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Nonstationary signal inversion based on shaping regularization for random noise attenuation

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Applied Geophysics 2020年第3期17卷 432-442页

作者： Yang wu-Yang Wang Wei Li Guo-Fa Wei Xin-Jian Wang Wan-Li chen de-wu Research Institute of Petroleum Exploration&development-Northwest PetroChinaLanzhou 730020China. State Key Laboratory of Petroleum Resources and Prospecting CUP(Beijing)Beijing 102249China. CNPC Key Laboratory of Geophysical Prospecting CUP(Beijing)Beijing 102249China.

Prediction filtering is one of the most commonly used random noise attenuation methods in the industry;however,it has two ***,it assumes that the seismic signals are piecewise stationary and ***,the seismic signal exhibits nonstationary due to the complexity of the underground ***,the method predicts noise from seismic data by convolving with a prediction error filter(PEF),which applies inconsistent noise models before and after ***,the assumptions and model inconsistencies weaken conventional prediction filtering's performance in noise attenuation and signal *** this paper,we propose a nonstationary signal inversion based on shaping regularization for random noise *** main idea of the method is to use the nonstationary prediction operator(NPO)to describe the complex structure and obtain seismic signals using nonstationary signal inversion instead of *** from the convolutional predicting filtering,the proposed method uses NPO as the regularization constraint to directly invert the eff ective signal from the noisy seismic *** NPO varies in time and space,enabling the inversion system to describe complex(nonstationary and nonlinear)underground geological structures in *** synthetic and field data results demonstrate that the method eff ectively suppresses random noise and preserves seismic refl ection signals for nonstationary seismic data.

关键词： noise attenuation nonstationary inversion shaping regularization

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异型单元式拼装人行天桥雨棚施工技术应用

广州建筑 2024年第4期52卷 53-57页

作者：陈德武胡健健赵运郭伟河广州市盾建建设有限公司广州511400 中建四局土木工程有限公司深圳518000

为解决异型拼装式人行天桥雨棚安装精度及安装效率等问题,通过采用BIM+Midas Gen有限元分析软件进行几何建模和网格划分,建立胎架和吊装构件模型,合理地划分雨棚网格,将其分成弧度较小的单元后进行单独吊装及空中原位安装,合理布置吊点... 详细信息

为解决异型拼装式人行天桥雨棚安装精度及安装效率等问题,通过采用BIM+Midas Gen有限元分析软件进行几何建模和网格划分,建立胎架和吊装构件模型,合理地划分雨棚网格,将其分成弧度较小的单元后进行单独吊装及空中原位安装,合理布置吊点和精密测控。结果表明:采用BIM+有限元软件分析、分段分节优化、安装方法优化、支撑胎架布置等一系列措施,得出施工过程中拱桁架最大竖向位移为39.68 mm,最大压应力为92.30 N/mm^(2),最大拉应力为104.30 N/mm^(2)。结构容许变形值、最大压应力和拉应力均满足规范要求;可以精确实现大跨度人行天桥钢结构的安装作业,且可以显著提高安装效率。研究成果也可为结构造型复杂、悬挑长度长、跨度大、且在空间呈现异形弯扭造型的人行天桥雨棚施工提供新思路。

关键词：钢结构雨棚异型双曲面单元式拼装有限元分析

Endoscopic diagnosis of gastrointestinal graft-versus-host disease

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World Journal of Gastroenterology 2008年第14期14卷 2262-2267页

作者： Chun-Fang Xu Lan-Xiang Zhu Xiao-Ming Xu Wei-Chang chen de-Pei wu department of Gastroenterology The First Affiliated Hospital of SooChow University 188 Shizi Street Suzhou 215006 Jiangsu Province China

AIM:To evaluate the diagnostic value of endoscopy in patients with gastrointestinal graft-versus-host disease (GI GVHD). METHODS:We identified 8 patients with GI GVHD following allogeneic hematopoietic stem cell trans-plantation (HSCT). GVHD was defined histologically as the presence of gland apoptosis, not explained by other inflammatory or infectious etiologies. RESULTS:The symptoms of GI GVHD included anorexia, nausea, vomiting, watery diarrhea, abdominal pain, GI bleeding, etc. Upper endoscopic appearance varied from subtle mucosal edema, hyperemia, erythema to obvious erosion. Colonoscopic examination showed diffuse edema, hyperemia, patchy erosion, scattered ulcer, sloughing and active bleeding. Histological changes in GI GVHD included apoptosis of crypt epithelial cells, dropout of crypts, and lymphocytic infiltration in epithelium and lamina propria. The involvement of stomach and rectocolon varied from diffuse to focal. CONCLUSION:Endoscopy may play a significant role in early diagnosis of GI GVHD patients following allogeneic HSCT, and histologic examination of gastrointestinal biopsies is needed to confirm the final diagnosis.

关键词： Gastrointestinal graft-versus-host disease Endoscopy Diagnosis Allogeneic hematopoietic stem cell transplantation

Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

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China Foundry 2024年第2期21卷 185-196页

作者： Wei-li wu Chang-gui cheng Yang Li Shi-fa Wei de-li chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Technology Center Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab *** order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT *** show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either *** the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes *** increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

关键词： continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate

Mixed H_(∞)/Passive Exponential Synchronization for delayed Memristive Neural Networks with Switching Event-Triggered Control

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Journal of Systems Science & Complexity 2024年第1期37卷 294-317页

作者： wu Wenhuang GUO Lulu chen Hong Shanghai Research Institute for Intelligent Autonomous Systems Tongji UniversityShanghai 200092China department of Control Science and Engineering Tongji UniversityShanghai 201804China

This paper is devoted to event-triggered synchronization of delayed memristive neural networks with H∞and passivity *** aim is to guarantee the exponential synchronization and mixed H∞and passivity control for memristive neural networks by using event-triggered ***,a switching system is constructed under the event-triggered control ***,by adopting a piece-wise Lyapunov functional,a sufficient condition is established for the exponential synchronization and mixed H_(∞)and passivity ***,an event-triggered controller design scheme is proposed using matrix decoupling ***,the effectiveness of the designed controller is exemplified by a numerical example.

关键词： Event-triggered control exponential synchronization memristive neural networks time delays.

Study on damage mechanism and damage distribution of the rear plate under impact of debris cloud

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defence Technology（防务技术） 2024年第5期35卷 151-167页

作者： chenyang wu Xiaowei chen Qiguang He State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyHaidian DistrictBeijing 100081China School of Mechatronical Engineering Beijing Institute of TechnologyHaidian DistrictBeijing 100081China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 621900SichuanChina

The debris cloud generated by the hypervelocity impact(HVI)of orbiting space debris directly threatens the spacecraft.A full understanding of the damage mechanism of rear plate is useful for the optimal design of protective *** this study,the hypervelocity yaw impact of a cylindrical aluminum projectile on a double-layer aluminum plate is simulated by the FE-SPH adaptive method,and the damage process of the rear plate under the impact of the debris cloud is analyzed based on the debris cloud *** damage process can be divided into the main impact stage of the debris cloud and the structural response of the rear *** main impact stage lasts a short time and is the basis of the rear plate *** the stage of structure response,the continuous deformation and inertial motion of the rear plate dominate the perforation of the rear *** further analyze the damage mechanism and damage distribution characteristics of the rear plate in ***,the connection between velocity space and position space of the debris cloud is established,which promotes the general analysis of the damage law of debris *** on the relationship,the features of typical damage areas are identified by the localized fine *** the cumulative effect and structural response cause the perforation of rear plate;in the non-perforated area,cratering by the impact of hazardous fragments is the main damage mode of the rear plate.

关键词： Damage of rear plate debris cloud Secondary impact Hypervelocity yaw impact FE-SPH adaptive method

Method for determining the position of landslide slip-surface with a typical inclinometric curves

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Journal of Mountain Science 2024年第2期21卷 413-432页

作者： chen Hao wu Hong-gang Ocean College Zhejiang UniversityZhoushan 316000China China Northwest Research Institute Co.Ltd.of CREC Lanzhou 730070China

In the actual monitoring of deep hole displacement,the identification of slip surfaces is primarily based on abrupt changes observed in the inclinometric *** conventional identification methods,inclinometric curves exhibiting indications of sliding can be categorized into three types:B-type,D-type,and *** position of the slip surface is typically determined by identifying the depth corresponding to the point of maximum displacement ***,this method is sensitive to the interval of measurement points and the observation scale of the coordinate axes and suffers from unclear sliding surfaces and uncertain *** on the variation characteristics of these diagonal curves,we classified the landslide into three components:the sliding body,the sliding interval,and the immobile ***,three different generalization models were established to analyze the relationships between the curve form and the slip surface location based on different physical indicators such as displacement rate,relative displacement,and *** results show that the displacement rate curves of an r-type slope exhibit a clustering feature in the sliding interval,and by solving for the depth of discrete points within the step phase,it is possible to determine the location of the slip *** the other hand,D-type slopes have inflection points in the relative displacement curve located at the slip *** acceleration curves of B-type slopes exhibit clustering characteristics during the sliding interval,while the scattered acceleration data demonstrate wandering ***,the slip surface location can be revealed by solving the depth corresponding to the maximum acceleration with cubic spline *** approach proposed in this paper was applied to the monitoring data of a landslide in Yunnan Province,*** results indicate that our approach can accurately identify the slip surface location and enable computability of its po

关键词： Inclinometric curve Slip-surface position Displacement rate Relative displacement Acceleration

Paclitaxel-lipid prodrug liposomes for improved drug delivery and breast carcinoma therapy

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Chinese Chemical Letters 2024年第2期35卷 335-340页

作者： Xin wu Xinmei chen Xinyu Wang Haisheng He Jianming chen Wei wu Key Laboratory of Smart Drug delivery of MOE School of PharmacyFudan UniversityShanghai 201203China department of Pharmacy Fujian University of Traditional Chinese MedicineFuzhou 350122China Shanghai Wei Er Lab Shanghai 201707China Shanghai Skin Disease Hospital Tongji University School of MedicineShanghai 200443China

Paclitaxel(PTX)is widely applied for the treatment of unresectable and metastasis breast carcinoma as well as other cancers,whereas its efficacy is always impeded by poor *** are one kind of the most successful drug carriers which are capable of solubilizing PTX and improving patients’tolerance owing to excellent biocompatibility and ***,poor compatibility between PTX and liposomes compromises the stability,drug loading and anti-tumor capacity of liposomal *** address this issue,three lipids with various chain lengths,namely,myristic acid(MA,14C),palmitic acid(PA,16C)and stearic acid(SA,18C),were conjugated to PTX via ester bonds and the synthesized prodrugs with high lipophilicity were further formulated into liposomes,*** liposomes show high stability and drug loadings,as well as sustained drug *** chain lengths of lipids are negatively correlated with drug release and enzymatic conversion rates,which further impact the pharmacokinetics,tumor accumulation,and anti-tumor efficacy of liposomal *** rapid nor slow drug release facilitates high tumor accumulation as well as anti-tumor efficacy of *** all liposomes,PTX-PA-loaded liposomes show the longest circulation and highest tumor accumulation of PTX and exert the most potent anti-tumor capacities in vivo,owing to its moderate drug release and enzymatic conversion *** its superior safety,PTX-PA liposomes hold potential for further clinical translation.

关键词： Paclitaxel Lipids Prodrugs Liposomes Drug release Chemotherapy

Toxicity mechanisms of photodegraded polyvinyl chloride nanoplastics on pea seedlings

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Frontiers of Environmental Science & Engineering 2024年第4期18卷 111-124页

作者： Hao wu Beibei He Bocheng chen An Liu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Nanoplasctics(NPs),which are very small in particle size,exert toxic effect to ***,compared to original NPs,photodegraded NPs would pose higher *** is because their relatively higher specific surface areas and the presence of additives which can more easily *** original NPs and aged NPs affect plant growth has not been widely *** work chose polyvinyl chloride NPs(PVC-NPs)that were subjected to up to 1000 h UV light radiation to explore the impact of PVC-NPs on the growth of pea seedlings(Pisum Sativum L.).The results indicated the existence of PVC-NPs with longer UV light radiation time and higher concentrations had more negative influences on pea seedlings’growth such as germination rate(decreased by 10.6%–22.5%),stem length(decreased by 2.8%–8.1%),dry weight(decreased by 6.3%–7.1%)and fresh weight(decreased by 6.7%–14.8%).It was also noted that photodegraded PVC-NPs resulted in damage to leaf stomata and roots,hindering photosynthesis and absorption of nutrients and hence the decrease in chlorophyll and soluble sugar *** to transcriptomic investigation results,the presence of aged PVC-NPs primarily influenced protein processing in endoplasmic reticulum(upregulated metabolic pathway)and phenylpropanoid biosynthesis(downregulated metabolic pathway)of pea *** results provide an in-depth understanding of how NPs influence the growth of plants.

关键词： Nanoplasctics Polyvinyl chloride Toxicity mechanisms Plant growth