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Semiannual oscillation,annual oscillation,quasibiennial oscillation,and solar cycle variation of the OH airglow emission in the mesopause region

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Earth and Planetary Physics 2024年第3期8卷 479-496页

作者： sheng-Yang Gu dong wang YuSong Qin Liang Tang YaFei Wei XianKang Dou Electronic Information School Wuhan UniversityWuhan 430072China School of Optoelectronic Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

The vertically integrated emission rate,centroid altitude,peak emission rate,and peak height of the hydroxyl(OH)airglow were calculated from Thermosphere Ionosphere Mesosphere Energetics and Dynamics(TIMED)/Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)observations to study the seasonal and interannual variations in the intensity and location of the OH *** emission rate is inversely proportional to the height of the emission,with the semiannual oscillation dominating at low latitudes and the annual oscillation dominating at higher *** OH emission is modulated by the quasibiennial oscillation at the equator,and the quasibiennial oscillation signal is weak at other *** represented the vertical transport of atomic oxygen by using atomic oxygen concentrations obtained from a global atmospheric model,the Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension *** with the amplitudes of the migrating diurnal tide(DW1)calculated from temperature data observed by TIMED/SABER,we found that both the vertical transport of atomic oxygen and DW1 amplitudes in the equatorial region exhibit semiannual oscillation and quasibiennial oscillation,which have a strong correlation with the variations in the amplitude and phase of semiannual oscillation and quasibiennial oscillation in OH *** is likely that the DW1 affects the vertical transport of atomic oxygen that is involved in the reaction to produce O3,thus affecting the OH *** analyzed the relationship between OH emission and solar activity by using the solar radio flux at 10.7 cm as a proxy for solar *** results showed that the OH emission is well correlated with solar activity,and the modulation of OH emission by solar activity has a significant latitudinal *** small correlation between emission height and solar activity indicates that solar activity modulates OH emission mainly thr

关键词： OH airglow semiannual oscillation quasibiennial oscillation solar activity diurnal tide

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Dynamic response characteristics of muddy sandstone in pumped storage mine under action of high-stress dynamic disturbance

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Journal of Central South University 2024年第8期31卷 2736-2747页

作者： Liang, Bin wang, dong Luan, Heng-jie dong, Ling Liu, Jian-kang wang, Chang-sheng State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and Technology Qingdao China

During the construction and operation of the abandoned mine pumped storage power station, the underground space surrounding rock body faces the complex stress environment under the action of mining disturbance, frequent pumping, water storage and other dynamic disturbances. The stability of the abandoned mine surrounding rock body is the basis for guaranteeing the safety and effectiveness of water storage in the underground space of the abandoned mine. By considering the two main factors of different stress levels and disturbance amplitudes, the mechanical properties, damage characteristics and acoustic emission characteristics of the abandoned mine perimeter rock body under dynamic disturbance were investigated using a creep-disturbed dynamic impact loading system. The experimental results show that: 1) The stress level is considered to be the major contributing factor of the failure of muddy sandstone, followed by the amplitude of the disturbances; 2) The time required for the destruction of muddy sandstone decreases with the increase of amplitude. When the stress level is 80%, the sandstone specimens have a decreasing number of cycles as the disturbance amplitude increases. The disturbance amplitude is sequentially increased from 4 MPa to 5, 6, 7, and 8 MPa, the number of cycles required for specimen destruction decreases significantly by 96.71%, 99.13%, 99.60%, and 99.93%, respectively; 3) Disturbance amplitude and stress level have a significant effect on muddy sandstone damage and damage occurs only after a certain threshold is reached. With the increase of stress level and disturbance amplitude, the macroscopic damage of muddy sandstone is mainly conical, with obvious flake spalling and poor damage integrity; 4) According to the time-dependent changes in AE energy and ringing counts, the acoustic emission activity during the failure process could be divided into three phases, namely, weakening period, smooth period, and surge period, corresponding to the comp

关键词： abandoned mine pumped storage dynamic disturbance muddy sandstone acoustic emission

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Global Dynamic Responses and Progressive Failure of Submerged Floating Tunnel Under Cable Breakage Conditions

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China Ocean Engineering 2024年第4期38卷 676-688页

作者： ZHOU Xiang-bo QIAO dong-sheng wang Ming TANG Guo-qiang LU Lin OU Jinping State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

The Submerged Floating Tunnel(SFT)relies on a tensioned mooring system for precise *** sudden breakage of a single cable can trigger an immediate alteration in the constraint conditions of the tube,inducing a transient heave response within the structure along with a transient increase in cable tension experienced by adjacent *** more severe cases,this may even lead to a progressive failure culminating in the global destruction of the *** study used ANSYS/AQWA to establish a numerical model of the entire length SFT for the hydrodynamic response analysis,and conducted a coupled calculation of the dynamic responses of the SFT-mooring line model based on Orca Flex to study the global dynamic responses of the SFT at the moment of cable breakage and the redistribution of cable internal *** most unfavorable position for SFT cable breakage was identified,the influence mechanism of cable breakage at different positions on the global dynamic response was revealed,and the progressive chain failure pattern caused by localized cable breakage are also clarified.

关键词： submerged floating tunnel cable breakage global dynamic responses progressive failure

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瞬变电磁法在非煤地下矿山隐蔽致灾因素普查中的应用

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世界有色金属 2024年第13期 232-234页

作者：廖鑫黄惠勇杨百顺黄泽王东升四川省安全科学技术研究院四川成都610045 四川安信科创科技有限公司四川成都610045 重大危险源测控四川省重点实验室四川成都610045 四川省安科技术咨询有限公司四川成都610045

我国非煤地下矿山数量大、类型多、工艺复杂,部分矿山开采历史久远,基础资料缺乏,存在矿山隐蔽致灾因素辨识不清、各矿山隐蔽致灾因素普查成果水平参差不齐等问题。研究表明瞬变电磁法具有施工便捷、低阻敏感、探测距离较深等技术特点,... 详细信息

我国非煤地下矿山数量大、类型多、工艺复杂,部分矿山开采历史久远,基础资料缺乏,存在矿山隐蔽致灾因素辨识不清、各矿山隐蔽致灾因素普查成果水平参差不齐等问题。研究表明瞬变电磁法具有施工便捷、低阻敏感、探测距离较深等技术特点,可以查明地下矿山历史采空区位置、范围、边界和含水性等信息,科学高效支撑非煤地下矿山蔽致灾因素普查工作。

关键词：瞬变电磁法非煤地下矿山隐蔽致灾因素

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Atomic-Scale Insights into Damage Mechanisms of GGr15 Bearing Steel Under Cyclic Shear Fatigue

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1265-1278页

作者： Qiao-sheng Xia dong-Peng Hua Qing Zhou Ye-Ran Shi Xiang-Tao Deng Kai-Ju Lu Hai-Feng wang Xiu-Bing Liang Zhao-dong wang State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an710072China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China Defense Innovation Institute Academy of Military ScienceBeijing100071China

Alternating shear stress is a critical factor in the accumulation of damage during rolling contact fatigue,severely limiting the service life of ***,the specific mechanisms responsible for the cyclic shear fatigue damage in bearing steel have not been fully *** the mechanical response and microstructural evolution of a model GGr15 bearing steel under cyclic shear loading are investigated through the implementation of molecular dynamics *** samples undergo 30 cycles under three different loading conditions with strains of 6.2%,9.2%,and 12.2%,*** findings indicate that severe cyclic shear deformation results in early cyclic softening and significant accumulation of plastic damage in the bearing ***,samples subjected to higher strain-controlled loading exhibit higher plastic strain energy and shorter fatigue ***,strain localization is identified as the predominant damage mechanism in cyclic shear fatigue of the bearing steel,which accumulates and ultimately results in fatigue ***,simulation results also revealed the microstructural reasons for the strain localization(e.g.,BCC phase transformation into FCC and HCP phase),which well explained the formation of white etching *** study provides fresh atomic-scale insights into the mechanisms of cyclic shear fatigue damage in bearing steels.

关键词： Cyclic shear fatigue Molecular dynamic simulation Bearing steels Plastic damage accumulation

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Study on Lewis acid promoted condensation of allylalkoxysilanes with (-)-menthyl glyoxylate

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Chinese Journal of Chemistry 1994年第5期12卷 440-448页

作者： CHEN, Yong-Jun HUANG, Liang wang, dong LI, Ji-sheng Institute of Chemistry, Chinese Academy of Science, Beijing 100080, China Institute of Chemistry Chinese Academy of Science Beijing 100080 China

Allylalkoxydimethylsilanes (2) condense with (-)-menthyl glyoxylate (3) in the presence of Lewis acid to give optically active menthyl 2-hydroxy-4-pentenoate (7) with optical purity of 31-42%. Factors affecting the yi... 详细信息

关键词： Chiral glyoxylate allylalkoxysilane Lewis acid chelation asymmetric reaction.

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Genotypic Differences in Grain Yield and Physiological Nitrogen Use Efficiency Among Rice Cultivars

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Pedosphere 2009年第6期19卷 681-691页

作者： ZHANG Ya-Li, FAN Jian-Bo, wang dong-sheng and SHEN Qi-Rong2College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China) College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing 210095 (China)

Efficient use of N in agricultural practice can increase yield, decrease production costs and reduce the risk of environmental pollution. Effects of N fertilizer application rates on grain yield and physiological N use efficiency (PE) in relation to the accumulation and redistribution of biomass and N in rice (Oryza sativa L.) cultivars were studied at two experimental farms of Nanjing Agricultural University, Nanjing, China in 2004. Three high N use efficiency (NUE) rice cultivars (Wuyunjing 7, Nanguang and 4007) and one low NUE rice cultivar (Elio) with similar growth patterns were studied under seven N rates (0, 60, 120, 180, 240, 300 and 360 kg ha -1 ). Grain yield increased with the N application rate and attained plateau at 180 kg N ha -1 for rice cultivars at each site. Increasing N rate decreased PE for biomass and grain yield. Grain yield and PE of Elio were about 20% and 18% lower than those of high NUE cultivars. Differences in biomass, N accumulation and N redistribution were observed at the post-heading stage among rice cultivars with differing NUEs. The less reproductive tillers of Elio resulted in less demand for C and N during grain filling, thus leading to lower PE of Elio compared with the high NUE rice cultivars.

关键词： accumulation biomass N application rate redistribution

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Copper slag assisted coke reduction of phosphogypsum for sulphur dioxide preparation

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Chinese Journal of Chemical Engineering 2024年第1期65卷 43-53页

作者： dong Ma Qinhui wang State Key Laboratory of Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou 310027China

The reduction of phosphogypsum(PG)to lime slag and SO_(2)using coke can effectively alleviate the environmental problems caused by ***,the PG decomposition temperature remains high and the product yield remains *** adding additives,the decomposition temperature can be further reduced and PG decomposition rate and product yield can be ***,the use of current additives such as Fe_(2)O_(3)and SiO_(2)brings the problem of increasing economic ***,it is proposed to use solid waste copper slag(CS)as a new additive to reduce PG to prepare SO2,which can reduce the cost and meet the environmental benefits at the same *** effects of proportion,temperature and thermostatic time on PG decomposition are investigated by experimental and kinetic analysis combined with FactSage thermodynamic calculations to optimize the roasting ***,the reaction mechanism is *** is found that adding CS to the coke and PG system can increase the rate of PG decomposition and SO_(2)yield while lowering the PG decomposition *** example,when the CS/PG mass ratio increases from 0 to 1,PG decomposition rate increases from 83.38%to 99.35%,SO_(2)yield increases from 78.62%to 96.81%,and PG decomposition temperature decreases from 992.4℃to 949.6℃.The optimal reaction parameters are CS/PG mass ratio of 1,Coke/PG mass ratio of 0.06 at 1100℃for 20 min with 99.35%PG decomposition rate and 96.81%SO_(2) *** process proceeds according to the following reactions:2CaSO_(4)+ 0.7C + 0.8Fe_(2)SiO_(4)→0.8Ca_(2)SiO_(4)+ 0.2Ca_(2)Fe_(2)O_(5)+ 0.4Fe_(3)O_(4)+2SO_(2)+ 0.7CO_(2)Finally,a process for decomposing PG with coke and CS is proposed.

关键词： Phosphogypsum Sulfur dioxide Copper slag Fluidized-bed Reduction Waste treatment

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An Efficient Optimization Design Framework for Low-Resistance Shape of Bionic Amphibious Robot

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China Ocean Engineering 2024年第1期38卷 117-128页

作者： ZHANG Dai-yu ZHANG Man-yu wang Zhi-dong ZHENG Wen-sheng LING Hong-jie HU Jun-ming School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

To realize the low-resistance shape optimization design of amphibious robots,an efficient optimization design framework is proposed to improve the geometric deformation flexibility and optimization *** the proposed framework,the free-form deformation parametric model of the flat slender body is established and an analytical calculation method for the height constraints is *** method is introduced to carry out the high-precision resistance calculation and a constrained Kriging-based optimization method is built to improve the optimization efficiency by circularly infilling the new sample points which satisfying the ***,the shape of an amphibious robot example is optimized to get the low-resistance shape and the results demonstrate that the presented optimization design framework has the advantages of simplicity,flexibility and high efficiency.

关键词： amphibious robot optimization method free-form deformation CFD-based hydrodynamic calculation

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Landsat Image-Based Spatiotemporal Variation Analysis of Erosion and Deposition off the Qingshuigou of the Yellow River Delta from 1984 to 2021

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Journal of Ocean University of China 2024年第5期23卷 1173-1184页

作者： dong sheng LI Songda TAO Shanshan College of Engineering Ocean University of China

Owing to climate change and human activity, the Qingshuigou of the Yellow River Delta(YRD) has undergone dynamic changes in erosion and deposition. Therefore, studying these changes is important to ensure ecological protection and sustainable development. In this study, the trend of erosion-deposition evolution in the Qingshuigou was investigated based on 38 coastline phases extracted from Landsat series images of the YRD at one-year intervals from 1984 to 2021. The periodicity of the scouring and deposition evolution was also analyzed using wavelet analysis. Results showed that the total area of the Qingshuigou was affected by deposition and erosion and that the fluctuation first increased and then decreased. The total area reached a maximum in 1993. The depositional area first increased and then decreased, whereas the overall erosion area decreased. Deposition and erosion areas showed periodic changes to some extent; however, the periodic signal intensity decreased. Furthermore, factors including channel morphological evolution and variations in water and sediment discharge affect the spatiotemporal dynamics of erosion and deposition processes. The application of nonconsistency tests finally revealed that deposition area and flushing magnitude exhibited non-stationarities, which are potentially attributed to impacts from climatic change drivers.

关键词： coastline erosion and deposition remote sensing wavelet analysis Yellow River Delta

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