检索结果-南通市图书馆

A Local Macroscopic Conservative(LoMaC)Low Rank Tensor Method with the Discontinuous Galerkin Method for the Vlasov Dynamics

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第1期6卷 550-575页

作者： Wei Guo Jannatul Ferdous ema Jing-Mei Qiu Department of Mathematics and Statistics Texas Tech UniversityLubbockTX70409USA Department of Mathematical Sciences University of DelawareNewarkDE19716USA

In this paper,we propose a novel Local Macroscopic Conservative(LoMaC)low rank tensor method with discontinuous Galerkin(DG)discretization for the physical and phase spaces for simulating the Vlasov-Poisson(VP)*** LoMaC property refers to the exact local conservation of macroscopic mass,momentum,and energy at the discrete *** recently developed LoMaC low rank tensor algorithm(arXiv:2207.00518)simultaneously evolves the macroscopic conservation laws of mass,momentum,and energy using the kinetic flux vector splitting;then the LoMaC property is realized by projecting the low rank kinetic solution onto a subspace that shares the same macroscopic *** paper is a generalization of our previous work,but with DG discretization to take advantage of its compactness and flexibility in handling boundary conditions and its superior accuracy in the long *** algorithm is developed in a similar fashion as that for a finite difference scheme,by observing that the DG method can be viewed equivalently in a nodal *** the nodal DG method,assuming a tensorized computational grid,one will be able to(i)derive differentiation matrices for different nodal points based on a DG upwind discretization of transport terms,and(ii)define a weighted inner product space based on the nodal DG grid *** algorithm can be extended to the high dimensional problems by hierarchical Tucker(HT)decomposition of solution tensors and a corresponding conservative projection *** a similar spirit,the algorithm can be extended to DG methods on nodal points of an unstructured mesh,or to other types of discretization,e.g.,the spectral method in velocity *** numerical results are performed to showcase the efficacy of the method.

关键词： Hierarchical Tucker(HT)decomposition Conservative SVD Energy conservation Discontinuous Galerkin(DG)method

Probing the fate of transplanted hematopoietic stem cells: is the combinational approach “FIT” for purpose?

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2020年第11期63卷 1755-1758页

作者： Fang Dong Hui Cheng Hideo ema Tao Cheng State Key Laboratory of Experimental Hematology National Clinical Research Center for Blood DiseasesInstitute of Hematology&Blood Diseases HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeTianjin 300020China Center for Stem Cell Medicine Chinese Academy of Medical SciencesTianjin 300020China Department of Stem Cell&Regenerative Medicine Peking Union Medical CollegeTianjin 300020China

Hematopoietic stem cells (HSCs)—with their self-renewal and multi-lineage differentiation potential—are top of the hematopoietic cell hierarchy. Stress conditions activate the quiescent HSCs, which in turn enter cel... 详细信息

关键词： hematopoietic al. stem

Nonlinear Dynamics in a Nonextensive Complex Plasma with Viscous Electron Fluids

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2016年第6期33卷 67-70页

作者： M.R. Hossen S.A. ema A.A. Mamun Department of Natural Sciences Daffodil International University Department of EEE Sonargaon University Department of Physics Jahangirnagar University

Cylindrical and spherical dust-electron-acoustic （DEA） shock waves and double layers in an unmagnetized, col- lisionless, complex or dusty plasma system are carried out. The plasma system is assumed to be composed of inertial and viscous cold electron fluids, nonextensive distributed hot electrons, Maxwellian ions, and negatively charged stationary dust grains. The standard reductive perturbation technique is used to derive the nonlinear dynamical equations, that is, the nonplanar Burgers equation and the nonplanar further Burgers equation. They are also numerically analyzed to investigate the basic features of shock waves and double layers （DLs）. It is observed that the roles of the viscous cold electron fluids, nonextensivity of hot electrons, and other plasma parameters in this investigation have significantly modified the basic features （such as, polarity, amplitude and width） of the nonplanar DEA shock waves and DLs. It is also observed that the strength of the shock is maximal for the spherical geometry, intermediate for cylindrical geometry, while it is minimal for the planar geometry. The findings of our results obtained from this theoretical investigation may be useful in understanding the nonlinear phenomena associated with the nonplanar DEA waves in both space and laboratory plasmas.

关键词： in on is as it of Nonlinear Dynamics in a Nonextensive Complex Plasma with Viscous Electron Fluids with

A novel paradigm for feedback control in LPBF:layer-wise correction for overhang structures

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2022年第2期10卷 326-344页

作者： ema Vasileska Ali Gokhan Demir Bianca Maria Colosimo Barbara Previtali Department of Mechanical Engineering Polytechnic University of MilanVia La Masa 120156 MilanItaly

In laser powder bed fusion(LPBF),it is common practice to select process parameters to achieve high density parts starting from simple geometries such as cubes or ***,additive manufacturing is usually adopted to producevery complex geometries,where parameters should be tuned locally,depending on the local features to be *** fact,geometrical features,such as overhangs,acute corners,and thin walls may lead to over-or under-heating conditions,which may result in geometrical inaccuracy,high roughness,volumetric errors(i.e.,porosity)oreven job failure due to *** work proposes a layer-wise control strategy to improve the geometrical precision of overhanging regions using a coaxial melt pool monitoring *** meltpool images acquired at each layer are used in a controlloop toadapt theprocess parameters locally at the next layer in order to minimize surface *** particular,the laser duty cycle is used as a controllable parameterto correct the energy *** work presents the main architecture of the proposed approach,the control strategy and the experimental procedure that need to be applied to design the control *** layer-wise control strategy was tested on AISI 316L stainless steel using an open LPFB *** results showed that the proposed layer-wise control solution results in a constant melt pool observed via the laser heated area size starting from the second layer onward,leading to a significant improvement in the geometrical accuracy of 5 mm-long bridge geometries.

关键词： Closed-loop control Melt pool monitoring:Defect correction Pulsed-wave emission

欧盟警示奈玛特韦片/利托那韦片组合包装与治疗窗窄的免疫抑制剂合用时严重和潜在致死性不良反应的风险

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国药物警戒 2024年第4期21卷 434-434页

作者： ema网站国家药品不良反应监测中心

2024年2月9日,欧洲药品管理局(ema)的药物警戒风险评估委员会(PRAC)发布信息提示医务人员,奈玛特韦片/利托那韦片组合包装(商品名:Paxlovid)与某些安全剂量范围较窄(剂量的微小变化可能导致严重不良反应)的免疫抑制剂合并使用时,有发生... 详细信息

2024年2月9日,欧洲药品管理局(ema)的药物警戒风险评估委员会(PRAC)发布信息提示医务人员,奈玛特韦片/利托那韦片组合包装(商品名:Paxlovid)与某些安全剂量范围较窄(剂量的微小变化可能导致严重不良反应)的免疫抑制剂合并使用时,有发生严重和潜在致死性不良反应的风险,因为药物相互作用导致人体消除这些药物的能力降低。Paxlovid用于治疗伴有进展为重症高风险因素且不需要吸氧的新冠病毒感染的成人患者。相关的免疫抑制剂包括钙调神经磷酸酶抑制剂(他克莫司、环孢素)和mTOR抑制剂(依维莫司、西罗莫司),上述药物可降低免疫系统活性,常用于治疗某些自身免疫性疾病或防止移植器官排斥。

关键词：药物警戒利托那韦成人患者免疫抑制剂自身免疫性疾病药物相互作用组合包装西罗莫司

欧盟药品安全委员会建议暂停己酸羟孕酮上市许可

在线全文

学校读者我要写书评

暂无评论

中国药物警戒 2024年第7期21卷 758-758页

作者： ema网站国家药品不良反应监测中心

欧洲药品管理局(ema)5月17日发布信息,称其药品安全委员会(PRAC)建议暂停己酸羟基孕酮(17-OHPC)在欧盟的上市许可。PRAC的一项评估发现,子宫暴露于己酸羟基孕酮的人群可能存在癌症风险,该风险尚未被完全证实。此外,评估认为己酸羟基孕... 详细信息

欧洲药品管理局(ema)5月17日发布信息,称其药品安全委员会(PRAC)建议暂停己酸羟基孕酮(17-OHPC)在欧盟的上市许可。PRAC的一项评估发现,子宫暴露于己酸羟基孕酮的人群可能存在癌症风险,该风险尚未被完全证实。此外,评估认为己酸羟基孕酮在预防早产方面无效,在其他适应症用途中有效性数据有限。在一些欧盟国家,己酸羟孕酮被批准作为注射剂用于预防孕妇流产或早产,以及治疗各种妇科疾病和生育障碍,包括缺乏黄体酮激素引起的疾病。PRAC回顾了一项基于人群的大型研究,该研究关注从出生起约50年内,子宫暴露于己酸羟孕酮的人群中罹患癌症的风险。这项研究的数据表明,与未接触该药物的人群相比,子宫暴露于己酸羟孕酮人群罹患癌症的风险可能增加。然而,PRAC指出,该研究中癌症病例数量较少,存在一些局限性,例如关于癌症危险因素的信息有限。因此,委员会得出结论认为,子宫暴露于己酸羟孕酮人群罹患癌症的风险是可能存在的,但由于不确定性,尚不能证实。

关键词：孕妇流产上市许可己酸羟孕酮病例数量药品安全妇科疾病危险因素黄体酮

Nonplanar Shock Structures in a Relativistic Degenerate Multi-Species Plasma

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2014年第12期61卷 888-894页

作者： M.R.Hossen S.A.ema A.A.Mamun Department of Natural Sciences Daffodil International University Sukrabad Dhaka-1207 Bangladesh Department of Physics Jahangirnagar University Savar Dhaka-1342 Bangladesh

A nonlinear propagation of cylindrical and spherical modified ion-acoustic(m IA) waves in an unmagnetized,collisionless, relativistic, degenerate multi-species plasma has been investigated theoretically. This plasma system is assumed to contain non-relativistic degenerate light ions, both non-relativistic and ultra-relativistic degenerate electron and positron fluids, and arbitrarily charged static heavy ions. The restoring force is provided by the degenerate pressures of the electrons and positrons, whereas the inertia is provided by the mass of ions. The arbitrarily charged static heavy ions participate only in maintaining the quasi-neutrality condition at equilibrium. The modified Burgers(m B) equation is derived by using reductive perturbation technique and numerically analyzed to identify the basic features of m IA shock structures. The basic characteristics of m IA shock waves are found to be significantly modified by the effects of degenerate pressures of electron, positron, and ion fluids, their number densities, and various charge state of heavy ions. The implications of our results to dense plasmas in astrophysical compact objects(e.g., non-rotating white dwarfs,neutron stars, etc.) are briefly discussed.

关键词： modified ion-acoustic waves shock waves degenerate pressure relativity compact objects

欧盟就CAR-T细胞疗法的继发性T细胞恶性肿瘤风险发布致医务人员函

在线全文

学校读者我要写书评

暂无评论

中国药物评价 2024年第4期41卷 264-264页

作者：欧盟ema网站

欧洲药品管理局(ema)近期就靶向CD19或BCMA的CAR-T细胞疗法(商品名分别为:Abecma、Breyanzi、Carvykti、Kymriah、Tecartus、Yescarta)的继发性T细胞恶性肿瘤风险发布致医务人员函(direct healthcare professional communications,DHPC)。目前获批的靶向CD19或BCMA的CAR-T细胞疗法涵盖包括B细胞急性白血病、特定亚型的B细胞淋巴瘤、多发性骨髓瘤在内的一系列适应证。

关键词：多发性骨髓瘤急性白血病欧洲药品管理局 CAR B细胞淋巴瘤 CD19 恶性肿瘤医务人员

The Success of Advertising through TikTok for Business

在线全文

学校读者我要写书评

暂无评论

The Success of Advertising through TikTok for Business

作者： ema Ademaj 北京工商大学

学位级别：硕士

作为世界上下载量最大的新出现的一款应用软件,抖音(Tik Tok)面临着巨大的挑战。广告为抖音带来巨额收益,同时也是其面临的最主要的挑战之一。本论文首次通过对抖音广告业务的研究,来剖析抖音通过广告给企业创造价值的最有影响力的主要... 详细信息

作为世界上下载量最大的新出现的一款应用软件,抖音(Tik Tok)面临着巨大的挑战。广告为抖音带来巨额收益,同时也是其面临的最主要的挑战之一。本论文首次通过对抖音广告业务的研究,来剖析抖音通过广告给企业创造价值的最有影响力的主要因素。本文通过剖析目标客户群体、客户参与广告的过程及正确的参与方式,以及哪些内容是抖音广告的关键。客户的行为和习惯是千差万别的,本论文的研究以西欧文化为背景(主要是英国、法国、西班牙、意大利和德国)。为了实现本研究的目标,我向抖音的用户及在抖音上做广告的企业分别发放了问卷。通过卡方的分析方法,基于不同群体分类变量的分析,我们检验了被调查者的答案在统计学上的显著性差异。结果显示,企业通过抖音开展广告成功与否取决于企业最初的目标和动机。结论同时也显示,最常被客户点击的广告更多是通过“为你(For You)”界面而出现的广告。这点对广告商来说更有趣的一点是,有相当一部分用户更愿意访问他们在广告中设置的外部链接。此外,基于对细节的分析,我们根据广告的频率和类型推导出了广告的平均成功率。基于以上调研数据的分析,本论文提出了抖音广告中存在的问题,同时为用户和企业更好地利用这个平台开展其广告业务提出了有效的对策和建议。

关键词：抖音广告社交传媒