Polymerization of mixed alpha-olefins originating from the Fischer-Tropsch synthesis catalyzed by theBu)_3/[Me_2NHPh]^+[B(C_6F_5)_4]^-,was studied.The effects of the Zr/olefin mole ratio,Al/Zr mole ratio,reaction temp...Polymerization of mixed alpha-olefins originating from the Fischer-Tropsch synthesis catalyzed by theBu)_3/[Me_2NHPh]^+[B(C_6F_5)_4]^-,was studied.The effects of the Zr/olefin mole ratio,Al/Zr mole ratio,reaction temperature,and reaction time on the viscosity and molecular weight of the product were investigated.The conversion under optimized conditions reached 97.3%.The product structure was characterized by ^(13)C NMR spectrometry and ~1H NMR spectrometry,and the conversion of olefins with different carbon numbers under different conditions was determined by GC analysis.The polymer obtained under optimized conditions has a high viscosity index of 262 with a narrow molecular weight distribution of 1.95,which is a desired component for lubricating base oil.展开更多
Low-temperature viscosity of lube oils mixed with paraffinic base oil and naphthenic base oil at different mass ratios has been tested by experiments. The influence of paraffinic base oil on the performance of naphthe...Low-temperature viscosity of lube oils mixed with paraffinic base oil and naphthenic base oil at different mass ratios has been tested by experiments. The influence of paraffinic base oil on the performance of naphthenic base oil was investigated by studying the low-temperature viscosity of tested oils. The viscosity of lube oils increased with an increasing content of high-viscosity paraffinic base oil in the oil mixture. And the low-temperature viscosity was less influenced when the content of paraffinic base oil in the mixture was insignificant. In order to reduce the cost for formulating lubricating oil, a small fraction of paraffinic base oil can be added into naphthenic base oil as far as the property of lubricating oil can meet the specification. According to the study on low-temperature viscosity of the oil mixed with paraffinic base oil and naphthenic base oil, a basic rule was worked out for the preparation of qualified lubricating oils.展开更多
A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphoma(FL).Colonoscopic examination revealed a rectal submucosal tumor(SMT)without any erosions and ulcers.In this patient,it was diff...A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphoma(FL).Colonoscopic examination revealed a rectal submucosal tumor(SMT)without any erosions and ulcers.In this patient,it was difficult to distinguish non-Hodgkin's lymphoma(NHL)invasion from other disorders of the colon including carcinoid tumor merely based on endoscopic findings.Histopathologic and immunohistochemical studies on biopsy specimens showed an infiltration of atypical lymphocytes that were positive for CD20 and BCL2 but negative for UCHL-1.Fluorescence in situ hybridization on paraffin-embedded tissue sections (T-FISH)identified a translocation of BCL2 with IGHgene. Based on these findings,the tumor was defined as an invasion of FL.T-FISH method is useful for the detection of a monoclonality of atypical lymphocytes in an SMT of the gastrointestinal tract,and particularly for the detection of chromosomal translocations specific to lymphoma subtypes.展开更多
文摘Polymerization of mixed alpha-olefins originating from the Fischer-Tropsch synthesis catalyzed by theBu)_3/[Me_2NHPh]^+[B(C_6F_5)_4]^-,was studied.The effects of the Zr/olefin mole ratio,Al/Zr mole ratio,reaction temperature,and reaction time on the viscosity and molecular weight of the product were investigated.The conversion under optimized conditions reached 97.3%.The product structure was characterized by ^(13)C NMR spectrometry and ~1H NMR spectrometry,and the conversion of olefins with different carbon numbers under different conditions was determined by GC analysis.The polymer obtained under optimized conditions has a high viscosity index of 262 with a narrow molecular weight distribution of 1.95,which is a desired component for lubricating base oil.
文摘Low-temperature viscosity of lube oils mixed with paraffinic base oil and naphthenic base oil at different mass ratios has been tested by experiments. The influence of paraffinic base oil on the performance of naphthenic base oil was investigated by studying the low-temperature viscosity of tested oils. The viscosity of lube oils increased with an increasing content of high-viscosity paraffinic base oil in the oil mixture. And the low-temperature viscosity was less influenced when the content of paraffinic base oil in the mixture was insignificant. In order to reduce the cost for formulating lubricating oil, a small fraction of paraffinic base oil can be added into naphthenic base oil as far as the property of lubricating oil can meet the specification. According to the study on low-temperature viscosity of the oil mixed with paraffinic base oil and naphthenic base oil, a basic rule was worked out for the preparation of qualified lubricating oils.
文摘A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphoma(FL).Colonoscopic examination revealed a rectal submucosal tumor(SMT)without any erosions and ulcers.In this patient,it was difficult to distinguish non-Hodgkin's lymphoma(NHL)invasion from other disorders of the colon including carcinoid tumor merely based on endoscopic findings.Histopathologic and immunohistochemical studies on biopsy specimens showed an infiltration of atypical lymphocytes that were positive for CD20 and BCL2 but negative for UCHL-1.Fluorescence in situ hybridization on paraffin-embedded tissue sections (T-FISH)identified a translocation of BCL2 with IGHgene. Based on these findings,the tumor was defined as an invasion of FL.T-FISH method is useful for the detection of a monoclonality of atypical lymphocytes in an SMT of the gastrointestinal tract,and particularly for the detection of chromosomal translocations specific to lymphoma subtypes.
