There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of wa...There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT- genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content （18.95% on average） than those with TT- genotype （all below 16%）, but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 （P〈0.01）.展开更多
Heteroatom-doped carbon-based transition-metal single-atom catalysts(SACs) are promising electrocatalysts for oxygen reduction reaction(ORR). Herein, with the aid of hierarchically porous silica as hard template, a fa...Heteroatom-doped carbon-based transition-metal single-atom catalysts(SACs) are promising electrocatalysts for oxygen reduction reaction(ORR). Herein, with the aid of hierarchically porous silica as hard template, a facile and general melting perfusion and mesopore-confined pyrolysis method was reported to prepare single-atomic Fe/N–S-doped carbon catalyst(FeNx/NC-S) with hierarchically porous structure and well-defined morphology. The FeNx/NC-S exhibited excellent ORR activity with a half-wave potential(E_(1/2)) of 0.92 V, and a lower overpotential of 320 mV at a current density of 10 mA cm^(-2)for OER under alkaline condition. The remarkable electrocatalysis performance can be attributed to the hierarchically porous carbon nanospheres with S doping and high content of Fe-Nx sites(up to 3.7 wt% of Fe), resulting from the nano-confinement effect of the hierarchically porous silica spheres(NKM-5) during the pyrolysis process. The rechargeable Zn-air battery with FeNx/NC-S as a cathode catalyst demonstrated a superior power density of 194.5 mW cm-2charge–discharge stability. This work highlights a new avenue to design advanced SACs for efficient sustainable energy storage and conversion.展开更多
Comprehensive quantitative evaluation of shale gas content and the controlling factors in different occurrence states is of great significance for accurately assessing gas-bearing capacity and providing effective well...Comprehensive quantitative evaluation of shale gas content and the controlling factors in different occurrence states is of great significance for accurately assessing gas-bearing capacity and providing effective well-production strategies. A total of 122 core samples from well JY-A in the Fuling shale gas field were studied to reveal the characteristics of S_1 l shale,15 of which were selected to further predict the shale gas content in different occurrence states, which are dependent on geological factors in the thermal evolution process. Geological parameters were researched by a number of laboratory programs, and the factors influential in controlling shale gas content were extracted by both PCA and GRA methods and prediction models were confirmed by the BE method using SPSS software. Results reveal that the adsorbed gas content is mainly controlled by TOC, Ro, SSA, PD and pyrite content, and the free gas content is mainly controlled by S_2, quartz content, gas saturation and formation pressure for S_1 l in well JY-A. Three methods, including the on-site gas desorption method, the empirical formula method, and the multiple regression analysis method were used in combination to evaluate the shale gas capacity of well JY-A, all of which show that the overall shale gas content of well JY-A is in the range of 2.0–5.0 m^3/t and that the free gas ratio is about 50%, lower than that of well JY-1. Cause analysis further confirms the tectonics and preservation conditions of S_1 l in the geological processes, especially the influence of eastern boundary faults on well JY-A, as the fundamental reasons for the differences in shale gas enrichment in the Jiaoshiba area.展开更多
Based on dynastic period division and AMS ^14 C dating performed on the sedimentary layers at Zhongba and Yuxi sites,and also the analysis of Na,Ca and Mg of 201 sedimentary samples from Zhongba site and that of Ca an...Based on dynastic period division and AMS ^14 C dating performed on the sedimentary layers at Zhongba and Yuxi sites,and also the analysis of Na,Ca and Mg of 201 sedimentary samples from Zhongba site and that of Ca and Na in 47 sedimentary samples from Yuxi by using an inductively coupled plasma-mass spectrometry（ICP）,we found that there were 35 time periods when the contents of Ca and Na were reversely correlated,i.e.whenever the content of Ca was the highest,the content of Na was the lowest,and vice versa. Among them,there were 21 time periods when the content of Ca was the highest,and Na was the lowest,indicating that there were about 21 prosperous periods of ancient salt production at Zhongba site since 3000BC.Other 14 time periods with the peak values of Na while the low values of Ca indicate 14 declined periods of salt production at Zhongba site since 3000BC.The conclusion obtained from the reverse relationship between Ca and Na contents in this paper is consistent with that＂the salt production at Zhongba site started in the new stone age,developed in the Xia and Shang dynasties,reached at the heyday in periods from the Western Zhou to the Han Dynasties,maintained stable to develop in the Tang and the Song dynasties,and gradually declined after the Song Dynasty because the sea salt were conveyed into Sichuan region,however,still had production in the 1970s-1980s＂,educed from archeological exploration.All the above mentioned results indicate that there is a reverse relationship obviously between the contents of Na and Ca in sediments at Zhongba site for ancient salt production,which can be used to reveal the process of rise and decline of ancient salt industry at Zhongba site.展开更多
A brief description of infrared IRA-935 water vapour measuring instrument is presented and integrated vertical water vapour content W 0 in the atmosphere at Gaomeigu and Fenghuangshan sites and precision analyses are ...A brief description of infrared IRA-935 water vapour measuring instrument is presented and integrated vertical water vapour content W 0 in the atmosphere at Gaomeigu and Fenghuangshan sites and precision analyses are given in the paper. The daily variation and distributions of W 0 in a whole year and monthly average W 0 measurements at these two sites are discussed in more detail. The statistical results of the observational data in the whole year are also analysed and discussed.展开更多
文摘There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT- genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content （18.95% on average） than those with TT- genotype （all below 16%）, but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 （P〈0.01）.
基金supported by National Natural Science Foundation of China (21773128)。
文摘Heteroatom-doped carbon-based transition-metal single-atom catalysts(SACs) are promising electrocatalysts for oxygen reduction reaction(ORR). Herein, with the aid of hierarchically porous silica as hard template, a facile and general melting perfusion and mesopore-confined pyrolysis method was reported to prepare single-atomic Fe/N–S-doped carbon catalyst(FeNx/NC-S) with hierarchically porous structure and well-defined morphology. The FeNx/NC-S exhibited excellent ORR activity with a half-wave potential(E_(1/2)) of 0.92 V, and a lower overpotential of 320 mV at a current density of 10 mA cm^(-2)for OER under alkaline condition. The remarkable electrocatalysis performance can be attributed to the hierarchically porous carbon nanospheres with S doping and high content of Fe-Nx sites(up to 3.7 wt% of Fe), resulting from the nano-confinement effect of the hierarchically porous silica spheres(NKM-5) during the pyrolysis process. The rechargeable Zn-air battery with FeNx/NC-S as a cathode catalyst demonstrated a superior power density of 194.5 mW cm-2charge–discharge stability. This work highlights a new avenue to design advanced SACs for efficient sustainable energy storage and conversion.
基金financially supported by the Natural Science Foundation of China (NSFC Grant 41572106)+1 种基金the National Science and Technology Major Project "The enrichment conditions, evaluation technology and application of shale gas in the Sichuan Basin and its periphery" (Item No. 2017ZX05035002-006)State Key Laboratory of oil and gas resources and exploration, Chinese University of Petroleum-Beijing
文摘Comprehensive quantitative evaluation of shale gas content and the controlling factors in different occurrence states is of great significance for accurately assessing gas-bearing capacity and providing effective well-production strategies. A total of 122 core samples from well JY-A in the Fuling shale gas field were studied to reveal the characteristics of S_1 l shale,15 of which were selected to further predict the shale gas content in different occurrence states, which are dependent on geological factors in the thermal evolution process. Geological parameters were researched by a number of laboratory programs, and the factors influential in controlling shale gas content were extracted by both PCA and GRA methods and prediction models were confirmed by the BE method using SPSS software. Results reveal that the adsorbed gas content is mainly controlled by TOC, Ro, SSA, PD and pyrite content, and the free gas content is mainly controlled by S_2, quartz content, gas saturation and formation pressure for S_1 l in well JY-A. Three methods, including the on-site gas desorption method, the empirical formula method, and the multiple regression analysis method were used in combination to evaluate the shale gas capacity of well JY-A, all of which show that the overall shale gas content of well JY-A is in the range of 2.0–5.0 m^3/t and that the free gas ratio is about 50%, lower than that of well JY-1. Cause analysis further confirms the tectonics and preservation conditions of S_1 l in the geological processes, especially the influence of eastern boundary faults on well JY-A, as the fundamental reasons for the differences in shale gas enrichment in the Jiaoshiba area.
基金The Key Project of National Natural Science Foundation of China, No.90411015 University Doctoral Foundation of China, Grand No.20050284011+2 种基金 The Prior study project for Key Basic Scientific Issue of Nanjing University, Grand No. 0209005206 Open Foundation of the State Key Laboratory of Loess and Quaternary Geology from the Institute of Earth Environment, CAS, No.SKLLQG0503 Foundation of Modern Analyses Center of Nanjing University, No.0209001309.
文摘Based on dynastic period division and AMS ^14 C dating performed on the sedimentary layers at Zhongba and Yuxi sites,and also the analysis of Na,Ca and Mg of 201 sedimentary samples from Zhongba site and that of Ca and Na in 47 sedimentary samples from Yuxi by using an inductively coupled plasma-mass spectrometry（ICP）,we found that there were 35 time periods when the contents of Ca and Na were reversely correlated,i.e.whenever the content of Ca was the highest,the content of Na was the lowest,and vice versa. Among them,there were 21 time periods when the content of Ca was the highest,and Na was the lowest,indicating that there were about 21 prosperous periods of ancient salt production at Zhongba site since 3000BC.Other 14 time periods with the peak values of Na while the low values of Ca indicate 14 declined periods of salt production at Zhongba site since 3000BC.The conclusion obtained from the reverse relationship between Ca and Na contents in this paper is consistent with that＂the salt production at Zhongba site started in the new stone age,developed in the Xia and Shang dynasties,reached at the heyday in periods from the Western Zhou to the Han Dynasties,maintained stable to develop in the Tang and the Song dynasties,and gradually declined after the Song Dynasty because the sea salt were conveyed into Sichuan region,however,still had production in the 1970s-1980s＂,educed from archeological exploration.All the above mentioned results indicate that there is a reverse relationship obviously between the contents of Na and Ca in sediments at Zhongba site for ancient salt production,which can be used to reveal the process of rise and decline of ancient salt industry at Zhongba site.
文摘A brief description of infrared IRA-935 water vapour measuring instrument is presented and integrated vertical water vapour content W 0 in the atmosphere at Gaomeigu and Fenghuangshan sites and precision analyses are given in the paper. The daily variation and distributions of W 0 in a whole year and monthly average W 0 measurements at these two sites are discussed in more detail. The statistical results of the observational data in the whole year are also analysed and discussed.
