A new baccharane-type triterpene, 3-acetoxy-9(11)-baccharene(1),as well as a known compound, a-amyrin(2), has been isolated from the ether extract of the roots of Saussurea lappa C. B. Clarke. The structure of the new...A new baccharane-type triterpene, 3-acetoxy-9(11)-baccharene(1),as well as a known compound, a-amyrin(2), has been isolated from the ether extract of the roots of Saussurea lappa C. B. Clarke. The structure of the new compound was identified by spectrum analysis.展开更多
[Objective] The aim was to study the reproduction of the three-line genic male sterile (GMS) lineparent Mian7MB-1 (B. NapusL.) and the seed production of F1 through somatic tissue culture. [Methed] Through hybridi...[Objective] The aim was to study the reproduction of the three-line genic male sterile (GMS) lineparent Mian7MB-1 (B. NapusL.) and the seed production of F1 through somatic tissue culture. [Methed] Through hybridization, a new breeding material Mian 7MB-1 in three-line genic temporary maintainer line propagated by tissue culture was used to improve the sterile plant rate of rapeseed in dual-purpose recessive GMS line, such as Mian 7AB type, S45AB type, and etc. And then the variety comparative test was performed. [Result] In order to avoid some fertility restoration phenomena occurring during the process of self-reproduction, Mian 7AB was propagated in bulk with somatic tissue culture of temporary maintainer line plant stem. The propagated temporary maintainer line seedlings were applied to the breeding and seed production of net room male sterile line parent, promoting the sterile plant rate of the male sterile line parent to 91.7% -93.5%. The male sterile line parents per hectare were enough for the seed production of hybrid F1 in 7 500 -15 000 hm^2. [ Conclusion ] Compared with the original dual-purpose GMS line, the seed production ultilizing male sterile line with high sterile plant rate greatly reduced the labor, significantly improved the seed yield, ensuring the seed quality and forming a perfect breeding and seed production system.展开更多
This study proposes a method to derive the climatological limit thresholds that can be used in an operational/historical quality control procedure for Chinese high vertical resolution(5–10 m)radiosonde temperature an...This study proposes a method to derive the climatological limit thresholds that can be used in an operational/historical quality control procedure for Chinese high vertical resolution(5–10 m)radiosonde temperature and wind speed data.The whole atmosphere is divided into 64 vertical bins,and the profiles are constructed by the percentiles of the values in each vertical bin.Based on the percentile profiles(PPs),some objective criteria are developed to obtain the thresholds.Tibetan Plateau field data are used to validate the effectiveness of the method in the application of experimental data.The results show that the derived thresholds for 120 operational stations and 3 experimental stations are effective in detecting the gross errors,and those PPs can clearly and instantly illustrate the characteristics of a radiosonde variable and reveal the distribution of errors.展开更多
In order to investigate the transformation among the precipitation,groundwater,and surface water in the Sanjiang Plain,Northeast China,precipitation and groundwater samples which were collected at the meteorological s...In order to investigate the transformation among the precipitation,groundwater,and surface water in the Sanjiang Plain,Northeast China,precipitation and groundwater samples which were collected at the meteorological station of the Sanjiang Mire Wetland Experimental Station,Chinese Academy of Sciences and the surface water which collected from the Wolulan River were used to identify the transformation of three types of water.The isotope composition of different kinds of water sources were analyzed via stable isotope(deuterium and oxygen-18) investigation of natural water.The results show a clear seasonal difference in the stable isotopes in precipitation.During the cold half-year,the mean stable isotope in precipitation in the Sanjiang Plain reaches its minimum with the minimum temperature.The δ18O and δD values are high in the rainy season.In the Wolulan River,the evaporation is the highest in August and September.The volume of evaporation and the replenishment to the river is mostly same.The groundwater is recharged more by the direct infiltration of precipitation than by the river flow.The results of this study indicate that the water bodies in the Sanjiang Plain have close hydrologic relationships,and that the transformation among each water system frequently occurs.展开更多
In this paper, we reconsider the defining but often overlooked ‘hinge' function of megalopolises by analyzing how megalopolises have articulated national and international urban systems in the context of a global...In this paper, we reconsider the defining but often overlooked ‘hinge' function of megalopolises by analyzing how megalopolises have articulated national and international urban systems in the context of a globalizing knowledge economy. Taking the case of China's Yangtze River Delta(YRD) region, we particularly focus on knowledge circulation within and beyond the YRD region by analyzing the pattern and process of knowledge collaboration at different geographical scales during the 2004–2014 period. Results show that the structure of scientific knowledge collaboration as reflected by co-publications has been strongest at the national scale whereas that of technological knowledge collaboration as measured by co-patents has been strongest at the global scale. Despite this difference, the structure of both scientific and technological knowledge collaboration has been functionally polycentric at the megalopolitan scale but become less so at the national and global scales. The ‘globally connected but locally disconnected' pattern of Shanghai's external knowledge collaboration suggests that the gateway role of the YRD megalopolis in promoting knowledge collaboration at different geographical scales will take time before it is fully realized.展开更多
Three-dimensional(3D) printing(3DP) is a rapid prototyping technology that has gained increasing recognition in many different fields. Inherent accuracy and low-cost property enable applicability of 3DP in many areas,...Three-dimensional(3D) printing(3DP) is a rapid prototyping technology that has gained increasing recognition in many different fields. Inherent accuracy and low-cost property enable applicability of 3DP in many areas, such as manufacturing, aerospace,medical, and industrial design. Recently, 3DP has gained considerable attention in the medical field. The image data can be quickly turned into physical objects by using 3DP technology. These objects are being used across a variety of surgical specialties. The shortage of cadaver specimens is a major problem in medical education. However, this concern has been solved with the emergence of 3DP model. Custom-made items can be produced by using 3DP technology. This innovation allows 3DP use in preoperative planning and surgical training. Learning is difficult among medical students because of the complex anatomical structures of the liver. Thus, 3D visualization is a useful tool in anatomy teaching and hepatic surgical training. However,conventional models do not capture haptic qualities. 3DP can produce highly accurate and complex physical models. Many types of human or animal differentiated cells can be printed successfully with the development of 3D bio-printing technology. This progress represents a valuable breakthrough that exhibits many potential uses, such as research on drug metabolism or liver disease mechanism. This technology can also be used to solve shortage of organs for transplant in the future.展开更多
Since the beginning of the 20th century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in C...Since the beginning of the 20th century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in China. The increase of land area alleviated the contradiction of supply and demand between human and land, which provided the guarantee for agricultural production and industrial development. However, marine ecological environment has been seriously damaged due to the increasing scale of tideland reclamation. This paper took the Hangzhou Bay in the Yangtze River Delta as a study area to explore the evolution law, socioeconomic effect and eco-environmental effect of reclaimed land from 1985 to 2015. The result showed that as follows:(1) The area of tideland reclamation was 460.67 km^2 with 16.57% cultivated land and 15.93% construction land, and its land use was inefficient;(2) Land use change has spatial and temporal difference, the speed of tideland reclamation had been increasing from 1985 to 2015 in time and the scale of reclaimed land in the southern(84.07%) of Hangzhou Bay was larger than the northern region(15.93%) in space;(3) The evolution law of land use was from tideland to swampland and coastal waters to agricultural facility land, to cultivated land to industrial-mining land to idle land, rural-urban construction land, and formed obviously hierarchical structure;(4) Effect analysis of land use change found that the socio-economic effect had increased but the eco-environmental effect had decreased from 1985 to 2015, it reflected socio-economic effect was acquired through sacrificing eco-environmental effect;(5) It pointed out the existing problems on land extensive inefficient, environmental degradation and economy excessive growth without scientific planning, and offered some suggestions in land comprehensive improvement project, industrial transformation and upgrading and scientific planning and legal safeguardto promote sustainable development in the Hangzhou Bay in the new period.展开更多
Negative skin friction (NSF) is one of the important problems when designing a pile foundation. However, the influence of loading sequence on the dragload and downdrag for pile foundation is seldom studied. In this pa...Negative skin friction (NSF) is one of the important problems when designing a pile foundation. However, the influence of loading sequence on the dragload and downdrag for pile foundation is seldom studied. In this paper, a three-dimensional numerical model was established using FLAC3D. Compared with the results of model test, the established model could be used to study the NSF of pile foundation. The influencing factors were discussed including the length-diameter ratio of pile and the loading sequence of pile head load and surcharge. A case history was analyzed using FLAC3D. The calculated results are in good agreement with the measured results. It is concluded that the dragload and downdrag are remarkably influenced by the loading sequence of pile head load and surcharge. The dragload and downdrag reach the maximum values under the condition of surcharge after pile head load.展开更多
Samples of thickened waste activated sludge (TWAS) at two different concentrations were exposed to microwave radiation. Some of the samples were not allowed to heat up, to study the athermal effect of microwaves. Th...Samples of thickened waste activated sludge (TWAS) at two different concentrations were exposed to microwave radiation. Some of the samples were not allowed to heat up, to study the athermal effect of microwaves. The samples exposed to microwaves where their temperature was allowed to increase showed a higher degree of chemical oxygen demand (COD), protein and carbohydrate solubilization compared to a control. The size distribution of particles was changed after exposure of TWAS to microwaves. These results were also observed in the samples exposed to microwaves but kept at a constant temperature, suggesting the occurrence of a microwave athermal effect. Thermally (samples experiencing a temperature increase) and athermally (samples that were maintained at ambient temperature) microwaved subsequent anaerobic biodegradation. samples produced more methane than the non-microwaved controls in展开更多
The Spurge family (Euphorbiaceae) is a large family of flowering plants. Two plant species of this family were collected from the Egyptian desert, extracted with methanol subjected to silica gel column chromatograph...The Spurge family (Euphorbiaceae) is a large family of flowering plants. Two plant species of this family were collected from the Egyptian desert, extracted with methanol subjected to silica gel column chromatography to give six compounds, three compounds from each plant. The compounds isolated from the methanol extract of Euphorbia retusa Forssk were identified as kaempferol-3-beta-D glucopyranosyl (1), 3-O-alpha-L-xylopyranosyl (1→3)-alpha-L xylopyranosyl (1→2), beta-D glucopyranosyllup 1,12-diene-3,21-diol (2) and 5,7,8,3',4'-pentahydroxy-3-methoxyflavone (3) and the compounds isolated from Euphorbia paralais L. identified as 3,5,3'-trihydroxy-6,7-d-methoxy-4' (7"-hydroxygeranyl-1"-ether) flavones (4), 3-O-syringic acid (1→4)-alpha-L- xylopyranosyl (1→3), beta-D-rahminopyranosyl hederagenin (5) and 3-O-syringic acid (1→4), beta-D-rahminopyranosyl (1→3),beta-D-rahminopyranosyl hederagenin (6). The structure of the isolated compounds was elucidated by chemical and spectrometric analysis such as Infera red (IR), proton and carbon nuclear magnetic resonance (1H-, 13C-NMR) and chemical ionization mass spectrometry (CI-MS).展开更多
This paper reports some results of geo-scientific evaluation of the petroleum systems in the northeastern area of the Song Hong Basin offshore Vietnam. Geological-geophysical data, including regional studies, 2D and 3...This paper reports some results of geo-scientific evaluation of the petroleum systems in the northeastern area of the Song Hong Basin offshore Vietnam. Geological-geophysical data, including regional studies, 2D and 3D seismic & logging interpretation results as well as core/cutting samples analysis were integrated to reveals that the north-eastern area were controlled by pull apart activities along Song Hong river fault system, rifting phase during Eocene-Oligocene and subsidence during Miocene-Quaternary. Inversion activities at the end of Oligocene and late Miocene also play very important roles. These activities convert Pre-tertiary carbonate basement rocks to be potential reservoirs. The main source rock, overlying and adjacent to basement highs, was deposited in the lacustrine environment during rifting phase of Eocene and Oligocene and is still at the depth of oil generation window. The mentioned source rock layer is also considered as a good top seal for the basement. Petroleum system has been proven by the drilling and testing results and the studied area become more attractive and have higher chance of success.展开更多
Based on the mechanism of resid hydrotreating reaction by coordinating the catalyst activity and stability, the diffusion mechanism and catalyst reactivity, the cost and catalyst performance, and the production and ap...Based on the mechanism of resid hydrotreating reaction by coordinating the catalyst activity and stability, the diffusion mechanism and catalyst reactivity, the cost and catalyst performance, and the production and application requirements, the third-generation series catalysts for residue hydrotreating have been developed by Research Institute of Petroleum Processing, SINOPEC. The new series RHT catalysts possess higher activity for HDS, HDM and HDCCR performance as well as longer run length. The commercial results for application of these catalysts have demonstrated that the new catalyst system performs better than the reference ones.展开更多
To investigate the chemical components from the stems of Casearia velutina Bl.,the constituents were isolated by repeated chromatography with silica gel,Sephadex LH-20,and ODS columns.The structures were elucidated by...To investigate the chemical components from the stems of Casearia velutina Bl.,the constituents were isolated by repeated chromatography with silica gel,Sephadex LH-20,and ODS columns.The structures were elucidated by spectroscopic analysis.Eleven triterpenoids and its glycosides were isolated from the crude extract of C.velutina,and their structures were identified as friedelin-2,3-lactone(1),friedelane(2),epifriedelanol(3),friedelin(4),2α,3α,19α-trihydroxy-urs-12-en-28-oic acid(5),2α,3β,19α-trihydroxy-urs-12-en-28-oic acid(6),2α,3α,23-trihydroxy-urs-12-en-28-oic acid(7),2α,3α,23-trihydroxy-olean-12-en-28-oic acid(8),2α,3α,19α,23-tetrahydroxy-urs-12-en-28-oic acid(9),2α,3α,19α,23-tetrahydroxy-urs-12-en-28-oic acid-28-O-β-D-glucopyranosyl ester(10),and 3β,19α-dihydroxy-urs-12-en-28-oic acid 3-O-α-L-arabinopyranoside(11).All the compounds described above were isolated from this species for the first time.Compound 1 is a rarely occurred seco-friedelolactone in Flacourtiaceae.展开更多
In recent years,three-dimensional topological insulators(3DTI) as a novel state of quantum matter have become a hot topic in the fields of condensed matter physics and materials sciences.To fulfill many spectacularly ...In recent years,three-dimensional topological insulators(3DTI) as a novel state of quantum matter have become a hot topic in the fields of condensed matter physics and materials sciences.To fulfill many spectacularly novel quantum phenomena predicted in 3DTI,real host materials are of crucial importance.In this review paper,we first introduce general methods of searching for new 3DTI based on the density-functional theory.Then,we review the recent progress on materials realization of 3DTI including simple elements,binary compounds,ternary compounds,and quaternary compounds.In these potential host materials,some of them have already been confirmed by experiments while the others are not yet.The 3DTI discussed here does not contain the materials with strong electron-electron correlation.Lastly,we give a brief summary and some outlooks in further studies.展开更多
基金This work was supported by the Kunming Institute of Botany,Chinese Academy of Sciences.
文摘A new baccharane-type triterpene, 3-acetoxy-9(11)-baccharene(1),as well as a known compound, a-amyrin(2), has been isolated from the ether extract of the roots of Saussurea lappa C. B. Clarke. The structure of the new compound was identified by spectrum analysis.
基金Supported by "11thFive-Year" Crop Breeding Research of SichuanProvince "11thFive-Year" Joint Breeding Research Project Fun-ding of Sichuan Province.~~
文摘[Objective] The aim was to study the reproduction of the three-line genic male sterile (GMS) lineparent Mian7MB-1 (B. NapusL.) and the seed production of F1 through somatic tissue culture. [Methed] Through hybridization, a new breeding material Mian 7MB-1 in three-line genic temporary maintainer line propagated by tissue culture was used to improve the sterile plant rate of rapeseed in dual-purpose recessive GMS line, such as Mian 7AB type, S45AB type, and etc. And then the variety comparative test was performed. [Result] In order to avoid some fertility restoration phenomena occurring during the process of self-reproduction, Mian 7AB was propagated in bulk with somatic tissue culture of temporary maintainer line plant stem. The propagated temporary maintainer line seedlings were applied to the breeding and seed production of net room male sterile line parent, promoting the sterile plant rate of the male sterile line parent to 91.7% -93.5%. The male sterile line parents per hectare were enough for the seed production of hybrid F1 in 7 500 -15 000 hm^2. [ Conclusion ] Compared with the original dual-purpose GMS line, the seed production ultilizing male sterile line with high sterile plant rate greatly reduced the labor, significantly improved the seed yield, ensuring the seed quality and forming a perfect breeding and seed production system.
基金supported by the National Innovation Project for Meteorological Science and Technology grant number CMAGGTD003-5the National Key R&D Program of China grant number2017YFC1501801。
文摘This study proposes a method to derive the climatological limit thresholds that can be used in an operational/historical quality control procedure for Chinese high vertical resolution(5–10 m)radiosonde temperature and wind speed data.The whole atmosphere is divided into 64 vertical bins,and the profiles are constructed by the percentiles of the values in each vertical bin.Based on the percentile profiles(PPs),some objective criteria are developed to obtain the thresholds.Tibetan Plateau field data are used to validate the effectiveness of the method in the application of experimental data.The results show that the derived thresholds for 120 operational stations and 3 experimental stations are effective in detecting the gross errors,and those PPs can clearly and instantly illustrate the characteristics of a radiosonde variable and reveal the distribution of errors.
基金Under the auspices of Major Science and Technology Program for Water Pollution Control and Treatment(No.2012ZX07201004)National Natural Science Foundation of China(No.41101470)
文摘In order to investigate the transformation among the precipitation,groundwater,and surface water in the Sanjiang Plain,Northeast China,precipitation and groundwater samples which were collected at the meteorological station of the Sanjiang Mire Wetland Experimental Station,Chinese Academy of Sciences and the surface water which collected from the Wolulan River were used to identify the transformation of three types of water.The isotope composition of different kinds of water sources were analyzed via stable isotope(deuterium and oxygen-18) investigation of natural water.The results show a clear seasonal difference in the stable isotopes in precipitation.During the cold half-year,the mean stable isotope in precipitation in the Sanjiang Plain reaches its minimum with the minimum temperature.The δ18O and δD values are high in the rainy season.In the Wolulan River,the evaporation is the highest in August and September.The volume of evaporation and the replenishment to the river is mostly same.The groundwater is recharged more by the direct infiltration of precipitation than by the river flow.The results of this study indicate that the water bodies in the Sanjiang Plain have close hydrologic relationships,and that the transformation among each water system frequently occurs.
文摘In this paper, we reconsider the defining but often overlooked ‘hinge' function of megalopolises by analyzing how megalopolises have articulated national and international urban systems in the context of a globalizing knowledge economy. Taking the case of China's Yangtze River Delta(YRD) region, we particularly focus on knowledge circulation within and beyond the YRD region by analyzing the pattern and process of knowledge collaboration at different geographical scales during the 2004–2014 period. Results show that the structure of scientific knowledge collaboration as reflected by co-publications has been strongest at the national scale whereas that of technological knowledge collaboration as measured by co-patents has been strongest at the global scale. Despite this difference, the structure of both scientific and technological knowledge collaboration has been functionally polycentric at the megalopolitan scale but become less so at the national and global scales. The ‘globally connected but locally disconnected' pattern of Shanghai's external knowledge collaboration suggests that the gateway role of the YRD megalopolis in promoting knowledge collaboration at different geographical scales will take time before it is fully realized.
基金supported by a grant from the National HighTech Research and Development Projects (Grant No. 2015AA020303)
文摘Three-dimensional(3D) printing(3DP) is a rapid prototyping technology that has gained increasing recognition in many different fields. Inherent accuracy and low-cost property enable applicability of 3DP in many areas, such as manufacturing, aerospace,medical, and industrial design. Recently, 3DP has gained considerable attention in the medical field. The image data can be quickly turned into physical objects by using 3DP technology. These objects are being used across a variety of surgical specialties. The shortage of cadaver specimens is a major problem in medical education. However, this concern has been solved with the emergence of 3DP model. Custom-made items can be produced by using 3DP technology. This innovation allows 3DP use in preoperative planning and surgical training. Learning is difficult among medical students because of the complex anatomical structures of the liver. Thus, 3D visualization is a useful tool in anatomy teaching and hepatic surgical training. However,conventional models do not capture haptic qualities. 3DP can produce highly accurate and complex physical models. Many types of human or animal differentiated cells can be printed successfully with the development of 3D bio-printing technology. This progress represents a valuable breakthrough that exhibits many potential uses, such as research on drug metabolism or liver disease mechanism. This technology can also be used to solve shortage of organs for transplant in the future.
基金funded by the grants from the Major Project of National Social Science Foundation of China (15ZDA021)National Natural Science Foundation of China (Grant Nos.41130748, 41471143)
文摘Since the beginning of the 20th century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in China. The increase of land area alleviated the contradiction of supply and demand between human and land, which provided the guarantee for agricultural production and industrial development. However, marine ecological environment has been seriously damaged due to the increasing scale of tideland reclamation. This paper took the Hangzhou Bay in the Yangtze River Delta as a study area to explore the evolution law, socioeconomic effect and eco-environmental effect of reclaimed land from 1985 to 2015. The result showed that as follows:(1) The area of tideland reclamation was 460.67 km^2 with 16.57% cultivated land and 15.93% construction land, and its land use was inefficient;(2) Land use change has spatial and temporal difference, the speed of tideland reclamation had been increasing from 1985 to 2015 in time and the scale of reclaimed land in the southern(84.07%) of Hangzhou Bay was larger than the northern region(15.93%) in space;(3) The evolution law of land use was from tideland to swampland and coastal waters to agricultural facility land, to cultivated land to industrial-mining land to idle land, rural-urban construction land, and formed obviously hierarchical structure;(4) Effect analysis of land use change found that the socio-economic effect had increased but the eco-environmental effect had decreased from 1985 to 2015, it reflected socio-economic effect was acquired through sacrificing eco-environmental effect;(5) It pointed out the existing problems on land extensive inefficient, environmental degradation and economy excessive growth without scientific planning, and offered some suggestions in land comprehensive improvement project, industrial transformation and upgrading and scientific planning and legal safeguardto promote sustainable development in the Hangzhou Bay in the new period.
基金Supported by National Natural Science Foundation of China (No.50679015)China Postdoctoral Science Foundation (No.20090461062)
文摘Negative skin friction (NSF) is one of the important problems when designing a pile foundation. However, the influence of loading sequence on the dragload and downdrag for pile foundation is seldom studied. In this paper, a three-dimensional numerical model was established using FLAC3D. Compared with the results of model test, the established model could be used to study the NSF of pile foundation. The influencing factors were discussed including the length-diameter ratio of pile and the loading sequence of pile head load and surcharge. A case history was analyzed using FLAC3D. The calculated results are in good agreement with the measured results. It is concluded that the dragload and downdrag are remarkably influenced by the loading sequence of pile head load and surcharge. The dragload and downdrag reach the maximum values under the condition of surcharge after pile head load.
文摘Samples of thickened waste activated sludge (TWAS) at two different concentrations were exposed to microwave radiation. Some of the samples were not allowed to heat up, to study the athermal effect of microwaves. The samples exposed to microwaves where their temperature was allowed to increase showed a higher degree of chemical oxygen demand (COD), protein and carbohydrate solubilization compared to a control. The size distribution of particles was changed after exposure of TWAS to microwaves. These results were also observed in the samples exposed to microwaves but kept at a constant temperature, suggesting the occurrence of a microwave athermal effect. Thermally (samples experiencing a temperature increase) and athermally (samples that were maintained at ambient temperature) microwaved subsequent anaerobic biodegradation. samples produced more methane than the non-microwaved controls in
文摘The Spurge family (Euphorbiaceae) is a large family of flowering plants. Two plant species of this family were collected from the Egyptian desert, extracted with methanol subjected to silica gel column chromatography to give six compounds, three compounds from each plant. The compounds isolated from the methanol extract of Euphorbia retusa Forssk were identified as kaempferol-3-beta-D glucopyranosyl (1), 3-O-alpha-L-xylopyranosyl (1→3)-alpha-L xylopyranosyl (1→2), beta-D glucopyranosyllup 1,12-diene-3,21-diol (2) and 5,7,8,3',4'-pentahydroxy-3-methoxyflavone (3) and the compounds isolated from Euphorbia paralais L. identified as 3,5,3'-trihydroxy-6,7-d-methoxy-4' (7"-hydroxygeranyl-1"-ether) flavones (4), 3-O-syringic acid (1→4)-alpha-L- xylopyranosyl (1→3), beta-D-rahminopyranosyl hederagenin (5) and 3-O-syringic acid (1→4), beta-D-rahminopyranosyl (1→3),beta-D-rahminopyranosyl hederagenin (6). The structure of the isolated compounds was elucidated by chemical and spectrometric analysis such as Infera red (IR), proton and carbon nuclear magnetic resonance (1H-, 13C-NMR) and chemical ionization mass spectrometry (CI-MS).
文摘This paper reports some results of geo-scientific evaluation of the petroleum systems in the northeastern area of the Song Hong Basin offshore Vietnam. Geological-geophysical data, including regional studies, 2D and 3D seismic & logging interpretation results as well as core/cutting samples analysis were integrated to reveals that the north-eastern area were controlled by pull apart activities along Song Hong river fault system, rifting phase during Eocene-Oligocene and subsidence during Miocene-Quaternary. Inversion activities at the end of Oligocene and late Miocene also play very important roles. These activities convert Pre-tertiary carbonate basement rocks to be potential reservoirs. The main source rock, overlying and adjacent to basement highs, was deposited in the lacustrine environment during rifting phase of Eocene and Oligocene and is still at the depth of oil generation window. The mentioned source rock layer is also considered as a good top seal for the basement. Petroleum system has been proven by the drilling and testing results and the studied area become more attractive and have higher chance of success.
文摘Based on the mechanism of resid hydrotreating reaction by coordinating the catalyst activity and stability, the diffusion mechanism and catalyst reactivity, the cost and catalyst performance, and the production and application requirements, the third-generation series catalysts for residue hydrotreating have been developed by Research Institute of Petroleum Processing, SINOPEC. The new series RHT catalysts possess higher activity for HDS, HDM and HDCCR performance as well as longer run length. The commercial results for application of these catalysts have demonstrated that the new catalyst system performs better than the reference ones.
基金Changjiang Scholar and Innovative Team in University (Grant No. 985-2-063-112)
文摘To investigate the chemical components from the stems of Casearia velutina Bl.,the constituents were isolated by repeated chromatography with silica gel,Sephadex LH-20,and ODS columns.The structures were elucidated by spectroscopic analysis.Eleven triterpenoids and its glycosides were isolated from the crude extract of C.velutina,and their structures were identified as friedelin-2,3-lactone(1),friedelane(2),epifriedelanol(3),friedelin(4),2α,3α,19α-trihydroxy-urs-12-en-28-oic acid(5),2α,3β,19α-trihydroxy-urs-12-en-28-oic acid(6),2α,3α,23-trihydroxy-urs-12-en-28-oic acid(7),2α,3α,23-trihydroxy-olean-12-en-28-oic acid(8),2α,3α,19α,23-tetrahydroxy-urs-12-en-28-oic acid(9),2α,3α,19α,23-tetrahydroxy-urs-12-en-28-oic acid-28-O-β-D-glucopyranosyl ester(10),and 3β,19α-dihydroxy-urs-12-en-28-oic acid 3-O-α-L-arabinopyranoside(11).All the compounds described above were isolated from this species for the first time.Compound 1 is a rarely occurred seco-friedelolactone in Flacourtiaceae.
基金supported by the National Basic Research Program of China (Grants No.2011CBA00100)the National Natural Science Foundation of China(Grant Nos.10974231 and 11174337)
文摘In recent years,three-dimensional topological insulators(3DTI) as a novel state of quantum matter have become a hot topic in the fields of condensed matter physics and materials sciences.To fulfill many spectacularly novel quantum phenomena predicted in 3DTI,real host materials are of crucial importance.In this review paper,we first introduce general methods of searching for new 3DTI based on the density-functional theory.Then,we review the recent progress on materials realization of 3DTI including simple elements,binary compounds,ternary compounds,and quaternary compounds.In these potential host materials,some of them have already been confirmed by experiments while the others are not yet.The 3DTI discussed here does not contain the materials with strong electron-electron correlation.Lastly,we give a brief summary and some outlooks in further studies.