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选择性痔上黏膜吻合术治疗混合痔后肛门狭窄的影响因素 被引量:1
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作者 孙承宇 李希全 黄大年 《当代医学》 2022年第7期132-134,共3页
目的探讨选择性痔上黏膜吻合术治疗混合痔后肛门狭窄的影响因素。方法选取2016年4月至2021年1月于本院接受选择性痔上黏膜吻合术治疗的209例混合痔患者作为研究对象,根据术后是否发生肛门狭窄分为正常组和狭窄组,比较两组患者临床资料,... 目的探讨选择性痔上黏膜吻合术治疗混合痔后肛门狭窄的影响因素。方法选取2016年4月至2021年1月于本院接受选择性痔上黏膜吻合术治疗的209例混合痔患者作为研究对象,根据术后是否发生肛门狭窄分为正常组和狭窄组,比较两组患者临床资料,采用Logistic回归分析肛门狭窄的影响因素。结果209例患者中术后共发生肛门狭窄18例,发生率为8.61%。单因素分析显示,两组性别、年龄、肛门手术史、吻合口感染、瘢痕史、吻合口高度、手术时间及术后大便形态分级比较差异具有统计学意义(P<0.05)。经二元Logistic回归分析显示,既往有肛门手术史、瘢痕史、术后有吻合口感染及手术时间长是影响术后肛门狭窄的独立危险因素(P<0.05),而术后大便形态分级为Ⅳ~Ⅴ为术后肛门狭窄的保护因素(P<0.05)。结论肛门手术史、瘢痕史及术后大便形状是术后肛门狭窄的影响因素,避免术后吻合口感染和手术时间过长,一定程度上可能有助于降低肛门狭窄的风险。 展开更多
关键词 选择性痔上黏膜吻合术 混合痔 肛门狭窄 影响因素
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地球深部探测计划中地学软件研发关键技术
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作者 于平 张琦 +1 位作者 黄大年 肖丽 《吉林大学学报(地球科学版)》 EI CAS CSCD 北大核心 2018年第2期501-506,共6页
针对高效率、高精度快速移动平台联合探测技术,发展由此带来的海量数据综合信息处理、解释和地质建模一体化所需的大型软件平台技术,可为实现复杂环境条件下有效实施大面积资源勘探调查、实现重大找矿突破目标提供切实可行的技术保障。... 针对高效率、高精度快速移动平台联合探测技术,发展由此带来的海量数据综合信息处理、解释和地质建模一体化所需的大型软件平台技术,可为实现复杂环境条件下有效实施大面积资源勘探调查、实现重大找矿突破目标提供切实可行的技术保障。采用引进和自主研发的"红蓝军"双轨路线,基于已有的地震数据处理解释基础,完善了高端软件平台地震和非震数据分析功能的联合,形成了具有跨操作平台、数据融合、二次开发、数据共享管理等功能的综合研究一体化分析软件平台,填补了国外软件产品在地震-非震数据联合分析方面的空白,为地球深部探测数据分析提供技术支撑。 展开更多
关键词 双轨路线 一体化 数据融合 地球深部探测 地学软件
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小波结合幂次变换方法在边界识别中的应用 被引量:4
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作者 谭晓迪 黄大年 +2 位作者 李丽丽 马国庆 张代磊 《吉林大学学报(地球科学版)》 EI CAS CSCD 北大核心 2018年第2期420-432,共13页
在位场数据边界识别传统方法理论的基础上,前人研究了各种场源边界增强技术来提高信噪比和定位精度,但仍然存在受噪声影响大、场源边界不够收敛等问题。本文在传统边界识别方法的基础上进行改进,利用小波变换与传统方法相结合来增强对... 在位场数据边界识别传统方法理论的基础上,前人研究了各种场源边界增强技术来提高信噪比和定位精度,但仍然存在受噪声影响大、场源边界不够收敛等问题。本文在传统边界识别方法的基础上进行改进,利用小波变换与传统方法相结合来增强对噪声的压制能力,并且提出了幂次变换法对识别出的边界进行有效收敛。将改进方法与传统方法应用于地质体的边界识别;同时选取3种传统数值计算方法,结合模型数据、四川盆地重力异常数据及朱日和地区磁异常数据进行对比分析。结果表明:小波结合幂次变换法能够有效识别出研究区域内地质体的边界,能很好地起到压制噪声的作用;并且识别出的边界收敛,提高了边界识别的精度,在边界识别中取得了良好的效果。 展开更多
关键词 边界识别 小波变换 幂次变换 压制噪声 边界收敛
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基于重力梯度结构张量特征值斜导数边界识别方法及其在南海的应用 被引量:9
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作者 戴伟铭 黄大年 +1 位作者 李桐林 张功成 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2018年第6期2494-2507,共14页
边界识别对地质构造解释具有十分重要的意义,其可以指出地下断层、接触带和其他构造单元的边界位置.现有的边界识别滤波器大多数基于重力梯度数据及其水平和垂直导数.然而,这些传统方法具有一定的局限性,对噪音的敏感,且不能有效的均衡... 边界识别对地质构造解释具有十分重要的意义,其可以指出地下断层、接触带和其他构造单元的边界位置.现有的边界识别滤波器大多数基于重力梯度数据及其水平和垂直导数.然而,这些传统方法具有一定的局限性,对噪音的敏感,且不能有效的均衡深浅异常的振幅,尤其是当测量异常中同时出现正异常和负异常将产生假的边界结果,对后期构造解释带来误导.针对传统方法的缺点,本文提出Tilt-Eigen边界识别方法,利用重力梯度结构张量矩阵特征值通过倾斜角计算结果的最大值实现边界识别.通过理论模型试验,该方法不仅能均衡深部浅部振幅异常的边界,避免引入额外的虚假边界异常,且识别的边界结果更加准确、收敛.将Tilt-Eigen方法用于南海实际重力数据处理,获得了20条比较清晰的边界结果.根据这些边界结果,本文推断红河断裂往ES方向延伸到南海南部区域后,开始朝正南方向延伸,与越东万安断裂相连接;推断出南沙海槽东北部为古南海缝合带,而其西南部并不是缝合带,缝合带位于其南侧的文莱沙巴附近;将南海分为8个地质构造单元. 展开更多
关键词 结构张量特征值 边界识别 红河断裂延伸 古南海缝合带 南海构造分区
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基于并行预处理算法的三维重力快速反演 被引量:1
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作者 王泰涵 黄大年 +2 位作者 马国庆 李野 林松 《吉林大学学报(地球科学版)》 EI CAS CSCD 北大核心 2018年第2期384-393,共10页
随着地球物理设备和探测技术的不断发展,快速处理大规模地球物理数据的需求也随之增长。为了解决三维重力数据密度反演的耗时问题,提出一种并行的预处理共轭梯度算法来提高计算效率。本文分别采用两种不同的预处理算子通过组合模型数据... 随着地球物理设备和探测技术的不断发展,快速处理大规模地球物理数据的需求也随之增长。为了解决三维重力数据密度反演的耗时问题,提出一种并行的预处理共轭梯度算法来提高计算效率。本文分别采用两种不同的预处理算子通过组合模型数据反演进行测试比较,并利用迭代残差和计算用时共同评价其加速效果。结果表明:对称逐次超松弛预处理方法比对角预处理方法反演计算速度快,密度结果更贴近实际模型;与传统串行的共轭梯度算法相比,本文并行预处理快速算法可以获得近19倍的加速比。将该算法应用于美国Vinton盐丘的实测重力数据中,反演结果能够很好地圈定出岩体的位置,验证了本文并行预处理共轭梯度法在三维重力数据快速反演中的高效性和可行性。 展开更多
关键词 三维重力反演 预处理共轭梯度算法 并行算法 对称逐次超松弛迭代法
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Edge detection using directional eigenvalues of potential field gradient tensor data 被引量:2
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作者 ZHOU Shuai huang danian 《Global Geology》 2015年第3期188-195,共8页
Edge detection of potential field interpretation is an important task. The traditional edge detection methods have poor ability in outlining weak amplitude anomalies clearly. The resolved edges position is blurred.We ... Edge detection of potential field interpretation is an important task. The traditional edge detection methods have poor ability in outlining weak amplitude anomalies clearly. The resolved edges position is blurred.We purposed new edge detection methods based on directional eigenvalues of potential field gradient tensor for the causative sources. In order to balance strong and weak amplitude anomalies simultaneously,we present one normalization method using different orders of vertical derivatives to improve the new filters. The presented filters were tested on synthetic and real potential field data to verify its feasibility. All of the results have shown that the new edge detection methods can not only display the sources edges precisely and clearly,but also bring out more geological subtle details. 展开更多
关键词 边缘检测方法 张量 梯度 势场 特征值 方向特征 数据验证 边缘信息
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3D inversion of borehole gravity data using cokriging 被引量:3
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作者 GENG Meixia huang danian XU Bowen 《Global Geology》 2014年第4期225-230,共6页
Borehole gravity has been used in mineral exploration recently with the advent of slim-hole gravimeters. It is logical to perform inversion to utilize the information in the newly acquired data. The inversions were ca... Borehole gravity has been used in mineral exploration recently with the advent of slim-hole gravimeters. It is logical to perform inversion to utilize the information in the newly acquired data. The inversions were carried out by using cokriging,which is a geostatistical method of estimation that minimizes the error variance by applying cross-correlation between several variables. In this study the estimated densities are derived by using boreholes gravity and known densities along the borehole. This method does not need iterative process and computes efficiently. The selection of examples demonstrates that this method has the ability to include physical property from borehole measurements in the inversion. The synthetic examples demonstrate the density variation along a borehole can be well determined without depth constraints in the inversion. The resolution of the recovered model can be further improved by including the densities along the borehole for inversion. However,this capability decreases dramatically with the increasing of distance between the anomalous body and the borehole. 展开更多
关键词 钻孔测量 三维反演 重力数据 克里格 协同 密度变化 地质统计方法 矿产勘查
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Detection of UXO magnetic anomaly in Jinshan area 被引量:2
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作者 WU Guochao huang danian +1 位作者 ZHANG Chong YUAN Yuan 《Global Geology》 2015年第1期54-58,共5页
Magnetic survey is one of the most successful techniques for locating buried unexploded ordnances( UXO). For the location and identification of buried UXO in Jinshan area,a total-field magnetic survey is applied. The ... Magnetic survey is one of the most successful techniques for locating buried unexploded ordnances( UXO). For the location and identification of buried UXO in Jinshan area,a total-field magnetic survey is applied. The analytic signal of magnetic field is widely used to outline the boundaries of geology bodies,slightly dependent on the magnetization direction. In order to locate the UXO position,the analytic signal is applied to process the magnetic UXO data,which performs better than the conventional magnetic data. Then a typical UXO anomaly is extracted from the original data to invert for its depth by an improved Euler method proposed.The calculated depth is close to the real buried depth. 展开更多
关键词 金山地区 爆炸物 磁异常 区域检测 未爆弹药 技术定位 解析信号 磁化方向
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Edge detection of gravity anomaly with an improved 3D structure tensor
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作者 DAI Weiming LI Tonglin +3 位作者 huang danian YUAN Yuan LIU Kai QIAO Zhongkun 《Global Geology》 2018年第2期108-113,共6页
Edge detection plays an important role in geological interpretation of potential field data,which can indicate the subsurface faults,contact,and other tectonic features.A variety of methods have been proposed to detec... Edge detection plays an important role in geological interpretation of potential field data,which can indicate the subsurface faults,contact,and other tectonic features.A variety of methods have been proposed to detect and enhance the edges.3 D structure tensor can well delineate the edges of geological bodies,however,it is sensitive to noise and additional false edges need to be removed artificially.In order to overcome these disadvantages,this paper redefines the 3 D structure tensor with a Gaussian envelop and proposes a new normalized edge detector,which can remove the additional false edges and reduce the influence of noise effectively,and balance the edges of different amplitude anomalies completely.This method has been tested on the synthetic and measured gravity data,showing that the new improved method achievesbetter results and reveals more details. 展开更多
关键词 EDGE detection IMPROVED 3D structure TENSOR GRAVITY ANOMALY
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QTL analysis of rice low temperature germinability 被引量:14
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作者 TENG Sheng ZENG Dali +3 位作者 QIAN Qian Kunihifo Yasufumi huang danian Zhu Lihuang 《Chinese Science Bulletin》 SCIE EI CAS 2001年第21期1800-1804,共5页
A double haploid population, derived from anther culture of F, hybrid between a typical indica and a japonica (ZYQ8/JX17), has been used to investigate the low temperature germinability (LTG) at 15℃. The low temperat... A double haploid population, derived from anther culture of F, hybrid between a typical indica and a japonica (ZYQ8/JX17), has been used to investigate the low temperature germinability (LTG) at 15℃. The low temperature germinability of two parents was significantly different. In 6-11 d, the germination percentage of ZYQ8 was higher than that of JX17. In 12-16 d, the germination percentage of JX17 was higher than that of ZYQ8. The quantitative trait loci (QTLs) of every day for low temperature germinabilityhave been mapped based on a molecular linkage map constructed from this population. In 8-11 d, qLTG-9 was identified in C397B-RZ617B on chromosome 9, the additive effect was positive, showing that, the allele from JX17 could increase low temperature germinability. In 12-16 d, qLTG-4 was mapped between RG908 and CT563 on chromosome 4, the additive effect was negative, showing that the allele from ZYQ8 could increase low temperature germinability. These two QTLs were detected at different stages, 展开更多
关键词 INDICA and JAPONICA SUBSPECIES DH population low temperature GERMINABILITY QTL detection DYNAMICAL analysis.
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Salt tolerance of transgenic rice (Oryza sativa L.) with mtlD gene and gutD gene 被引量:5
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作者 WANG Huizhong huang danian +3 位作者 LU Ruifang LIU Junjun QIAN Qian PENG Xuexian 《Chinese Science Bulletin》 SCIE EI CAS 2000年第18期1685-1690,共6页
Southern blot analysis indicated that mtID gene (encoding mannitol-1 -phosphate dehydrogenase) and gutD gene (encoding glucitol-6-phosphate dehydrogenase) had been integrated into the rice genome mediated by Agrobacte... Southern blot analysis indicated that mtID gene (encoding mannitol-1 -phosphate dehydrogenase) and gutD gene (encoding glucitol-6-phosphate dehydrogenase) had been integrated into the rice genome mediated by Agrobacterium tumefaciens LBA4404(pBIGM). The expression of the above two genes in transgenic rice plants was demonstrated by Northern blot analysis and enzymatic activity assay. Analysis of sugar alcohol showed that transgenic rice plants could produce and accumulate mannitol and sorbitol. The salt tolerance of transgenic plants was much higher than that of their controls. 展开更多
关键词 Oryza sativa L. Agrobacterium TUMEFACIENS D-mannitol-1-phosphate DEHYDROGENASE D-glucitol-6-phosphate DEHYDROGENASE salt tolerance.
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