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Physical characteristics of high concentrated gas hydrate reservoir in the Shenhu production test area,South China Sea
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作者 Jiapeng JIN Xiujuan WANG +7 位作者 Zhenyu ZHU Pibo SU Lixia LI Qingping LI Yiqun GUO Jin QIAN Zhendong LUAN Jilin ZHOU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第2期694-709,共16页
High concentrated and heterogeneous distribution of gas hydrates have been identified in the gas hydrate production test region in the Shenhu area,South China Sea.The gas hydrate-bearing sediments with high saturation... High concentrated and heterogeneous distribution of gas hydrates have been identified in the gas hydrate production test region in the Shenhu area,South China Sea.The gas hydrate-bearing sediments with high saturation locate at two ridges of submarine canyon with different thickness and saturations just above the bottom simulating reflection.The crossplots of gamma ray,acoustic impedance(P-impedance)and porosity at four sites show that the sediments can be divided into the upper and lower layers at different depths,indicating different geotechnical reservoir properties.Therefore,the depositional environments and physical properties at two ridges are analyzed and compared to show the different characteristics of hydrate reservoir.High porosity,high P-wave velocity,and coarse grain size indicate better reservoir quality and higher energy depositional environment for gas hydrate at Sites W18 and W19 than those at Sites W11 and W17.Our interpretation is that the base of canyon deposits at Sites W18 and W19 characterized by upward-coarsening units may be turbidity sand layers,thus significantly improving the reservoir quality with increasing gas hydrate saturation.The shelf and slope sliding deposits compose of the fine-grained sediments at Sites W11 and W17.The gas hydrate production test sites were conducted at the ridge of W11 and W17,mainly because of the thicker and larger area of gas hydrate-bearing reservoirs than those at Sites W18 and W19.All the results provide useful insights for assessing reservoir quality in the Shenhu area. 展开更多
关键词 reservoir properties gas hydrate production test region depositional environment South China Sea
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Technical Problems and Approval Standards for the Regional Trials of Soybean Varieties in Liaoning Province
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作者 唐红丽 《Agricultural Science & Technology》 CAS 2014年第11期1847-1848,1882,共3页
The technical problems and approval standards for the regional test of soybean varieties in Liaoning Province were discussed. The technical key points for the soybean regional trials were the selection of trial fields... The technical problems and approval standards for the regional test of soybean varieties in Liaoning Province were discussed. The technical key points for the soybean regional trials were the selection of trial fields, preparations in lab be-fore sowing, preparations in regional trial field before sowing, sowing in suitable time and strict with sowing process, field management and survey record, harvest and sampling as wel as lab test and summary. In addition, the approval standards for common varieties and quality varieties for the soybean regional trials in Liaoning were introduced, with the aim to provide accurate and scientific theoretical basis for the approval of soybean varieties. 展开更多
关键词 Liaoning soybean regional test Technical problems Approval stan-dards
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Optimal Design of Multiple Stress Constant Accelerated Life Test Plan on Non-rectangle Test Region 被引量:8
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作者 CHEN Wenhua GAO Liang +2 位作者 LIU Juan QIAN Ping PAN Jun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第6期1231-1237,共7页
For optimal design of constant stress accelerated life test(CSALT) with two-stress, if the stresses could not reach the highest levels simultaneously, the test region becomes non-rectangular. For optimal CSALT desig... For optimal design of constant stress accelerated life test(CSALT) with two-stress, if the stresses could not reach the highest levels simultaneously, the test region becomes non-rectangular. For optimal CSALT design on non-rectangle test region, the present method is only focused on non-rectangle test region with simple boundary, and the optimization algorithm is based on experience which can not ensure to obtain the optimal plan. In this paper, considering the linear-extreme value model and the optimization goal to minimize the variance of lifetime estimate under normal stress, the optimal design method of two-stress type-I censored CSALT plan on general non-rectangular test region is proposed. First, two properties of optimal test plans are proved and the relationship of all the optimal test plans is determined analytically. Then, on the basis of the two properties, the optimal problem is simplified and the optimal design method of two-stress CSALT plan on general non-rectangular test region is proposed. Finally, a numerical example is used to illustrate the feasibility and effectiveness of the method, The result shows that the proposed method could obtain the optimal test plan on non-rectangular test regions with arbitrary boundaries. This research provides the theory and method for two-stress optimal CSALT planning on non-rectangular test regions. 展开更多
关键词 accelerated life test non- rectangular test region test plan optimal design
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Regional seismicity triggered by the HyogoKen Nanbu, Japan, M=7.2 earthquake on January 17, 1995 被引量:1
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作者 刘桂萍 傅征祥 《Acta Seismologica Sinica(English Edition)》 EI CSCD 1999年第3期277-284,共8页
The time and spatial feature of the regional seismicity triggered by the Hyogo-Ken Nanbu, Japan, M=7.2 earthquake on January 17, 1995, was studied. The concerned region is about several hundred kilometers in length a... The time and spatial feature of the regional seismicity triggered by the Hyogo-Ken Nanbu, Japan, M=7.2 earthquake on January 17, 1995, was studied. The concerned region is about several hundred kilometers in length and breadth surrounding the epicenter (33°-37°N, 133°-138°E). It is divided into 16 subregions. The seismicity of these subregions from January of 1976 to June of 1996 has been analyzed. It is showed that, 1) there were significant seismicity changes in 10 subregions triggered by the Hyogo-Ken Nanbu, Japan, M=7.2 earthquake on January 17, 1995. These changes passed a Z statistic test exceeding 0.95 confidence level and the greatest epicenter distance of these subregions was 280 km; 2) seismicity changes were triggered within 1-5 days in three subregions near the main shock while in other subregions the seismicity changes were triggered within several ten days after the main shock; 3) the greatest triggered event is 5.4, which is about the same size as the greatest aftershock; 4) the regional stress change resulted from the main shock may be the triggered mechanism of the regional seismicity. 展开更多
关键词 regional seismicity triggering Zstatistic test the Hyogo-Ken Nanbu earthquake in Japan
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Model test study of frost heaving pressures in tunnels excavated in fractured rock mass in cold regions 被引量:2
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作者 Bing Sun 《Research in Cold and Arid Regions》 2010年第5期405-410,共6页
Based on the similarity theory, taking the horseshoe, city-gate and round linings as examples, the value and distribution regularities of normal frost heaving pressures (hereinafter as frost heaving pressures) in tu... Based on the similarity theory, taking the horseshoe, city-gate and round linings as examples, the value and distribution regularities of normal frost heaving pressures (hereinafter as frost heaving pressures) in tunnels excavated in fractured rock mass in cold regions under different constraints and freezing depths were studied by a test model. It was found that the larger the frozen depth, the larger the frost heaving pressure, and the stronger the top constraint, the larger the frost heaving pressure. For the horseshoe lining and city-gate lining, the top constraint has a greater effect on the frost heaving pressures on the arch and the inverted arch. For the round lining, the influences of the top constraint on the frost heaving pressure in all linings are almost the same. The frost heaving pressure is maximum on the city-gate lining and minimal on the round lining. The largest frost heaving pressure all occur near the foot of the inverted arch for the three kinds of lining. Thus, the test data basically coincide with the observed in situ data. 展开更多
关键词 tunnel in cold region fractured rock mass frost heaving pressure model test
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Analysis of yield and quality characteristics of winter oilseed rape in China from 2001 to 2015: towards future breeding goals
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作者 Xiangxiang Zhang Qiong Liu +2 位作者 Meiyan Hong Lixia Luo Ruixing Guo 《Oil Crop Science》 2018年第3期165-175,共11页
The exciting outcomes of national regional trials have led to production and industrialization of China oilseed rape to a larger extent. To understand current trends of yield and quality traits of new varieties, data ... The exciting outcomes of national regional trials have led to production and industrialization of China oilseed rape to a larger extent. To understand current trends of yield and quality traits of new varieties, data of national winter oilseed rape trials from 2001 to 2015 in 4 districts (upper, middle, lower Yangtze River and Huang-Huai River) was comprehensively analyzed. Results showed that average yield of new varieties of winter oilseed rape increased during the study period. In 2013, average yield of each district reached its highest level. Number of pod per plant reached its peak in 2011 and then declined rapidly in the next 4 years. Average number of seeds per pod did not signif-cantly changed in any districts. Moreover, 1,000 seeds weight increased most obviously in Huang-Huai River district. After 2007, new oilseed rape varieties encountered the dou-ble-low quality (i.e., low erucic acid and low glucosinolate). In addition, oil content of new oilseed rape varieties increased over 15 years period and average oil content of all tested varieties during 2006-2015 was 42.96%, which was 2.38% higher than in 2005. Future breeding goals should be set to further improve yield, oil content, oil quality (such as high oleic acid and low saturated fatty acids), achieve full mechanization of oilseed rape pro-duction process and develop ideotypes. 展开更多
关键词 oilseed rape winter type regional testing varieties yield trait quality trait EVOLUTION
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Myricetin protects hippocampal CA3 pyramidal neurons and improves learning and memory impairments in rats with Alzheimer's disease 被引量:6
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作者 Matin Ramezani Niloufar Darbandi +1 位作者 Fariba Khodagholi Azam Hashemi 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第12期1976-1980,共5页
There is currently no treatment for effectively slowing the progression of Alzheimer's disease, so early prevention is very important. Numerous studies have shown that flavonoids can improve memory impairment. The pr... There is currently no treatment for effectively slowing the progression of Alzheimer's disease, so early prevention is very important. Numerous studies have shown that flavonoids can improve memory impairment. The present study investigated the effects of myricetin, a member of the flavonoids, on intracerebroventricular streptozotocin induced neuronal loss and memory impairment in rat models of Alzheimer's disease. Myricetin at 5 or 10 mg/kg was intraperitoneally injected into rats over 21 days. Control rats were treated with 10 m L/kg saline. Behavioral test(the shuttle box test) was performed on day 22 to examine learning and memory in rats. Immediately after that, hematoxylin-eosin staining was performed to observe the morphological change in hippocampal CA3 pyramidal neurons. Myricetin greatly increased the number of hippocampal CA3 pyramidal neurons and improved learning and memory impairments in rats with Alzheimer's disease. These findings suggest that myricetin is beneficial for treatment of Alzheimer's disease. 展开更多
关键词 nerve regeneration myricetin Alzheimer's disease streptozotocin hippocampus pyramidal neurons CA3 region behavioral test neural regeneration
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Advances in crop phenotyping and multi-environment trials 被引量:7
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作者 Zhe LIU Fan ZHANG +5 位作者 Qin MA Dong AN Lin LI Xiaodong ZHANG Dehai ZHU Shaoming LI 《Frontiers of Agricultural Science and Engineering》 2015年第1期28-37,共10页
Efficient evaluation of crop phenotypes is a prerequisite for breeding, cultivar adoption, genomics and phenomics study. Plant genotyping is developing rapidly through the use of high-throughput sequencing techniques,... Efficient evaluation of crop phenotypes is a prerequisite for breeding, cultivar adoption, genomics and phenomics study. Plant genotyping is developing rapidly through the use of high-throughput sequencing techniques,while plant phenotyping has lagged far behind and it has become the rate-limiting factor in genetics, large-scale breeding and development of new cultivars. In this paper,we consider crop phenotyping technology under three categories. The first is high-throughput phenotyping techniques in controlled environments such as greenhouses or specifically designed platforms. The second is a phenotypic strengthening test in semi-controlled environments, especially for traits that are difficult to be tested in multi-environment trials(MET), such as lodging, drought and disease resistance. The third is MET in uncontrolled environments, in which crop plants are managed according to farmer's cultural practices. Research and application of these phenotyping techniques are reviewed and methods for MET improvement proposed. 展开更多
关键词 crop breeding GENOTYPING PHENOTYPING genotype-environment interaction cultivar regional test
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