检索结果-南通市图书馆

Distribution assessment of soil erosion with revised RUSLE model in Tianshan Mountains

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第3期21卷 850-866页

作者： WEI wenyu liu ya ZHANG Lixia LI Lanhai State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Reaserch Center of Educational in Xinjiang Xinjiang Normal UniversityUrumqi 830017China

aSoil degradation caused by soil erosion is one of the world's most critical environmental *** erosion in the Tianshan Mountains has caused various environmental problems in the surrounding *** study used remote sensing data to analyze the distribution of the factors influencing soil erosion,and the revised universal soil loss equation(RUSLE)to calculate the total amount and distribution characteristics of soil erosion in the Tianshan Mountains in *** to the large error of RUSLE in soil erosion estimation in mountainous areas,this study modified RUSLE equation based on the characteristics of snow cover in the Tianshan *** results show that the average soil erosion was 1690.3 t/(km^(2)·year),of which insignificant erosion,slight erosion and moderate erosion accounted for 42,8%,22.4%and 9.9%,*** erosion and above accounted for 13.3%.The accuracy of the soil erosion modulus calculated by the RUSLE was only 61.9%,with an average error of 1631.9 t/(km^(2)·year).The average error of the double-coefficient correction method was 1259.1 t/(km^(2)·year),and the average error of the modified formula method was reduced by 40.3%compared with the RUSLE,reaching 973.7 t/(km^(2)·year),and its accuracy reached 76.2%.Very severe erosion and catastrophic erosion are distributed on mountain ridges with higher elevation and on the northern area with higher *** cover has a certain inhibitory effect on soil erosion,and snow cover in alpine mountains is a factor that cannot be ignored in soil erosion research.

关键词： RUSLE Snow cover Erosion categories High-elevation area

Neither luciferin nor oxyluciferin of Latia is fluorescent-evidence from theoretical study

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Neither luciferin nor oxyluciferin of Latia is fluorescent-e...

第十三届全国量子化学会议

作者： Mo-Han Yu ya-jun liu Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education College of ChemistryBeijing Normal University

Latia neritoides is a small limpet-like snail that produces a bright green bioluminescence（BL） via a unique light-emitting system. Its bioluminescent process, mechanism and even light emitter remains unknown, although this BL has been reported for decades. Unlike the other BLs, neither luciferin（Luc） nor oxyluciferin（OxyLuc） of Latia is fluorescent according to the previously experimental studies. In order to identify its bioluminophore, we studied the geometrical and electronic structures and absorption and fluorescence spectra of Latia Luc and its six analogues as well as its OxyLuc in the gas phase and water. The calculated results provide clear evidence to nonfluorescence of Luc and OxyLuc of Latia. For the analogues of Latia Luc, the electron-withdrawing or electron-donating ability of the substituted group influences the fluorescence. This study sheds new light on the road to understand the Latia BL.

关键词： Latia luciferin oxyluciferin absorption spectrum fluorescence spectrum

New Insights into the Activation of Lingulodinium Polyedrum Luciferase Revealed by Molecular Dynamics Simulation

在线全文

cnki会议

学校读者我要写书评

暂无评论

New Insights into the Activation of Lingulodinium Polyedrum ...

第十三届全国量子化学会议

作者： Ming-Yu Wang ya-jun liu Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education College of ChemistryBeijing Normal University

Lingulodinium Polyedrum is a marine bioluminescent dinoflagellate specie. Luciferase(LCF) regulates its bioluminescence via catalyzing the oxidation of luciferin(LH), an open tetrapyrrole derivative *** L. Polyedrum LCF comprises three homologous domains within a single molecule. Both of the full-length molecule and its every domain are most active at pH 6.3, and display little activity at pH 8.0. Schultz et al. has determined the crystal structure of the third domain of LCF of ***. The activation mechanism of unique pH-dependent catalysis is suggested involving protonation of four conserved histidines by mutagenesis experiment. However, there is still no clear structural evidence in support of this hypothesis. In this study, we employed molecular dynamics simulation of protonated LCFs and some mutants at varying degrees by GROMACS package(version 2016.1). Our simulation results are in agreements with the proposed activation mechanism. The three-helix bundle in the N-terminal function as a lid being unlocked by protonation of four crucial histidines.

关键词： Dinoflagellate luciferase molecular dynamics simulations

Theoretical Study of Fridericia heliota Bioluminescence

在线全文

cnki会议

学校读者我要写书评

暂无评论

Theoretical Study of Fridericia heliota Bioluminescence

第十三届全国量子化学会议

作者： Yi-Qi Tang ya-jun liu Key Laboratory of Theoretical and Computational Photochemistry Ministry of EducationCollege of ChemistryBeijing Normal University

Fridericia heliota is a novel bioluminescent oligochaete worm whose luminescent system is different from those of other luminous representatives in Oligochaeta. This uniqueness is of obvious interest to researchers and can also be potentially useful for analytical *** novel mechanism of light production seems to be highly similar to that of the well-studied firefly bioluminescence. Unfortunately, the lack of biological material significantly hampers the progress in unraveling its detailed mechanism and verifying the actual light emitter for the natural system. Herein, we have investigated the geometries and properties of the luciferin and oxyluciferin of Fridericia heliota via the density functional calculations. The calculations were performed in the gas phase and solution. The calculated results are expected to give some help for the above questions in theory.

关键词： Fridericia heliota luciferin oxyluciferin bioluminescence

Color-Tuning of the firefly oxyluciferin analogs investigated by Hybrid QM/MM simulations

在线全文

cnki会议

学校读者我要写书评

暂无评论

Color-Tuning of the firefly oxyluciferin analogs investigate...

中国化学会第29届学术年会

作者： Yuan-Yuan Cheng ya-jun liu College of Chemistry Beijing Normal University

To improve the visualization of living cells,extend the firefly bioluminescence is of practical *** modification of luciferase and luciferin are the two main aspects of tuning the color of firefly *** present,we focus on the study of luciferin *** theory study of oxyluciferin analogs’emission spectra in gas and in solutions has been reported.1 In this work,we study the firefly bioluminescence spectra of nine synthesized oxyluciferin analogs,some of which have been reported2,in protein by hybrid quantum mechanics/molecular mechanics（QM/MM）*** results are compared with that of the phenolate-keto-oxyluciferin,which is the only light emitter of *** on the calculated results,the H bond effects,rotation effects,andπ-πstacking effects are discussing.

关键词：

The noise spectral characteristics and noise reduction schemes of screw air-source heat pump:A case study

在线全文

cnki会议

学校读者我要写书评

暂无评论

Building Simulation 2024年第1期17卷 53-70页

作者： Dongsheng liu yaohan Feng Jikang Jia Pengfei Si ya Feng China Southwest Architecture Design and Research Institute Co.Ltd. Chengdu 610041China CSCEC Green Construction Engineering Research Center Chengdu 610041China

The screw air-source heat pump can cause incessant high noise levels during operation,which might hinder adoption of this energy-efficient heat ***,acoustic measurements and comparison testing were performed in this *** measurements revealed that the compressor is the main noise source of the heat pump,and it shows a multipeak frequency distribution and a wide frequency spectrum under different work conditions,with multiple peaks at 63,250,and 1000 ***,a compressor sound insulation cover with broadband absorption was proposed,and it was experimentally proven that the insulation cover can reduce the maximum sound pressure level of one unit from 89.8 dBA to 79.1 ***,we proposed several noise reduction strategies and compared their noise reduction effects using computer *** results showed that the noise problem can be effectively improved through the rational design of the sound barrier and the layout and opening options of heat *** distance between the sound barrier and heat pump and the sound attenuation due to diffraction ALa exhibit a U-shaped *** buildings of different heights,the optimal heights of noise barrier are *** 5.5-meter is the optimal height of the sound barrier for single-story *** conclusions can be applied to other building projects for heat pump noise reduction.

关键词： acoustic simulation broadband noise noise reduction air-source heat pump sound barrier

Game theory based finite-time formation control using artificial potentials for tethered space net robot

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

Chinese Journal of Aeronautics 2024年第8期37卷 358-372页

作者： Yifeng MA Yizhai ZHANG Panfeng HUANG ya liu Fan ZHANG The Research Center for Intelligent Robotics School of AstronauticsNorthwestern Polytechnical UniversityXi’an 710072China School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The Tethered Space Net Robot(TSNR)is an innovative solution for active space debris capture and *** large envelope and simple capture method make it an attractive option for this ***,capturing maneuverable debris with the flexible and elastic underactuated net poses significant *** address this,a novel formation control method for the TSNR is proposed through the integration of differential game theory and robust adaptive control in this ***,the trajectory of the TSNR is obtained through the solution of a real-time feedback pursuit-evasion game with a dynamic target,where the primary condition is to ensure the stability of the ***,to minimize tracking errors and maintain a specific configuration,a robust adaptive formation control scheme with Artificial Potential Field(APF)based on a Finite-Time Convergent Extended State Observer(FTCESO)is *** proposed control method has a key advantage in suppressing complex oscillations by a new adaptive law,thus precisely maintaining the ***,numerical simulations are performed to demonstrate the effectiveness of the proposed scheme.

关键词： Game theory Formation control Artificial potential field Relative distance constraint Tethered space net robot(TSNR)

Intermediate phase-assisted growth of CsPbBr_(3) for high performance of carbon-based perovskite solar cells

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

Rare Metals 2024年第5期43卷 2222-2229页

作者： Bo-yan liu He-Ming yang Yu-Dong Zuo Zhi-Hao Tao jun-Chun Li ya-Jing Chang Guo-Qing Tong yang Jiang School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China State Key Laboratory of Pulsed Power Laser Technology National University of Defense TechnologyHefei 230037China

CsPbBr_(3)inorganic perovskites have been regarded as the promising materials in the field of photo-voltaics because of the high tolerance against *** high energy barrier of phase transition from lead bromide(PbBr_(2))to CsPbBr_(3)perovskite and low solubility of perovskite in organic solvent impede the further improvement of device performance in terms of CsPbBr_(3)solar ***,an intermediate phase-assisted growth of CsPbBr_(3)perovskite was proposed by introducing tetraphenylphosphonium bromide(TPPB)as *** TPPB is expected to react with PbBr_(2)in organic solvent to form an intermediate phase of[***]-PbBr_(2),which not only effectively improves the crystallinity of PbBr2 crystals,but also greatly reduces the phase transition energy barrier,leading to uniform and compact CsPbBr_(3)perovskite films with large grain size and high *** combination with carbon electrode,the CsPbBr_(3)solar cells yield a champion device performance of 9.57%in comparison of pristine CsPbBr_(3)solar cells showing a low efficiency of 8.17%.Furthermore,the intermediate phaseassisted growth of CsPbBr_(3)-based solar cells displays an outstanding storage over720 h.

关键词： CsPbBr_(3) Perovskite solar cells Carbon electrode Hole transport layer free Intermediate phase

An active learning workflow for predicting hydrogen atom adsorption energies on binary oxides based on local electronic transfer features

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第10期9卷 1489-1496页

作者： Wenhao Jing Zihao Jiao Mengmeng Song ya liu Liejin Guo International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Department of Energy and Power Engineering Shandong University of Technology

Machine learning combined with density functional theory（DFT） enables rapid exploration of catalyst descriptors space such as adsorption energy, facilitating rapid and effective catalyst screening. However, there is still a lack of models for predicting adsorption energies on oxides,due to the complexity of elemental species and the ambiguous coordination environment. This work proposes an active learning workflow（Le NN） founded on local electronic transfer features（e） and the principle of coordinate rotation invariance. By accurately characterizing the electron transfer to adsorption site atoms and their surrounding geometric structures, Le NN mitigates abrupt feature changes due to different element types and clarifies coordination environments. As a result, it enables the prediction of *H adsorption energy on binary oxide surfaces with a mean absolute error（MAE） below 0.18 e V. Moreover, we incorporate local coverage（θl） and leverage neutral network ensemble to establish an active learning workflow, attaining a prediction MAE below 0.2 e V for 5419 multi-*H adsorption structures. These findings validate the universality and capability of the proposed features in predicting *H adsorption energy on binary oxide surfaces.

关键词： Machine learning Adsorption energy Binary oxide Electron transfer Active learning