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A new model for predicting hydraulic fracture penetration or termination at an orthogonal interface between dissimilar formations

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Petroleum Science 2022年第6期19卷 2810-2829页

作者： Yu Zhao Yong-Fa Zhang Guo-Dong Tian Chao-Lin Wang Jing bi College of Civil Engineering Guizhou UniversityGuiyang550025GuizhouChina Guizhou Provincial Key Laboratory of Rock and Soil Mechanics and Engineering Safety(Guizhou University) Guiyang550025GuizhouChina School of Civil Engineering Chongqing UniversityChongqing400045China

Vertical height growth of hydraulic fractures(HFs)can unexpectedly penetrate a stratigraphic interface and propagate into neighboring layers,thereby resulting in low gas-production efficiency and high risk of groundwater contamination or fault reactivation.Understanding of hydraulic fracture behavior at the interface is of pivotal importance for the successful development of layered reservoirs.In this paper,a twodimensional analytical model was developed to examine HF penetration and termination behavior at an orthogonal interface between two dissimilar materials.This model involves changes in the stress singularity ahead of the HF tip,which may alter at the formation interface due to material heterogeneity.Three critical stress conditions were considered to assess possible fracture behavior(i.e.,crossing,slippage,and opening)at the interface.Then,this model was verified by comparing its theoretical predictions to numerical simulations and three independent experiments.Good agreement with the simulation results and experimental data was observed,which shows the validity and reliability of this model.Finally,a parametric study was conducted to investigate the effects of key formation parameters(elastic modulus,Poisson’s ratio,and fracture toughness)between adjacent layers.These results indicate that the variation in the introduced parameters can limit or promote vertical HF growth by redistributing the induced normal and shear stresses at the interface.Among the three studied parameters,Poisson’s ratio has the least influence on the formation interface.When the fracture toughness and elastic modulus of the bounding layer are larger than those of the pay zone layer,the influence of fracture toughness will dominate the HF behavior at the interface;otherwise,the HF behavior will more likely be influenced by elastic modulus.

关键词： Analytical model Hydraulic fracture Interface of dissimilar materials Vertical propagation behavior Parametric sensitivity analysis

Danzhi Jiangtang capsule(丹蛭降糖胶囊)reduces renal injury in rats with diabetes induced by high fat diet and streptozotocin via downregulating toll-like receptor 4-nuclear factor-κB pathway and apoptosis

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Journal of Traditional Chinese Medicine 2023年第2期43卷 312-321页

作者： XIE jing bi Zheng WANG Sihai SHEN Guoming FANG Zhaohui Department of Endocrinology the First Affiliated Hospital of Anhui University of Traditional Chinese MedicineHefei 230031China Anhui Academic of Traditional Chinese Medicine Diabetes Research Institute Hefei 230031China

OBJECTIVE:To investigate the effect and mechanisms of Danzhi Jiangtang capsule(丹蛭降糖胶囊,DJC)on renal injury in streptozotocin(STZ)-induced diabetes of rats.METHODS:Sprague-Dawley rats were fed with high fat diet for 6 weeks followed by streptozotocin(STZ,35 mg/kg)injection.These rats were then treated with DJC(270,540 and 1080 mg/kg)daily for 8 weeks.RESULTS:A combination of high fat diet and STZ significantly increased blood glucose creatinine,urea nitrogen,and urine albumin in rats.Meanwhile,the glomerular and tubular lesions were observed in rats fed with high fat diet and injected with STZ.These biochemical and pathological changes were significantly attenuated by DJC treatments in a dose-dependent manner.Mechanistically,DJC treatments significantly decreased toll-like receptor 4(TLR4),mitogen-activated protein kinase(MAPK),and nuclear factor-κB(NF-κB)signals in the kidney of rats fed with high fat diet and injected with STZ.Terminal deoxynucleotidyl transferase dU TP nick end labeling staining and caspase-8 levels showed that renal apoptosis was increased in rats fed with high fat diet and injected with STZ,and this was attenuated by DJC treatments.CONCLUSIONS:DJC treatments protect against diabetic kidney disease,and the mechanism may be closely related to downregulation of TLR4/MAPK/NF-κB pathways and apoptosis.This study provides further evidence of using DJC as a potential therapeutic option for diabetic kidney disease.

关键词： diabetic nephropathies inflammation apoptosis toll-like receptor 4 mitogen-activated protein kinase kinases NF-kappa B Danzhi Jiangtang capsule

Numerical Investigations on Harbor Oscillations Induced by Falling Objects

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China Ocean Engineering 2023年第3期37卷 458-470页

作者： GAO Jun-liang bi Wen-jing ZHANG Jian ZANG Jun School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China Key Laboratory of Water Security Guarantee in Guangdong-Hong Kong-Marco Greater Bay Area of Ministry of Water Resources Guangzhou 510611China Centre for Infrastructure Geotechnical and Water Engineering(IGWE)Department of Architecture and Civil EngineeringUniversity of BathBA27AYUK

In this paper,the open-sourced computational fluid dynamics software,OpenFOAM~?,is used to study the fluctuation phenomenon of the water body inside a horizontally one-dimensional enclosed harbor basin with constant water depth triggered by falling wedges with various horizontal falling positions,initial falling velocities and masses.Based on both Fourier transfo rm analysis and wavelet spectrum analysis for the time series of the free surface elevations inside the harbor basin,it is found for the first time that the wedge falling inside the harbor can directly trigger harbor resonance.The influences of the three factors(including the horizontal falling position,the initial falling velocity,and the mass)on the response amplitudes of the lowest three resonant modes are also investigated.The results show that when the wedge falls on one of the nodal points of a resonant mode,the mode would be remarkably suppressed.Conversely,when the wedge falls on one of the anti-nodal points of a resonant mode,the mode would be evidently triggered.The initial falling velocity of the wedge mainly has a remarkable effect on the response amplitude of the most significant mode,and the latter shows a gradual increase trend with the increase of the former.While for the other two less significant modes,their response amplitudes fluctuate around certain constant values as the initial falling velocity rises.In general,the response amplitudes of all the lowest three modes are shown to gradually increase with the mass of the wedge.

关键词： harbor oscillations seiches falling objects resonant mode response amplitude

Workload-aware request routing in cloud data center using software-defined networking

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Journal of Systems Engineering and Electronics 2015年第1期26卷 151-160页

作者： Haitao Yuan Jing bi Bohu Li School of Automation Science and Electrical Engineering Beihang University Department of Automation Tsinghua University

Large latency of applications will bring revenue loss to cloud infrastructure providers in the cloud data center. The existing controllers of software-defined networking architecture can fetch and process traffic information in the network. Therefore, the controllers can only optimize the network latency of applications. However, the serving latency of applications is also an important factor in delivered user-experience for arrival requests. Unintelligent request routing will cause large serving latency if arrival requests are allocated to overloaded virtual machines. To deal with the request routing problem, this paper proposes the workload-aware software-defined networking controller architecture. Then, request routing algorithms are proposed to minimize the total round trip time for every type of request by considering the congestion in the network and the workload in virtual machines（VMs）. This paper finally provides the evaluation of the proposed algorithms in a simulated prototype. The simulation results show that the proposed methodology is efficient compared with the existing approaches.

关键词： cloud data center（CDC） software-defined networking request routing resource allocation network latency optimization

Experimental and numerical study on dynamic mechanical behaviors of shale under true triaxial compression at high strain rate

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International Journal of Mining Science and Technology 2024年第2期34卷 149-165页

作者： Xiaoping Zhou Linyuan Han Jing bi Yundong Shou School of Civil Engineering Wuhan UniversityWuhan 430072China College of Civil Engineering Guizhou UniversityGuiyang 550025China

High-energy gas fracturing of shale is a novel,high efficacy and eco-friendly mining technique,which is a typical dynamic perturbing behavior.To effectively extract shale gas,it is important to understand the dynamic mechanical properties of shale.Dynamic experiments on shale subjected to true triaxial compression at different strain rates are first conducted in this research.The dynamic stress-strain curves,peak strain,peak stress and failure modes of shale are investigated.The results of the study indicate that the intermediate principal stress and the minor principal stress have the significant influence on the dynamic mechanical behaviors,although this effect decreases as the strain rate increases.The characteristics of compression-shear failure primarily occur in shale subjected to triaxial compression at high strain rates,which distinguishes it from the fragmentation characteristics observed in shale under dynamic uniaxial compression.Additionally,a numerical three-dimensional Split Hopkinson Pressure Bar(3D-SHPB),which is established by coupling PFC3D and FLAC3D methods,is validated to replicate the laboratory characteristics of shale.The dynamic mechanical characteristics of shale subjected to different confining stresses are systematically investigated by the coupling PFC3D and FLAC3D method.The numerical results are in good agreement with the experimental data.

关键词： Dynamic behaviors True triaxial compression High strain rates Dynamic failure mechanism PFC3D-FLAC3D coupled method

Diagnostic value of 3D-FLAIR MRI in children with sudden deafness caused by inner ear hemorrhage

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World Journal of Pediatric Surgery 2021年第4期4卷 16-20页

作者： Fu Sheng Gao Xuan Jia XiaoHui Ma Jing bi Qiang Shu Department of Radiology Children's Hospital Zhejiang University School of MedicineNational Clinical Research Center For Child HealthHangzhouZhejiangChina Department of Otorhinolaryngology Children's Hospital Zhejiang University School of MedicineNational Clinical Research Center For Child HealthHangzhouZhejiangChina Department of Cardio-Thoracic Surgery Children's Hospital Zhejiang University School of MedicineNational Clinical Research Center For Child HealthHangzhouZhejiangChina

Objective To investigate the diagnostic value of three-dimensional fluid-attenuated inversion recovery(3D-FLAIR)MRI in children with sudden deafness caused by inner ear hemorrhage.Methods The diagnostic efficacies of three different MRI sequences in the examination of the inner ear for 32 children with sudden deafness were compared.Hearing examination results and 3-month follow-up outcomes were analyzed.Results The age of 32 children with sudden deafness ranged from 5 to 18 years.MRI was performed from 1 to 18 days after onset.Six cases of sudden deafness caused by inner ear hemorrhage were finally diagnosed clinically.For different MRI sequences,the 3D-FLAIR sequence detected five positive cases;the conventional T1-weighted image sequence also detected five positive cases;but the conventional T2-weighted image sequence only detected three positive cases.The sensitivity and specificity of the 3D-FLAIR sequence in the diagnosis of inner ear hemorrhage were 83.3%(5/6)and 96.2%(25/26),respectively,and the area under the curve value of the receiver operating characteristic curve was 0.897.In the hemorrhage group,all six cases had extremely severe sensorineural hearing loss,and the hearing recovery was ineffective after 3 months of follow-up.The degree of hearing impairment,3-month short-term treatment efficacy,and 3D-FLAIR MRI in the diagnosis of inner ear hemorrhage between hemorrhage group and non-hemorrhage group were statistically significant(p=0.043,p=0.000,p=0.000).Conclusions 3D-FLAIR MRI is helpful for the diagnosis of inner ear hemorrhage in children with sudden deafness.Besides,short-term treatment indicates poor effects on children with severe hearing impairment.

关键词： hemorrhage diagnosis treatment

Heuristic Virtual Machine Allocation for Multi-Tier Ambient Assisted Living Applications in a Cloud Data Center

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China Communications 2016年第5期13卷 56-65页

作者： Jing bi Haitao Yuan Ming Tie Xiao Song School of Software Engineering Beijing University of TechnologyBeijing 100124China Beijing Engineering Research Center for IoT Software and Systems Beijing 100124China School of Software Engineering Beijing Jiaotong UniversityBeijing 100044China Science and Technology on Space Physics Laboratory Beijing 100076China Beijing Institute of Near space Vehicle's Systems Engineering Beijing 100076China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Cloud computing provides the essential infrastructure for multi-tier Ambient Assisted Living(AAL) applications that facilitate people's lives. Resource provisioning is a critically important problem for AAL applications in cloud data centers(CDCs). This paper focuses on modeling and analysis of multi-tier AAL applications, and aims to optimize resource provisioning while meeting requests' response time constraint. This paper models a multi-tier AAL application as a hybrid multi-tier queueing model consisting of an M/M/c queueing model and multiple M/M/1 queueing models. Then, virtual machine(VM) allocation is formulated as a constrained optimization problem in a CDC, and is further solved with the proposed heuristic VM allocation algorithm(HVMA). The results demonstrate that the proposed model and algorithm can effectively achieve dynamic resource provisioning while meeting the performance constraint.

关键词：分配算法数据中心虚拟机启发式 M/M/1排队模型应用生活环境

High yield synthesis of nigerooligosaccharides by transglycosylation catalyzed by α-glucosidase TaAglA from Thermoplasma acidophilum

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Food bioscience 2022年第3期47卷 245-252页

作者： Wei Xia Yifan Wang Ran bi jing Wu State Key Laboratory of Food Science and Technology Jiangnan University1800 Lihu AvenueWuxi214122China School of biotechnology and Key Laboratory of Industrial biotechnology Ministry of Education Jiangnan University1800 Lihu AvenueWuxi214122China International Joint Laboratory on Food Safety Jiangnan University1800 Lihu AvenueWuxi214122China

Nigerooligosaccharides (NOS) is a new functional oligosaccharide containing α-1,3 glucosidic bond with good anti-digestive properties and intestinal probiotics.Transglycosylation catalyzed by α-glucosidase is an effective method for the preparation of oligosaccharides.However,there are few reports on the enzymatic synthesis of nigerooligosaccharides by α-glucosidase at present.This study was aimed to investigate the transglycosylation property of the GH31 α-glucosidase from Thermoplasma acidophilum,TaAglA,and also evaluate its application performance in the preparation of NOS.It was found that TaAglA exhibited selectivity for α-1,3 and α-1,4 linkages when catalyzing hydrolysis,but for α-1,3 and α-1,6 linkages when catalyzing transglycosylation.Using 10% glucose and 20% maltose as substrates,TaAglA yielded 88.5 g/L NOS under the condition of pH 6.0,80 ℃ and 1 U/mL enzyme addition,which was the highest level to our knowledge.In addition,components with higher polymerization degrees,i.***.nigerotriose and nigerosyl-glucose,occupied 53.6% proportion of the total NOS products,giving it better probiotic functions.Futhermore,after purification by glucoamylase digestion and yeast culture,the final yield of NOS was 26.1%,and the purity of the product was 93%.These findings on TaAglA were expected to provide a new candidate for large-scale enzymatic synthesis of NOS,and also have important theoretical significance for the study of GH31 α-glucosidase.

关键词： Nigerooligosaccharides α-glucosidase α-1,3 glucosidic bond Enzymatic synthesis Transglycosylation

The spatial distribution and breeding behavior of neighbors affect the reproductive success of tits

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Avian Research 2022年第1期13卷 68-71页

作者： Yiting Jiang Yujia bi Ruiyao Ma jing Zhang Dongmei Wan Laboratory of Animal Resource and Epidemic Prevention School of Life SciencesLiaoning UniversityShenyang110036China

The spatial distribution and breeding behavior of neighboring birds(conspecific and heterospecific)may influence reproduction and the effects differ across species.In this study,we investigated intra-and inter-specific spatial distribution of breeding via artificial nestboxes and examined whether overlap with neighbors affected reproductive success of the focal breeding pair.Regarding spatial distribution,Varied Tits(Sittiparus varius)and Cinereous Tits(Parus cinereus)showed similar pattern:distances of nestboxes containing conspecific tits were greater than those with heterospecific ones.In terms of breeding behavior,reproductive success was not significantly related to the distance from their neighbor’s nest.The reproductive success of Varied Tits was significantly related to that of their neighbors,while in Cinereous Tits,no strong link was found to any recorded reproductive behavior of the neighbors.These findings explain spatial variation in nest site selection of Varied Tits and Cinereous Tits.Reproductive success rate of Varied Tits is affected by that of the neighbors while that of Cinereous Tits is not.The results highlight that there are differences in reproductive outcome among related species and offer suggestions on the use of artificial nestboxes in experiment and conservation programs.

关键词： Cinereous Tit Conspecific nest distance Heterospecific nest distance Reproductive effect Varied Tit