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39篇 您的检索式:作者名="DINGHui"
    题名 作者 年代 出处 被引量
1Effects of the Biot and the squirt-flow coupling interaction on anisotropic elastic waves显示文摘Considering the velocity anisotropy of the solid/fluid relative motion and employment of the BISQ theory based on the one-dimensional porous isotropic case, we establish a two-phase anisotropic elastic wave equation to simultaneously include the Biot and the squirt mechanisms in terms of both the basic principles of the fluid’s mass conservation and the elastic-wave dynamical equations in the two-phase anisotropic rock. Numerical results, while the Biot-flow and the squirt-flow effects are simultaneously considered in the transversely isotropic (Tl) poroelastic medium, show that the attenuation of the quasi P-wave and the quasi SV-wave strongly depend on the permeability anisotropy, and the attenuation behavior at low and high frequencies is contrary. Meanwhile, the attenuation and dispersion of the quasi P-wave are also affected seriously by the anisotropic solid/fluid coupling additional density.YANG Dinghui & ZHANG Zhongjie Department of Mathematical Sciences, Tsinghua University, Beijing 100084, China Institute of Geophysics, Chinese Academy of Sciences, Beijing 100101, China 2000Chinese Science Bulletin2000,45,23:33
2Full waveform inversion based on the ensemble Kalman filter method using uniform sampling without replacement显示文摘Full waveform inversion(FWI) has been increasingly more and more important in seismology to better understand the interior structure of the Earth. FWI, by taking advantage of both the traveltime and amplitude in the data, provides high-resolution model parameters of the earth which can produce images with high resolution. However, this inversion method conventionally suffers from non-uniqueness due to many local minima of the objective function and large computing costs. In this study, we propose a new FWI method in a semi-random framework by integrating the ensemble Kalman filter and uniform sampling without replacement. Numerical results demonstrate that the new method can achieve highresolution results and a wider convergence domain. Accordingly, the new method overcomes the disadvantage of conventional FWIs that depend strongly on the initial model.Jian Wang Dinghui Yang Hao Jing Hao Wu 2019Science Bulletin2019,64,5:13
3Wave dispersion and attenuation in viscoelastic isotropic media containing multiphase flow and its application显示文摘In this paper,we introduce the complex modulus to express the viscoelasticity of a medium.According to the correspondence principle,the Biot-Squirt(BISQ)equations in the steady-state case are presented for the space-frequency domain described by solid displacements and fluid pressure in a homogeneous viscoelastic medium.The effective bulk modulus of a multiphase flow is computed by the Voigt formula,and the characteristic squirt-flow length is revised for the gas-included case.We then build a viscoelastic BISQ model containing a multiphase flow.Through using this model,wave dispersion and attenuation are studied in a medium with low porosity and low permeability.Furthermore,this model is applied to observed interwell seismic data.Analysis of these data reveals that the viscoelastic parameter tanδ is not a constant.Thus,we present a linear frequency-dependent function in the interwell seismic frequency range to express tanδ.This improves the fit between the observed data and theoretical results.YANG Lei YANG DingHui NIE JianXin 2014Science China(Physics,Mechanics & Astronomy)2014,57,6:13
4Photosynthetic bicarbonate utilization in Porphyra haitanensis(Bangiales,Rhodophyta)显示文摘The activities of carbonic anhydrase (CA) and photosynthesis of Porphyra haitanensis were investigated in order to see its photosynthetic utilization of inorganic carbon source. Both intra- and extra-cellular CA activities existed in the thallus. CA inhibitors, acetazolamide (AZ) and ethoxy-zolamide (EZ), remarkably depressed the photosynthetic oxygen evolution in seawater of pH 8.2 and 10.0, and EZ showed stronger inhibition than AZ. The observed net photosynthetic rate in seawater of pH 8.2 was much higher than that of CO2 supply theoretically derived from spontaneous dehydration of HCO3. P. haitanensis also showed a rather high pH compensation point (9.9). The results demonstrated that P. haitanensis could utilize bicarbonate as the external inorganic carbon source for photosynthesis. The bicarbonateutilization was closely associated with HCO3- dehydrationcatalyzed by extracellular CA activity. The inorganic carbon composition in seawater could well saturate the photosynthesis of P. haitanensis. TheZOU Dinghui GAO Kunshan 2002Chinese Science Bulletin2002,47,19:11
5A unified poroviscoelastic model with mesoscopic and microscopic heterogeneities显示文摘The wave-induced fluid flow(WIFF) is considered to be the main cause of dispersion and attenuation of seismic waves in fluid-saturated porous media. Among numerous theories, the mesoscopic and microscopic heterogeneities are considered to be the primary mechanisms causing the WIFF. Furthermore,in most rocks, the mesoscopic and microscopic heterogeneities exist simultaneously and can cause obvious transitions of the fast P-wave velocity, which means it is necessary to consider the influence of the two mechanisms on the dispersion and attenuation simultaneously. Numerous results have shown that the dispersions and attenuations caused by these two mechanisms can be approximated in terms of the Zener model. To combine the two mechanisms into a unified model, we introduce a new generalized Zener model into the Biot poroelasticity theory to obtain a new poroviscoelastic model. Comparisons between the numerical results and two groups of experimental data further confirm the validity of our new model.Boya Zhang Dinghui Yang Yuanfeng Cheng Yunyin Zhang 2019Science Bulletin2019,64,17:9
6Carbon sequestration processes and mechanisms in coastal mariculture environments in China显示文摘China is the global leader in mariculture production. Increasing sequestered marine carbon(also known as blue carbon) via mariculture activities is a promising approach for mitigating climate change and promoting the development of a low-carbon economy. Mariculture blue carbon is also considered an important component of China's 'sea granary'. In addition to shellfish and macroalgae yields, which represent carbon removed from mariculture environment, blue carbon also includes other important components, which have been largely neglected in the past, such as the carbon transformed by microbes,dissolved organic carbon(mainly referred to as recalcitrant dissolved organic carbon), and sedimentary particulate carbon. Hence,from different aspects, a comprehensive study on the formation processes and mechanisms of carbon sequestration is of great significance for comprehensively unveiling the carbon sequestration capability in coastal mariculture environment, which will contribute to the sustainable development of the fishery economy and construction of an ecological civilization. Moreover, it may add significant economic benefits to the future carbon-trading market.ZHANG YongYu ZHANG JiHong LIANG YanTao LI HongMei LI Gang CHEN Xiao ZHAO Peng JIANG ZengJie ZOU DingHui LIU XiaoYong LIU JiHua 2017Science China Earth Sciences2017,60,12:7
7Altered seawater salinity levels affected growth and photosynthesis of Ulva fasciata(Ulvales, Chlorophyta)germlings显示文摘Seawater salinity is greatly influenced by tide, evaporation and rain falls. In this study, we investigated the growth and photosynthetic responses of zygote-derived Ulva fasciata Delile germlings to short-term(minutes) and prolonged(days) exposure to different salinity gradients, to evaluate the effect of salinity variation on the early stage of life history in this seaweed. The results showed that, the maximum net photosynthetic rates(NPRm) of U.fasciata germlings was observably decreased in desalted(25 and 15) and high(45) salinity seawater in short-term exposure tests(in minutes). However, after 30 min, the photosynthesis activity in medium salinity(25) was maintained at a relative high level(above 70%). After 8 d prolonged culture, the photosynthesis and mean relative growth rate(RGR) of germlings were all markedly lowered, whereas the malondialdehyde(MDA) contents increased as the salinity desalted from 34 to 15. The salinity decrease from 34 to 25 had no significant effect on the RGR, but obviously influenced the morphology of the germlings. High salinity level(45) significantly depressed the RGR and photosynthesis of U. fasciata germlings, while it notably increased the MDA contents. The results showed that the salinity elevation had more detrimental effects on Ulva fasciata germlings than salinity decrease did. The germlings grown at the salinity seawater levels from 25 to 34, performed preferable photosynthetic acclimation both in temporary and prolonged culture. Broad salinity tolerance from 25 to 34 in U. fasciata germlings may have partly evolved as a response to regular diurnal tides.CHEN Binbin ZOU Dinghui 2015Acta Oceanologica Sinica2015,34,8:7
8Analysis of High-temperature Boiler Tube Failure for T91 &T22显示文摘The tube failures took place frequently in the superheater of 2x600MW units in a power plant. According to the condition of tube failures, the mechanical property and microstructure on running and failed tubes were tested and evaluated. The chemical composition and structure phase of inner oxide scale and deposit inside of the tubes were examined.The fractured surfaces of failed tube samples were observed. And the material examination was performed for original tube steels SA213-T91 and SA213-T22. The results show that raw materials of SA213-T91 and SA213-T22 tube in superheater are qualified. Besides, the characteristics of the SA213-T91 and SA213-T22 tube failure are typical short-term overheated rupture. The rupture temperature is located between two phase Ac1 ~ Ac3 of the two steels. It is recognized that putting SA213-T22 tubes in operation under the condition of long-term over heating causes the rupture of SA213-T91 and SA213-T22.SHUGuo-gang DINGHui ZHAOYan-fen XUEFei ZHAOLing-song ZHANGLu LIUJiang-nan WANGZheng-pin 2004材料热处理学报2004,25,5:5
9Dark respiration in the light and in darkness of three marine macroalgal species grown under ambient and elevated CO_2 concentrations显示文摘Dark respiration (non-photorespiratory mitochondrial respiration),which occurs both in the light and in darkness,is vital for growth and survival of algae and plays a critical role in modulating the carbon balance of them.In the present study,we have investigated dark respiration in the light (R L) and in darkness (R D) in three marine macroalgal species,Hizikia fusiformis (phaeophyta),Gracilaria lemaneiformis (Rhodophyta) and Ulva lactuca (Chlorophyta),cultured at 20℃ using aeration with two CO 2 conditions:current ambient (CO 2 concentration about 380 μl/L) and elevated CO 2 (approximately 720 μl/L) air.R L was estimated by using the Kok method,whereas R D was determined as the rate of O 2 influx at zero light.The results showed that both R L and R D were unchanged for the elevated CO 2-grown algae relative to ambient CO 2 concentration for all the algal species tested.However,R L was significantly lower than R D across all the algal species and growth CO 2 treatments,demonstrating that daytime respiration was partly depressed by the light.The percentage of inhibition of respiration by light was similar between ambient and elevated CO 2 grown algae.The ratio of respiration to photosynthesis,which tended to decrease when estimated using R L instead of R D,was not altered for the elevated relative to ambient CO 2 concentration.The results suggest that R L,rather than R D,is a more accurate estimate of nonphotorespiratory carbon loss in marine macroalgae during the daytime.It would not be anticipated that elevated atmospheric CO 2 would exert a substantial influence on respiratory flux either in the light or in darkness in these particular marine macroalgal species.ZOU Dinghui GAO Kunshan XIA Jianrong 2011Acta Oceanologica Sinica2011,30,1:5
10A modified nearly analytic discrete method and wavefield simulations in transversely isotropic media显示文摘Nearly analytic discrete method (NADM) is a higher accurate method for elastic wave equation that can suppress effectively numerical dispersion caused by discretizing the wave equation. In this paper we investigate the efficient implementation of NADM and present a refinement of the original NADM. Our theoretical analyses show that the modified NADM can improve significantly over the original one in numerous perspectives including numerical errors, storage spaces, and computational costs. Three-component synthetic VSP seismograms in 3-layered transversely isotropic (TI) media generated by the modified NADM are also reported. Theoretical analyses and numerical results show that the modified NADM can reduce storage space about 53 percent and computational costs about 30 percent compared with the original NADM. Moreover the accuracy of the modified NADM in time increases from 2-order of the original NADM to 4-order. Numerical results suggest that the modified NADM is more suitable to large-scale modeling because the modified method has little numerical dispersions even when too-coarse grids are used.LU Ming YANG Dinghui 2005Science China Earth Sciences2005,48,8:4
11A Weighted Runge-Kutta Method with Weak Numerical Dispersion for Solving Wave Equations显示文摘In this paper, we propose a weighted Runge-Kutta (WRK) method to solvethe 2D acoustic and elastic wave equations. This method successfully suppresses thenumerical dispersion resulted from discretizing the wave equations. In this method,the partial differential wave equation is first transformed into a system of ordinarydifferential equations (ODEs), then a third-order Runge-Kutta method is proposedto solve the ODEs. Like the conventional third-order RK scheme, this new methodincludes three stages. By introducing a weight to estimate the displacement and itsgradients in every stage, we obtain a weighted RK (WRK) method. In this paper, weinvestigate the theoretical properties of the WRK method, including the stability criteria, numerical error, and the numerical dispersion in solving the 1D and 2D scalarwave equations. We also compare it against other methods such as the high-ordercompact or so-called Lax-Wendroff correction (LWC) and the staggered-grid schemes.To validate the efficiency and accuracy of the method, we simulate wave fields in the2D homogeneous transversely isotropic and heterogeneous isotropic media. We conclude that the WRK method can effectively suppress numerical dispersions and sourcenoises caused in using coarse grids and can further improve the original RK methodin terms of the numerical dispersion and stability condition.Shan Chen Dinghui Yang Xiaoying Deng 2010Communications in Computational Physics2010,7,5:3
12Quasi-waveform seismic tomography of crustal structures in the capital circle region of China显示文摘Seismic tomography is one of the main tools to explore the interior of the earth.In this study,the quasi-waveform seismic tomographic method is used for the first time to reveal the crustal structures in the capital region of China.3-D highresolution V_P,V_S and the Poisson’s ratio models are generated by inverting 29839 direct P-and 29972 direct S-wave traveltimes selected from 3231 local earthquakes.The results reveal strong crustal heterogeneities.The velocity anomalies at shallow depths are well consistent with surface geologic structures.The relatively low-velocity anomaly layer in the middle crust may be the result of multiple phases of tectonic activity.Earthquakes generally occurred on the boundaries of high-and low-velocity and Poisson’s ratio anomalies.There are obvious low-velocity anomalies below the hypocenters of the Tangshan earthquake and the historical Sanhe-Pinggu earthquake,implying the existence of fluids.The similar velocity structures around the hypocenters of the two earthquakes indicate that the occurrences of the two earthquakes may be related to the same mechanism.The highresolution velocity models provide important observational constraints on the small-scale heterogeneities and dynamic mechanism of the crust in the capital region of China.Xueyuan HUANG Dinghui YANG Ping TONG Yuan GAO Yutao SHI Hao WU 2021Science China Earth Sciences2021,64,1:2
13A wave propagation model with the Biot and the fractional viscoelastic mechanisms显示文摘Energy loss in porous media containing fluids is typically caused by a variety of dynamic mechanisms.In the Biot theory,energy loss only includes the frictional dissipation between the solid phase and the fluid phase,resulting in underestimation of the dispersion and attenuation of the waves in the low frequency range.To develop a dynamic model that can predict the high dispersion and strong attenuation of waves at the seismic band,we introduce viscoelasticity into the Biot model and use fractional derivatives to describe the viscoelastic mechanism,and finally propose a new wave propagation model.Unlike the Biot model,the proposed model includes the intrinsic dissipation of the solid frame.We investigate the effects of the fractional order parameters on the dispersion and attenuation of the P-and S-waves using several numerical experiments.Furthermore,we use several groups of experimental data from different fluid-saturated rocks to testify the validity of the new model.The results demonstrate that the new model provides more accurate predictions of high dispersion and strong attenuation of different waves in the low frequency range.Jiaming YANG Dinghui YANG Hongwei HAN Lingyun QIU Yuanfeng CHENG 2021Science China Earth Sciences2021,64,3:2
14Geometry-preserving full-waveform tomography and its application in the Longmen Shan area显示文摘Classic L2-norm-based waveform tomography is often plagued by insurmountable cycle skipping problems;as a result,the iterative inversion falls into local minima,yielding erroneous images.According to the optimal transportation theory,we adopt a novel geometry-preserving misfit function based on the quadratic Wasserstein metric(W2-norm),which improves the stability and convexity of the inverse problem.Numerical experiments illustrate that W2-norm-based full-waveform tomography has a larger convergence radius and a faster convergence rate than the L2-norm and can effectively mitigate cycle skipping issues.We apply this method to the Longmen Shan area and obtain a reliable lithospheric velocity model.Our tomographic results indicate that the crystalline crust underlying the Sichuan Basin wedges into the crustal interior of the Tibetan Plateau,and the mid-lower crust of the eastern Tibetan Plateau is characterized by low shear-wave velocities,indicating that ductile crustal flow and strong interactions between terranes jointly dominate the uplift behavior of the Longmen Shan.Furthermore,we find that large earthquakes(e.g.,the Wenchuan and Lushan events)occur not only at the junction between high-and low-velocity regions but also in the transition zone from positive to negative radial anisotropy.These findings improve our understanding of the mechanism responsible for large earthquakes in this region.Xingpeng DONG Dinghui YANG Hejun ZHU Yun CHEN 2022Science China Earth Sciences2022,65,3:2
15Metal bioaccumulation in plant leaves from an industrious area and the Botanical Garden in Beijing显示文摘The concentrations of Fe, Mn, Al, Zn, Pb, Ni, Cr, and As were measured in soils and leaves from 21 plant species growing on hills near the Beijing Steel Factory(BSF) and 17 plant species in the Beijing Botanical Garden(BBG). The results showed that soils from BSF were Zn contaminated according to the threshold of natural background of China. There was a metal contamination of the soils by Ni, and Cr in BSF comparing with those in BBG. The comparison between concentrations of metals in leaves from both sites indicated that, in general, accumulation of metals in the leaves of the same species was significantly different between the two sites. Even within the same locality each species accumulation of metals was significantly variable. The study aimed to screen landscape plants for the capacity to clean-up toxic metals in soils, and developed an overall metal accumulation index(MAI) for leaves and then categorized the MAI that can be applied broadly in the selection of species in polluted areas. To do this, the spectrum of MAI values were divided into four classes: strongly accumulated(SA or grade I), moderately accumulated(MA or grade II), intermediately accumulated(IA or grade III), and weakly accumulated(WA or grade IV). The results showed that elemental association between Fe, Al, Ni, and As was generally highly correlated with each other in the sampling sites. This may suggest their common biochemical characteristics. Generally, those species containing strong and moderate accumulation in both sites are considered including Vitex negundo, Broussonetia papyrifera, Ulmus pumila, and Rubia cordifolia. At BSF and other industrial sites with a similar ecosystem, strong and moderate accumulation species include Sophora japonica, Ampelopsis aconitifolia var. glabra, Platycladus orientalis, Wikstroemia chamaedaphne, Cleistogenes squarrosa, Grewia biloba, and in BBG, in addition Setaria viridis, Cotinus coggygria, Lespedeza floribunda, Rhamnus parvifolia, Lespedeza tomentosa.LIUYan-ju DINGHui ZHUYong-guan 2005Journal of Environmental Sciences2005,17,2:2
16A new method for calculation of elastic properties of anisotropic material by constant pressure molecular dynamics显示文摘Kailiang Yin Dinghui Zou Jing Zhong Duanjun Xu 2006Computational Materials Science2006,,3:1
17Chaotic encryption and decryption of QR code two value image显示文摘ZHANG Dinghui GUO Jingbo JIANG Ping 2011Mobile Communications2011,35,3:1
18The effect of activated carbon adsorption on the photocatalytic removal of formaldehyde显示文摘Yuanwei Lu Dinghui Wang Chongfang Ma Hongchang Yang 2009Building and Environment2009,,3:1
19The Burner Ar- rangement and the NOx Prom Boiler Flue Gas Emission Research 显示文摘WANG Chunchang WANG Dinghui 2006Thermal Power Generation2006,,11:1
20Researches and application of a hybrid fault diagnosis expert system显示文摘Zhang Dinghui Dai Shuguang Zheng Youqin 2000Intelligent Control and Automation2000,,:1
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