检索结果-南通市图书馆

NPR锚索对跨断层软岩大变形隧道控制技术研究

在线全文

学校读者我要写书评

暂无评论

隧道建设（中英文） 2024年第S1期44卷 113-123页

作者：陶志刚林伟军李勇孙滢滢熊弋文陈明亮中国矿业大学(北京)隧道工程灾变防控与智能建养全国重点实验室北京100083 中国矿业大学(北京)力学与土木工程学院北京100083 中国矿业大学(北京)地球科学与测绘工程学院北京100083 中国矿业大学(北京)煤炭资源与安全开采国家重点实验室北京100083

为探究NPR锚索对东马场跨断层软岩大变形隧道控制效果,首先对NPR锚索进行静力拉伸试验,验证其恒阻大变形的能力和具有良好的抵御外力的效果;随后开展NPR锚索对东马场隧道围岩变形控制的三维物理模型试验。试验现象和数据表明:在开挖过程... 详细信息

为探究NPR锚索对东马场跨断层软岩大变形隧道控制效果,首先对NPR锚索进行静力拉伸试验,验证其恒阻大变形的能力和具有良好的抵御外力的效果;随后开展NPR锚索对东马场隧道围岩变形控制的三维物理模型试验。试验现象和数据表明:在开挖过程中,隧道围岩也没有出现较大垮落和坍塌,NPR锚索对软岩隧道围岩有较好的支护效果。在加载完成后,NPR锚索对非断层处的隧道围岩最大位移约为14 mm,断层处的围岩最大位移约为21 mm,隧道区域所受应力分布的不规律性,导致隧道围岩出现挤压变形,位移曲线呈振荡状。在NPR锚索的支护下,围岩应力最大发生在左拱肩,围岩临空面3 cm处切应力最大(0.3 MPa),隧道未出现大规模的不对称破坏现象,隧道总体呈现出“小塌而不垮”,变形总体可控。

关键词：断层隧道软岩大变形 NPR锚索物理模型试验

Acoustic radiation force on a rigid cylinder near rigid corner boundaries exerted by a Gaussian beam field

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第4期31卷 373-380页

作者： Qin Chang Yuchen Zang weijun lin Chang Su Pengfei Wu Institute of Acoustics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Beijing Deep Sea Drilling Measurement Engineering Technology Research Center Beijing 100190China

Acoustic manipulation is one of the well-known technologies of particle control and a top research in acoustic *** of acoustic radiation force on a particle nearby boundaries is one of the critical tasks,as it approximates realistic ***,it is quite difficult to solve the problem by theoretical method when the boundary conditions are *** this study,we present a finite element method numerical model for the acoustic radiation force exerting on a rigid cylindrical particle immersed in fluid near a rigid *** effects of the boundaries on acoustic radiation force of a rigid cylinder are analyzed with particular emphasis on the non-dimensional frequency and the distance from the center of cylinder to each *** results reveal that these parameters play important roles in acoustic manipulation for particle-nearby complicated rigid *** study verifies the feasibility of numerical analysis on the issue of acoustic radiation force calculation close to complex boundaries,which may provide a new idea on analyzing the acoustic particle manipulation in confined space.

关键词： acoustic radiation force finite element method Gaussian beam field acoustic manipulation

Regulatory dynamics of the higher-plant PSI-LHCI supercomplex during state transitions

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2023年第12期16卷 1937-1950页

作者： Jianghao Wu Shuaijiabin Chen Chao Wang weijun lin Chao Huang Chengxu Fan Dexian Han Dandan Lu Xiumei Xu SenFang Sui Lixin Zhang State Key Laboratory of Crop Stress Adaptation and Improvement School of Life SciencesHenan UniversityJinming AvenueKaifeng 475004China School of Life Science Southern University of Science and TechnologyShenzhen 518055China State Key Laboratory of Membrane Biology Beijing Advanced Innovation Center for Structural BiologyBeijing Frontier Research Center for Biological StructureSchool of Life SciencesTsinghua UniversityBeijing 100084China Cryo-EM Center Southern University of Science and TechnologyShenzhen 518055China Photosynthesis Research Center Key Laboratory of PhotobiologyInsttute of BotanyChinese Academy of SciencesBejing 100093China

State transition is a fundamental light acclimation mechanism of photosynthetic organisms in response to the environmental light *** process rebalances the excitation energy between photosystemI(PSl)and photosystem Il through regulated reversible binding of the light-harvesting complex Il(LHCll)to ***,the structural reorganization of PSI-LHCI,the dynamic binding of LHCll,and the regulatory mechanisms underlying state transitions are less understood in higher *** this study,using cryoelectron microscopy we resolved the structures of PSI-LHCI in both state 1(PSI-LHCI-ST1)and state 2(PSILHCI-LHCll-ST2)from Arabidopsis *** genetic and functional analyses revealed novel contacts between Lhcb1 and PsaK that further enhanced the binding of the LHCll trimer to the PSI core with the known interactions between phosphorylated Lhcb2 and the PsaL/PsaH/PsaO ***,PsaO was absent in the PSI-LHCI-ST1 supercomplex but present in the PSI-LHCI-LHCIl-ST2 supercomplex,in which the PsaL/PsaK/PsaA subunits undergo several conformational changes to strengthen the binding of PsaO in ***,the PSI-LHCI module adopts a more compact configuration with shorter Mg-to-Mg distances between the chlorophylls,which may enhance the energy transfer efficiency from the peripheral antenna to the PSl core in ***,our work provides novel structural and functional insights into the mechanisms of light acclimation during state transitions in higher plants.

关键词： state transitions dynamic conformation photosystem l regulatory mechanism Arabidopsis thaliana

A numerical investigation of the acoustic mode waves in a deviated borehole penetrating a transversely isotropic formation

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(Physics,Mechanics & Astronomy) 2015年第8期58卷 49-57页

作者： LIU Le lin weijun ZHANG HaiLan WANG XiuMing State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

A 2.5-dimensional method in frequency wave-number domain is developed to investigate the mode waves in a deviated borehole penetrating a transversely isotropic formation. The phase velocity dispersion characteristics of the fast and slow flexural mode waves excited by a dipole source are computed accurately at various deviation angles for both hard and soft formations. The sensitivities of the flexural mode waves to all elastic constants in a transversely isotropic formation are calculated. Numerical results show that, for a soft formation, the fast flexural mode wave is dominated by c66 at high deviation angles and low frequencies, while the slow flexural mode wave is dominated by c44 at the same conditions. Waveforms in time domain are also presented to support the conclusions.

关键词： deviated borehole transverse isotropy acoustic mode waves dispersion curve sensitivity analysis

Reply to “Comment on ‘A numerical investigation of the acoustic mode waves in a deviated borehole penetrating a transversely isotropic formation' ”

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2016年第8期59卷 91-92页

作者： Chang Su XiuMei Zhang weijun lin HaiLan Zhang XiuMing Wang State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

We appreciate the comment from Horne,Miller and Wang on the paper‘A numerical investigation of the acoustic mode waves in a deviated borehole penetrating a transversely isotropic formation’by Liu et al.（2015）[1],for the opportunity to consider and clarify the group and phase velocity issue in sonic logging with a deviated borehole penetrating a VTI *** re-read the paper by Liu et al.[1]and did some numerical tests and analyses.

关键词： penetrating Comment on Reply to isotropic borehole sonic opportunity logging comment appreciate

Acoustic radiation torque on a spheroidal droplet in standing Bessel beams

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 2021年第4期40卷 566-582页

作者： ZANG Yuchen lin weijun SU Chang WU Pengfei Institute of Acoustics Chinese Academy of SciencesBeijing 100190 University of Chinese Academy of Sciences Beijing 100049

In the actual acoustic manipulation,a droplet often takes the shape of a spheroid due to the combined effects of the acoustic radiation force,surface tension and gravitational force,which can be rotated by the torque in helicoidal sound *** on the sound scattering theory,the scattering coefficients of a spheroidal droplet in standing Bessel beams are solved using the partial-wave series expansion method,and the analytical expression of the acoustic radiation torque is also *** this basis,the results for both the incompressible and the compressible spheroidal droplets are calculated *** simulated results show that the acoustic radiation torque on the incompressible droplet is more closely related to the half-cone angle of the beam,while the torque on the compressible droplet is more dependent on specific *** growth of the beam order will increase the peaks of the acoustic radiation torque,but it is difficult to obtain an obvious radiation torque for compressible droplets at low and medium *** results of this study are expected to provide a theoretical guide for manipulating droplets using helicoidal acoustic beams.

关键词： Bessel compressible beam

在线全文

学校读者我要写书评

暂无评论

自由空间中球形粒子的负向声辐射力

声学学报 2022年第3期47卷 379-393页

作者：臧雨宸林伟军苏畅吴鹏飞常钦中国科学院声学研究所北京100190 中国科学院大学北京100049

针对一定声场作用下自由空间中的球形粒子,首先分析了声散射过程中的吸收声功率、散射声功率和损失声功率以及三者之间的关系,并通过计算发现了由于参数选取不当导致的负吸收现象。接着从动量守恒定律出发推导了声辐射力的一般表达式,... 详细信息

针对一定声场作用下自由空间中的球形粒子,首先分析了声散射过程中的吸收声功率、散射声功率和损失声功率以及三者之间的关系,并通过计算发现了由于参数选取不当导致的负吸收现象。接着从动量守恒定律出发推导了声辐射力的一般表达式,阐释了声辐射力与声能流之间的关系,并从理论和计算两方面验证了负向声辐射力的存在。当负向声辐射力产生时,声波的背向散射被抑制。在此基础上,进一步研究了粒子的偏心特性和流体的黏度这两种常见因素对负向声辐射力的影响。利用球函数的加法公式推导了偏心球的散射系数和声辐射力公式,结果显示偏心距离、粒子的材料等都会显著改变负向声辐射力的产生条件。在低频近似下,由于流体黏度附加的正向声辐射力是否能完全抵消原来的负向声辐射力将决定最终的声辐射力方向。该结果对利用负向声辐射力制成单行波声学镊子来实现对特定粒子的操控有着理论指导意义。

关键词：球形粒子自由空间声功率动量守恒定律背向散射散射系数偏心距离声能流

在线全文

学校读者我要写书评

暂无评论

弹性波传播模拟的Chebyshev谱元法

声学学报 2007年第6期32卷 525-533页

作者：林伟军中国科学院声学研究所北京100080

通过在每一个单元中采用谱展开近似,Chebyshev谱元法兼具了有限元处理边界及复杂结构的灵活性和谱方法的快速收敛特性,为弹性波传播的数值模拟提供了一种有效工具。从加权余量原理出发,详细阐述了Chebyshev谱元法用于弹性波传播模拟的... 详细信息

通过在每一个单元中采用谱展开近似,Chebyshev谱元法兼具了有限元处理边界及复杂结构的灵活性和谱方法的快速收敛特性,为弹性波传播的数值模拟提供了一种有效工具。从加权余量原理出发,详细阐述了Chebyshev谱元法用于弹性波传播模拟的基本理论及相应数学公式.给出了使用Chebyshev正交多项式展开得到的,存在等参变换时有关单元质量矩阵和单元刚度矩阵的精确积分公式。同时应用逐元技术极大地减少了内存和计算需求.最后,两个数值算例被用于验证这种谱元方法的高精度和强适应性。

关键词： Chebyshev 弹性波传播传播模拟谱元法单元刚度矩阵多项式展开收敛特性复杂结构

The DELLA-ABI4-HY5 module integrates light and gibberellin signals to regulate hypocotyl elongation

在线全文

学校读者我要写书评

暂无评论

Plant Communications 2023年第5期4卷 223-233页

作者： Haibo Xiong Dandan Lu Zhiyuan Li Jianghao Wu Xin Ning weijun lin Zechen Bai Canhui Zheng Yang Sun Wei Chi Lixin Zhang Xiumei Xu State Key Laboratory of Crop Stress Adaptation and Improvement School of Life SciencesHenan UniversityJinming AvenueKaifeng 475004China Sanya Institute of Henan University Sanya 572025China Photosynthesis Research Center Key Laboratory of PhotobiologyInstitute of BotanyChinese Academy of SciencesNanxincun 20XiangshanBeijing 100093China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

Plant growth is coordinately controlled by various environmental and hormonal signals,of which light and gibberellin(GA)signals are two critical factors with opposite effects on hypocotyl *** interactions between the light and GA signaling pathways have been studied extensively,the detailed regulatory mechanism of their direct crosstalk in hypocotyl elongation remains to be fully ***,we reported that ABA INSENSITIVE 4(ABI4)controls hypocotyl elongation through its regulation of cellelongation-related genes,but whether it is also involved in GA signaling to promote hypocotyl elongation is *** this study,we showthat promotion of hypocotyl elongation by GA is dependent on ABI4 *** interact directly with ABI4 and inhibit its DNA-binding *** turn,ABI4 combined with ELONGATED HYPOCOTYL 5(HY5),a key positive factor in light signaling,feedback regulates the expression of the GA2ox GA catabolism genes and thus modulates GA *** together,our results suggest that the DELLA-ABI4-HY5 module may serve as a molecular link that integrates GA and light signals to control hypocotyl elongation.

关键词： light signal GA signal hypocotyl elongation DELLA ABI4 HY5