oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 106 )

2018 ( 1389 )

2017 ( 1377 )

2016 ( 1294 )

Custom range...

Search Results: 1 - 10 of 87379 matches for " ZHENG Xiao-yan "
All listed articles are free for downloading (OA Articles)
Page 1 /87379
Display every page Item
Species composition and abundance variation of protozoa in Dianshan Lake
淀山湖原生动物种类组成及数量变动

ZHENG Xiao-yan,WANG Li-qing,
郑小燕
,王丽卿

生态学杂志 , 2009,
Abstract: 应用淡水浮游生物调查方法,查明了2004—2006年淀山湖浮游原生动物的种类组成及数量变动,并研究了原生动物数量变动、Margalef多样性指数与水体富营养化的关系,以期为淀山湖湖泊水质管理提供基础的生物资料。共鉴定原生动物(仅肉足虫类和纤毛虫类)48种,隶属33属7目,其中肉足虫10种、纤毛虫38种;优势种为淡水筒壳虫(Tintinnidium fluviatile Stein)、恩茨筒壳虫(T. entzii Chiang)、绿急游虫(Strombidium viride Stein)、小单环栉毛虫(Didinium balbiamii nanum Kahl)及钟形钟虫(Vorticella companula Ehrenberg),优势种密度之和最高可占总密度的69.8%;3年原生动物年均密度季节变化,春季(7685 ind·L-1)>冬季(3241 ind·L-1)>秋季(2153 ind·L-1)>夏季(1680 ind·L-1);水平变化表现为村落周边St2站点(4405 ind·L-1)和进水口St5站点(4976 ind·L-1)居高;原生动物密度水平分布与修正的卡尔森营养综合指数变动趋势基本一致;Margalef多样性指数(D)均值为1.45,变幅为1.15~1.99;D值变化与水质状况密切相关。
Adaptive Rood Pattern Search for Fast Block-Matching Motion Estimation
用于快速块匹配运动估计的自适应十字模式搜索

Wang Xiao-yan,Zheng Jian-hong,
王晓燕
,郑建宏

电子与信息学报 , 2005,
Abstract: This paper proposes an adaptive rood pattern search, a new fast block-matching motion estimation algorithm. It combines the advantages of fixed search pattern and spatial correlation search pattern. Compared to the popular diamond search pattern, it has better performances.
Novel face recognition method based on KPCA plus KDA
一种融合KPCA和KDA的人脸识别新方法

ZHOU Xiao-yan,ZHENG Wen-ming,
周晓彦
,郑文明

计算机应用 , 2008,
Abstract: Kernel Discriminant Anlaysis (KDA) and Kernel Principal Component Analysis (KPCA) are the nonlinear extensions of Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA) respectively. In this paper, we presented a feature extraction algorithm by combing KDA and KPCA to extract reliable and robust features for recognition. Furthermore, a generalized nearest feature line (GNFL) method was also presented for constructing powerful classifier. The performance of the proposed method was demonstrated through real data.
Role of contrast-enhanced ultrasound in follow-up assessment after ablation for hepatocellular carcinoma
Shu-Guang Zheng,Hui-Xiong Xu,Ming-De Lu,Xiao-Yan Xie
World Journal of Gastroenterology , 2013, DOI: 10.3748/wjg.v19.i6.855
Abstract: AIM: To assess the usefulness of contrast-enhanced ultrasound (CEUS) during follow-up after percutaneous ablation therapy for hepatocellular carcinoma (HCC). METHODS: A total of 141 patients with HCCs who received percutaneous ablation therapy were assessed by paired follow-up CEUS and contrast-enhanced computed tomography (CECT). The follow-up scheme was designed prospectively and the intervals between CEUS and CECT examinations were less than 14 d. Both images of follow-up CEUS and CECT were reviewed by radiologists. The ablated lesions were evaluated and classified as local tumor progression (LTP) and LTP-free. LTP was defined as regrowth of tumor inside or adjacent to the successfully treated nodule. The detected new intrahepatic recurrences were also evaluated and defined as presence of intrahepatic new foci. On CEUS and CECT, LTP and new intrahepatic recurrence both were displayed as typical enhancement pattern of HCC (i.e., hyper-enhancing during the arterial phase and washout in the late phase). With CECT as the reference standard, the ability of CEUS in detecting LTP or new intrahepatic recurrence during follow-up was evaluated. RESULTS: During a follow-up period of 1-31 mo (median, 4 mo), 169 paired CEUS and CECT examinations were carried out for the 141 patients. For a total of 221 ablated lesions, 266 comparisons between CEUS and CECT findings were performed. Thirty-three LTPs were detected on CEUS whereas 40 LTPs were detected on CECT, there was significant difference (P < 0.001). In comparison with CECT, the numbers of false positive and false negative LTPs detected on CEUS were 6 and 13, respectively; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy of CEUS in detecting LTPs were 67.5%, 97.4%, 81.8%, 94.4% and 92.3%, respectively. Meanwhile, 131 new intrahepatic recurrent foci were detected on CEUS whereas 183 were detected on CECT, there was also significant difference (P < 0.05). In comparison with CECT, the numbers of false positive and false negative intrahepatic recurrences detected on CEUS were 13 and 65, respectively; the sensitivity, specificity, PPV, NPV and overall accuracy of CEUS in detecting new intrahepatic recurrent foci were 77.7%, 92.0%, 92.4%, 76.7% and 84.0%, respectively. CONCLUSION: The sensitivity of CEUS in detecting LTP and new intrahepatic recurrence after percutaneous ablation therapy is relatively low in comparison with CECT.
Ecological Security Pattern and Spatial Development Pattern in Mindong Region
ZHENG Xiao-yan,YOU Wei-bin,HE Dong-jin,QIN De-hua
Journal of Chongqing Normal University , 2013,
Abstract: Mindong is one of the most prospective coastal cities in the west-strait economic zone. It faces a challenge of urban economy and ecological environment development on the background of rapid urbanization. On the basis of Mindong resource advantage and historical cultural background, landscape ecological security patterns of flood control, biological conservation, cultural heritage protection, waters protection and recreation were constructed by using 3S technology. And these patterns were stacked into a comprehensive ecological security pattern. This paper analyzed features of spatial development patterns. The results showed that in low, medium and high levels, the land use proportion of ecological infrastructure which is used to maintain ecological security pattern was 22.68%, 55.22%, 72.78%. Ecological land area per capita was 867, 2 113, 2 785 m2. Ecological infrastructure was mainly distributed in middle-south region which has more waters, natural and cultural resources in Mindong, but it was contrary in northeast. Middle-south region was key region to implement protection for natural resources and landscape process, and maintain ecological security pattern sustainably. Spatial development patterns features of ecological security in high level are each ecosystem ensures the implementation of function commendably, it provides various natural service normally in the long time. And quality of natural service improves gradually.
(E)-2-Chloro-N′-(4-hydroxybenzylidene)benzohydrazide
Xiao-Yan Li
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812005661
Abstract: The title hydrazone molecule, C14H11ClN2O2, has a trans conformation with respect to the methylidene unit. The dihedral angle between the two benzene rings is 37.6 (3)°. In the crystal, the presence of O—H...O, O—H...N and N—H...O hydrogen bonds leads to the formation of a three-dimensional network. The title compound crystallized in the chiral orthorhombic space group P212121 and was refined as an inversion twin [Flack parameter = 0.20 (18)].
(E)-4-Nitro-N′-(3-nitrobenzylidene)benzohydrazide
Xiao-Yan Li
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812004540
Abstract: The title compound, C14H10N4O5, has an E conformation with respect to the C=N bond. The dihedral angle between the benzene rings is 2.41 (14)°. In the crystal, molecules are linked through N—H...O hydrogen bonds to form chains along the c axis. C—H...O interactions are also present, linking the chains to form a three-dimensional network.
(E)-3-Nitro-N′-(3-nitrobenzylidene)benzohydrazide
Xiao-Yan Li
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812005466
Abstract: In the title compound, C14H10N4O5, the molecule exists in a trans conformation with respect to the methylidene unit. The dihedral angle between the benzene rings is 9.8 (2)°. In the crystal, molecules are linked through N—H...O hydrogen bonds to form chains along the c axis.
(E)-4-Hydroxy-N′-(2-hydroxy-3,5-diiodobenzylidene)-3-methoxybenzohydrazide methanol monosolvate
Xiao-Yan Li
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812004552
Abstract: In the title compound, C15H12I2N2O4·CH3OH, the hydrazone molecule exists in an E conformation with respect to the C=N bond. The dihedral angle between the rings is 11.9 (2)°. There is one intramolecular O—H...N hydrogen bond in the hydrazone molecule. In the crystal, the hydrazone and methanol molecules are linked through O—H...O and N—H...O hydrogen bonds and C—H...O interactions to form two-dimensional networks lying parallel to (001).
(E)-N′-(3,5-Dichloro-2-hydroxybenzylidene)-2-methoxybenzohydrazide
Xiao-Yan Li
Acta Crystallographica Section E , 2011, DOI: 10.1107/s160053681102366x
Abstract: In the title compound, C15H12Cl2N2O3, the dihedral angle between the two substituted aromatic rings is 5.4 (4)°. Intramolecular O—H...N and N—H...O hydrogen bonds affect the planarity of the molcular conformation, with a mean deviation from the plane defined by the non-H atoms of 0.062 (2) . The molecule exists in a trans configuration with respect to the methylidene unit. In the crystal, molecules are linked by N—H...O interactions.
Page 1 /87379
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.