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181.
目的:观察柔肝通络汤治疗脑梗死急性期(阴虚络瘀证)的临床疗效。方法:将脑梗死急性期(阴虚络瘀证)患者80例,随机分为2组,每组各40例。治疗组采用柔肝通络汤治疗,对照组采用西医常规治疗。结果:综合疗效总有效率治疗组为87.5%,对照组为72.5%,组间比较,差异有统计学意义(P<0.05);中医证候疗效总有效率治疗组为90.0%,对照组为75.0%,组间比较,差异有统计学意义(P<0.05);2组血液流变学指标、NIHSS评分治疗前后组内比较及治疗后组间比较,差异均有统计学意义(P<0.01)。结论:柔肝通络汤治疗脑梗死急性期(阴虚络瘀证)有较好疗效,优于西医常规治疗。  相似文献   
182.
在轨卫星或者空间碎片数量的增多,是对空间目标地基自动观测的一个挑战。尽管北美防空司令部编目管理了绝大多数直径超过10 cm的空间物体,但由于轨道摄动,空间目标的位置信息(基于6个轨道根数)依然非常重要,并需要定期更新。在过去的几十年里,配备电子传感器的现代地基光电望远镜已广泛用于天体测量领域。然而,这种设备的跟踪性能主要取决于空间目标的大小和亮度。这些目标所在的天文图像会有不同的背景;而且,在基于凝视模式的短曝光实时观测过程中,运动目标和背景恒星在不同的信噪比下显示为类似的点扩散函数,难以辨认。本研究是为了实现对非高斯和动态背景的高灵敏度检测和跟踪能力的提高,并具有简单的系统机制和出色的计算效率。为突破该限制,将重点放在利用状态估计技术对微小卫星和暗弱目标进行跟踪上。提出一种基于神经网络的自适应运行高斯平均算法,用以从恒星背景及干扰下提取运动的空间目标。该方法随后被集成到了一个检测前跟踪框架中。该框架利用基于蒙特卡洛的粒子滤波跟踪空间目标。三段来自亚太地基光学空间目标观测系统(APOSOS)图像序列被用来对该跟踪策略进行评估。实验结果表明,该方法能够达到满意的跟踪性能。  相似文献   
183.
We present optical luminosity functions(LFs) of galaxies in the~(0.1) g,~(0.1) r,~(0.1) i bands, calculated using data in~40 deg~2 sky area of the LAMOST Complete Spectroscopic Survey of Pointing Area(LaCoSSPAr) in the Southern Galactic Cap. Redshifts for galaxies brighter than r = 18.1 were obtained mainly with LAMOST. In each band, LFs derived using both parametric and non-parametric maximum likelihood methods agree well with each other. In the0.1 r band, our fitting parameters of the Schechter function are φ_*=(1.65 ± 0.36) × 10~(-2) h~3 Mpc~(-3), M_*=-20.69 ± 0.06 mag and α =-1.12 ± 0.08,which agree with previous studies. Separate LFs are also derived for emission line galaxies and absorption line galaxies. The LFs of absorption line galaxies show a dip at~(0.1) r ~18.5 and can be fitted well by a double-Gaussian function, suggesting a bimodality in passive galaxies.  相似文献   
184.
Zhang  Man  Chen  Yaning  Shen  Yanjun  Li  Baofu 《地理学报(英文版)》2019,29(1):3-28
Journal of Geographical Sciences - Under the impacts of climate change and human activities, great uncertainties still exist in the response of climate extremes, especially in Central Asia (CA). In...  相似文献   
185.
Land use and cover change(LUCC) is an important indicator of the human-earth system under climate/environmental change,which also serves as a key impact factor of carbon balance,and a major source/sink of soil carbon cycles.The Heihe River Basin(HRB) is known as a typical ecologically fragile area in the arid/semi-arid regions of northwestern China,which makes it more sensitive to the LUCC.However,its sensitivity varies in a broad range of controlling factors,such as soil layers,LUCCs and calculation methods(e.g.the fixed depth method,FD,and the equivalent mass method,ESM).In this study,we performed a meta-analysis to assess the response of soil organic carbon(SOC) and total nitrogen(TN) storage to the LUCC as well as method bias based on 383 sets of SOC data and 148 sets of TN data from the HRB.We first evaluated the calculation methods and found that based on the FD method,the LUCC caused SOC and TN storage to decrease by 17.39% and 14.27%,respectively;while the losses estimated using the ESM method were 19.31% and 18.52%,respectively.The deviations between two methods were mainly due to the fact that the FD method ignores the heterogeneity of soil bulk density(BD),which may underestimate the results subsequently.We then analyzed the response of SOC and TN storage to various types of the LUCC.In particular,when woodland and grassland were converted into cultivated land or other land types,SOC and TN suffered from heavy losses,while other LUCCs had minor influences.Finally,we showed that increasing the depth of the soil layers would reduce the losses of SOC and TN storage.In summary,we identified a series of controlling factors(e.g.soil layer,the LUCC and calculation method) to evaluate the impact of the LUCC on SOC and TN storage in the HRB,which should be considered in future research.  相似文献   
186.
Xu  Yue  Shen  Zehao  Ying  Lingxiao  Zang  Runguo  Jiang  Youxu 《地理学报(英文版)》2019,29(7):1142-1158
Journal of Geographical Sciences - Understanding biogeographic patterns and the mechanisms underlying them has been a main issue in macroecology and biogeography, and has implications for...  相似文献   
187.
青藏高原脆弱的高寒植被对外界干扰十分敏感,使其成为研究植被对气候变化响应的理想区域之一。青藏高原气候变化剧烈,在较短的合成时间研究气候变化对植被的影响十分必要。因此,本文利用GIMMS NDVI时间序列数据集,研究了1982-2012年青藏高原生长季月尺度植被生长的时空动态变化,探讨了其与气温、降水量和日照时数等气候因子的响应关系。结果表明:在区域尺度上,除8月外,其他各月份植被均呈增加趋势,显著增加多发生在4-7月和9月;大部分月份的NDVI增加速率随着时段的延长显著减小,表明NDVI增加趋势放缓;在像元尺度上,月NDVI显著变化的区域多呈增加趋势,但显著减少范围的扩张多快于显著增加。4月和7月植被生长主要是受气温和日照时数共同作用,6月和9月受气温的控制,而8月则主要受降水量的影响。长时间序列NDVI数据集的出现为采用嵌套时段研究植被生长变化趋势奠定了前提,而植被活动变化趋势的持续性则有助于形象表征植被活动变化过程、深入理解植被对气候变化的响应和预测植被未来生长变化趋势。由此推测,青藏高原月NDVI未来增加趋势总体上趋于缓和,但在像元尺度显著变化的区域趋于增加。  相似文献   
188.
采用线性回归和最小二乘法拟合建立无线电探空可降水量(RS-PWV)与GPS对流层延迟(GPS-ZTD)、地面温度及大气压之间的直接转换模型,并将直接转换模型得到的PWV分别与RS-PWV及GPS反演得到的可降水量(GPS-PWV)进行比较。结果表明,RS-PWV与GPS-ZTD之间存在良好的线性关系,相关系数达0.927 6;RS-PWV与4阶拟合温度和大气压呈现较好的相关性,相关系数分别为0.640 1和-0.626 3;基于ZTD的单阶单因子模型PWV与GPS-PWV的相关系数达到0.969 9;基于ZTD、温度及大气压的单阶多因子模型PWV比基于ZTD的单阶单因子模型PWV精度明显提高,RMS从4.3 mm提高到3.3 mm。  相似文献   
189.
基于1951—2018年哈德里中心海温资料、美国气象环境预报中心和美国国家大气研究中心再分析资料和第四代欧洲中心汉堡模式, 针对1994年、2018年等西北太平洋热带气旋(TC)生成异常多的年份, 研究了引起TC增加的海表温度异常(SSTA)模态及其影响机制。结果表明, 北半球热带中太平洋增暖与印度洋变冷是夏季西北太平洋TC生成频数增加的主要原因, 北大西洋负三极型式SSTA促使TC生成的进一步增加。热带中太平洋增暖与印度洋冷却在菲律宾以东激发出西风异常和气旋性环流异常。北大西洋负三极型式SSTA在我国南海、菲律宾至东南沿岸激发出气旋性环流异常。前者在西北太平洋中部, 后者在南海产生有利于TC生成的局地环境。1994年和2018年夏季热带中太平洋出现暖SSTA、印度洋为冷SSTA、北大西洋呈现负三极型式SSTA, 西北太平洋TC生成频数极端增多。近30年来, 当出现热带中太平洋增暖和印度洋冷却时, 北大西洋表现出比1989年以前更强的负三极型式SSTA, 使西北太平洋TC生成频数和北半球热带印度洋-太平洋SSTA梯度的线性相关更显著。  相似文献   
190.
Urban planning construction land standard is the technical specification for scientifically allocating various types of urban construction land, and it is the basis for drawing up and revising the overall urban planning scheme. Considering China's current urban planning construction land standard, many problems exist, such as the gap in the land use control threshold, the lack of regional differences in the climate revision, and failing to consider the topographic factors. To resolve these problems, this study proposed a step-by-step process framework and quantitative calculation method for the establishment and revision of standards in accordance with the principle of Total-Structure control. By setting the conditions, a universal basic standard for construction land was established. Quantitative analysis was then conducted on the relationship between the basic standard and the selected key indicators, such as urban population size, sunshine spacing coefficient, the width of river valleys or inter-montane basins, and terrain slope, among others. Finally, revised standards were formed for climate conditions, topography, and geomorphologic conditions, which were matched with the basic standards. The key results are three-fold:(1) The per capita construction land standard of 95 m~2/person can be used as the total indicator of China's urban planning basic standard, and the corresponding per capita single construction land comprises 32.50% of residential land, 7.42% of public management and public service land, 22.50% of industrial land, 17.50% of transportation facilities, 12.50% of green space, and 7.58% of other land-use types. The results of the revision of the urban population size indicate that the difference in population size has little effect on the total amount of per capita construction land.(2) The climate revision results of per capita residential land and per capita construction land in major cities reveal that the revised climate value varies greatly between north and south China. The revised climate values of the per capita area of construction land vary by latitude as follows: the value at 20°N is 93 m~2/person, the value at 30°N is 97 m~2/person, the value at 40°N is 103 m~2/person, and the value at 50°N is 115 m~2/person. The basic standard land value of 95 m~2/person is generally distributed across the Xiamen-Guilin-Kunming line.(3) The cities located in mountainous areas, hilly valleys, or inter-montane basins can reduce the allocation of community parks and comprehensive parks when the average width of an existing river valley or inter-montane basin is less than 2 km. When the average width of the valley or inter-montane basin is between 2 km to 4 km, the allocation of the comprehensive parks can be reduced. The revised results of per capita sloping construction land reveal that the terrain slope greatly affects the revised value of per capita construction land. Specifically, the revised value at 3° is 3.68% higher than the basic standard value, and the increase rates at 8°, 15°, and 25° are 11.25%, 26.49%, and 68.47%, respectively.  相似文献   
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