclusion complexes.