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A Modified Cost Estimation Formulae for Calculating Manufacturing Cost of Injection Part/Mold
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作者 WANG Hui, ZHOU Xiong hui, RUAN Xue yu National Die & Mold CAD Research Center, Shanghai Jiaotong University, Shanghai 200030, P.R.China 《International Journal of Plant Engineering and Management》 2002年第1期15-20,共6页
In modern society, a plastic part has its own important position. To the managers and decision makers in the field of plastic component, how to decide the manufacturing cost of the injection part or injection mold as... In modern society, a plastic part has its own important position. To the managers and decision makers in the field of plastic component, how to decide the manufacturing cost of the injection part or injection mold as quickly as possible is most valuable. Cost estimation formulae (CEF) are the most common method to evaluate the cost of injection part/mold, which is similar to our ordinary thinking. In this paper, a CEF method used by Dr. Weiyi Hu in Massachusetts University is first discussed. To the problems existed in the formulae, we propose an improved algorithm. This algorithm can be used to estimate the manufacturing cost of injection part/mold accurately in the early design stage. 展开更多
关键词 injection part/mold cost estimation CEF ALGORITHM
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Experimental study of the influencing factors and mechanisms of the pressure-reduction and augmented injection effect by nanoparticles in ultra-low permeability reservoirs
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作者 Pan Wang Yu-Hang Hu +8 位作者 Liao-Yuan Zhang Yong Meng Zhen-Fu Ma Tian-Ru Wang Zi-Lin Zhang Ji-Chao Fang Xiao-Qiang Liu Qing You Yan Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期1915-1927,共13页
Nanoparticles(NPs)have gained significant attention as a functional material due to their ability to effectively enhance pressure reduction in injection processes in ultra-low permeability reservoirs.NPs are typically... Nanoparticles(NPs)have gained significant attention as a functional material due to their ability to effectively enhance pressure reduction in injection processes in ultra-low permeability reservoirs.NPs are typically studied in controlled laboratory conditions,and their behavior in real-world,complex environments such as ultra-low permeability reservoirs,is not well understood due to the limited scope of their applications.This study investigates the efficacy and underlying mechanisms of NPs in decreasing injection pressure under various injection conditions(25—85℃,10—25 MPa).The results reveal that under optimal injection conditions,NPs effectively reduce injection pressure by a maximum of 22.77%in core experiment.The pressure reduction rate is found to be positively correlated with oil saturation and permeability,and negatively correlated with temperature and salinity.Furthermore,particle image velocimetry(PIV)experiments(25℃,atmospheric pressure)indicate that the pressure reduction is achieved by NPs through the reduction of wall shear resistance and wettability change.This work has important implications for the design of water injection strategies in ultra-low permeability reservoirs. 展开更多
关键词 NANOpartICLE Pressure reduction Augmented injection Ultra-low permeability reservoir
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Application effect of phloroglucinol injection in elderly patients with spastic abdominal pain in emergency department 被引量:1
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作者 Yu-Fei Liu Jian Chen 《World Journal of Clinical Cases》 SCIE 2023年第23期5440-5446,共7页
BACKGROUND Although norepinephrine injection is commonly used in emergency situations,it is associated with risks for elderly patients with spasmodic liver pain.This study explores the safety and effectiveness of mebe... BACKGROUND Although norepinephrine injection is commonly used in emergency situations,it is associated with risks for elderly patients with spasmodic liver pain.This study explores the safety and effectiveness of mebendazole injection,an alternative treatment option,for the emergency management of spasmodic abdominal pain,while minimizing adverse reactions,in elderly patients.AIM To explore the development of norepinephrine injection and the adverse reactions of this drug in emergency elderly patients with spasmodic liver pain.METHODS The control group consisted of 56 elderly patients visiting our hospital from January 2021 to December 2021.After hospital admission,the control group was intravenously administered tolopin.The experimental group consisted of 56 emergency patients with spasmodic abdominal pain who visited our hospital until June 2022.After hospital admission,the experimental group was intravenously administered toloxazole.The two groups were treated for 3 d.The disappearance of clinical symptoms was observed before and after the treatment,and the difference in adverse reactions between the two groups was compared.RESULTS The pain of the wife,fire,diarrhea,drowning,and surrounding time disappeared in the experimental group.No statistical difference was observed between the experimental and control groups in visual pain analog scale(VAS)scores before and after the treatment(P>0.05).The VAS scores of abdominal pain severity after 0.5 h,1.0 h,and after 6.0 h of treatment were significantly lower for the experimental group than for the control group.After the treatment,the therapeutic effect in the experimental group was higher and statistically significant than that in the control group(P<0.05).The probability of adverse reactions before the treatment was lower in the experimental group than in the control group.CONCLUSION During emergency,mebendazole injection exhibited a good therapeutic value when used for the clinical treatment of elderly patients with spasmodic stomach pain.It accelerated the disappearance of clinical symptoms such as stomach pain,reduced the stomach weight,and improved clinical activity.Reducing and promoting the frequency of high treatment safety with mebendazole injection is worthwhile. 展开更多
关键词 M-triophenol injection EMERGENCY Spasmodic abdominal pain in the elderly Abdominal pain disappearance time Adverse reactions Therapeutic effect
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Cross-upgrading of biomass hydrothermal carbonization and pyrolysis for high quality blast furnace injection fuel production:Physicochemical characteristics and gasification kinetics analysis
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作者 Han Dang Runsheng Xu +2 位作者 Jianliang Zhang Mingyong Wang Jinhua Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第2期268-281,共14页
The paper proposes a biomass cross-upgrading process that combines hydrothermal carbonization and pyrolysis to produce high-quality blast furnace injection fuel.The results showed that after upgrading,the volatile con... The paper proposes a biomass cross-upgrading process that combines hydrothermal carbonization and pyrolysis to produce high-quality blast furnace injection fuel.The results showed that after upgrading,the volatile content of biochar ranged from 16.19%to 45.35%,and the alkali metal content,ash content,and specific surface area were significantly reduced.The optimal route for biochar pro-duction is hydrothermal carbonization-pyrolysis(P-HC),resulting in biochar with a higher calorific value,C=C structure,and increased graphitization degree.The apparent activation energy(E)of the sample ranges from 199.1 to 324.8 kJ/mol,with P-HC having an E of 277.8 kJ/mol,lower than that of raw biomass,primary biochar,and anthracite.This makes P-HC more suitable for blast furnace injection fuel.Additionally,the paper proposes a path for P-HC injection in blast furnaces and calculates potential environmental benefits.P-HC of-fers the highest potential for carbon emission reduction,capable of reducing emissions by 96.04 kg/t when replacing 40wt%coal injec-tion. 展开更多
关键词 blast furnace injection BIOMASS cross-upgrading hydrothermal carbonization PYROLYSIS physicochemical properties gasific-ation properties
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Shenqi Fuzheng injection alleviates chemotherapy-induced cachexia by restoring glucocorticoid signaling in hypothalamus
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作者 Entezar Berik Zijia Zhang +16 位作者 Wei Li Yawen Liu Sihan Chen Wenyong Wu Zhaojun Wang Xinqin Kong Wenqiang Pei Huiqing Dong Huali Long Min Lei Jennifer Yiyang Wang Liangfeng Liu Jinjun Hou Jing Feng Zhaoxia Li Wanying Wu De-an Guo 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第3期431-434,共4页
Chemotherapy-induced cachexia(CIC)is a debilitating condition characterized by weight loss,muscle atrophy,and anorexia[1].While peripheral mechanisms of cachexia have been extensively studied,the involvement of the ce... Chemotherapy-induced cachexia(CIC)is a debilitating condition characterized by weight loss,muscle atrophy,and anorexia[1].While peripheral mechanisms of cachexia have been extensively studied,the involvement of the central nervous system(CNS)in CIC is often overlooked.Chemotherapeutic drugs cause stress responses and inflammation,which may impact the hypothalamus and disrupt systemic energy and neuroendocrine functions.Understanding hypothalamic roles in regulating these processes can provide insights into CIC's mechanisms and aid in developing novel therapies. 展开更多
关键词 injection DRUGS GLUCOCORTICOID CHEMOTHERAPY
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A Probabilistic Trust Model and Control Algorithm to Protect 6G Networks against Malicious Data Injection Attacks in Edge Computing Environments
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作者 Borja Bordel Sánchez Ramón Alcarria Tomás Robles 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期631-654,共24页
Future 6G communications are envisioned to enable a large catalogue of pioneering applications.These will range from networked Cyber-Physical Systems to edge computing devices,establishing real-time feedback control l... Future 6G communications are envisioned to enable a large catalogue of pioneering applications.These will range from networked Cyber-Physical Systems to edge computing devices,establishing real-time feedback control loops critical for managing Industry 5.0 deployments,digital agriculture systems,and essential infrastructures.The provision of extensive machine-type communications through 6G will render many of these innovative systems autonomous and unsupervised.While full automation will enhance industrial efficiency significantly,it concurrently introduces new cyber risks and vulnerabilities.In particular,unattended systems are highly susceptible to trust issues:malicious nodes and false information can be easily introduced into control loops.Additionally,Denialof-Service attacks can be executed by inundating the network with valueless noise.Current anomaly detection schemes require the entire transformation of the control software to integrate new steps and can only mitigate anomalies that conform to predefined mathematical models.Solutions based on an exhaustive data collection to detect anomalies are precise but extremely slow.Standard models,with their limited understanding of mobile networks,can achieve precision rates no higher than 75%.Therefore,more general and transversal protection mechanisms are needed to detect malicious behaviors transparently.This paper introduces a probabilistic trust model and control algorithm designed to address this gap.The model determines the probability of any node to be trustworthy.Communication channels are pruned for those nodes whose probability is below a given threshold.The trust control algorithmcomprises three primary phases,which feed themodel with three different probabilities,which are weighted and combined.Initially,anomalous nodes are identified using Gaussian mixture models and clustering technologies.Next,traffic patterns are studied using digital Bessel functions and the functional scalar product.Finally,the information coherence and content are analyzed.The noise content and abnormal information sequences are detected using a Volterra filter and a bank of Finite Impulse Response filters.An experimental validation based on simulation tools and environments was carried out.Results show the proposed solution can successfully detect up to 92%of malicious data injection attacks. 展开更多
关键词 6G networks noise injection attacks Gaussian mixture model Bessel function traffic filter Volterra filter
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Wetting front migration model of ion-adsorption rare earth during the multi-hole unsaturated liquid injection
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作者 Yu Wang Xiaojun Wang +8 位作者 Yuchen Qiu Hao Wang Gang Li Kaijian Hu Wen Zhong Zhongqun Guo Bing Li Chunlei Zhang Guangxiang Ye 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第2期483-496,共14页
In the process of ion-adsorption rare earth ore leaching,the migration characteristics of the wetting front in multi-hole injection holes and the influence of wetting front intersection effect on the migration distanc... In the process of ion-adsorption rare earth ore leaching,the migration characteristics of the wetting front in multi-hole injection holes and the influence of wetting front intersection effect on the migration distance of wetting fronts are still unclear.Besides,wetting front migration distance and leaching time are usually required to optimize the leaching process.In this study,wetting front migration tests of ionadsorption rare earth ores during the multi-hole fluid injection(the spacing between injection holes was 10 cm,12 cm and 14 cm)and single-hole fluid injection were completed under the constant water head height.At the pre-intersection stage,the wetting front migration laws of ion-adsorption rare earth ores during the multi-hole fluid injection and single-hole fluid injection were identical.At the postintersection stage,the intersection accelerated the wetting front migration.By using the Darcy’s law,the intersection effect of wetting fronts during the multi-hole liquid injection was transformed into the water head height directly above the intersection.Finally,based on the Green-Ampt model,a wetting front migration model of ion-adsorption rare earth ores during the multi-hole unsaturated liquid injection was established.Error analysis results showed that the proposed model can accurately simulate the infiltration process under experimental conditions.The research results enrich the infiltration law and theory of ion-adsorption rare earth ores during the multi-hole liquid injection,and this study provides a scientific basis for optimizing the liquid injection well pattern parameters of ion-adsorption rare earth in situ leaching in the future. 展开更多
关键词 Ion-adsorption rare earth ore Multi-hole unsaturated liquid injection In situ leaching Intersection effect Calculation model
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Tofacitinib combined with local low-dose ixekizumab injection benefits those with peripheral psoriatic arthritis
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作者 Yours Sincerely Ruiyuan Xia +2 位作者 Weixin Zhang Jing Hang Zhiqiang Yin 《The Journal of Biomedical Research》 CAS CSCD 2024年第1期92-94,共3页
Dear Editor,Treating psoriatic arthritis(PsA)is always difficult.Systemic treatments can be administered either orally or through intramuscular and intra-articular injection,including conventional synthetics,biologics... Dear Editor,Treating psoriatic arthritis(PsA)is always difficult.Systemic treatments can be administered either orally or through intramuscular and intra-articular injection,including conventional synthetics,biologics and targeted synthetic disease-modifying antirheumatic drugs[1].The alternatives,topical external therapies,are not effective on joint lesions due to drug permeability issues.Drugs injected into the articular cavity are also unsuitable for small peripheral joint lesions,the most common manifestations of PsA.The limited treatment options for PsA present a challenge. 展开更多
关键词 injection DRUGS cavity treatment
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Does HSP27 injection induce glaucoma damage in mice?
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作者 Stephanie C.Joachim Sabrina Reinehr 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第11期2347-2348,共2页
In a further aging society,excellent eyesight is an integral part of overall well-being and quality of life.Preserving good vision is crucial to maintaining mobility,independence,and mental health.There can be several... In a further aging society,excellent eyesight is an integral part of overall well-being and quality of life.Preserving good vision is crucial to maintaining mobility,independence,and mental health.There can be several reasons for visual impairment in elderly people,these include age-related macular degeneration,the leading cause of vision loss among older adults,cataract,glaucoma,diabetic retinopathy,retinal detachment,and others. 展开更多
关键词 HSP27 injection DAMAGE
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Large-scale physical simulation of injection and production of hot dry rock in Gonghe Basin,Qinghai Province,China
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作者 ZHAO Peng ZHU Haiyan +4 位作者 LI Gensheng CHEN Zuo CHEN Shijie SHANGGUAN Shuantong QI Xiaofei 《Petroleum Exploration and Development》 SCIE 2024年第3期741-752,共12页
Based on the independently developed true triaxial multi-physical field large-scale physical simulation system of in-situ injection and production,we conducted physical simulation of long-term multi-well injection and... Based on the independently developed true triaxial multi-physical field large-scale physical simulation system of in-situ injection and production,we conducted physical simulation of long-term multi-well injection and production in the hot dry rocks of the Gonghe Basin,Qinghai Province,NW China.Through multi-well connectivity experiments,the spatial distribution characteristics of the natural fracture system in the rock samples and the connectivity between fracture and wellbore were clarified.The injection and production wells were selected to conduct the experiments,namely one injection well and two production wells,one injection well and one production well.The variation of several physical parameters in the production well was analyzed,such as flow rate,temperature,heat recovery rate and fluid recovery.The results show that under the combination of thermal shock and injection pressure,the fracture conductivity was enhanced,and the production temperature showed a downward trend.The larger the flow rate,the faster the decrease.When the local closed area of the fracture was gradually activated,new heat transfer areas were generated,resulting in a lower rate of increase or decrease in the mining temperature.The heat recovery rate was mainly controlled by the extraction flow rate and the temperature difference between injection and production fluid.As the conductivity of the leak-off channel increased,the fluid recovery of the production well rapidly decreased.The influence mechanisms of dominant channels and fluid leak-off on thermal recovery performance are different.The former limits the heat exchange area,while the latter affects the flow rate of the produced fluid.Both of them are important factors affecting the long-term and efficient development of hot dry rock. 展开更多
关键词 hot dry rock simulation of injection and production heat extraction performance CONDUCTIVITY dominant channel fluid leak-off
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Numerical Simulation of Asphaltene Precipitation and Deposition during Natural Gas and CO_(2) Injection
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作者 Shasha Feng Yi Liao +3 位作者 Weixin Liu Jianwen Dai Mingying Xie Li Li 《Fluid Dynamics & Materials Processing》 EI 2024年第2期275-292,共18页
Asphaltene deposition is a significant problem during gas injection processes,as it can block the porous medium,the wellbore,and the involved facilities,significantly impacting reservoir productivity and ultimate oil re... Asphaltene deposition is a significant problem during gas injection processes,as it can block the porous medium,the wellbore,and the involved facilities,significantly impacting reservoir productivity and ultimate oil recovery.Only a few studies have investigated the numerical modeling of this potential effect in porous media.This study focuses on asphaltene deposition due to natural gas and CO_(2) injection.Predictions of the effect of gas injection on asphaltene deposition behavior have been made using a 3D numerical simulation model.The results indicate that the injection of natural gas exacerbates asphaltene deposition,leading to a significant reduction in permeability near the injection well and throughout the reservoir.This reduction in permeability strongly affects the ability of gas toflow through the reservoir,resulting in an improvement of the displacement front.The displacement effi-ciency of the injection gas process increases by up to 1.40%when gas is injected at 5500 psi,compared to the scenario where the asphaltene model is not considered.CO_(2) injection leads to a miscible process with crude oil,extracting light and intermediate components,which intensifies asphaltene precipitation and increases the viscosity of the remaining crude oil,ultimately reducing the recovery rate. 展开更多
关键词 Reservoir simulation asphaltenes deposition natural gas injection CO_(2)injection
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Background diseases and the number of previous intravitreal aflibercept injections on immediate intraocular pressure increase and vitreous reflux rate in phakic eyes
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作者 Tetsuya Muto Shigeki Machida Shinichiro Imaizumi 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期545-550,共6页
●AIM:To evaluate the effect of background diseases and number of previous intravitreal aflibercept injections(IVAIs)on immediate intraocular pressure(IOP)increase and vitreous reflux(VR)rate and to evaluate the corre... ●AIM:To evaluate the effect of background diseases and number of previous intravitreal aflibercept injections(IVAIs)on immediate intraocular pressure(IOP)increase and vitreous reflux(VR)rate and to evaluate the correlation of both age and axial length with immediate IOP increase and VR rate.●METHODS:This study included 105 patients with cystoid macular edema secondary to retinal vein occlusion,35 patients with diabetic macular edema,69 patients with neovascular age-related macular degeneration(nAMD),and 12 patients with myopic choroidal neovascularization,which underwent first-time IVAI.The correlation of immediate IOP increase and VR rates with the four background diseases was investigated.Moreover,the correlation of age with immediate IOP increase and VR rate as well as correlation of axial length with immediate IOP increase and VR rate were evaluated.Further,54 patients with nAMD were treated with IVAI>10 times(multiple IVAIs).Moreover,the correlation of immediate IOP increase and VR rates with first-time and multiple IVAIs in nAMD was determined.●RESULTS:The immediate IOP increase(P=0.16)and VR rates(P=0.50)were almost similar among the four background diseases.The immediate postinjection IOP and age,VR rate and age,immediate postinjection IOP and axial length,or VR rate and axial length were not correlated in the four background diseases.The immediate IOP increase(P=0.66)and VR rates(P=0.28)did not significantly differ between first-time and multiple IVAIs in nAMD.●CONCLUSION:Background diseases and number of previous IVAIs have no effect on immediate IOP increase and VR rate.Further,age and axial length have no correlation on immediate IOP increase and VR rate. 展开更多
关键词 AFLIBERCEPT intraocular pressure vitreous reflux intravitreal injection
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Short-term fluctuation of intraocular pressure and influencing factors following intravitreal injection in patients with retinal vascular diseases
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作者 Jing-Peng Miao Yi-Yun Zeng +1 位作者 Xin-Ming Gu Xin-Yuan Zhang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第11期2052-2059,共8页
AIM:To investigate the patterns of short-term intraocular pressure(IOP)fluctuations and identify the contributing factors following intravitreal injection in patients with retinal vascular diseases.METHODS:Totally 81 ... AIM:To investigate the patterns of short-term intraocular pressure(IOP)fluctuations and identify the contributing factors following intravitreal injection in patients with retinal vascular diseases.METHODS:Totally 81 patients were enrolled in this case control study.Eyes were categorized into 7 groups,including age-related macular degeneration(AMD),polypoidal choroidal vasculopathy(PCV),idiopathic choroidal neovascularization(CNV),proliferative diabetic retinopathy(PDR),diabetic macular edema(DME),macular edema secondary to branch(BVOME)and central(CVOME)retinal vein occlusion.IOP was measured in all patients using rebound tonometer at 7 preset time points perioperatively.Additionally,based on the administered medication,the eyes were classified into three treatment groups,including dexamethasone intravitreal implant(IVO),intravitreal conbercept(IVC),and intravitreal ranibizumab(IVR).To compare IOP values at various time points across groups,we employed one-way ANOVA,independent sample t-test or χ^(2) test and multivariate logistic regression analysis.RESULTS:Peak IOP values across all groups were observed at 40s,and 5min after intravitreal injection.Statistical differences in IOP were detected at the 5min among the 7 indication groups(F=2.50,P=0.029).When examing the impact of medications,the IVO group exhibited lower average IOP values at both 40s and 5min compared to the IVC and IVR groups(P<0.001;P=0.007).The IOP values at 40s and 5min were significantly higher in BVOME and CVOME group compared to non-retinal vein occlusionsecondary macular edema(RVOME)group(P<0.001).Multivariate logistic regression analysis further confirmed that IOP measurement at 40s was significantly higher in CVOME group than in non-RVOME group(OR=1.64,95%CI:1.09-2.47;P=0.018).CONCLUSION:Needle size plays a crucial role in the transient changes of IOP following intravitreal injection.Before administering intravitreal injection to patients with central retinal vein occlusion,it is essential to exclude any underlysing causes of increased IOP. 展开更多
关键词 intravitreal injection rebound tonometer intraocular pressure retinal vein occlusion ocular fundus diseases
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A New Heat Transfer Model for Multi-Gradient Drilling with Hollow Sphere Injection
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作者 Jiangshuai Wang Chuchu Cai +3 位作者 Pan Fu Jun Li Hongwei Yang Song Deng 《Fluid Dynamics & Materials Processing》 EI 2024年第3期537-546,共10页
Multi-gradient drilling is a new offshore drilling method.The accurate calculation of the related wellbore temperature is of great significance for the prediction of the gas hydrate formation area and the precise cont... Multi-gradient drilling is a new offshore drilling method.The accurate calculation of the related wellbore temperature is of great significance for the prediction of the gas hydrate formation area and the precise control of the wellbore pressure.In this study,a new heat transfer model is proposed by which the variable mass flow is properly taken into account.Using this model,the effects of the main factors influencing the wellbore temperature are analyzed.The results indicate that at the position where the separation injection device is installed,the temperature increase of the fluid in the drill pipe is mitigated due to the inflow/outflow of hollow spheres,and the temperature drop of the fluid in the annulus also decreases.In addition,a lower separation efficiency of the device,a shallower installation depth and a smaller circulating displacement tend to increase the temperature near the bottom of the annulus,thereby helping to reduce the hydrate generation area and playing a positive role in the prevention and control of hydrates in deepwater drilling. 展开更多
关键词 Multi-gradient drilling wellbore temperature HYDRATE separate injection device variable mass
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Endoscopic band ligation or endoscopic tissue adhesive injection in the treatment of gastric varices:Which is better?
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作者 Li-Zhi Yi Sheng-Bing Zhao 《World Journal of Gastroenterology》 SCIE CAS 2024年第21期2827-2828,共2页
The combination of endoscopic ultrasound with endoscopic treatment of type 1 gastric variceal hemorrhage may improve the robustness and generalizability of the findings in future studies.Moreover,the esophageal varice... The combination of endoscopic ultrasound with endoscopic treatment of type 1 gastric variceal hemorrhage may improve the robustness and generalizability of the findings in future studies.Moreover,the esophageal varices should also be included in the evaluation of treatment efficacy in subsequent studies to reach a more convincing conclusion. 展开更多
关键词 Gastric varices Esophageal varices Endoscopic band ligation Endoscopic tissue adhesive injection Endoscopic ultrasound
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Experimental Investigation on Condensate Revaporization During Gas Injection Development in Fractured Gas Condensate Reservoirs
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作者 Lei Zhang Yingxu He +3 位作者 Jintao Wu Haojun Wu Lei Huang Linna Sun 《哈尔滨工程大学学报(英文版)》 CSCD 2024年第3期575-582,共8页
The gas field in the Bohai Bay Basin is a fractured metamorphic buried-hill reservoir with dual-media characteristics. The retrograde vaporization mechanism observed in this type of gas condensate reservoir differs si... The gas field in the Bohai Bay Basin is a fractured metamorphic buried-hill reservoir with dual-media characteristics. The retrograde vaporization mechanism observed in this type of gas condensate reservoir differs significantly from that observed in sand gas condensate reservoirs. However, studies on improving the recovery of fractured gas condensate reservoirs are limited;thus, the impact of retrograde vaporization on condensate within fractured metamorphic buried-hill reservoirs remains unclear. To address this gap, a series of gas injection experiments are conducted in pressure-volume-temperature(PVT) cells and long-cores to investigate the retrograde vaporization effect of condensate using different gas injection media in fractured gas condensate reservoirs. We analyze the variation in condensate volume, gas-to-oil ratio, and condensate recovery during gas injection and examine the influence of various gas injection media(CO_(2), N_(2), and dry gas) under different reservoir properties and varying gas injection times. The results demonstrate that the exchange of components between injected gas and condensate significantly influences condensate retrograde vaporization in the formation. Compared with dry gas injection and N_(2) injection,CO_(2) injection exhibits a superior retrograde vaporization effect. At a CO_(2) injection volume of 1 PV, the percentage shrinkage volume of condensate is 13.82%. Additionally, at the maximum retrograde condensation pressure, CO_(2) injection can increase the recovery of condensate by 22.4%. However, the condensate recovery is notably lower in fractured gas condensate reservoirs than in homogeneous reservoirs, owing to the creation of dominant gas channeling by fractures, which leads to decreased condensate recovery. Regarding gas injection timing, the effect of gas injection at reservoir pressure on improving condensate recovery is superior to that of gas injection at the maximum retrograde condensation pressure. This research provides valuable guidance for designing gas injection development plans and dynamic tracking adjustments for fractured gas condensate reservoirs. 展开更多
关键词 Buried-hill fractured reservoir Gas condensate reservoir Retrograde condensation CO_(2)injection Retrograde vaporization
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Horizontal well spacing optimization and gas injection simulation for the ultra-low-permeability Yongjin reservoir
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作者 Yao Zhang Chengyuan Lv +3 位作者 Zengmin Lun Shuxia Zhao Yingfu He Ran Gao 《Energy Geoscience》 EI 2024年第1期196-203,共8页
Optimal spacing for vertical wells can be effectively predicted with several published methods,but methods suitable for assessing the proper horizontal well spacing are rare.This work proposes a method for calculating... Optimal spacing for vertical wells can be effectively predicted with several published methods,but methods suitable for assessing the proper horizontal well spacing are rare.This work proposes a method for calculating the optimal horizontal well spacing for an ultra-low permeability reservoir e the Yongjin reservoir in the Juggar Basin,northwestern China.The result shows that a spacing of 640m is the most economical for the development of the reservoir.To better develop the reservoir,simulation approaches are used and a new model is built based on the calculated well spacing.Since the reservoir has an ultralow permeability,gas injection is regarded as the preferred enhanced oil recovery(EOR)method.Injection of different gases including carbon dioxide,methane,nitrogen and mixed gas are modelled.The results show that carbon dioxide injection is the most efficient and economical for the development of the reservoir.However,if the reservoir produces enough methane,reinjecting methane is even better than injecting carbon dioxide. 展开更多
关键词 Ultra-low-permeability reservoir Well spacing optimization Numerical simulation Gas injection EOR
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Effect of high-multiple water injection on rock pore structure and oil displacement efficiency
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作者 Xiao Lei Chunpeng Zhao +2 位作者 Qiaoliang Zhang Panrong Wang Runfu Xiong 《Energy Geoscience》 EI 2024年第1期234-238,共5页
Experimental methods,including mercury pressure,nuclear magnetic resonance(NMR)and core(wateroil)displacement,are used to examine the effects of high-multiple water injection(i.e.water injection with high injected por... Experimental methods,including mercury pressure,nuclear magnetic resonance(NMR)and core(wateroil)displacement,are used to examine the effects of high-multiple water injection(i.e.water injection with high injected pore volume)on rock properties,pore structure and oil displacement efficiency of an oilfield in the western South China Sea.The results show an increase in the permeability of rocks along with particle migration,an increase in the pore volume and the average pore throat radius,and enhanced heterogeneity after high-multiple water injection.Compared with normal water injection methods,a high-multiple water injection is more effective in improving the oil displacement efficiency.The degree of recovery increases faster in the early stage due to the expansion of the swept area,and the transition from oil-wet to water-wet.The degree of recovery increases less in the late stage due to various factors,including the enhancement of heterogeneity in the rocks.Considering both the economic aspect and the production limit of water flooding,it is recommended to adopt other technologies to further enhance oil recovery after 300 PV water injection. 展开更多
关键词 High multiple Water injection Rock permeability Pore structure Oil displacement efficiency
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Characteristics of water alternating CO_(2)injection in low-permeability beach-bar sand reservoirs
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作者 Maolei Cui Rui Wang +1 位作者 Zengmin Lun Chengyuan Lv 《Energy Geoscience》 EI 2024年第1期224-229,共6页
Water flooding can be ineffective in highly heterogeneous low-permeability beach-bar sand reservoirs.The introduction of CO_(2)flooding helps boost the oil production of the reservoirs but only in an early stage.Durin... Water flooding can be ineffective in highly heterogeneous low-permeability beach-bar sand reservoirs.The introduction of CO_(2)flooding helps boost the oil production of the reservoirs but only in an early stage.During the late stage of flooding,gas channeling would occur.Water alternating gas(CO_(2))(WAG)process can be used to delay gas channeling and improve the effect of CO_(2)injection,though its adaptability to beach-bar sand reservoirs remains unclear.In order to clarify CO_(2)injection characteristics in these reservoirs,experiments were carried out in high-temperature high-pressure NMR on-line displacement experiment apparatus to simulate different flooding modes on synthetic cores that can reflect the vertical heterogeneity of beach-bar reservoirs.Different CO_(2)injection modes were implemented on these cores and the displacement characteristics and residual oil distribution features during both WAG injection and continuous CO_(2)injection were analyzed quantitatively and qualitatively.The results show that the scheme of WAG injection after continuous CO_(2)injection can obtain better oil displacement efficiency than that of the scheme of continuous CO_(2)injection after WAG injection,but there is no significant difference in respect of oil displacement efficiency of WAG flooding between the mode of bar-injection e beach-production(injection into bar sand e production from beach sand)and the mode of beach-injection e beach-production(injection into and production from beach sand),with the former mode having a higher oil recovery rate.The wider pore-size distribution range of microscopic residual oil after WAG injection shows great potential of enhancing oil recovery from subsequent continuous gas injection.When WAG injection is implemented prior to continuous CO_(2)injection,the displacement effect of the latter is more significant.This research may provide a theoretical basis for CO_(2)EOR in this type of reservoirs. 展开更多
关键词 Beach-bar sand Low permeability CO_(2)injection WAG NMR
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Permanent Magnet Temperature Estimation for PMSMs Using Virtual Position-offset Injection
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作者 Beichen Ding Yuting Lu +2 位作者 Kaide Huang Guodong Feng Chunyan Lai 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第1期51-60,共10页
This paper proposes a virtual position-offset injection based permanent magnet temperature estimation approach for permanent magnet synchronous machines(PMSMs). The concept of virtual position-offset injection is math... This paper proposes a virtual position-offset injection based permanent magnet temperature estimation approach for permanent magnet synchronous machines(PMSMs). The concept of virtual position-offset injection is mathematically transforming the machine model to a virtual frame with a position-offset. The virtual frame temperature estimation model is derived to calculate the permanent magnet temperature(PMT) directly from the measurements with computation efficiency. The estimation model involves a combined inductance term, which can simplify the establishment of saturation compensation model with less measurements. Moreover, resistance and inverter distorted terms are cancelled in the estimation model, which can improve the robustness to the winding temperature rise and inverter distortion. The proposed approach can achieve simplified computation in temperature estimation and reduced memory usage in saturation compensation. While existing model-based approaches could be affected by either the need of resistance and inverter information or complex saturation compensation. Experiments are conducted on the test machine to verify the proposed approach under various operating conditions. 展开更多
关键词 PMSM Magnet temperature estimation Virtual position offset injection Inverter nonlinearity
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