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QTL Mapping and Q×E Interactions of Grain Cooking and Nutrient Qualities in Rice Under Upland and Lowland Environments 被引量:2
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作者 郭咏梅 穆平 +2 位作者 刘家富 卢义宣 李自超 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第5期420-428,共9页
Grain cooking and nutrient qualities are the most important components of rice (Oryza sativa L.) quality. A doubled haploid (DH) population from a cross between two japonica cultivars was used to examine the pheno... Grain cooking and nutrient qualities are the most important components of rice (Oryza sativa L.) quality. A doubled haploid (DH) population from a cross between two japonica cultivars was used to examine the phenotypic values and potential QTLs for the quality traits. The cooking and nutrient quality traits, including the amylose content (AC), the gel consistency (CJC), the gelatinization temperature (GT), and the protein content (PC), in rice grown under upland and lowland environments were evaluated. Significant differences for AC, GC, GT, and PC between upland and lowland environments were detected. The phenotypic values of all four traits were higher under upland environment than lowland environment. The value of PC under upland environment was significantly higher (by 37.9%) than that under lowland environment. This suggests that upland cultivation had large effect on both cooking and nutrient qualifies. A total of seven QTLs and twelve pairs of QTLs were detected to have significant additive and epistatic effects for the four traits. Significant Q x E interaction effects of two QTLs and two pairs of QTLs were also discovered. The general contribution of additive QTLs ranged from 1.91% to 19.77%. The Q × E interactions of QTLs QGt3 and QAc6 accounted for 8.99% and 47.86% of the phenotypic variation, respectively, whereas those of the 2 pairs of epistatic QTLs, QAc6-QAcllb and QAc8-QAc9, accounted for 32.54% and 11.82%, respectively. Five QTLs QGt6b, QGt8, QGt11, QGcl, and QPc2, which had relatively high general contribution and no Q x E interactions, were selected to facilitate the upland rice grain quality breeding. 展开更多
关键词 upland rice cooking quality nutrient quality QTL mapping Q × E interaction effects
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从唐太宗用人说起
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作者 刘正平 《决策》 1995年第10期48-48,共1页
李世民曾问侍臣:“古代帝王有的能平定境内,却不能服外戎狄。我才能比不上古人,成功却比他们大,这是什么缘故?你们不要有顾虑,直说你们的见解。”侍臣们歌功颂德,说的都是谀言。李世民说:“你们说得不对。我成功的原因有五条。第一,古... 李世民曾问侍臣:“古代帝王有的能平定境内,却不能服外戎狄。我才能比不上古人,成功却比他们大,这是什么缘故?你们不要有顾虑,直说你们的见解。”侍臣们歌功颂德,说的都是谀言。李世民说:“你们说得不对。我成功的原因有五条。第一,古帝王往往妒忌有才能的人。 展开更多
关键词 唐太宗 李世民 侍臣 魏征 李建成 定境 戎狄 古帝 贤才 犯错误
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Directional drilling in unstable environments 被引量:2
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作者 Hungerford Frank Ren Ting 《International Journal of Mining Science and Technology》 SCIE EI 2014年第3期397-402,共6页
Directional drilling has been established in the coal industry as a viable means of gas drainage, exploration and water management. But the environment in and around coal seams is not always conducive to stable condit... Directional drilling has been established in the coal industry as a viable means of gas drainage, exploration and water management. But the environment in and around coal seams is not always conducive to stable conditions while drilling and borehole stability after the drilling has been completed. This paper identifies the conditions which cause unstable drilling conditions and the various means which are used to attempt to manage or bypass those conditions. Ultimately, equipment does become bogged in these adverse environments and requires recovery by over-coring. 展开更多
关键词 Directional dril ing Borehole Stability Unstable dril ing conditions Over-coring
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Sex Determination Mechanisms in Fish 被引量:2
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作者 ZHANG Quanqi SUN Xiaohua QI Jie WANG Zhigang WANG Xinglian WANG Xubo ZHAI Teng 《Journal of Ocean University of China》 SCIE CAS 2009年第2期155-160,共6页
In fish,sex determination(SD) system shows high variation. The SD mechanisms include environmental and genetic regulation. The research on SD system and related genes in intensively studied fish species was reviewed. ... In fish,sex determination(SD) system shows high variation. The SD mechanisms include environmental and genetic regulation. The research on SD system and related genes in intensively studied fish species was reviewed. Although some genes have been described as sex-related,only DMRT1bY can be considered as a master sex determination gene and none of them has been utilized in aquaculture. The variation of fish SD system,the importance of sex-related genes in evolution research and the relations between environmental factors and sex-related genes were also discussed. The fish sex determination mechanism remains largely unknown. Further research needs to be done considering the significance of fish SD studies in basic and applied aspects. 展开更多
关键词 sex determination environmental factors sex-related gene FISH
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Identification of Modal Parameters with Linear Structure under Non-stationary Ambient Excitation 被引量:2
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作者 续秀忠 华宏星 +1 位作者 李中付 陈兆能 《Journal of Donghua University(English Edition)》 EI CAS 2004年第1期146-151,共6页
Empirical mode decomposition (EMD) is proposed to identify linear structure under non-stationary excitation,and non-white noise coefficient is introduced under the assumption of random signals consisting of white nois... Empirical mode decomposition (EMD) is proposed to identify linear structure under non-stationary excitation,and non-white noise coefficient is introduced under the assumption of random signals consisting of white noise and non-white noise signals. The cross-correlation function of response signal is decomposed into mode functions and residue by EMD method. The identification technique of the modal parameters of single freedom degree is applied to each mode function to obtain natural frequencies, damping ratios and mode shapes. The results of identification of the five-degree freedom linear system demonstrate that the proposed method is effective in identifying the parameters of linear structures under non-stationary ambient excitation. 展开更多
关键词 Nonstationary excitation empirical mode decomposition (EMD) non-white noise coefficient modal parameter identification linear structure
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Quantitative prediction of mining subsidence and its impact on the environment 被引量:14
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作者 Jianjun Song Chunjian Han +6 位作者 Ping Li Junwei Zhang Deyuan Liu Minde Jiang Lin Zheng Jingkai Zhang Jianying Song 《International Journal of Mining Science and Technology》 2012年第1期69-73,共5页
This study is focused on the prediction of mining subsidence and its impact on the environment in the Hongqi mining area. The study was carried out by means of a probability integral model based, in first instance bas... This study is focused on the prediction of mining subsidence and its impact on the environment in the Hongqi mining area. The study was carried out by means of a probability integral model based, in first instance based on field surveys and the analysis of data collected from this area. Isolines of mining sub- sidence were then drawn and the impact caused by mining subsidence on the environment was analyzed quantitatively by spatial analysis with Geographic Information System (GIS). The results indicate that the subsidence area of the first working-mine can be as large as 2.54 km2, the maximum subsidence is 3440 mrn which will cause 1524 houses to be relocated. The entire subsidence area of the mine can reach 8.09 km2, with a maximum subsidence of 3590 ram. Under these circumstances the value of the loss of ecosystem services Will reach 5.371 million Yuan and the cost of relocating buildings will increase to 6.858 million Yuan. 展开更多
关键词 Mining subsidence PREDICTION Ecological environment Quantitative analysis
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CO_2 Emissions Embodied in China-U.S.Trade 被引量:4
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作者 Yan Yunfeng Yang Laike 《Chinese Journal of Population,Resources and Environment》 2009年第3期3-10,共8页
After the Kyoto Protocol was implemented,carbon leakage exerts great influences on international trade and economy.Trade creates a mechanism for consumers to shift environmental pollution associated with their consump... After the Kyoto Protocol was implemented,carbon leakage exerts great influences on international trade and economy.Trade creates a mechanism for consumers to shift environmental pollution associated with their consumption to other countries.China has overtaken the U.S.as the world's biggest CO2 emitter since 2006.As China's second largest trade partner,the U.S.has the biggest trade deficit with China which has aroused a lot of disputes between the two parties.But so far the assessments of the trade imbalance of China-U.S.have paid little attention to environmental impacts associated with the trade imbalance.Applied an input-output approach,the article estimates the amount of CO2 embodied in China-U.S.trade during 1997-2007.It was found that through trade with China,the U.S.reduced its CO2 emissions compared with a non-trade scenario.Due to the greater carbon-intensity and relatively less efficient production processes of Chinese industry,China-U.S.trade resulted in more CO2 emissions in China and the world.In the end,the article gives some suggestions:it is equal and sustainable that the international accounting methodologies should be improved,for CO2 emissions responsibility must be designed to account for the dynamic nature of international trade. 展开更多
关键词 China-U.S. trade embodied C02 emissions inputoutput approach
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Lubricant Biodegradation Enhancers: Designed Chemistry and Engineered Technology 被引量:8
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作者 Chen Boshui Gao Lingyue +3 位作者 Fang Jianhua Zhang Nan Wu Jiang Wang Jiu 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第3期102-110,共9页
In recent decades, a growing worldwide trend of developing the biodegradable lubricants has been prevailing to form a specific field of green chemistry and green engineering. Enhancement of biodegradability of unreadi... In recent decades, a growing worldwide trend of developing the biodegradable lubricants has been prevailing to form a specific field of green chemistry and green engineering. Enhancement of biodegradability of unreadily biodegradable petroleum-based lubricants has as such become an urgent must. For over a decade the authors have been focusing on the improvement of biodegradability of unreadily biodegradable lubricants such as petroleum-based lubricating oils and greases. A new idea of lubricant biodegradation enhancer was put forward by the authors with the aim to stimulate the biodegradation of unreadily biodegradable lubricants by incorporating the enhancer into the lubricants in order to turn the lubricants into greener biodegradable ones and to help in situ bioremediation of lubricant-contaminated environment. This manuscript summarizes our recent efforts relating to the chemistry and technology of biodegradation enhancers for lubricants. Firstly, the chemistry of lubricant biodegradation enhancers was designed based on the principles of bioremediation for the treatment of hydrocarbon contaminated environment. Secondly, the ability of the designed biodegradation enhancers for increasing the biodegradability of unreadily biodegradable industrial lubricants was investigated through biodegradability evaluation tests, microbial population analysis, and biodegradation kinetics modeling. Finally, the impact of biodegradation enhancers on some crucial performance characteristics of lubricants such as lubricity and oxidation stability was tested via tribological evaluation and oxidation determinations. Our results have shown that the designed chemistry of nitrogenous and/or phosphorous compounds such as lauroyl glutamine, oleoyl glycine, oleic diethanolamide phosphate and lauric diethanolamide borate was outstanding in boosting biodegradation of petroleum-based lubricants which was ascribed to increase the microbial population and decrease the oil-water interfacial tension during the biodegradation process. Lubricants doped with the biodegradation enhancers exhibited much better biodegradability and higher biodegradation rate in the surrounding soils which could be well modeled by the exponential biodegradation kinetics. Furthermore, as lubricant dopants, the biodegradation enhancers also provided excellent capability in reducing friction and wear and in retarding oxidation of lubricants. In the nature of things, lubricant biodegradation enhancers, which are multi-functional not only in the improvement of biodegradability, but also in the fortification of lubricity and in the inhibition of oxidation of lubricants, are expected to be promising as a new category of lubricant additives. 展开更多
关键词 LUBRICANT biodegradation enhancer BIODEGRADABILITY biodegradation kinetics lubricity.
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Quilitative Analysis of a Class of Simulate Seasons Environm ent Chem ostat Systems 被引量:1
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作者 宋国华 杨晓忠 李秀琴 《Chinese Quarterly Journal of Mathematics》 CSCD 1998年第4期77-82, ,共6页
In this paper, a class of chemostat systems with simulate seasons Environment in the following form =(1+be(t)-s)Q+x(msa+s-k) =x(msa+s-k)-Qxis discussed. It is abstained that the system has not periodic solution when b... In this paper, a class of chemostat systems with simulate seasons Environment in the following form =(1+be(t)-s)Q+x(msa+s-k) =x(msa+s-k)-Qxis discussed. It is abstained that the system has not periodic solution when b=0; if b≠0 and b1 then system has 2 π periodic solution of system. globally asymptotically stable as mQ<μ *-1 and is unstable as mQ>μ *-1 and there exists at last one minimal 2 π periodic solution (s(t),x(t)) with \{x(t)>0,\}0<s(t)<s *(t). 展开更多
关键词 simulate seasons environment periodic solution quilitative analysis
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Signal Path Reckoning Localization Method in Multipath Environment 被引量:5
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作者 Junhui Zhao Lei Li +1 位作者 Hao Zhang Yi Gong 《China Communications》 SCIE CSCD 2017年第3期182-189,共8页
In the wireless localization application, multipath propagation seriously affects the localization accuracy. This paper presents two algorithms to solve the multipath problem. Firstly, we improve the Line of Possible ... In the wireless localization application, multipath propagation seriously affects the localization accuracy. This paper presents two algorithms to solve the multipath problem. Firstly, we improve the Line of Possible Mobile Device(LPMD) algorithm by optimizing the utilization of the direct paths for single-bound scattering scenario. Secondly, the signal path reckoning method with the assistance of geographic information system is proposed to solve the problem of localization with multi-bound scattering paths. With the building model's idealization, the proposed method refers to the idea of ray tracing and dead reckoning. According to the rule of wireless signal reflection, the signal propagation path is reckoned using the measurements of emission angle and propagation distance, and then the estimated location can be obtained. Simulation shows that the proposed method obtains better results than the existing geometric localization methods in multipath environment when the angle error is controlled. 展开更多
关键词 wireless localization multipath propagation signal reflection path reckoning
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Analysis of soft rock roadway deformation mechanism in Zhangshuanglou Mine 被引量:1
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作者 顾士亮 《Journal of Coal Science & Engineering(China)》 2003年第1期38-41,共4页
On basis of ground stress surveying and analysis of physical nature and mechanics character of rock, the deformation mechanism of west main roadway in Zhangshuanglou Mine is studied. It is put forward that engineering... On basis of ground stress surveying and analysis of physical nature and mechanics character of rock, the deformation mechanism of west main roadway in Zhangshuanglou Mine is studied. It is put forward that engineering mechanics nature, infiltration of water and concentrated stress on pillar are the main factors to affect stability of the west main roadway. The overall thinking used to restore the roadway is raised. 展开更多
关键词 soft rock ROADWAY deformation mechanism floor heave
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Mechanism and Geo-mechanics Models of Landslides Triggered by 5.12 Wenchuan Earthquake 被引量:11
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作者 HUANG Runqiu XU Qiang HUO Junjie 《Journal of Mountain Science》 SCIE CSCD 2011年第2期200-210,共11页
Due to the extremely high magnitude, long duration, and the complicated geo-environment in the disaster area, the great 5.12 Wenchuan Earthquake not only produced a huge number of landslides and rockfalls, but also in... Due to the extremely high magnitude, long duration, and the complicated geo-environment in the disaster area, the great 5.12 Wenchuan Earthquake not only produced a huge number of landslides and rockfalls, but also involved complicated dynamic processes. These processes are quite different from the characteristics of landslides and rockfalls under general gravitational force, and presently human knowledge is very poor in this field. In order to describe the special dynamic processes, some terms such as shattering-cracking, shattering-sliding, shattering-falls and ejection are defined in this paper. Combined with slope structures, a mechanism classification system of strong earthquake-triggered landslide and rockfall is suggested, which is divided into 5 categories and 14 types. This paper also analyzes the basic characteristics, dynamic processes and geo-mechanics conceptual models of some typologies, especial the type of shattering-sliding for most large-scales landsides. This paper initially reveals the formation mechanism, geo-mechanics models and dynamic features of landslides and rockfalls triggered by the great Wenchuan Earthquake. 展开更多
关键词 5.12 Wenchuan Earthquake LANDSLIDE ROCKFALL Geo-mechanics model
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Geomorphological mapping for the valorization of the alpine environment. A methodological proposal tested in the Loana Valley(Sesia Val Grande Geopark, Western Italian Alps) 被引量:2
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作者 Irene BOLLATI Beatrice CROSA LENZ +1 位作者 Enrico ZANOLETTI Manuela PELFINI 《Journal of Mountain Science》 SCIE CSCD 2017年第6期1023-1038,共16页
Geomorphological mapping plays a key role in landscape representation: it is the starting point for many applications and for the realization of thematic maps, such as hazard and risk maps, geoheritage and geotourism ... Geomorphological mapping plays a key role in landscape representation: it is the starting point for many applications and for the realization of thematic maps, such as hazard and risk maps, geoheritage and geotourism maps. Traditional geomorphological maps are useful for scientific purposes but they need to be simplified for different aims as management and education. In tourism valorization, mapping of geomorphological resources(i.e., geosites, and geomorphosites), and of geomorphic evidences of past hazardous geomorphological events, is important for increasing knowledge about landscape evolution and active processes, potentially involving geomorphosites and hiking trails. Active geomorphosites, as those widespread in mountain regions, testify the high dynamicity of geomorphic processes and their link with climatic conditions. In the present paper, we propose a method to produce and to update cartographic supports(Geomorphological Boxes)realized starting from a traditional geomorphological survey and mapping. The Geomorphological Boxes are geomorphological representation of single, composed or complex landforms drawn on satellite images, using the official Italian geomorphological legend(ISPRA symbols). Such cartographic representation is also addressed to the analysis(identification, evaluation and selection) of Potential Geomorphosites and Geotrails. The method has been tested in the upper portion of the Loana Valley(Western Italian Alps), located within the borders of the Sesia Val Grande Geopark, recognized by UNESCO in 2013. The area has a good potential for geotourism and for educational purposes. We identified 15 Potential Geomorphosites located along 2 Geotrails; they were ranked according to specific attributes also in relation with a Reference Geomorphosite located in the Loana hydrographic basin and inserted in official national and regional databases of geosites(ISPRA; Regione Piemonte). Finally, the ranking of Potential Geomorphosites allowed to select the most valuable ones for valorization or geoconservation purposes. In thisframework, examples of Geomorphological Boxes are proposed as supports to geo-risk education practices. 展开更多
关键词 Geomorphological mapping Geomorphological Boxes Mountain geomorphosites Geotrails GIS-Geographical Information Systems Loana Valley Western Italian Alps
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FIRST AMMONITE AND INOCERAMID DATA FROM THE UPPER CRETACEOUS OF THE TINGRI SECTION IN SE-TIBET:BIOSTRATIGRAPHICAL AND PALAEOENVIRONMENTAL IMPLICATIONS
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作者 Jens LEHMANN Ines WENDLER +2 位作者 Jens WENDLER Helmut WILLEMS Xiumian HU 《地学前缘》 EI CAS CSCD 北大核心 2005年第2期105-112,共8页
A section in the Zhepure Mountains near Old Tingri in SE-Tibet,ranging from the Upper Albian to Paleogene,was described in detail by Willems et al.(1996).These authors worked on the litho-and microfacies and set up th... A section in the Zhepure Mountains near Old Tingri in SE-Tibet,ranging from the Upper Albian to Paleogene,was described in detail by Willems et al.(1996).These authors worked on the litho-and microfacies and set up the biostratigraphical framework by planktonic foraminifera.Willems et al.(1996)established their section as a standard for southern Tibet and compared it to the Gamba area.During the 2004 Tibet-expedition of Chengdu University of Technology in China,in co-operation with Bremen and Kiel universities in Germany,the locality was revisited for the purpose of collecting invertebrate fossils.This field-work included only the Upper Cretaceous part of the Tingri section and its invertebrate faunal content.Until today almost no ammonite and inoceramid data existed for this section.This is true for most Cretaceous sections in Tibet,although the Upper Cretaceous succession was interpreted as shelf environment.which in other parts of the world contains rich faunas of these macrofossil groups.The newly discovered continuous record of rare ammonites and inoceramids is probably limited since the preservation in the wacke-and packstones is poor.In addition,sampling conditions were unfavorable and the environmental conditions disadvantageous for most groups of invertebrates,as possibly indicated by larger amounts of small bivalve debris(filaments)in the upper part of the Gamba Group.Although the collected fauna is sparse and poorly preserved,the following biostratigraphical data can be added to the hitherto described microfauna:Calycoceras?from the Upper Gamba Group is Late Cenomanian in age and is accompanied by indeterminable juvenile desmoceratids.Superjacent follows a record of the ammonite Forresteria sp.,indicating that this level in the upper part of the Gamba Group belongs to the Lower Coniacian.This supports the finding of Inoceramus(Cremnoceramus)waltersdorfensis?hannovrensis?from the same interval.Anagaudryceras?is an individual ammonite finding from the Zhepure Shanbei or Zhepure Shanpo Formation,corresponding to the Santonian-Maastrichtian part of the succession. 展开更多
关键词 ammonite inoceramid Upper Cretaceous BIOSTRATIGRAPHY PALAEOENVIRONMENT Tingri MAASTRICHTIAN TIBET
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EFFECTS OF RAPAMYCIN ON INTRACELLULAR CHOLESTEROL HOMEOSTASIS OF GLOMERULAR MESANGIAL CELL IN THE PRESENCE OF INTERLEUKIN-1β
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作者 Guo-iuan Zhang Hang Li Xue-wang Li 《Chinese Medical Sciences Journal》 CAS CSCD 2008年第4期205-211,共7页
Objective To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms. Methods Intracellular cholesterol accumulation was measured by Oil Red O stain... Objective To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms. Methods Intracellular cholesterol accumulation was measured by Oil Red O staining and high performance liquid chromatography. The effects of rapamycin on interleukin-1β(1L-1β)-induced mRNA and protein changes of low-density lipoprotein receptor (LDLR) and ATP-binding cassette transporter Al (ABCAl) were assayed by quantitative real-time PCR and Western blot. Transient expressions of 3 types of mammalian target of rapamycin (mTOR), including mTOR-WT (wild type), mTOR-RR (rapamycin resistant, with kinase activity), and mTOR-RR-KD (rapamycin resistant, without kinase activity), were obtained by plasmid transfection. Results Rapamycin had no significant influence on intracellular cholesterol concentration trader normal condition, but it significantly decreased the intracellular cholesterol concentration in the presence of IL-1β. Rapamycin dose-dependently suppressed the increased expression of LDLR induced by IL-1β and up-regulated the suppressed expression of ABCAl caused by IL-1β Transient expression of 3 types of mTOR all reduced ABCAl mRNA expression significantly, which all could be overroded by rapamycin. Conclusions Rapamycin may contribute to the maintaining of glomerular mesangial cell intracellular cholesterol homeostasis under inflammatory state by both reducing cholesterol uptake and increasing cholesterol effiux. And the effect may be not completely mediiated by mTOR. 展开更多
关键词 RAPAMYCIN glomerular mesangial cell CHOLESTEROL low-density lipoprotein receptor ATP-binding ca sette transporter A1
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Mediation of Computerized Accounting System (CAS) Adoption on Relationship Between Environmental Uncertainty and Organizational Performance 被引量:1
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作者 Quang Linh Huynh Lin Yaling 《Journal of Modern Accounting and Auditing》 2013年第6期747-755,共9页
This paper investigates the mediation of the adoption of computerized accounting system (CAS) on the relationship between environmental uncertainty and organizational performance. The authors use factor analysis, pa... This paper investigates the mediation of the adoption of computerized accounting system (CAS) on the relationship between environmental uncertainty and organizational performance. The authors use factor analysis, path analysis, and regression model to examine the effects of CAS adoption on the relationship between environmental uncertainty and organizational performance. The findings reveal that the adoption level of CAS is positively associated with organizational characteristics, environmental uncertainty, and organizational performance, and the usage of CAS has a statistically significant mediating effect on the relationship between environmental uncertainty and organizational performance. This paper will be significant to business managers in the decision to adopt CAS. 展开更多
关键词 computerized accounting system (CAS) environmental uncertainty organizational performance
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Negative Corona Discharge Ion Source Under Ambient Conditions with Mini Line-cylinder Electrodes 被引量:1
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作者 Kun Liu Fei Tang +2 位作者 Xiao-hao Wang Liang Zhang Xue-ye Wei 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第1期107-112,共6页
A novel ambient negative corona discharge ion source with mini line-cylinder electrodes is designed. The diameters of inner and outer electrode are 0.16 and 4 mm respectively. With a special assembly method, a perfect... A novel ambient negative corona discharge ion source with mini line-cylinder electrodes is designed. The diameters of inner and outer electrode are 0.16 and 4 mm respectively. With a special assembly method, a perfect coaxiality of the two electrodes is obtained. An injection system utilizing a temperature control technique, achieves a constant and stable concentration of the sample, which is critical to the experiment. The formulas of the corona onset voltage of line-cylinder electrodes are also introduced. The experiment results show that negative substances such as formic acid and acetic acid can be ionized under ambient conditions. When combined with micro electrical mechanical system fabricationprocess, the volume of the ion source can be reduced dramatically, but there is an undesirable surface discharge. To solve the surface discharge problem, an improved structure was designed and tested. The simplicity of the interface of the ion source makes it suitable for mass spectrometer, micro mass spectrometer, ion mobility spectrometer, and high-field asymmetric waveform ion mobility spectrometer applications. 展开更多
关键词 Line-cylinder corona discharge Ion source Surface discharge Ambient mass spectrometry Micro electrical mechanical system
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Lyapunov-Krasovskii functional based power system stability analysis in environment of WAMS 被引量:3
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作者 李婷 吴敏 何勇 《Journal of Central South University》 SCIE EI CAS 2010年第4期801-806,共6页
In order to analyze power system stability in environment of WAMS(wide area measurement system),a new steady state stability model with time-varying delay was proposed for power system.The factors of exciter and power... In order to analyze power system stability in environment of WAMS(wide area measurement system),a new steady state stability model with time-varying delay was proposed for power system.The factors of exciter and power system stabilizer with delay were introduced into analytical model.To decrease conservativeness of stability analysis,an improved Lyapunov-Krasovskii functional was constructed,and then a new delay-dependent steady state stability criterion for power system,which overcomes the disadvantages of eigenvalue computation method,was derived.The proposed model and criterion were tested on synchronous-machine infinite-bus power system.The test results demonstrate that Lyapunov-Krasovskii functional based power system stability analysis method is applicable and effective in the analysis of time delay power system stability. 展开更多
关键词 power system steady state stability time-varying delay power system stabilizer
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Sacrificial Anode Stability and Polarization Potential Variation in a Ternary Al-xZn-xMg Alloy in a Seawater-Marine Environment 被引量:1
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作者 Abubakar Muazu Yaro Shehu Aliyu +1 位作者 Malik Abdulwahab Abimbola Patricia Idowu Popoola 《Journal of Marine Science and Application》 CSCD 2016年第2期208-213,共6页
In this paper, the effects of zinc (Zn) and magnesium (Mg) addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, ... In this paper, the effects of zinc (Zn) and magnesium (Mg) addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, protection efficiency, and polarized potential were the parameters used. The percentages of Zn and Mg in the anodes were varied from 2% to 8% Zn and 1% to 4% Mg. The alloys produced were tested as sacrificial anodes for the protection of mild steel in seawater at room temperature. Current efficiency as high as 88.36% was obtained in alloys containing 6% Zn and 1% Mg. The polarization potentials obtained for the coupled (steel/Al-based alloys) are as given in the Pourbaix diagrams, with steel lying within the immunity region/cathodic region and the sacrificial anodes within the anodic region. The protection offered by the sacrificial anodes to the steel after the 7th and 8th week was measured and protection efficiency values as high as 99.66% and 99.47% were achieved for the A1-6%Zn-l%Mg cast anode. The microstructures of the cast anodes comprise of intermetallic structures of hexagonal Mg3Zn2 and body-centered cubic A12Mg3Zn3. These are probably responsible for the breakdown of the passive alumina film, thus enhancing the anode efficiency. 展开更多
关键词 sacrificial anode anode efficiency protection efficiency polarization potential intermetallic phase alloying elements theoretical current capacity flee electron seawater surface films
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A navigation method based on POMDP for smart wheelchair in uncertain environments
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作者 陶永 Wang Tianmiao Wei Hongxing Chen Diansheng 《High Technology Letters》 EI CAS 2010年第2期164-170,共7页
A navigation method based on the partially observable markov decision process (POMDP) for smart wheelchairs in uncertain environments is presented in this paper. The design key factors for the navigation system of a... A navigation method based on the partially observable markov decision process (POMDP) for smart wheelchairs in uncertain environments is presented in this paper. The design key factors for the navigation system of a smart wheelchair are discussed. A kinematics model of the smart wheelchair is given, and the model and principle of POMDP are introduced. In order to respond in uncertain local environments, a novel navigation methodology based on POMDP using the sensors perception and the user's joystick input is presented. The state space, the action set, the observations and the sensor fusion of the navigation method are given in detail, and the optimal policy of the POMDP model is proposed. Experimental results demonstrate the feasibility of this navigation method. Analysis is also conducted to investigate performance evaluation, advantages of the approach and potential generalization of this paper. 展开更多
关键词 service robot smart wheelchair navigation method partially observable markov decision process (POMDP)
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