Rice is a staple food crop in China.Since the 1950’s,many new varieties havebeen used and resulted in great increase ofyield.However there were still some barriersin the nationwide extension of new varietiesdue to th...Rice is a staple food crop in China.Since the 1950’s,many new varieties havebeen used and resulted in great increase ofyield.However there were still some barriersin the nationwide extension of new varietiesdue to the insufficient information about thecharacteristics of varieties.So,it is impor-tant to find ways of determining the potential展开更多
To improve egg production performance of local chicken breed in Guizhou Province, Libo Yaoshan chicken, with dopamine receptor 2 ( DRD2 ) as one of the candidate genes, we detected its genetic variation in 196 Libe ...To improve egg production performance of local chicken breed in Guizhou Province, Libo Yaoshan chicken, with dopamine receptor 2 ( DRD2 ) as one of the candidate genes, we detected its genetic variation in 196 Libe Yaoshan hens using PCR-SSCP (single-strand conformation polymorphism) and sequencing method, and analyzed the correlation between genetic variation and egg production traits. The results showed that TT and TG genotypes in mRNA SNlX)62 (C→T) loci of the DRD2 gene had extremely significant difference in egg production at 38 weeks age (P 〈0.01 ), and significant difference in egg weight at 300 days age (P 〈0.05 ). The single nucleotide polymorphisms (SNPs) mutation induced synonymous mutation of the 312th amino acids (leucine) in DRD2 protein, from L (CTG) to L (TI'G). The mRNA SNP962 (C→T) loci had a larger genetic effect on egg production at 38 weeks age, and could be used as a molecular marker in early breeding of Libo Yaoshan chicken.展开更多
The present work adopted Reliability Centered Maintenance (RCM) methodology to evaluate marginal oilfield Early Production Facility (EPF) system to properly understand its functional failures and to develop an efficie...The present work adopted Reliability Centered Maintenance (RCM) methodology to evaluate marginal oilfield Early Production Facility (EPF) system to properly understand its functional failures and to develop an efficient maintenance strategy for the system. The outcome of the RCM conducted for a typical EPF within the Niger Delta zone of Nigeria provides an indication of equipment whose failure can significantly affect operations at the production facility. These include the steam generation unit and the wellhead choke assembly, using a risk-based failure Criticality Analysis. Failure Mode and Effect Analysis (FMEA) was conducted for the identified critical equipment on a component basis. Each component of the equipment was analyzed to identify the failure modes, causes and the effect of the failure. The outcome of the FMEA analysis aided the development of a robust maintenance management strategy, which is based on an optimized mix of corrective, preventive and condition-based monitoring maintenance for the marginal oilfield EPF.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
Natural decline in various mainstream oilfield reserves and the high investment capital in upstream exploration and project development have promoted attention towards smaller oilfields referred to as Marginal fields....Natural decline in various mainstream oilfield reserves and the high investment capital in upstream exploration and project development have promoted attention towards smaller oilfields referred to as Marginal fields. This provides operators the opportunity to commence exploration and production with minimum requirements of design, installation, and operations. Although the low Capital Expenditure (CAPEX) requirement favors the start-up of marginal oilfield operations, several operators are not able to sustain the field’s operations due to the high Operational Expenditure (OPEX), particularly arising from facilities’ maintenance. The aim of this paper is to review the maintenance strategies adopted in marginal oilfields, assess their effectiveness, and provide a pointer towards efficient and viable maintenance strategies for the sustainability of marginal oilfields. The study showed that time-based preventive maintenance is predominant in the oil industry, which constitutes up to 40% of net operational expenses. In other cases, reactive maintenance is adopted, which often results in an unplanned shutdown, known to be responsible for nearly half of the overall losses of an oil facility. A paradigm shift in maintenance to Reliability Centered Maintenance (RCM) was explored for marginal oilfield, with a comprehensive review of various maintenance strategies, ranging from maintenance optimization strategies, Heuristics and Metaheuristics, Artificial Intelligence (AI), and Data Mining techniques. It was observed that the application of AI best addresses the proposed RCM for marginal oilfields. This was drawn from the recorded limitations of the other concepts from verifiable similar works, where different AI techniques and Data analytics methods have been successfully applied to aid RCM.展开更多
文摘Rice is a staple food crop in China.Since the 1950’s,many new varieties havebeen used and resulted in great increase ofyield.However there were still some barriersin the nationwide extension of new varietiesdue to the insufficient information about thecharacteristics of varieties.So,it is impor-tant to find ways of determining the potential
基金Supported by Breeding and Demonstration Promotion of New Yaoshan Chicken Strains(QNYZ[2014]008)Key Gene Screening of Broodiness Breeding of Yaoshan Chicken(QKHJ[2014]2012)Doctoral Starting up Foundation of Guizhou Institute of Animal Husbandry and Veterinary in 2014:STAT5Gene Mutation Detection of Yaoshan Chicken and Associated Analysis with Egg Production Traits&CDS Region’s Cloning and Differential Expression of ONECUT1 Gene in Yaoshan Chicken and Associated Analysis with Production Traits(QKH LH[2015]7067)
文摘To improve egg production performance of local chicken breed in Guizhou Province, Libo Yaoshan chicken, with dopamine receptor 2 ( DRD2 ) as one of the candidate genes, we detected its genetic variation in 196 Libe Yaoshan hens using PCR-SSCP (single-strand conformation polymorphism) and sequencing method, and analyzed the correlation between genetic variation and egg production traits. The results showed that TT and TG genotypes in mRNA SNlX)62 (C→T) loci of the DRD2 gene had extremely significant difference in egg production at 38 weeks age (P 〈0.01 ), and significant difference in egg weight at 300 days age (P 〈0.05 ). The single nucleotide polymorphisms (SNPs) mutation induced synonymous mutation of the 312th amino acids (leucine) in DRD2 protein, from L (CTG) to L (TI'G). The mRNA SNP962 (C→T) loci had a larger genetic effect on egg production at 38 weeks age, and could be used as a molecular marker in early breeding of Libo Yaoshan chicken.
文摘The present work adopted Reliability Centered Maintenance (RCM) methodology to evaluate marginal oilfield Early Production Facility (EPF) system to properly understand its functional failures and to develop an efficient maintenance strategy for the system. The outcome of the RCM conducted for a typical EPF within the Niger Delta zone of Nigeria provides an indication of equipment whose failure can significantly affect operations at the production facility. These include the steam generation unit and the wellhead choke assembly, using a risk-based failure Criticality Analysis. Failure Mode and Effect Analysis (FMEA) was conducted for the identified critical equipment on a component basis. Each component of the equipment was analyzed to identify the failure modes, causes and the effect of the failure. The outcome of the FMEA analysis aided the development of a robust maintenance management strategy, which is based on an optimized mix of corrective, preventive and condition-based monitoring maintenance for the marginal oilfield EPF.
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Natural decline in various mainstream oilfield reserves and the high investment capital in upstream exploration and project development have promoted attention towards smaller oilfields referred to as Marginal fields. This provides operators the opportunity to commence exploration and production with minimum requirements of design, installation, and operations. Although the low Capital Expenditure (CAPEX) requirement favors the start-up of marginal oilfield operations, several operators are not able to sustain the field’s operations due to the high Operational Expenditure (OPEX), particularly arising from facilities’ maintenance. The aim of this paper is to review the maintenance strategies adopted in marginal oilfields, assess their effectiveness, and provide a pointer towards efficient and viable maintenance strategies for the sustainability of marginal oilfields. The study showed that time-based preventive maintenance is predominant in the oil industry, which constitutes up to 40% of net operational expenses. In other cases, reactive maintenance is adopted, which often results in an unplanned shutdown, known to be responsible for nearly half of the overall losses of an oil facility. A paradigm shift in maintenance to Reliability Centered Maintenance (RCM) was explored for marginal oilfield, with a comprehensive review of various maintenance strategies, ranging from maintenance optimization strategies, Heuristics and Metaheuristics, Artificial Intelligence (AI), and Data Mining techniques. It was observed that the application of AI best addresses the proposed RCM for marginal oilfields. This was drawn from the recorded limitations of the other concepts from verifiable similar works, where different AI techniques and Data analytics methods have been successfully applied to aid RCM.