Methamidophos (Met) is a broad spectrum organophosphorus insecticide and acaricide.Even a trace of its residue is harmful to humans and many animals.In this study,the synthesis and identification of colloidal gold par...Methamidophos (Met) is a broad spectrum organophosphorus insecticide and acaricide.Even a trace of its residue is harmful to humans and many animals.In this study,the synthesis and identification of colloidal gold particles and antibody-colloidal gold conjugates were performed,and the preparation of colloidal gold immunochromatography strip was conducted for detection of Met residue.The size of colloidal gold particles was checked using a transmission electron microscope (TEM).The formation of antibody-coll...展开更多
A new triterpenoid glycoside 1, 1 beta, 2 alpha, 3 alpha, 19 alpha -tetrahydroxyurs-12-en-28-oic acid beta -D glucopyranosyl ester was isolated from Dichotomanthes tristaniaecarpa. The structure was elucidated on the ...A new triterpenoid glycoside 1, 1 beta, 2 alpha, 3 alpha, 19 alpha -tetrahydroxyurs-12-en-28-oic acid beta -D glucopyranosyl ester was isolated from Dichotomanthes tristaniaecarpa. The structure was elucidated on the basis of spectral means.展开更多
Two new diterpenoids, maoecrystal U and epi-maoecrystal P were isolated from the leaves of Isodon eriocalyx. Their structures were determined as 6 beta-acetoxy-15 beta-hydroxy-3 alpha, 20epoxy-ent-kaur-16-ene-1,7-dion...Two new diterpenoids, maoecrystal U and epi-maoecrystal P were isolated from the leaves of Isodon eriocalyx. Their structures were determined as 6 beta-acetoxy-15 beta-hydroxy-3 alpha, 20epoxy-ent-kaur-16-ene-1,7-dione 1 and 16 (s)-methoxymethyl-6 beta,7 beta-dihydroxy-7 alpha,20-epoxy-ent-kaur-2,3-ethenylene-1, 15-dione 2 respectively, by spectroscopic methods.展开更多
Erigoster A (la), a new compound with a novel basic skeleton, was isolated from Erigeron breviscapus. The structure elucidation and complete proton and carbon NMR assignments were achieved by the utilization of a comb...Erigoster A (la), a new compound with a novel basic skeleton, was isolated from Erigeron breviscapus. The structure elucidation and complete proton and carbon NMR assignments were achieved by the utilization of a combination of two-dimensional NMR techniques.展开更多
A series of rare earth hydroxides and oxides ultrafine powders have been prepared by precipitation method using alcohol as dispersive and proteclive reagent. It was first to find that the crystallite size of cubic rar...A series of rare earth hydroxides and oxides ultrafine powders have been prepared by precipitation method using alcohol as dispersive and proteclive reagent. It was first to find that the crystallite size of cubic rare earth oxides had lanthanide shrinking effect, but average crystal lattice distortion rate possessed lanthanide swelling effect; the change of diffraction intensity with atomic number presented an inverted W type, and double peaks structure was formed.展开更多
Two new amides, tataramide A (1) and tataramide B (2), were isolated from the roots of Acorus tatarinowii Schott. Their structures were determined by spectroscopic methods.
Ceratoside A (1), a new compound was isolated from the butanol-soluble fraction of Ceratostigma willmottianum, Its structure was determined by the utilization of 2D-NMR techniques.
Four new glycosides named ligurobustosides A, B, C and D have been isolated from Ligustrum robustum and their structures identified as geraniol 3-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranoside (1), geraniol-O-alpha-...Four new glycosides named ligurobustosides A, B, C and D have been isolated from Ligustrum robustum and their structures identified as geraniol 3-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranoside (1), geraniol-O-alpha-L-rhamnopyranosyl-4-cafferoyl-beta-D- glucopyranoside (2), geraniol 3-O-alpha-L-rhamnopyranosyl-4-trans-P-coumaroyl -beta-D-glucopyranoside (3) and geraniol 3-O-alpha-L-rhamnopyranosyl-4-cis P-coumaroyl-beta-D-glucopyranoside (4), respectively.展开更多
N-doped FZ-Si crystals and N-doped NTD FZ-Si crystals and their annealing behavior have been studied by IR spectrum. Two models of nitrogen configuration, nearly substitutional nitrogen and interstitial nitrogen pair,...N-doped FZ-Si crystals and N-doped NTD FZ-Si crystals and their annealing behavior have been studied by IR spectrum. Two models of nitrogen configuration, nearly substitutional nitrogen and interstitial nitrogen pair, have been proposed and two nitrogen-related IR absorption peaks at 767cm-1 and 963cm-1 have been well explained.展开更多
Two new norditerpenoid alkaloids leucostines A (1) and B (2) have been isolated from the soot of Aconitum leucostomum. Their structures were elucidated on the basis of spectral data and chemical evidence.
Four new taxanes were isolated from the roots of Taxus yunnanensis. Among them, two were determined to contain isobutyrate group and propionyloxy group on C-14 respectively, and one was determined as the least oxygena...Four new taxanes were isolated from the roots of Taxus yunnanensis. Among them, two were determined to contain isobutyrate group and propionyloxy group on C-14 respectively, and one was determined as the least oxygenated taxane. The structures were elucidated by spectroscopic means.展开更多
Grain size control of tungsten powder is essential for high quality tungsten products. Based on studies on the hydrogen reduction process of tungsten oxide, a microcomputer system is described for reduction process co...Grain size control of tungsten powder is essential for high quality tungsten products. Based on studies on the hydrogen reduction process of tungsten oxide, a microcomputer system is described for reduction process control. The system, now running in Zhuzhou Tungsten and Molybdenum Materials Plant, controls the temperature of the reduction furnace and hydrogen pressure. It also controls a mechanical pusher which pushs the boats charged with blue tungsten oxide into the furnace tubes. Some of the technical problems in the process are analysed.展开更多
Electrolyte electroreflectance (EER) has been widely employed to investigate the electronic energy band structure and related physical properties of semiconductors. The electrolyte electroreflectance (EER) method comb...Electrolyte electroreflectance (EER) has been widely employed to investigate the electronic energy band structure and related physical properties of semiconductors. The electrolyte electroreflectance (EER) method combined with electrochemical anodic dissolution was used to study GaAs/GaAlAs multilayer structural materials. According to variation of the EER spectra during anodic dissolution the characteristics of GaAs/GaAlAs multilayer structural materials such as properties of the interface, p-n junction positions and Al content profiles were obtained.展开更多
By the reaction of 1,8-diazabicyclo(5,4,0 )undec-7-ene (DBU) and chloromethylated polystyrene, polymer-anchored catalysts, PCS-DBU,are prepared and found to be effective to catalyze sequentially the cyclization of pro...By the reaction of 1,8-diazabicyclo(5,4,0 )undec-7-ene (DBU) and chloromethylated polystyrene, polymer-anchored catalysts, PCS-DBU,are prepared and found to be effective to catalyze sequentially the cyclization of propylene oxide and the transesterification of propylene carbonate with methanol. It is found that low degree of ring substitution (DRS) of chloromethylated polystyrene, high reaction temperature and the addition of potassium iodide can accelerate the reaction. PCS-DBU can easily be recovered after reaction by filtration and can be reused for many runs.展开更多
From the aerial parts of Clerodendrum indicum, bye new compounds, cleroindicins B-F (1-5) were isolated and their structures identified by spectral method.
基金the National Natural Science Foundation of China (No.39970519)the Guangdong Province Natural Science Foundation (No.05001814,06012298)the Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry and Personnel Ministry,the Tackle Key Research Project of Guangxi Autonomous Region and Nanning City (No.0537007-7-2,200501065B)
文摘Methamidophos (Met) is a broad spectrum organophosphorus insecticide and acaricide.Even a trace of its residue is harmful to humans and many animals.In this study,the synthesis and identification of colloidal gold particles and antibody-colloidal gold conjugates were performed,and the preparation of colloidal gold immunochromatography strip was conducted for detection of Met residue.The size of colloidal gold particles was checked using a transmission electron microscope (TEM).The formation of antibody-coll...
文摘A new triterpenoid glycoside 1, 1 beta, 2 alpha, 3 alpha, 19 alpha -tetrahydroxyurs-12-en-28-oic acid beta -D glucopyranosyl ester was isolated from Dichotomanthes tristaniaecarpa. The structure was elucidated on the basis of spectral means.
文摘Two new diterpenoids, maoecrystal U and epi-maoecrystal P were isolated from the leaves of Isodon eriocalyx. Their structures were determined as 6 beta-acetoxy-15 beta-hydroxy-3 alpha, 20epoxy-ent-kaur-16-ene-1,7-dione 1 and 16 (s)-methoxymethyl-6 beta,7 beta-dihydroxy-7 alpha,20-epoxy-ent-kaur-2,3-ethenylene-1, 15-dione 2 respectively, by spectroscopic methods.
文摘Erigoster A (la), a new compound with a novel basic skeleton, was isolated from Erigeron breviscapus. The structure elucidation and complete proton and carbon NMR assignments were achieved by the utilization of a combination of two-dimensional NMR techniques.
文摘A series of rare earth hydroxides and oxides ultrafine powders have been prepared by precipitation method using alcohol as dispersive and proteclive reagent. It was first to find that the crystallite size of cubic rare earth oxides had lanthanide shrinking effect, but average crystal lattice distortion rate possessed lanthanide swelling effect; the change of diffraction intensity with atomic number presented an inverted W type, and double peaks structure was formed.
文摘Two new amides, tataramide A (1) and tataramide B (2), were isolated from the roots of Acorus tatarinowii Schott. Their structures were determined by spectroscopic methods.
文摘Ceratoside A (1), a new compound was isolated from the butanol-soluble fraction of Ceratostigma willmottianum, Its structure was determined by the utilization of 2D-NMR techniques.
文摘Four new glycosides named ligurobustosides A, B, C and D have been isolated from Ligustrum robustum and their structures identified as geraniol 3-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranoside (1), geraniol-O-alpha-L-rhamnopyranosyl-4-cafferoyl-beta-D- glucopyranoside (2), geraniol 3-O-alpha-L-rhamnopyranosyl-4-trans-P-coumaroyl -beta-D-glucopyranoside (3) and geraniol 3-O-alpha-L-rhamnopyranosyl-4-cis P-coumaroyl-beta-D-glucopyranoside (4), respectively.
文摘N-doped FZ-Si crystals and N-doped NTD FZ-Si crystals and their annealing behavior have been studied by IR spectrum. Two models of nitrogen configuration, nearly substitutional nitrogen and interstitial nitrogen pair, have been proposed and two nitrogen-related IR absorption peaks at 767cm-1 and 963cm-1 have been well explained.
文摘Two new norditerpenoid alkaloids leucostines A (1) and B (2) have been isolated from the soot of Aconitum leucostomum. Their structures were elucidated on the basis of spectral data and chemical evidence.
文摘Four new taxanes were isolated from the roots of Taxus yunnanensis. Among them, two were determined to contain isobutyrate group and propionyloxy group on C-14 respectively, and one was determined as the least oxygenated taxane. The structures were elucidated by spectroscopic means.
文摘Grain size control of tungsten powder is essential for high quality tungsten products. Based on studies on the hydrogen reduction process of tungsten oxide, a microcomputer system is described for reduction process control. The system, now running in Zhuzhou Tungsten and Molybdenum Materials Plant, controls the temperature of the reduction furnace and hydrogen pressure. It also controls a mechanical pusher which pushs the boats charged with blue tungsten oxide into the furnace tubes. Some of the technical problems in the process are analysed.
文摘Electrolyte electroreflectance (EER) has been widely employed to investigate the electronic energy band structure and related physical properties of semiconductors. The electrolyte electroreflectance (EER) method combined with electrochemical anodic dissolution was used to study GaAs/GaAlAs multilayer structural materials. According to variation of the EER spectra during anodic dissolution the characteristics of GaAs/GaAlAs multilayer structural materials such as properties of the interface, p-n junction positions and Al content profiles were obtained.
文摘By the reaction of 1,8-diazabicyclo(5,4,0 )undec-7-ene (DBU) and chloromethylated polystyrene, polymer-anchored catalysts, PCS-DBU,are prepared and found to be effective to catalyze sequentially the cyclization of propylene oxide and the transesterification of propylene carbonate with methanol. It is found that low degree of ring substitution (DRS) of chloromethylated polystyrene, high reaction temperature and the addition of potassium iodide can accelerate the reaction. PCS-DBU can easily be recovered after reaction by filtration and can be reused for many runs.
文摘From the aerial parts of Clerodendrum indicum, bye new compounds, cleroindicins B-F (1-5) were isolated and their structures identified by spectral method.
