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Hybrid model for BOF oxygen blowing time prediction based on oxygen balance mechanism and deep neural network 被引量:1
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作者 Xin Shao Qing Liu +3 位作者 Zicheng Xin Jiangshan Zhang Tao Zhou Shaoshuai Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期106-117,共12页
The amount of oxygen blown into the converter is one of the key parameters for the control of the converter blowing process,which directly affects the tap-to-tap time of converter. In this study, a hybrid model based ... The amount of oxygen blown into the converter is one of the key parameters for the control of the converter blowing process,which directly affects the tap-to-tap time of converter. In this study, a hybrid model based on oxygen balance mechanism (OBM) and deep neural network (DNN) was established for predicting oxygen blowing time in converter. A three-step method was utilized in the hybrid model. First, the oxygen consumption volume was predicted by the OBM model and DNN model, respectively. Second, a more accurate oxygen consumption volume was obtained by integrating the OBM model and DNN model. Finally, the converter oxygen blowing time was calculated according to the oxygen consumption volume and the oxygen supply intensity of each heat. The proposed hybrid model was verified using the actual data collected from an integrated steel plant in China, and compared with multiple linear regression model, OBM model, and neural network model including extreme learning machine, back propagation neural network, and DNN. The test results indicate that the hybrid model with a network structure of 3 hidden layer layers, 32-16-8 neurons per hidden layer, and 0.1 learning rate has the best prediction accuracy and stronger generalization ability compared with other models. The predicted hit ratio of oxygen consumption volume within the error±300 m^(3)is 96.67%;determination coefficient (R^(2)) and root mean square error (RMSE) are0.6984 and 150.03 m^(3), respectively. The oxygen blow time prediction hit ratio within the error±0.6 min is 89.50%;R2and RMSE are0.9486 and 0.3592 min, respectively. As a result, the proposed model can effectively predict the oxygen consumption volume and oxygen blowing time in the converter. 展开更多
关键词 basic oxygen furnace oxygen consumption oxygen blowing time oxygen balance mechanism deep neural network hybrid model
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Measurement of solidprecipitation and blowing snow: current status and challenges
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作者 PAN Rui LIU Xichuan SHI Jiayi 《Advances in Polar Science》 CSCD 2024年第3期289-302,共14页
In this article,the relevant instruments and techniques for measuring solid precipitation and blowing snow are reviewed,with a focus on the in situ instrument measurements.Moreover,a literature review and specific obs... In this article,the relevant instruments and techniques for measuring solid precipitation and blowing snow are reviewed,with a focus on the in situ instrument measurements.Moreover,a literature review and specific observation activities for solid precipitation are provided,the working principles of several instruments are introduced,and the advantages and disadvantages,measurement performance,and specific application scenarios of the instruments are evaluated.Currently,there are numerous solid precipitation measurement instruments available,and the standardization and sustainability of these measurements also need to be considered.The purpose of the review is not to be exhaustive but to provide readers with information on the current status of the development of relevant technologies and the prospects for their application in the polar regions. 展开更多
关键词 solid precipitation blowing snow measurement instruments
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Exploration and Practice of Nitrogen Addition Process for LF Refining Ladle Bottom Blowing Nitrogen Steel Liquid
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作者 Maoin Hou Aiqing Ding 《Frontiers of Metallurgical Industry》 2024年第1期23-26,共4页
This article discusses and analyzes the law of nitrogen increase in liquid steel and the main factors affect-ing the nitrogen increasing of molten steel,through the way of adding nitrogen to molten steel by bottom blo... This article discusses and analyzes the law of nitrogen increase in liquid steel and the main factors affect-ing the nitrogen increasing of molten steel,through the way of adding nitrogen to molten steel by bottom blowing nitrogen gas in LF refining process.It is considered that the main factors affecting the nitrogen increasing instability of molten steel are the initial temperature of LF refining,nitrogen relative element,surface active elements[O]and[S]of steel liquid,and bottom blowing rate of ladle.The large-scale production practice shows that T[O]not more than 50×10-6 and[S]is not more than 0.020 in LF refining at the initial temperature of not less than 1570.The liquid steel nitrogen enrichment test is carried out by ladle bottom blowing nitrogen gas after 20 min of refining,the flow rate is set as(6.0~7.0)NL/min per ton,and it is turned to 2 NL/min at 6 min before the end of refining,the nitrogen increasing rate of liquid steel is basically stable at(5~6)×10-6 per minute. 展开更多
关键词 LF refine bottom blowing nitrogen gas nitrogen increase in liquid steel process practice
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Blown Film Extrusion Process for Polybags: Technical Overview and Applications
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作者 Sunil Badgujar Sudeep Asthana +6 位作者 Ravindra Kanawade Krunal Suthar Ankit Solanki Karuppiah Nagaraj Mahaveer Singh Bilkhu Harekrushna Sutar Swapna Rekha Panda 《Advances in Chemical Engineering and Science》 CAS 2024年第4期188-201,共14页
The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the... The choice of extrusion process is a decisive factor that affects the finished product quality for polybag manufacturing. One important component influencing the quality of the finished product is the selection of the extrusion technique. Two popular procedures that vary in the kind of dye used and the final product’s texture are cast film and blown film. In the horizontal extrusion moulding method known as “cast film”, heated resin is injected into a flat dye and allowed to cool on chill rolls. The film produced is clear, lightweight, and appropriate for lamination;its thickness varies based on the winding speed and the film is slower to crystallize and has less clarity but more durability because the resin molecules have reoriented, facing limitation of high wastage generation. This study primarily focused on the preparation of polybag film using the blown film extrusion process, utilizing high-quality polymer resins such as polyester polyethylene (PP) and linear low-density polyethylene (LLDPE) to minimize waste generation. The novelty of the process was reflected in minimising the waste generation. The control parameters considered in this study are temperature, pressure, and air intake volume. We investigated the influence of these critical process control parameters on the gauge thickness, optical properties, and mechanical strength of the polybag film produced through blown film extrusion. Additionally, we replicated the blown film process using simulation software developed at Pennsylvania College of Technology. The simulation results confirmed the overall stability of the polybag film produced through the blown film extrusion process. 展开更多
关键词 LLDPE Melt Flow Index blow-Up Ratio Lay-Flat Width Draw-down Ratio
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Effect of gas blowing nozzle angle on multiphase flow and mass transfer during RH refining process 被引量:2
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作者 Jiahao Wang Peiyuan Ni +2 位作者 Chao Chen Mikael Ersson Ying Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第5期844-856,共13页
A three-dimensional mathematical model was developed to investigate the effect of gas blowing nozzle angles on multiphase flow,circulation flow rate,and mixing time during Ruhrstahl-Heraeus(RH) refining process.Also,a... A three-dimensional mathematical model was developed to investigate the effect of gas blowing nozzle angles on multiphase flow,circulation flow rate,and mixing time during Ruhrstahl-Heraeus(RH) refining process.Also,a water model with a geometric scale of 1:4 from an industrial RH furnace of 260 t was built up,and measurements were carried out to validate the mathematical model.The results show that,with a conventional gas blowing nozzle and the total gas flow rate of 40 L·min^(-1),the mixing time predicted by the mathematical model agrees well with the measured values.The deviations between the model predictions and the measured values are in the range of about 1.3%–7.3% at the selected three monitoring locations,where the mixing time was defined as the required time when the dimensionless concentration is within 3% deviation from the bath averaged value.In addition,the circulation flow rate was 9 kg·s^(-1).When the gas blowing nozzle was horizontally rotated by either 30° or 45°,the circulation flow rate was found to be increased by about 15% compared to a conventional nozzle,due to the rotational flow formed in the up-snorkel.Furthermore,the mixing time at the monitoring point 1,2,and 3 was shortened by around 21.3%,28.2%,and 12.3%,respectively.With the nozzle angle of 30° and 45°,the averaged residence time of 128 bubbles in liquid was increased by around 33.3%. 展开更多
关键词 Ruhrstahl-Heraeus refining gas blowing nozzle angle circulation flow rate mixing time multiphase flow
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Successful treatment of a rare subcutaneous emphysema after a blow-out fracture surgery using needle aspiration:A case report 被引量:1
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作者 Ha-Jong Nam Syeo-Young Wee 《World Journal of Clinical Cases》 SCIE 2023年第9期2110-2115,共6页
BACKGROUND Many cases of emphysema associated with blow-out fractures occur before surgery due to trauma.However,emphysema can occur even after surgery,and most of such cases are managed conservatively and allowed to ... BACKGROUND Many cases of emphysema associated with blow-out fractures occur before surgery due to trauma.However,emphysema can occur even after surgery,and most of such cases are managed conservatively and allowed to resolve.Swelling in the periorbital area due to emphysema that occurs after surgery can make early recovery difficult.CASE SUMMARY Herein,we describe a case of postoperative subcutaneous emphysema that was treated using a simple needle aspiration method.A 48-year-old male patient visited the hospital with a blow-out fracture of the left medial orbital wall and nasal bone fracture.One day postoperatively,swelling and crepitus in the left periorbital area were observed,and follow-up computed tomography showed emphysema in the left periorbital subcutaneous area.Needle aspiration using an 18-gauge needle and syringe was used to relieve the emphysema.The symptoms of sudden swelling improved immediately,and no recurrence was observed.CONCLUSION We conclude that needle aspiration is a useful method that could help in relieving symptom,resolving discomfort,and enabling early return to daily life in patients with postoperative subcutaneous emphysema. 展开更多
关键词 blow out fracture Subcutaneous emphysemas Mechanical aspiration Case report
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Eco-friendly physical blowing agent mass loss of bio-based polyurethane rigid foam materials
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作者 Haozhen Wang Lin Lin Yingshu Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第4期782-789,共8页
Through systematical experiment design, the physical blowing agent(PBA) mass loss of bio-based polyurethane rigid foam(PURF)in the foaming process was measured and calculated in this study, and different eco-friendly ... Through systematical experiment design, the physical blowing agent(PBA) mass loss of bio-based polyurethane rigid foam(PURF)in the foaming process was measured and calculated in this study, and different eco-friendly PBA mass losses were measured quantitatively for the first time. The core of the proposed method is to add water to replace the difference, and this method has a high fault tolerance rate for different foaming forms of foams. The method was proved to be stable and reliable through the standard deviations σ1and σ2for R1(ratio of the PBA mass loss to the material total mass except the PBA) and R2(ratio of the PBA mass loss to the PBA mass in the material total mass) in parallel experiments. It can be used to measure and calculate the actual PBA mass loss in the foaming process of both bio-based and petroleumbased PURF. The results show that the PBA mass loss in PURF with different PBA systems is controlled by its initial mass content of PBA in PU materials ω. The main way for PBA to dissipate into the air is evaporation/escape along the upper surface of foam. This study further reveals the mechanism of PBA mass loss: the evaporation/escape of PBA along the upper surface of foam is a typical diffusion behavior. Its spread power comes from the difference between the chemical potential of PBA in the interface layer and that in the outside air. For a certain PURF system, R1has approximately linear relationship with the initial mass content of PBA in PU materials ω, which can be expressed by the functional relationship R1= kω, where k is a variable related to PBA’s own attributes. 展开更多
关键词 POLYURETHANE bio-based polyol eco-friendly physical blowing agent mass loss
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超临界CO_(2)管道瞬态输送工艺研究进展及方向 被引量:5
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作者 李欣泽 袁亮 +7 位作者 张超 王梓丞 邢晓凯 熊小琴 陈晓玲 尚妍 张文辉 陈潜 《大庆石油地质与开发》 CAS 北大核心 2024年第1期22-32,共11页
长距离超临界CO_(2)管道瞬态输送的核心技术还有待突破,相关模型和方法亟需工业规模示范工程的验证及修正。以成就型综述法,对超临界CO_(2)管道输送过程中停输、水击、泄漏和放空工况下形成的CO_(2)瞬态流加以描述、成果比较和综合评价... 长距离超临界CO_(2)管道瞬态输送的核心技术还有待突破,相关模型和方法亟需工业规模示范工程的验证及修正。以成就型综述法,对超临界CO_(2)管道输送过程中停输、水击、泄漏和放空工况下形成的CO_(2)瞬态流加以描述、成果比较和综合评价。结果表明:超临界CO_(2)瞬态流的关键因素是温度、压力、相态变化、协同作用;超临界CO_(2)管道安全停输时间可定义为从停输开始至管内任一点流体即将进入气液共存区的时间;CO_(2)发生相变首先造成流速突变,进而是压力的突变,产生水击现象,引起新的瞬变流动;站场放空系统的设计目标是在放空过程不出现冰堵、材料冷脆、噪声污染、放空系统激振等问题的前提下,放空时间尽量短;埋地管道泄漏规律涉及到土壤渗流场、温度场、浓度场等多场耦合问题。研究结果可为超临界CO_(2)管道流动安全保障提供参考。 展开更多
关键词 CO_(2)管输 瞬变特性 停输再启动 水击 放空 泄漏 相变
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Thermodynamic behavior and morphology of impurities in metallurgical grade silicon in process of O_2 blowing 被引量:7
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作者 伍继君 马文会 +3 位作者 李彦龙 杨斌 刘大春 戴永年 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第1期260-265,共6页
Gas blowing is a valid method to remove the impurities from metallurgical grade silicon(MG-Si) melt.The thermodynamic behavior of impurities Fe,Al,Ca,Ti,Cu,C,B and P in MG-Si was studied in the process of O2 blowing... Gas blowing is a valid method to remove the impurities from metallurgical grade silicon(MG-Si) melt.The thermodynamic behavior of impurities Fe,Al,Ca,Ti,Cu,C,B and P in MG-Si was studied in the process of O2 blowing.The removal efficiencies of impurities in MG-Si were investigated using O2 blowing in ladle.It is found that the removal efficiencies are higher than 90% for Ca and Al and nearly 50% for B and Ti.The morphology of inclusions was analyzed and the phases Al3Ni,NiSi2 and Al3Ni were confirmed in MG-Si by X-ray diffraction.It was found that SiB4 exists in Si?B binary system.The chemical composition of inclusions in MG-Si before and after refining was analyzed by SEM-EDS.It is found that the amount of white inclusion reduces for the removal of most Al and Ca in the forms of molten slag inclusion and the contents of Fe,Ni and Mn in inclusion increase for their inertia in silicon melt with O2 blowing. 展开更多
关键词 metallurgical grade silicon THERMODYNAMICS O2 blowing IMPURITIES INCLUSION removal efficiency
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一类非线性扩散方程解的blow up速率估计 被引量:1
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作者 容跃堂 马福敏 《纯粹数学与应用数学》 CSCD 北大核心 2006年第2期284-288,共5页
利用F riedm an-M cleod方法和变动尺度方法研究了一类具有非线性边界条件的非线性扩散方程解的b low up问题,证明了解在有限时间b low up,并且得到了b low up速率估计.
关键词 非线性扩散 blow up blow up速率 变动尺度方法
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具有非线性记忆的抛物型方程解的Blow up 被引量:1
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作者 容跃堂 成涛 《纺织高校基础科学学报》 CAS 2003年第4期303-305,110,共4页
讨论了m(t)不具单调性的条件下,具有非线性记忆的抛物型方程解的Blow up.
关键词 非线性记忆 抛物型方程 blow up
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一类非线性耗色散方程解的Blow-up 被引量:1
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作者 郑镇汉 姚正安 《数学理论与应用》 2009年第1期66-69,共4页
本文研究一类四阶非线性耗、色散波动方程的补边值问题,在一定条件下,得到了方程解的blow up性质。
关键词 非线性波动方程 色散 耗色 blow up
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具有非线性记忆的抛物型方程解的Blow up估计 被引量:1
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作者 容跃堂 《西北大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第4期351-354,共4页
讨论了 m( t)单调增加的条件下 ,具有非线性记忆的抛物型方程解的 Blow up,并给出了解的Blow
关键词 非线性记忆 抛物型方程 blow up估计 极值原理 特征值 特征函数
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非线性拟抛物方程解的Blow-up 被引量:1
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作者 徐润章 《哈尔滨理工大学学报》 CAS 2004年第4期122-123,126,共3页
用特征函数法分别研究了非线性拟抛物方程u_t—Δu_t=f(u,D_xu,D_x^2u),u_-Δu_t=-△y(u) 与u_t-Δu_t=f(u)+Δg(u)的初边值问题整体解的不存在性与有限时间Blow-up。
关键词 非线性拟抛物方程 初边值 整体解 不存在性 blow—up
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安钢2号高炉长期休风后恢复困难原因分析及对策
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作者 郑旭 张磊 《河南冶金》 2024年第4期16-19,共4页
安钢2号高炉6月25日检修60 h后复风难度大。对原料和燃料质量、炉缸状态、风口处理、料仓仓位等进行分析,发现入炉烧结矿质量、焦炭结构和质量的波动是造成恢复困难的主要原因,而炉缸工况差和休风时间长是炉况恢复缓慢的直接原因。通过... 安钢2号高炉6月25日检修60 h后复风难度大。对原料和燃料质量、炉缸状态、风口处理、料仓仓位等进行分析,发现入炉烧结矿质量、焦炭结构和质量的波动是造成恢复困难的主要原因,而炉缸工况差和休风时间长是炉况恢复缓慢的直接原因。通过改善原燃料质量,休风处理灌渣风口,临时堵部分风口以适当提高风速和鼓风动能,并提高煤气流分布均匀性等,使高炉炉况逐步得到恢复。 展开更多
关键词 高炉 炉缸状态 休风 炉况恢复
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Solution of idle LBO problem for high FAR aero combustor
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作者 CHIN Jushan ZENG Qinghua 《推进技术》 EI CAS CSCD 北大核心 2024年第10期96-104,共9页
The paper sheds light on the idle lean blow off(LBO)problem for high fuel air ratio(FAR)com⁃bustor,which is impossible to be addressed with traditional aero combustor design.A significant improvement in aero combustor... The paper sheds light on the idle lean blow off(LBO)problem for high fuel air ratio(FAR)com⁃bustor,which is impossible to be addressed with traditional aero combustor design.A significant improvement in aero combustor design is required to resolve the idle LBO issue.The authors detailed a practical and efficient solu⁃tion,which not only solved the idle LBO issue but also defined the aero-thermal design for high-FAR combustor.The design will usher in a new era of aero combustor. 展开更多
关键词 Aero engine COMBUSTOR Idle lean blow off High fuel air ratio Concentric circle zoning combustion
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某电厂循环冷却排污水达标排放方案设计与比较
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作者 倪斌 薛庆堂 +3 位作者 李洪峰 韩松 聂新辉 诸慧 《工业水处理》 CSCD 北大核心 2024年第1期213-218,共6页
针对某电厂的循环冷却系统排污水治理难题,提出了采用纳滤技术降低循环冷却系统排污水中含盐浓度和硫酸根浓度以满足地方环保标准实现达标排放的方案,并与采用反渗透技术的循环水旁路除盐处理方案进行了技术经济性比选。在方案比选中充... 针对某电厂的循环冷却系统排污水治理难题,提出了采用纳滤技术降低循环冷却系统排污水中含盐浓度和硫酸根浓度以满足地方环保标准实现达标排放的方案,并与采用反渗透技术的循环水旁路除盐处理方案进行了技术经济性比选。在方案比选中充分考量了2种方案对电厂脱硫废水零排放的影响,得出的结果表明经纳滤处理后达标排放的方案更具优势。 展开更多
关键词 循环冷却系统排污水 达标排放 纳滤 反渗透
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Bio-Based Rigid Polyurethane Foams for Cryogenic Insulation
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作者 Laima Vevere Beatrise Sture +2 位作者 Vladimir Yakushin Mikelis Kirpluks Ugis Cabulis 《Journal of Renewable Materials》 EI CAS 2024年第3期585-602,共18页
Cryogenic insulation material rigid polyurethane(PU)foams were developed using bio-based and recycled feedstock.Polyols obtained from tall oil fatty acids produced as a side stream of wood biomass pulping and recycled... Cryogenic insulation material rigid polyurethane(PU)foams were developed using bio-based and recycled feedstock.Polyols obtained from tall oil fatty acids produced as a side stream of wood biomass pulping and recycled polyethylene terephthalate were used to develop rigid PU foam formulations.The 4th generation physical blowing agents with low global warming potential and low ozone depletion potential were used to develop rigid PU foam cryogenic insulation with excellent mechanical and thermal properties.Obtained rigid PU foams had a thermal conductivity coefficient as low as 0.0171 W/m·K and an apparent density of 37-40 kg/m^(3).The developed rigid PU foams had anisotropic compression strength properties,which were higher parallel to the foaming direction.Moreover,the compression strength was also influenced by the type of applied bio-based polyol.The bio-based polyols with higher OH group functionality delivered higher crosslinking density of polymer matrix;thus,the mechanical properties were also higher.The mechanical strength of the foams increased when materials were tested at liquid nitrogen temperature due to the stiffening of the polymer matrix.The thermal properties of the developed materials were determined using differential scanning calorimetry,dynamic mechanical analysis,and thermogravimetric analysis methods.Lastly,the developed rigid PU foams had good adhesion to the aluminium substrate before and after applying cyroshock and an excellent safety coefficient of 4-5.Rigid PU foams developed using Solstice LBA delivered adhesion strength of~0.5 MPa and may be considered for application as cryogenic insulation in the aerospace industry. 展开更多
关键词 Cryogenic insulation polyurethanes tall oil 4th generation physical blowing agents
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含有Hénon项的非线性椭圆系统稳定解的Liouville定理
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作者 黄宇鑫 甘怡清 胡良根 《宁波大学学报(理工版)》 CAS 2024年第2期86-95,共10页
本文主要研究含有Hénon项的k-耦合椭圆系统-Δu_(i)=Σ_(j-1)^(k)β_(ij)|χ|^(α)|u_(i)|^(q-1)ui|uj|^(q+1),x∈R^(N)其中k是一个固定的正整数,i=1,2,…,k,q≥1,N≥3,B=(β_(ij))_(i,j=1)^(k)为实对称矩阵.首先使用Pohozaev恒等... 本文主要研究含有Hénon项的k-耦合椭圆系统-Δu_(i)=Σ_(j-1)^(k)β_(ij)|χ|^(α)|u_(i)|^(q-1)ui|uj|^(q+1),x∈R^(N)其中k是一个固定的正整数,i=1,2,…,k,q≥1,N≥3,B=(β_(ij))_(i,j=1)^(k)为实对称矩阵.首先使用Pohozaev恒等式构造单调公式,并发现其等价关系.当矩阵B严格余正时,联合使用Pohozaev恒等式、单调公式和爆缩序列方法证明了(无论是正的还是变号的)稳定解的Liouville定理. 展开更多
关键词 LIOUVILLE定理 稳定解 POHOZAEV恒等式 单调公式 爆缩序列
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一类退化抛物方程高初始能量下解的有限时刻爆破及整体存在性
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作者 刘功伟 杨坤 《Chinese Quarterly Journal of Mathematics》 2024年第1期97-110,共14页
We consider the initial-boundary value problem for finitely degenerate parabolic equation. We first give sufficient conditions for the blow-up and global existence of the parabolic equation at high initial energy leve... We consider the initial-boundary value problem for finitely degenerate parabolic equation. We first give sufficient conditions for the blow-up and global existence of the parabolic equation at high initial energy level. Then, we establish the existence of solutions blowing up in finite time with initial data at arbitrary energy level. Finally, we estimate the upper bound of the blow-up time under certain conditions. 展开更多
关键词 High energy Degenerate parabolic equations blow up Global existence
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