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三维副翼铰链力矩计算

航空学报 2007年第3期28卷 519-526页

作者：吴宗成朱自强丁宁陈泽民北京航空航天大学航空科学与工程学院北京100083

数值模拟了带副翼偏转构型的二维、三维亚、跨、超声速来流情况的绕流流场,采用有限体积方法和AUSM+迎风格式数值求解N-S方程,四步龙格-库塔时间推进,湍流模型为Baldwin-Lomax和Spalart-All-maras湍流模型。二维模拟压强分布与实验数据... 详细信息

数值模拟了带副翼偏转构型的二维、三维亚、跨、超声速来流情况的绕流流场,采用有限体积方法和AUSM+迎风格式数值求解N-S方程,四步龙格-库塔时间推进,湍流模型为Baldwin-Lomax和Spalart-All-maras湍流模型。二维模拟压强分布与实验数据以及CFD软件模拟结果吻合较好。采用交错对接网格,数值模拟了不同副翼偏角和缝隙、来流马赫数、迎角和雷诺数的三维构型流场。通过舵面铰链力矩与实验数据的对比分析表明了该数值方法模拟此类复杂流场的可靠性和舵面铰链力矩计算的有效性。发现并研究了亚声速来流时铰链力矩随迎角的反向变化趋势,初步分析了副翼的缝隙和雷诺数效应。

关键词：副翼铰链力矩 N-S方程

Influence of microstructural characteristics on corrosion behavior of Mg-5Sn-3In alloy in Hank’s solution

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Transactions of Nonferrous Metals Society of China 2021年第10期31卷 2999-3011页

作者： Xue-jian WANG zong-ning CHen Yu-bo ZHANG en-yu GUO Hui-jun KANG Pei HAN Tong-min WANG Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China ningbo Institute of Dalian University of Technology Ningbo 315000China Orthopaedic Department Shanghai Jiao Tong University Affiliated Sixth People’s HospitalShanghai 200233China

The microstructural observation,the mass loss test,potentiodynamic polarization measurements and corrosion morphology examinations were conducted to study the influence of microstructural characteristics on corrosion behavior of Mg–5Sn–3In alloys in Hank’s solution after *** results show that the corrosion rate of the as-cast alloy is similar to that of as-extruded alloy;however,the local corrosion susceptibility is greatly weakened in the as-extruded alloy,especially in the extrusion *** relatively uniform corrosion morphology of the as-extruded alloy is attributed to refined Mg_(2)Sn particles,uniform distribution of Mg_(2)Sn particles and favorable crystal ***,the cytotoxicity tests confirm that the Mg–5Sn–3In alloy exhibits cytotoxicity of Grade 0−1 for NIH3T3 cells,suggesting an acceptable cytotoxicity of this alloy in the vitro assay.

关键词： Mg–Sn alloy indium element microstructure corrosion behavior cytotoxicity

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固体杂多酸催化剂研究新进展

石油化工 2000年第1期29卷 49-55页

作者：温朗友闵恩泽石油化工科学研究院北京100083

杂多酸是由杂原子(如P、Si、Fe、Co等)和多原子(如Mo、W、V、Nb、Ta等)按一定的结构通过氧原子配位桥联组成的一类含氧多酸.作为一类新型的催化材料,杂多酸及其盐类化合物以其独特的酸性、'准液相'行为、多功能(酸、氧化、光电催化)等... 详细信息

杂多酸是由杂原子(如P、Si、Fe、Co等)和多原子(如Mo、W、V、Nb、Ta等)按一定的结构通过氧原子配位桥联组成的一类含氧多酸.作为一类新型的催化材料,杂多酸及其盐类化合物以其独特的酸性、'准液相'行为、多功能(酸、氧化、光电催化)等优点在催化研究领域中受到研究者们的广泛重视.对于杂多酸(盐)催化剂的研究已有大量的文献报道[1～12].本文从实际应用出发,仅对杂多酸(盐)作为固体酸催化剂的制备、催化性质、应用研究的最新进展进行评述.

关键词：固体催化剂杂多酸催化剂进展

Landslide displacement prediction based on the ICEEMDAN,Apen and the CNN-LSTM models

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Journal of Mountain Science 2023年第5期20卷 1220-1231页

作者： LI Li-min WANG Chao-yang Wen zong-zhou GAO Jian XIA Meng-fan College of Electronics and Information Xi’an Polytechnic UniversityXi’an 710600 China Shaanxi Yixin Network Technology Co. LtdXi’an 710065China

Landslide deformation is affected by its geological conditions and many environmental *** it has the characteristics of dynamic,nonlinear and unstable,which makes the prediction of landslide displacement *** view of the above problems,this paper proposes a dynamic prediction model of landslide displacement based on the improvement of complete ensemble empirical mode decomposition with adaptive noise(ICEEMDAN),approximate entropy(Apen)and convolution long short-term memory(CNN-LSTM)neural ***,ICEEMDAN and Ap en are used to decompose the cumulative displacements into trend,periodic and random ***,the least square quintic polynomial function is used to fit the displacement of trend term,and the CNN-LSTM is used to predict the displacement of periodic term and random ***,the displacement prediction results of trend term,periodic term and random term are superimposed to obtain the cumulative displacement prediction *** proposed model has been verified in Bazimen landslide in the Three Gorges Reservoir area of *** experimental results show that the model proposed in this paper can more effectively predict the displacement changes of *** compared with long short-term memory(LSTM)neural network,gated recurrent unit(GRU)network model and back propagation(BP)neural network,CNN-LSTM neural network had higher prediction accuracy in predicting the periodic displacement,with the mean absolute percentage error(MAPE)reduced by 3.621%,6.893% and 15.886% respectively,and the root mean square error(RMSE)reduced by 3.834 mm,3.945 mm and 7.422mm ***,this model not only has high prediction accuracy but also is more stable,which can provide a new insight for practical landslide prevention and control engineering.

关键词： Displacement prediction ICEenDAN Approximate entropy Long short-term memory Bazimen landslide

Pancreaticoduodenectomy for advanced gastric cancer with pancreaticoduodenal region involvement

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World Journal of Gastroenterology 2008年第21期14卷 3425-3429页

作者： Xin-bao Wang Li-Tao Yang ze-Wei Zhang Jian-min Guo Xiang-Dong Cheng Department of Hepato-Biliary- Pancreatico-Gastric Surgery Zhejiang Cancer Hospital Hangzhou 310022 Zhejiang Province China

AIM：To characterize the factors of the improved survival following combined pancreaticoduodenectomy（PD） and gastrectomy for the treatment of advanced gastric cancer with pancreaticoduodenal region involvement.METHODS：From 1995 to 2004,53 patients with primary gastric cancer were diagnosed with synchronous（n = 44） or metachronous（n = 9） pancreaticoduodenal region *** these,17 patients（32%） underwent total gastrectomy（TG） or distal subtotal gastrectomy（SG） combined with PD *** preoperative demographic,clinical information,clinicopathologic features and the surgical results of these 17 patients were considered as factors influencing survival and were analyzed by the Kaplan-Meier method with log-rank comparison.RESULTS：The actual 1-and 3-year survival rates of these 17 patients after resection were 77% and 34%,respectively,and three patients survived for more than 5 years after *** tumor-free resection margin（P = 0.0174） and a well-differentiated histologic type（P = 0.0011） were significant prognostic factors on univariate *** mortality occurred within one mo after operation,postoperative weight loss of different degree was present in all the patients with TG and 12 cases had other *** were 9（53%） cases of recurrence in 5-48 mo after *** survival rate in the palliative and explorative group was significantly（P = 0.0064） lower than in the combined PD group.CONCLUSION： Judicious use of en bloc PD and gastrectomy and strictly preventing postoperative complications may improve the long-term survival for advanced gastric cancer patients with pancreaticoduodenal region involvement. Well-differentiated histology and negative resection margin are the most important predictors of long survival.

关键词： Pancreaticoduodenectomy Gastric cancer Gastrectomy Predictive factor Patients

Nitrogen Desorption in Molten Stainless Steel During Immersion Argon Blowing

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Journal of Iron and Steel Research International 2010年第5期17卷 1-5页

作者： CHen Jian-bin CHen Qi-zhong HUANG zong-ze HU Ji-ye SUN Ya-qin PAN Jia-qi School of Materials Science and engineering Shanghai Institute of Technology Shanghai 200235 China Products and Technology Institute Research and Development Center Shanghai Baosteel Group Corporation Shanghai 201900 China

The behavior of nitrogen desorption reaction in molten stainless steel for AISI 304 and 316 during immersion argon blowing through an immersed alumina nozzle with 3 mm in I. D. has been investigated by sampling method. Some kinetic parameters such as reaction order, rate constant and apparent activation energy of nitrogen desorption reaction for AISI 304 and 316 have been obtained. Results show that nitrogen desorption reaction from molten stainless steel for AISI 304 and 316 is the second order reaction. The rate constant at 1550 ℃ and 1 580 ℃ for AISI 316 is 0. 08407%-1 · min^-1 and 0. 82370%-1 · min^-1 , respectively. The rate constant at 1550 ℃ for AISI 304 is 0. 416 6%-1 · min^-1. The apparent activation energy Ea of nitrogen desorption reaction for AISI 316 is 2 136.47 kJ/ mol. This huge value of apparent activation energy verifies that the nitrogen desorption reaction has a complex and multistep reaction mechanism. The rate of nitrogen desorption reaction from molten stainless steel is mixed controlled by the desorption reaction of diatomic molecule nitrogen or of monatomic nitrogen from molten metal at the gas-metal interface and the mass transfer of nitrogen in molten metal. The rate equation of process for nitrogen desorption has been deduced.

关键词： nitrogen desorption stainless steel immersion argon blowing sampling method kinetics

格子Boltzmann方法在斜坡非饱和带土体大孔隙流研究中的应用

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岩土工程学报 2017年第1期39卷 178-184页

作者：徐宗恒徐则民王志良云南师范大学旅游与地理科学学院云南昆明650500 昆明理工大学建筑工程学院云南昆明650500

大孔隙结构的建立和大孔隙流的渗流模拟能定性和定量的解释大孔隙流的产生机理及其动态变化过程。采用CT扫描获取斜坡非饱和带大孔隙域,基于不考虑外力项的格子Boltzmann方法,通过确定离散速度模型、平衡态分布函数和分布函数的演化方... 详细信息

大孔隙结构的建立和大孔隙流的渗流模拟能定性和定量的解释大孔隙流的产生机理及其动态变化过程。采用CT扫描获取斜坡非饱和带大孔隙域,基于不考虑外力项的格子Boltzmann方法,通过确定离散速度模型、平衡态分布函数和分布函数的演化方程三大组成部分,其中边界条件与计算假设依据染色示踪试验设定,定性定量化研究二维大孔隙流的渗流过程,研究结果表明:该方法能清晰定量化描述大孔隙流湿润前锋的推进过程,大孔隙效应明显,渗流场流速随着时间推移逐渐趋于稳定,大孔隙效应逐渐减弱;在连通性较好、孔径较大的区域流体流速较快,且在大孔隙中心流速最大,往两侧逐级递减;下层深度处的流体流量和流速往往受控于上一层大孔隙的孔径尺度。格子Boltzmann方法的应用能为大孔隙流特别是三维渗流过程的研究提供新手段。

关键词：格子Boltzmann方法非饱和带大孔隙流渗流过程

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OFDM系统有限字符集特性的盲信道估计

应用科学学报 2008年第5期26卷 441-447页

作者：居敏许宗泽南京航空航天大学信息科学与技术学院江苏南京210016

提出并证明了正交频分复用(OFDM)系统中基于信息符号有限字符集特性的信道盲可辨识的充分必要条件.在满足该条件的前提下,又提出一种频域最小距离(frequency-domain minimum distance,FMD)盲信道估计方法.该方法将信道频率响应序列多相... 详细信息

提出并证明了正交频分复用(OFDM)系统中基于信息符号有限字符集特性的信道盲可辨识的充分必要条件.在满足该条件的前提下,又提出一种频域最小距离(frequency-domain minimum distance,FMD)盲信道估计方法.该方法将信道频率响应序列多相分解为若干子向量,通过对其中一个子向量中元素的相位模糊度进行穷尽搜索,辨识出所有子载波上频率响应的相位.仿真结果表明,FMD算法的信道估计性能优于修正的最小距离(modifiedminimum distance,MMD)算法,而计算复杂度与MMD相等.

关键词：正交频分复用盲信道估计有限字符集特性多相分解

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异丙苯生产技术进展

石油化工 1999年第8期28卷 562-564页

作者：杜泽学闵恩泽石油化工科学研究院

异丙苯是重要的基本有机化工原料，主要用来生产用途广泛的苯酚和丙酮。目前，全球异丙苯的产量近千万吨，有９０％以上的异丙苯用来生产苯酚和丙酮，其余的用来生产苯乙酮以及橡胶和树脂的合成单体α－甲基苯乙烯。预计全球未来十年内... 详细信息

异丙苯是重要的基本有机化工原料，主要用来生产用途广泛的苯酚和丙酮。目前，全球异丙苯的产量近千万吨，有９０％以上的异丙苯用来生产苯酚和丙酮，其余的用来生产苯乙酮以及橡胶和树脂的合成单体α－甲基苯乙烯。预计全球未来十年内，异丙苯将以３８％的年增长率递增...

关键词：异丙苯分子筛催化剂技术进展