, 2010 应用枝系构型理论,研究了胡杨在克拉玛依市防护林中的分枝构型的特征,并重点针对3种配置类型:胡杨(Populus euphratica Oliv.)×沙枣(Elaeagnus angustifolia L.)、胡杨×银白杨(Populus alba L.)和胡杨×白榆(Ulmus pumila L.),分析了胡杨分枝构型在不同配置中的变化。结果表明:防护绿地中胡杨不同部位(树冠)构型格局中,各级分枝长度数值和各级分枝角度数值从上到下均表现为逐渐变大的趋势;不同配置类型对胡杨构型特征 ...
杨小艳 +3 more
core
[Clinical characteristics and influencing factors of extraglandular invasion of prostatic ductal adenocarcinoma]. [PDF]
Beijing Da Xue Xue Bao Yi Xue BanYang X, Zhang F, Ma L, Liu C.
europepmc +1 more source
Wide baseline image matching for 3D objects
, 2013 为了匹配立体目标的图像特征,提出一种仿射不变的局部特征提取算法。根据高斯滤波器的形状和大小要与图像结构相适应的原理,该算法利用图像中的最大稳定极值区域(MSER)的协方差矩阵衡量局部图像结构,并将局部图像结构变换到圆形高斯滤波器适用的形式下,以解决视角和尺度变化问题。为了保证图像变换的正确性,采用旋转压缩的方式将各向异性的图像结构变换为各向同性的图像结构。最后在各向同性的图像结构上提取尺度不变特征变换(SIFT)特征点,并将SIFT特征点的坐标变回原图像坐标 ...
史泽林, 尹健, 李威
core
工程科学与技术为保障消能减震结构设计符合我国规范要求并确保时程分析输入的科学性，本文提出一种基于分周期段的双阻尼比目标谱匹配选波方法。该方法依据我国规范的技术要求，通过震中距和特征周期、调幅系数控制与分周期段双阻尼比反应谱匹配，提出适用于消能减震结构时程分析的地震动筛选流程。方法将目标反应谱划分为短周期（0~0.5］ s、中周期（0.5~1.5］ s与长周期（1.5~5.5］ s这3个区间，在5%和10%双阻尼比下同时进行匹配，兼顾不同阻尼比下的谱一致性 ...
白佳鑫 +5 more
doaj
[Cluster-guided adaptive Transformer for muscle fatigue prediction]. [PDF]
Sheng Wu Yi Xue Gong Cheng Xue Za ZhiFan B, Bao X, Ding L, Wu J.
europepmc +1 more source
[Multicenter prospective study on the diagnostic value of syndecan-1 for necrotizing enterocolitis in preterm infants]. [PDF]
Zhongguo Dang Dai Er Ke Za ZhiYin XY, Zhao ZH, Wang Y, Cai N, Chen S.
europepmc +1 more source
[Native mass spectrometry and ultraviolet photodissociation reveal conformation-selectivity of zinc ion to α-synuclein]. [PDF]
Se PuQin H +5 more
europepmc +1 more source
[Comparison of functional outcomes between tenecteplase and alteplase as bridging thrombolysis prior to mechanical throm-bectomy for acute ischemic stroke patients with large vessel occlusion]. [PDF]
Zhejiang Da Xue Xue Bao Yi Xue BanShi Z +8 more
europepmc +1 more source
[Research progress in surgical treatment of calcaneal fracture malunions]. [PDF]
Zhongguo Xiu Fu Chong Jian Wai Ke Za ZhiJi D, Wang Q, Zhao H.
europepmc +1 more source
[Efficacy and safety of mechanical thrombectomy beyond 24 to 72 hours in acute ischemic stroke patients with large vessel occlusion]. [PDF]
Zhejiang Da Xue Xue Bao Yi Xue BanJiang X +8 more
europepmc +1 more source