检索结果-南通市图书馆

Target-oriented Gaussian beam migration using a modif ied ray tracing scheme

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2019年第6期16卷 1301-1319页

作者： Rui Zhang Jian-Ping Huang su-bin zhuang Zhen-Chun Li School of Geosciences China University of Petroleum(East China)Qingdao 266580China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China

For large-scale 3D seismic data,target-oriented reservoir imaging is more attractive than conventional full-volume migration,in terms of computation *** beam migration(GBM)is one of the most robust depth imaging method,which not only keeps the advantages of ray methods,such as high efficiency and flexibility,but also allows us to solve caustics and multipathing *** conventional Gaussian beam migration requires slant stack for prestack data,and ray tracing from beam center location to subsurface,which is not easy to be directly applied for target-oriented *** this paper,we modify the conventional Gaussian beam migration scheme,by shooting rays from subsurface image points to receivers to implement wavefield *** modification helps us to achieve a better subsurface illumination in complex structure and allows simple implementation for target reservoir ***,compared with the wavefi eld-based GBM,our method does not reconstruct the subsurface snapshots,which has higher *** the proposed method is not as efficient as the conventional Gaussian beam *** and field data examples demonstrate the validity and the target-oriented imaging capability of our method.

关键词： Gaussian beam migration Target-oriented imaging Illumination Ray tracing

A fast space-time-domain Gaussian beam migration approach using the dominant frequency approximation

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2022年第4期19卷 1555-1565页

作者： Dong-Lin Zhang Jian-Ping Huang Ji-Dong Yang Zhen-Chun Li su-bin zhuang Qing-Yang Li School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Pilot National Laboratory for Marine Science and Technology QingdaoShandong 266580China Geophysical Exploration Research Institute of Zhongyuan Oilfield Company PuyangHenan 457001China

The Gaussian beam migration(GBM) is a steady imaging approach, which has high accuracy and efficiency. Its implementation mainly includes the traditional frequency domain and the recent popular space-time domain. Firstly, we use the upward ray tracing strategy to get the backward wavefields. Then,we use the dominant frequency of the seismic data to simplify the imaginary traveltime calculation of the wavefields, which can cut down the Fourier transform number compared with the traditional GBM in the space-time domain. In addition, we choose an optimized parameter for the take-off angle increment of the up-going and down-going rays. These optimizations help us get an efficient space-time-domain acoustic GBM approach. Typical four examples show that the proposed method can significantly improve the computational efficiency up to one or even two orders of magnitude in different models with different model parameters and produce good imaging results with comparable accuracy and resolution with the traditional GBM in the space-time domain.

关键词： Gaussian beam Space-time-domain Fast Dominant frequency approximation

A novel small-animal locomotor activity recording device for biological clock research

在线全文

学校读者我要写书评

暂无评论

Animal Models and Experimental Medicine 2024年第1期7卷 71-76页

作者： Yi-Long Wu Ming Zhong Jun Yin Wei-Jie Ou Yu-bin zhuang Nan-Wen Zhang su Lin Yue-Yong Zhu Endoscopy Center The First Affiliated HospitalFujian Medical UniversityFuzhouChina Department of Endocrinology The First Affiliated HospitalFujian Medical UniversityFuzhouChina Chuangke Workshop Technology Co. LtdShenzhenChina Department of Digestive Nutrition Fujian Children's HospitalFuzhouChina Experimental Animal Center Fujian Medical UniversityFuzhouChina Department of Pharmacology Fujian Medical UniversityFuzhouChina Department of Hepatology Hepatology Research InstituteClinical Research Center for Liver and Intestinal Diseases of Fujian ProvinceThe First Affiliated HospitalFujian Medical UniversityFuzhouChina

The rodent running-wheel recording apparatus is a reliable approach for studying cir-cadian *** study demonstrated how to construct a simple and intelligent running-wheel recording *** running wheel was attached to the cage's base,whereas the Hall sensor was attached to the cage's ***,the RJ25 adaptor relayed the running signal to the main control ***,the main control board was connected to the USB port of the computer with the USB *** were collected using the online-accessible,self-created software *** Magturning,generated data were saved and exported in real ***,the device was validated by collecting data on the locomotor activities of mice under dif-ferent light *** conclusion,this new device can record circadian activity of *** device is appropriate for interdisciplinary investigations related to biological clock research.

关键词： biological clock circadian rhythm intelligent equipment locomotor activity running wheel

A novel stiffness optimization model of space telescopic boom based on locking mechanism

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第3期19卷 41-59页

作者： Kun XU Xinghan zhuang Zhou su Qiuhong LIN Shouzhi REN Hang XIAO Xilun DING School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beijing Institute of Spacecraft System Engineering Beijing 100094China

The deployable telescopic boom,whose mass and stiffness play crucial roles,is extensively used in the design of space-deployable ***,the most existing optimal design that neglects the influence of the locking mechanisms in boom joints cannot raise the whole stiffness while reducing the boom *** tackle this challenge,a novel optimization model,which utilizes the arrangement of the locking mechanisms to achieve synchronous improvement of the stiffness and mass,is *** proposed optimization model incorporates a novel joint stiffness model developed based on an equivalent parallel mechanism that enables the consideration of multiple internal stiffness factors of the locking mechanisms and tubes,resulting in more accurate representations of the joint stiffness *** analysis shows that the proposed stiffness model achieves more than at least 11% improved accuracy compared with existing ***,case verification shows that the proposed optimization model can improve stiffness while effectively reducing mass,and it is applied in boom optimization design.

关键词： deployable telescopic boom locking mechanism stiffness model clearance error optimization model

A review on the chemo-catalytic conversion of cellulose to bio-ethanol

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Chemical Engineering 2024年第3期5卷 276-289页

作者： Xiuzheng zhuang Haiyong Wang Shugen Jiang Xiaohong Hu Tong su Xinghua Zhang Longlong Ma Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing210096China Key Laboratory of Renewable Energy Guangzhou Institute of Energy ConversionChinese Academy of SciencesGuangzhou510640China Wuzhou Refrigeration Group Co.Ltd. Nanjing211100China

While the industry has produced sugar-derived ethanol from the conventional method of fermentation for hundreds of years,other effective routes involving the direct transformation of carbohydrates still remain extremely *** recently,an innovative chemo-catalytic method driven by the aqueous-phase catalysis was created for the synthesis of cellulosic ethanol,making a great breakthrough in the common ways as it can theoretically utilize all of the carbon atoms in sugars with faster kinetics;up to now,results from the relevant studies have been accumulated to a certain extent,but the periodic conclusions in this field are unfortunately *** this reason,this work tries to offer an overview of the cellulosic ethanol produced by chemo-catalytic routes,highlighting the present knowledge in relation to the technical efficiency,catalytic mechanisms as well as practical *** first,the advanced progress on the increasing efficiency from a varied type of catalytic systems are extensively discussed,which involves the specific functions of hybrid components from different strategies;meanwhile,the general influences of processing conditions,such as the hydrothermal severity and aqueous environments,are also ***,possible mechanisms behind the chemo-catalytic processes are widely elaborated by analyzing a number of experimental cases associated with the reaction network and its kinetic *** that,the actual effects of this technique on the real biomass are collected to identify the positive/negative interactions between multiple components,together with the potential solutions on the semi-continuous processes of pilot scale *** techno-economic analysis(TEA)is also calculated and compared with other similar methods,such as fermentation and ***,several proposals aimed at upgrading the whole chain of chemo-catalytic processes are clearly provided,which may function as a guideline for future studies on the pr

关键词： Cellulosic ethanol Chemo-catalytic method Influencing factors Catalytic mechanism Techno-economic analysis

Optimization of Gas-Flooding Fracturing Development in Ultra-Low Permeability Reservoirs

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第3期20卷 595-607页

作者： Lifeng Liu Menghe Shi Jianhui Wang Wendong Wang Yuliang su Xinyu zhuang Tight Oil Research Institute PetroChina Research Institute of Petroleum Exploration&DevelopmentBeijing100083China Key Laboratory of Unconventional Oil&Gas Development China University of Petroleum(East China)Qingdao266580China Oil&Gas Technology Research Institute Changqing Oilfield CompanyXi’an710018China

Ultra-low permeability reservoirs are characterized by small pore throats and poor physical properties, which areat the root of well-known problems related to injection and production. In this study, a gas injection floodingapproach is analyzed in the framework of numerical simulations. In particular, the sequence and timing of fracturechanneling and the related impact on production are considered for horizontal wells with different fracturemorphologies. Useful data and information are provided about the regulation of gas channeling and possible strategiesto delay gas channeling and optimize the gas injection volume and fracture parameters. It is shown that inorder to mitigate gas channeling and ensure high production, fracture length on the sides can be controlled andlonger fractures can be created in the middle by which full gas flooding is obtained at the fracture location in themiddle of the horizontal well. A Differential Evolution (DE) algorithm is provided by which the gas injectionvolume and the fracture parameters of gas injection flooding can be optimized. It is shown that an improvedoil recovery factor as high as 6% can be obtained.

关键词： Ultra-low permeability reservoir gas injection flooding component simulation fracture parameters intelligent optimization differential evolution

An Improved YOLOv7 tiny Algorithm for Vehicle and Pedestrian Detection with Occlusion in Autonomous Driving

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年

作者： Jian su Fang WANG Wei zhuang Nanjing University of Information Science and Technology

Future transportation is advancing in the direction of intelligent transportation systems, where an essential part is vehicle and pedestrian detection. Due to the complex urban traffic environment, vehicles and pedestrians in road monitoring have different forms of occlusion problems, resulting in the missed detection of objects. We design an improved you only look once version 7(YOLOv7) tiny algorithm for vehicle and pedestrian detection under occlusion, with the following four main improvements. In order to locate the object more accurately, 1 × 1 convolution and identity connection are added to the 3 × 3 convolution, and convolution reparameterization is used to enhance the inference speed of the network model. In view of the complex road background and more interference, the coordinate attention was added to the connection part of backbone and neck to enhance the network's capacity to detect the object and lessen interference from other targets. At the same time, before being sent to the detection head, global attention mechanism is added to improve the accuracy of model detection by capturing three-dimensional features. Considering the issue of imbalanced training samples, we propose focal complete intersection over union(CIOU) loss instead of CIOU loss to become the bounding box regression loss, so that the regression process attention to high-quality anchor boxes. Experiments show that the improved YOLOv7 tiny algorithm achieves 82.2%map@0.5 in Pattern Analysis, Statistical Modelling and Computational Learning Visual Object Classes(PASCAL VOC) dataset, which is 2.8% higher than before the improvement. The performance of map@0.5:0.95 is 5.2% better than the previous improvement. The proposed improved algorithm can availably to detect partial occlusion objects.

关键词：

AOYOLO Algorithm Oriented Vehicle and Pedestrian Detection in Foggy Weather

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年

作者： Jian su Shiang MAO Wei zhuang Nanjing University of Information Science and Technology

In the context of complex foggy environments, the acquired images often suffer from low visibility,high noise, and loss of detailed information. The direct application of general object detection methods fails to achieve satisfactory results. To address these issues, this paper proposes a foggy object detection method based on YOLOv8n,named AOYOLO. The all-in-one dehazing network(AOD-Net), a lightweight defogging network, is employed for data augmentation. Additionally, the ResCNet module is introduced in the backbone to better extract features from low-illumination images. The GACSP module is proposed in the neck to capture multi-scale features and effectively utilize them, thereby generating discriminative features with different scales. The detection head is improved using WiseI oU, which enhances the accuracy of object localization. Experimental evaluations are conducted on the publicly available datasets annotated realworld task-driven testing set(RTTS) and synthetic foggy KITTI dataset. The results demonstrate that the proposed AOYOLO algorithm outperforms the original YOLOv8n algorithm with an average mean average precision improvement of 3.3% and 4.6% on the RTTS and KITTI datasets, respectively. The AOYOLO method effectively enhances the performance of object detection in foggy scenes. Due to its improved performance and stronger robustness, this experimental model provides a new perspective for foggy object detection.

关键词：

Exploring the impact of Nafion modifier on electrocatalytic CO_(2) reduction over Cu catalyst

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第1期88卷 543-551,I0012页

作者： Yingshi su Yonghui Cheng Zhen Li Yanjia Cui Caili Yang Ziyi Zhong Yibing Song Gongwei Wang Lin zhuang College of Chemistry&Chemical Engineering and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou 515063GuangdongChina College of Chemistry and Molecular Sciences Hubei Key Lab of Electrochemical Power SourcesWuhan UniversityWuhan 430072HubeiChina The Institute for Advanced Studies Wuhan UniversityWuhan 430072HubeiChina Department of Chemistry Engineering Guangdong Technion-Israel Institute of Technology(GTIIT)Shantou 515063GuangdongChina Technion-Israel Institute of Technology(IIT) Haifa 32000Israel

Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode ***,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)***,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)*** found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product *** to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology ***,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance.

关键词： Nafion modifier CO_(2)reduction Cu nanoparticles In situ ATR-SEIRAS C_(2)product