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Search Results: 1 - 10 of 28492 matches for " 侯坤 "
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基于LS-SVM的改进统计降尺度方法
A Statistical Downscaling Method Based on Least Squares Support Vector Machines
 [PDF]

, 陈华, 黄逍, 许崇育
Journal of Water Resources Research (JWRR) , 2014, DOI: 10.12677/JWRR.2014.31012
Abstract: 统计降尺度方法作为一种计算量小、使用灵活的降尺度模型,被越来越多应用到气候变化研究当中。本文以湘江流域为例,开发了一种基于LS-SVM回归的改进统计降尺度算法,并与经典统计降尺度模型SDSM (Statistical Downscaling Model)进行比较。结果表明,在湘江流域,无论是降水模拟和温度模拟,基于LS-SVM回归算法的改进统计降尺度方法都能达到SDSM的效果,而温度的模拟,LS-SVM回归降尺度方法模拟结果更好。为了使得这种方法能更适合气候变化对水资源的影响研究,还需要在更多的区域进行应用证明。
 The statistical downscaling method has been more and more utilized in the climate change study for its simplicity and flexibility. A statistical downscaling method based on LS-SVM (least squares support vector machines) was developed and compared with SDSM (Statistical Downscaling Model) to test its ability in downscaling precipitation and temperature in Xiangjiang Basin. The results showed that the method based on LS-SVM has the similar performance with the SDSM method in simulating precipitation, while it was superior to SDSM in simulating temperature. The proposed method still needs to be applied to more regions to make it more suitable for studying the impact on water resources under climate change.
湘江流域SWAT模型建立及参数敏感性分析
The Application of SWAT to Simulate the Runoff in the Xiangjiang Basin and the Parameter Sensitivity Analysis
 [PDF]

, 黄逍, 陈华, 许崇育
Journal of Water Resources Research (JWRR) , 2014, DOI: 10.12677/JWRR.2014.32014
Abstract: 本文以湘江流域为研究区域,构建SWAT模型数字高程、土壤、土地利用及水文气象数据库,利用该流域1991~2005年日雨量和日径流资料,对湘江流域的涟水、渌水、洣水、衡阳以上以及衡阳到湘潭区间5个区域进行参数敏感性分析及率定。研究表明,在SWAT模型的参数中,alpha基流因子、河道曼宁系数等参数在以径流效率系数为优化目标的参数率定过程中具有较强敏感性;在检验期2001~2005年,湘江干流衡阳站和湘潭站的径流效率系数Ens均达到0.7以上,3个支流站径流效率系数也超过0.6,且水量平衡系数RE绝对值均控制在10%以内,说明湘江流域SWAT模型日径流模拟效果良好
A distributed SWAT model was introduced and applied in Xiangjiang basin. To construct the database of SWAT, those data, including DEM, land use, soil and hydro-meteorology have been collected, transformed and analyzed. The sensitive analysis of parameters, as well as their calibration and validation, was carried out in five sub-basins, by using the
经导管肝动脉栓塞技术在创伤性肝破裂出血治疗中的价值
Value of Transcatheter Hepatic Arterial Embolization in the Treatment of Traumatic Hepatic Rupture
 [PDF]

龚溪明, , 叶贤德, 阎波
Hans Journal of Surgery (HJS) , 2016, DOI: 10.12677/HJS.2016.52004
Abstract:
目的:探讨经导管肝动脉栓塞技术在创伤性肝破裂出血治疗中的价值。方法:回顾性分析我院2012年4月至2015年4月收治的57例创伤性肝破裂出血患者,依据治疗方法将这些患者随机分为两组,即研究组(n = 28)和对照组(n = 29)。介入组患者为经导管肝动脉栓塞技术及腹腔引流术治疗,对两组患者的术中输血量、术后住院时间及并发症发生情况进行统计分析。结果:和开放手术组相比,介入组患者的术中输血量明显较少(P < 0.05),术后住院时间明显较短(P < 0.05),术后并发症发生率35.7%显著低于对照组58.6% (P < 0.05)。结论:经导管肝动脉栓塞技术在创伤性肝破裂出血治疗中具有较高的应用价值,值得在临床推广。
Objective: To investigate the value of transcatheter hepatic arterial embolization in the treatment of traumatic hepatic rupture. Methods: 57 cases of patients with liver trauma bleeding who were treated in our hospital from April 2012 to April 2015 were selected. These patients were divided into two groups according to the treatment methods, namely the interventional therapy group (n = 28) and the open surgery group (n = 29). The interventional therapy group of patients were given transcatheter hepatic arterial embolization therapy and peritoneal drainage, and then the intraoperative blood transfusion, postoperative hospital stay and complications of the two groups of patients were analyzed statistically. Results: The intraoperative blood transfusion of the interventional therapy group of patients was significantly less than that of the open surgery group (P < 0.05). Postoperative hospital stay was significantly shorter (P < 0.05). The postoperative complication rate 35.7% was significantly lower than that of the open surgery group 58.6% (P < 0.05). Conclusion: Transcatheter hepatic arterial embolization is an effective and safe method in the treatment of traumatic hepatic rupture; so it is worthy of promotion in the clinical.
采矿权价格的期权定价模型
,运炳
煤炭学报 , 2005,
Abstract: 应用期权定价理论中的Black-Scholes模型对采矿权价格进行评估,依据矿业开采的特点,探讨模型应用中的期权期限,界定有效选择期限即采矿权的有效期限中扣除资源开发开采所需要的基本时间后的期限是合理的期权期限,并结合案例进一步分析,导出了在一定范围内适当增加采矿权的有效期限可以增加矿权地出让者的收益,以及运用Black-Scholes模型对采矿权价格进行评估可以起到鼓励大规模生产的作用.
中国金融加速器机制非对称传导的实证研究
杨胜刚,
中央财经大学学报 , 2011,
Abstract: ?本文运用中国1994年第一季度至2010年第三季度的相关数据对金融加速器传导机制的非对称传导特征进行了实证研究。实证结果表明我国的金融加速器传导机制具有明显的非对称性。负面冲击一旦产生,市场上的“反身性”作用会被压缩在一个狭窄的时段,这会使信贷量的紧缩和企业抵押资产的缩水紧密联系在一起,加速经济的衰退。
动力髋螺钉治疗老年股骨粗隆间骨折48例分析
德明,
宁夏医科大学学报 , 2011,
Abstract: 目的探讨应用动力髋螺钉(DHS)治疗老年股骨转子间骨折的特点及DHS内固定手术的技巧。方法对2003年10月-2008年10月通过DHS手术治疗并得到随访的老年人股骨转子间骨折48例的临床资料作回顾性分析。结果所有患者随访6~10个月,平均8个月。髋关节功能按Harris评分,优良率93.75%。结论DHS内固定治疗是治疗老年人股骨转子间骨折的一种有效的方法,且手术操作简便易行。
产业比较视角下的农业贷款绩效评价
Evaluation of agricultural loan performances based on perspective of industrial comparisons

,杜彦
- , 2017,
Abstract: 为全面了解农业贷款绩效状况,选取农业生产环节20种农产品,农产品加工业12个子产业,和其他工业部门共57个产业,根据历史财务状况构建项目,测算各产业项目贷款风险调整后绩效指标:相对绩效指标(EVA)与绝对绩效指标(aRAROC)。结果表明:1)受到收益和规模状况的双重制约,农业生产环节贷款两项指标表现均较差,面临着比较严重的贷款排斥;2)与其他产业相比,农产品加工业贷款的相对绩效优势明显,但受到贷款规模制约,绝对绩效排序下滑明显。最后根据上述结论提出改善农产品市场稳定性,提高农产品加工业规模化发展水平,和构建多层次农村金融体系的建议。
In order to obtain full understanding of the performances of agricultural loans,the historical financial data of 57 industries including 20 agricultural products and 12 agricultural processing industries-were selected,The risk-adjusted performance indicators of these industries were then calculated according to their historical performances which including the relative performance indicator aRAROC and absolute performance indicator EVA.The result showed that:1)Due to the double restriction of income and size factor,the performances of two indexes of agricultural production loans are poor,and the agricultural sector faces serious financial exclusion;2)Compared with other industries,agricultural processing industry loans have advantages in relative performance indicators,but restricted by the size of loans,and the absolute performance ranking fell significantly.Based on the analysis above,suggestions are put forwarded in this study on improve the stability of agricultural products market,develop the scale level of agricultural processing industry and construct Multi-level Rural Financial System.
用微量填充色谱柱分析丁烯中异丁烯杂质
,瑞玲
色谱 , 1984,
Abstract: 微填色谱柱具有柱效高、分析速度快及样品负荷量较大等优点,故可以直接进料和直接与质谱联用,对痕量分析有利。微填色谱柱可用填料范围广,填料用量又少,故可用一些难获得的性能好的填料,由于使用的填料能成批制备,且制柱方法简单,故制柱的重复性好。
基于统计降尺度模型预测鄱阳湖流域未来极值降水变化趋势
Projected Changes of Extreme Precipitation Characteristics for the Poyang Lake Basin Based on Statistical Downscaling Model
 [PDF]

洪兴骏, 郭生练, 郭家力, , 王乐
Journal of Water Resources Research (JWRR) , 2014, DOI: 10.12677/JWRR.2014.36063
Abstract:
本文以鄱阳湖流域为研究对象,研究变化环境下极端气候事件的时空分布及演变规律。利用流域内13个代表站点1961~2005年的逐日降水量资料,选用BCC-CSM1.1全球气候模式和三种(高、中、低)温室气体典型浓度路径排放情景,并与SDSM统计降尺度模型耦合,分析预测未来极值降水量级、强度和持续性指标的变化趋势。得出以下主要结论:进行偏差校正后的SDSM统计降尺度模型可应用于未来极值降水指标的计算;鄱阳湖流域未来极值降水量级、强度和持续性主要呈增加趋势;流域有降水集中化的趋势,这对于流域防洪较为不利,且未来可能面临较大的“旱涝急转”的风险。
As climate change will certainly result in strong response from extreme climatic events, investi-gating the spatio-temporal distribution and evolution laws of extreme climatic events is of great importance. Based on the daily precipitation from 1961 to 2005 from thirteen meteorological sta-tions within the Poyang Lake basin, daily precipitation for future period of 2010-2099 is simulated using the SDSM statistical downscaling model. Coupling a BCC-CSM1.1 GCM with three representa-tive concentration pathways (RCPs), the changing characteristics of magnitude, intensity and per-sistence of extreme precipitation are studied by means of several extreme precipitation indices. A bias correction procedure should be applied to the SDSM simulated historical precipitation before it can be used to simulate future precipitation. The extreme precipitation magnitude and intensity, as well as the persistence all show significantly increasing trends. Upgrading flood mitigation dif-ficulties due to a concentration tendency of precipitation, as well as the increasing potential of abrupt alternation between flood and drought will threaten the water resources security of the Poyang Lake basin.
CdTe/CdS量子点荧光探针测定司帕沙星含量
,那佳,
化学学报 , 2010,
Abstract: 在水溶液中合成了巯基乙酸修饰的CdTe/CdS量子点(QDs),基于喹诺酮类抗生素司帕沙星与CdTe/CdS量子点的荧光猝灭作用,建立了用CdTe/CdS量子点作为荧光探针检测微量司帕沙星的新方法.用荧光光谱、紫外光谱研究了CdTe/CdSQDs与司帕沙星的相互作用.研究表明该荧光猝灭的机理属于静态猝灭,反应的作用机理可能是司帕沙星促使QDs表面键合的有机分子发生变化,在Cd的电子空穴上形成了碲氧复合物,致使荧光猝灭.实验发现,pH为6.50的磷酸缓冲溶液中,量子点的浓度为3.75×10-4mol/L时,司帕沙星的浓度在0.1~50μg/mL范围与CdTe/CdS量子点荧光猝灭强度呈良好的线性关系,相关系数0.9992,检出限0.01399μg/mL.该方法简便、快捷、灵敏、线性范围宽,应用于司帕沙星片剂司帕沙星含量的测定,分析结果与标示量一致;用于牛奶中司帕沙星残留量的检测,回收率在93.1%~102.4%,结果满意.
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