The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental a...The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental analysis, IR, XPS, electronic spectra and 31 P NMR. The results show that the complex of η 2 form can be formed by C 60 bonding to Ru(NO) 2(PPh 3) 2 in the σ π way and there is hyperconjugation effect in the molecule. So electrons will flow easier and photoelectric effect for this new compound is expected. In addition, the structure of the complex has been supposed. The ruthenium is 4 coordinate in the complex, bonding to two carbon atoms, to one PPh 3 and to one NO.展开更多
采用熔盐顶部籽晶法从K 2 Mo 3 O 10-B 2 O 3助熔剂中生长出尺寸为20 mm的优质GdAl 3(BO 3)4(简称GAB)和Nd^3+激活的自变频激光晶体。确定了GAB晶体的透光波长范围、折射率和倍频系数随波长的变化,结果表明其在整个透光范围内均可实现...采用熔盐顶部籽晶法从K 2 Mo 3 O 10-B 2 O 3助熔剂中生长出尺寸为20 mm的优质GdAl 3(BO 3)4(简称GAB)和Nd^3+激活的自变频激光晶体。确定了GAB晶体的透光波长范围、折射率和倍频系数随波长的变化,结果表明其在整个透光范围内均可实现相位匹配。测定了Nd^3+∶GAB晶体在室温下的偏振吸收、荧光光谱和荧光寿命,进行了光谱计算,测试了晶体的自变频激光性能,实现了紫外-可见光-红外-中红外多波段激光输出。展开更多
Abstract Ergosterol,（1→3）-α-D-glucan and chitosan are important biomaterials. In this research, a process has been developed to integratively extract ergosterol, （1→3）-α-D-glucan, and chitosan from Penicillium...Abstract Ergosterol,（1→3）-α-D-glucan and chitosan are important biomaterials. In this research, a process has been developed to integratively extract ergosterol, （1→3）-α-D-glucan, and chitosan from Penicillium chrysongenum mycelium. First the mycelia are pretreated with 0.1mol·L^-1 of NaOH. After recovery by centrifugation the solid portion is made to undergo saponification and deacetylation reactaons by addition of 2mol·L^-1 NaOH and et anol.After reaction, extraction is carried out by addition of petroleum ether, which separates the reaction mixture into two phases. The upper layer of petroleum ether contains extracted ergosterol, and the .bottom layer of NaOH solution contains （1→3）-α-DEglucan; the chitosan is on the mycelia residuum. After isolation, the recovery yield of ergosterol is 0.52% of dry mycelium. That of （1→3）-α-D-glucan is about 8.2%; and chitosan is 5.7% with 86% deacetylation. The compositions have been characterized by 1R, HPLC analyses.展开更多
The adsorption and decomposition of trimethylgallium （Ga（CH3）3, TMG） on Pd（111） and the effect of pre-covered H and O were studied by temperature programmed desorption spectroscopy and X-ray photoelectron spectr...The adsorption and decomposition of trimethylgallium （Ga（CH3）3, TMG） on Pd（111） and the effect of pre-covered H and O were studied by temperature programmed desorption spectroscopy and X-ray photoelectron spectroscopy. TMG adsorbs dissociatively at 140 K and the surface is covered by a mixture of Ga（CH3）x （x=1, 2 or 3） and CHx（a） （x=1, 2 or 3） species. During the heating process, the decomposition of Ga（CH3）3 on clean Pd（111） follows a progressive Ga-C bond cleavage process with CH4 and H2 as the desorption products. The desorption of Ga-containing molecules （probably GaCH3） is also identi ed in the temperature range of 275-325 K. At higher annealing temperature, carbon deposits and metallic Ga are left on the surface and start to di use into the bulk of the substrate. The presence of precovered H（a） and O（a） has a signi cant effect on the adsorption and decomposition behavior of TMG. When the surface is pre-covered by saturated H2, CH4, and H2 desorptions are mainly observed at 315 K, which is ascribed to the dissociation of GaCH3 intermediate. In the case of O-precovered surface, the dissociation mostly occurs at 258 K, of which a Pd-O-Ga（CH3）2 structure is assumed to be the precusor. The presented results may provide some insights into the mechanism of surface reaction during the lm deposition by using trimethylgallium as precursor.展开更多
文摘The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental analysis, IR, XPS, electronic spectra and 31 P NMR. The results show that the complex of η 2 form can be formed by C 60 bonding to Ru(NO) 2(PPh 3) 2 in the σ π way and there is hyperconjugation effect in the molecule. So electrons will flow easier and photoelectric effect for this new compound is expected. In addition, the structure of the complex has been supposed. The ruthenium is 4 coordinate in the complex, bonding to two carbon atoms, to one PPh 3 and to one NO.
文摘采用熔盐顶部籽晶法从K 2 Mo 3 O 10-B 2 O 3助熔剂中生长出尺寸为20 mm的优质GdAl 3(BO 3)4(简称GAB)和Nd^3+激活的自变频激光晶体。确定了GAB晶体的透光波长范围、折射率和倍频系数随波长的变化,结果表明其在整个透光范围内均可实现相位匹配。测定了Nd^3+∶GAB晶体在室温下的偏振吸收、荧光光谱和荧光寿命,进行了光谱计算,测试了晶体的自变频激光性能,实现了紫外-可见光-红外-中红外多波段激光输出。
基金Supported by the National Natural Science Foundation of China （No.20636010, No.50373003, No.20406002）, Beijing Natural Science Foundation （No.2071002）, and the Special Funds for Major State Basic Research Program of China （973 Program, No.2007CB714305）.
文摘Abstract Ergosterol,（1→3）-α-D-glucan and chitosan are important biomaterials. In this research, a process has been developed to integratively extract ergosterol, （1→3）-α-D-glucan, and chitosan from Penicillium chrysongenum mycelium. First the mycelia are pretreated with 0.1mol·L^-1 of NaOH. After recovery by centrifugation the solid portion is made to undergo saponification and deacetylation reactaons by addition of 2mol·L^-1 NaOH and et anol.After reaction, extraction is carried out by addition of petroleum ether, which separates the reaction mixture into two phases. The upper layer of petroleum ether contains extracted ergosterol, and the .bottom layer of NaOH solution contains （1→3）-α-DEglucan; the chitosan is on the mycelia residuum. After isolation, the recovery yield of ergosterol is 0.52% of dry mycelium. That of （1→3）-α-D-glucan is about 8.2%; and chitosan is 5.7% with 86% deacetylation. The compositions have been characterized by 1R, HPLC analyses.
文摘The adsorption and decomposition of trimethylgallium （Ga（CH3）3, TMG） on Pd（111） and the effect of pre-covered H and O were studied by temperature programmed desorption spectroscopy and X-ray photoelectron spectroscopy. TMG adsorbs dissociatively at 140 K and the surface is covered by a mixture of Ga（CH3）x （x=1, 2 or 3） and CHx（a） （x=1, 2 or 3） species. During the heating process, the decomposition of Ga（CH3）3 on clean Pd（111） follows a progressive Ga-C bond cleavage process with CH4 and H2 as the desorption products. The desorption of Ga-containing molecules （probably GaCH3） is also identi ed in the temperature range of 275-325 K. At higher annealing temperature, carbon deposits and metallic Ga are left on the surface and start to di use into the bulk of the substrate. The presence of precovered H（a） and O（a） has a signi cant effect on the adsorption and decomposition behavior of TMG. When the surface is pre-covered by saturated H2, CH4, and H2 desorptions are mainly observed at 315 K, which is ascribed to the dissociation of GaCH3 intermediate. In the case of O-precovered surface, the dissociation mostly occurs at 258 K, of which a Pd-O-Ga（CH3）2 structure is assumed to be the precusor. The presented results may provide some insights into the mechanism of surface reaction during the lm deposition by using trimethylgallium as precursor.
