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Discovery and modification of cytochrome P450 for plant natural products biosynthesis

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Synthetic and Systems Biotechnology 2020年第3期5卷 187-199页

作者： Xiaonan Liu Xiaoxi Zhu Hui Wang Tian Liu jian cheng Huifeng jiang Key Laboratory of Systems Microbial Biotechnology Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin300308China University of Chinese Academy of Sciences Beijing100049China College of Biotechnology Tianjin University of Science&TechnologyTianjin300457China State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources College of Life Science and TechnologyGuangxi UniversityNanningGuangxi530004China

Cytochrome P450s are widespread in nature and play key roles in the diversification and functional modification of plant natural products.Over the last few years,there has been remarkable progress in plant P450s identification with the rapid development of sequencing technology,“omics”analysis and synthetic biology.However,challenges still persist in respect of crystal structure,heterologous expression and enzyme engineering.Here,we reviewed several research hotspots of P450 enzymes involved in the biosynthesis of plant natural products,including P450 databases,gene mining,heterologous expression and protein engineering.

关键词： P450 enzymes Plant natural products Synthetic biology

跨学科视角下的生态文明教育实践探究——以地理学科为例

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地理教学 2024年第11期 41-46,36页

作者：彭清思程健陈实华中师范大学人工智能教育学部湖北武汉430079 武汉市光谷第二高级中学湖北武汉430205 华中师范大学城市与环境科学学院湖北武汉430079

新时代生态文明建设需要生态文明教育的支持。地理课程蕴含丰富的生态文明教育资源,在渗透生态文明教育方面具有独特优势。在跨学科视角下开展生态文明教育,符合生态文明教育的相关政策要求,契合生态文明教育的内在学理依据,满足学生认... 详细信息

新时代生态文明建设需要生态文明教育的支持。地理课程蕴含丰富的生态文明教育资源,在渗透生态文明教育方面具有独特优势。在跨学科视角下开展生态文明教育,符合生态文明教育的相关政策要求,契合生态文明教育的内在学理依据,满足学生认知发展需求,具有坚实的实践基础。本研究搭建了“起点融合—载体依托—过程建构—学习反思”四过程的实践框架,并以景德镇陶瓷产业发展为例,列举了跨学科生态文明教育的教学案例,以期为跨学科视角下的生态文明教育提供参考。

关键词：跨学科生态文明教育实践框架地理教学

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多维地震对非对称地下空间结构反应影响分析

山西建筑 2024年第7期50卷 59-61,84页

作者：程剑合肥碧祥房地产有限公司安徽合肥230041

以一典型上层五跨和下层三跨的非对称地下空间结构为实际工程背景,同时考虑到土-结构相互作用效应,设计了水平向输入地震动、水平向及竖向联合输入地震动两类工况,采用通用有限元软件ABAQUS对该复杂地下空间结构的抗震性能与损伤情况开... 详细信息

以一典型上层五跨和下层三跨的非对称地下空间结构为实际工程背景,同时考虑到土-结构相互作用效应,设计了水平向输入地震动、水平向及竖向联合输入地震动两类工况,采用通用有限元软件ABAQUS对该复杂地下空间结构的抗震性能与损伤情况开展了研究,研究成果揭示了非对称地下空间结构在地震作用下的薄弱部位和损伤水准,为此类结构的抗震设计与分析提供合理的参考。

关键词：地下空间结构地震作用土-结构相互作用地震响应分析

地理跨学科主题学习的价值取向及课程组织策略

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地理教学 2024年第1期 49-54页

作者：程健彭清思陈实华中师范大学人工智能教育学部湖北武汉430079 华中师范大学城市与环境科学学院湖北武汉430079

地理跨学科主题学习是优化地理课程内容结构、发展学生核心素养的重要路径。地理跨学科主题学习具有回归真实世界、带动学科交叉、对接学科实践、转换评价思路等多重价值。合理的课程组织可以为学习提供框架和方向。本文将地理跨学科主... 详细信息

地理跨学科主题学习是优化地理课程内容结构、发展学生核心素养的重要路径。地理跨学科主题学习具有回归真实世界、带动学科交叉、对接学科实践、转换评价思路等多重价值。合理的课程组织可以为学习提供框架和方向。本文将地理跨学科主题学习分为学科主导型和学科融合型两类,并针对后者课程组织中的困惑,提出“要素分解—概念串联—目标融合—过程设计—成果展评”的实践策略。组织过程既关照地理课程内在逻辑线索,筑牢学科“个性”,又兼顾学习者的认知规律、兴趣需要,从学生问题解决过程中制造多学科的聚合,建立不同知识、方法的联系,实现学科边界的跨越。

关键词：初中地理跨学科主题学习价值取向课程组织

Potential damage threats to downstream optics caused by Gaussian mitigation pits on rear KDP surface

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High Power Laser Science and Engineering 2020年第4期8卷 59-67页

作者： Hao Yang jian cheng Zhichao Liu Qi Liu Linjie Zhao Chao Tan jian Wang Mingjun Chen State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Research Center of Laser Fusion China Academy of Engineering PhysicsMianyang 621900China

To determine whether a potassium dihydrogen phosphate(KDP)surface mitigated by micro-milling would potentially threaten downstream optics,we calculated the light-field modulation based on angular spectrum diffraction theory,and performed a laser damage test on downstream fused silica.The results showed that the downstream light intensification caused by a Gaussian mitigation pit of 800μm width and 10μm depth reached a peak value near the KDP rear surface,decreased sharply afterward,and eventually kept stable with the increase in downstream distance.The solved peak value of light intensification exceeded 6 in a range 8–19 mm downstream from the KDP rear surface,which is the most dangerous for downstream optics.Laser damage sites were then induced on the fused silica surface in subsequent laser damage tests.When the distance downstream was greater than 44 mm with a downstream light intensification of less than 3,there were no potential damage threats to downstream optics.The study proves that a mitigated KDP surface can cause laser damage to downstream optical components,to which attention should be paid in an actual application.Through this work,we find that the current manufacturing process and the mitigation index still need to be improved.The research methods and calculation models are also of great reference significance for related studies like optics mitigation and laser damage.

关键词： downstream threats KDP laser damage micro-milling mitigation

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基于实航数据驱动的无人艇操纵运动辨识建模

中国造船 2024年第1期65卷 146-155页

作者：王子豪程健谢文博宋锐彭艳上海大学人工智能研究院上海200444 海洋智能无人系统装备教育部工程研究中心上海200444 上海大学机电工程与自动化学院上海200444

为快速构建符合海洋航行器实际运动特性的操纵运动模型,开展基于“精海”无人艇实航湖试数据驱动的无人艇操纵运动辨识建模研究。无人艇操纵运动辨识建模的框架以非线性水动力模型和推进器经验模型作为先验知识约束,利用随机舵角序列激... 详细信息

为快速构建符合海洋航行器实际运动特性的操纵运动模型,开展基于“精海”无人艇实航湖试数据驱动的无人艇操纵运动辨识建模研究。无人艇操纵运动辨识建模的框架以非线性水动力模型和推进器经验模型作为先验知识约束,利用随机舵角序列激励下的航行数据作为训练集,采用支持向量机回归方法完成建模过程,着重探讨了在环境干扰下构建艇体动力学模型的可行性。结果表明,所提出的方法能够快速构建具有非线性特性的无人艇操纵运动模型;先验的模型结构有效降低了实航数据中浪和流的影响,构建的模型能够有效预测回转、Z形等操纵运动的状态变化,具有良好的泛化能力。

关键词：无人艇操纵性数据驱动辨识建模实航数据

Real-time observation of bainite formation at heterogeneous phases in a high-strength weathering steel

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Journal of Iron and Steel Research(International) 2019年第3期26卷 301-309页

作者： jian cheng Jia-sheng Qing Yue-hua Guo Hou-fa Shen Key Laboratory for Advanced Materials Processing Technology Ministry of EducationSchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Pangang Group Research Institute Co. Ltd.State Key Laboratory of Vanadium and Titanium Comprehensive UtilizationPanzhihua 617000SichuanChina

Due to the excellent comprehensive mechanical properties and toughness of bainite steels,bainite is regarded as a most desirable microstructure for the new generation of high-strength weathering steels.The formation of bainite was observed in real time in a high-strength weathering steel,and the results showed that bainite laths show impingement during phase transformation.The preferred regions of nucleation sites were identified,and the growth rate of bainite was measured.The growth mechanism of bainite was demonstrated to exhibit growth rate contributions from both the diffusion mechanism and the shear mechanism.Subsequently,the heterogeneous phases that form preferred sites for bainite nucleation were quantitatively identified by scanning electron microscopy(SEM),energy-dispersive X-ray spectrometry(EDS),and calculation of phase diagram(CALPHAD).The austenite grain sizes in crease with increasing austenite temperature,which leads to longer bainite laths.The influence of a small lattice disregistry between the heterogeneous phases and bainite on the bainite nucleation was studied.The disregistries between the favorable heterogeneous phases of VN,VC,TiN,or TiC and the ot-Fe in bainite are 2.9,3.1,3.9,and 4.6%,respectively.Therefore,VN,VC,TiN,and TiC can act as highly effective nuclei for bainite during the bainite transformation.

关键词： Bainite Real-time observation Plasticity Phase transformation Weathering steel

Study and performance test of 10 kW molten carbonate fuel cell power generation system

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International Journal of Coal Science & Technology 2021年第3期8卷 368-376页

作者： chengzhuang Lu Ruiyun Zhang Guanjun Yang Hua Huang jian cheng Shisen Xu State Key Laboratory of Coal Based Clean Energy Huaneng Clean Energy Research Institute Co.Ltd.Beijing 102209China Department of Energy and Power Engineering Tsinghua UniversityBeijing 100084China China Huaneng Group Ltd. Beijing 100031China

The use of high-temperature fuel cells as a power technology can improve the efficiency of electricity generation and achieve near-zero emissions of carbon dioxide.This work explores the performance of a 10 kW high-temperature molten carbonate fuel cell.The key materials of a single cell were characterized and analyzed using X-ray diffraction and scanning electron microscopy.The results show that the pore size of the key electrode material is 6.5 lm and the matrix material is a-LiAlO_(2).Experimentally,the open circuit voltage of the single cell was found to be 1.23 V.The current density was greater than 100 mA/cm^(2)at an operating voltage of 0.7 V.The 10 kW fuel cell stack comprised 80 single fuel cells with a total area of 2000 cm^(2)and achieved an open circuit voltage of greater than 85 V.The fuel cell stack power and current density could reach 11.7 kW and 104.5 mA/cm2 at an operating voltage of 56 V.The influence and long-term stable operation of the stack were also analyzed and discussed.The successful operation of a 10 kW high-temperature fuel cell promotes the large-scale use of fuel cells and provides a research basis for future investigations of fuel cell capacity enhancement and distributed generation in China.

关键词： Fuel cell stack Key materials Molten carbonate fuel cell Power generation test

A Direct Discontinuous Galerkin Method with Interface Correction for the Compressible Navier-Stokes Equations on Unstructured Grids

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Advances in Applied Mathematics and Mechanics 2018年第1期10卷 1-21页

作者： jian cheng Huiqiang Yue Shengjiao Yu Tiegang Liu School of Mathematics and Systems Science Beihang UniversityBeijing 100091China

Since the original DDG method has been introduced by Liu et al.[8]in 2009,a variety of DDG type methods have been proposed and further developed.In this paper,we further investigate and develop a new DDG method with interface correction(DDG(IC))as the discretization of viscous and heat fluxes for the compressible Navier-Stokes equations on unstructured grids.Compared to the original DDG method,the newly developed DDG(IC)method demonstrates its superior in delivering the optimal order of accuracy under demanding situations.Strategies in extension and application of this newly developed DDG(IC)method for solving the compressible Navier-Stokes equations and special treatments designed for handling boundary viscous fluxes are presented and examined in this work.The performance of the new DDG method with interface correction is carefully evaluated and assessed through a number of typical test cases.Numerical experiments show that the new DDG method with interface correction can achieve the optimal order of accuracy on both uniform structured grids and nonuniform unstructured grids,which clearly indicates its potential for further applications of real engineering practices.

关键词： Direct discontinuous Galerkin method high-order method compressible Navier-Stokes equations