Phytoplankton patchiness ubiquitously obser- ved in marine ecosystems is a simple phy- sical phenomenon. Only two factors are required for its formation: one is persistent variations of inhomogeneous distributions in ...Phytoplankton patchiness ubiquitously obser- ved in marine ecosystems is a simple phy- sical phenomenon. Only two factors are required for its formation: one is persistent variations of inhomogeneous distributions in the phytopl- ankton population and the other is turbulent stirring by eddies. It is not necessary to assume continuous oscillations such as limit cycles for realization of the first factor. Instead, a certain amount of noise is enough. Random fluctua-tions by environmental noise and turbulent ad-vection by eddies seem to be common in open oceans. Based on these hypotheses, we pro-pose seemingly the simplest method to simulate patchiness formation that can create realistic images. Sufficient noise and turbulence can induce patchiness formation even though the system lies on the stable equilibrium conditions. We tentatively adopt the two-component model with nutrients and phytoplankton, however, the choice of the mathematical model is not essen-tial. The simulation method proposed in this study can be applied to whatever model with stable equilibrium states including one-com-ponent ones.展开更多
Interconnected ramets of clonal plants can functionally specialize in the uptake of resources from aboveground and/or underground sources. Ramet pairs of the clonal stoloniferous herb Glechoma Iongltuba L. were grown ...Interconnected ramets of clonal plants can functionally specialize in the uptake of resources from aboveground and/or underground sources. Ramet pairs of the clonal stoloniferous herb Glechoma Iongltuba L. were grown In spatially heterogeneous environments with complementary availability of light and nutrients. Plasticity with respect to root-shoot ratio, fitness-related traits (biomass, number of ramets and dry weight per ramet), morphological traits (lamina area, root length) were experimentally examined. The aim was to understand the adaptation of G. Iongltuba to an environment with reciprocal patchiness of light and soil nutrients by plasticity In Its root-shoot ratio and clonal morphology. The results showed that the performance of ramets growing In patches with high light Intensity and low soil nutrients into the adjacent opposite patches was Increased in terms of fitness-related traits. However, the performance of those from patches with low light Intensity and high soil nutrients into the adjacent opposite patches was not changed. The root-shoot ratio and clonal morphology were plastic. Morphological traits such as lamina area and root length were altered In a way that enhanced the capture of light resources and soil nutrients. Apparent reciprocal resource transport between the ramets In an environment of reciprocal patchiness of resources can enhance the growth of ramets with complementary resource deficiencies.展开更多
Aims Most plants are clonal in nature.Clonal ramets can share water,nutrients and photosynthate,especially when they experience patchy resources.Patch contrast(i.e.a difference in resources among patches)and patch dir...Aims Most plants are clonal in nature.Clonal ramets can share water,nutrients and photosynthate,especially when they experience patchy resources.Patch contrast(i.e.a difference in resources among patches)and patch direction(i.e.source–sink relations)are among the basic attributes of spatial patchiness.Here,I hypothesize that young established ramets in nutrient-rich patches support old ramets in nutrient-poor patches when ramets are subjected to different patch contrasts and patch directions.Methods In a greenhouse experiment,old and young ramets of Glechoma longituba were grown in four combinations consisting of patch contrast and patch direction.Minus patch direction refers to a patch combination in which parent ramets grow in nutrient-rich patches while connected daughter ramets grow in nutrient-poor ones and plus patch direction is the opposite direction.Imeasured photosynthesis and fluorescence traits,harvested all ramets,took morphological measures,weighed their dry mass and determined their nutrient uptake and use.Important Findings For parental ramets of G.longituba,patch contrast and patch direction and their interactions had no significant effects on net photosynthetic rate,maximal fluorescence yield,photochemical quenching(quenching refers to any process which decreases the fluorescence intensity of a given substance),non-photochemical quenching,nutrient uptake,biomass and stolon weight ratio.Patch direction alone significantly affected root weight ratio.Large patch contrast enhanced N use efficiency(NUE)and P use efficiency(PUE);plus patch direction decreased NUE,but increased PUE;the patch contrast by patch direction interaction affected PUE and K use efficiency(KUE).There were significant interactions between patch direction and patch contrast on PUE and KUE.It is concluded that soil nutrient patchiness may influence nutrient use strategies,but not nutrient uptake,photosynthesis and growth of parent ramets of G.longituba connected to daughter ramets,and that patch contrast and patch direction jointly affect PUE and KUE.展开更多
The ion-to-electron temperature ratio is a good indicator of the processes involved in the plasma sheet.Observations have suggested that patchy reconnection and the resulting earthward bursty bulk flows(BBFs)transport...The ion-to-electron temperature ratio is a good indicator of the processes involved in the plasma sheet.Observations have suggested that patchy reconnection and the resulting earthward bursty bulk flows(BBFs)transport may be involved in causing the lower temperature ratios at smaller radial distances during southward IMF periods.In this paper,we estimate theoretically how a patchy magnetic reconnection electric field can accelerate ions and electrons differently.If both ions and electrons are non-adiabatically accelerated only once within each reconnection,the temperature ratio would be preserved.However,when reconnection occurs closer to the Earth where magnetic field lines are shorter,particles mirrored back from the ionosphere can cross the reconnection region more than once within one reconnection;and electrons,moving faster than ions,can have more crossings than do ions,leading to electrons being accelerated more than ions.Thus as particles are transported from tail to the near-Earth by BBFs through multiple reconnection,electrons should be accelerated by the reconnection electric field more times than are ions,which can explain the lower temperature ratios observed closer to the Earth.展开更多
The ion-to-electron temperature ratio is a good indicator of the processes involved in solar wind plasma entering and being transported inside Earth’s plasma sheet.In this study,we have demonstrated that patchy magne...The ion-to-electron temperature ratio is a good indicator of the processes involved in solar wind plasma entering and being transported inside Earth’s plasma sheet.In this study,we have demonstrated that patchy magnetic reconnection has the potential to preserve the ion-to-electron temperature ratio under certain conditions.If the charged particles are non-adiabatically accelerated no more than once in a single reconnection,the temperature ratio would be preserved;on the other hand,this ratio would not be preserved if they are accelerated multiple times.Consequently,under a northward interplanetary magnetic field(IMF)condition,the reconnection in the nonlinear phase of the Kelvin-Helmholtz instability is the dominant process for solar-originated plasma entering the Earth’s magnetosphere,and the ion-to-electron temperature ratio is preserved inside the plasma sheet.When the direction of the IMF is southward,the reflection of electrons from the magnetic mirror point,and subsequent multiple non-adiabatic accelerations at the reconnection site,are the primary reasons for the observed low ion-to-electron temperature ratio close to the Earth at midnight.While reconnections that occur in the night-side far tail might preserve the ratio,turbulence on the boundaries of the bursty bulk flows(BBFs)could change the ratio in the far tail through the violation of the frozen-in condition of the ions.The plateau in the contour of the calculated ion-to-electron temperature ratio in the down tail distance between 40 and 60 Earth radii may explain the strong correlation between the ion and electron temperatures in the outer central plasma sheet,which has not been clearly understood till date.展开更多
Coastal vegetation is capable of decreasing wave run-up.However,because of regrowth,decay or man-made damage,coastal vegetation is always distributed in patches,and its internal distribution is often non-uniform.This ...Coastal vegetation is capable of decreasing wave run-up.However,because of regrowth,decay or man-made damage,coastal vegetation is always distributed in patches,and its internal distribution is often non-uniform.This study investigates the effects of patchy vegetation on solitary wave run-up by using a numerical simulation.A numerical model based on fully nonlinear Boussinesq equations is established to simulate the wave propagation on a slope with patchy vegetation.By using the model,the process of solitary wave run-up attenuation due to patchy vegetation is numerically analysed.The numerical results reveal that patchy vegetation can considerably attenuate the wave run-up in an effective manner.In addition,high-density patched vegetation can attenuate the solitary wave run-up more effectively than low-density patched vegetation can.For the same density,patchy vegetation with a uniform distribution has a better attenuation effect on wave run-up compared to that of patchy vegetation with a non-uniform distribution.展开更多
Most basaltic shergottites are too Mg-rich to represent parent melt compositions because they contain some cumulus pyroxenes. However, basaltic shergottite Northwest Africa(NWA) 8656 with subophitic texture can be use...Most basaltic shergottites are too Mg-rich to represent parent melt compositions because they contain some cumulus pyroxenes. However, basaltic shergottite Northwest Africa(NWA) 8656 with subophitic texture can be used as the parent melt composition in petrogenetic studies because it contains no or rare cumulus pyroxenes. Its pyroxene cores(Mg# 66-68, the most magnesian) are in equilibrium with the bulk rock composition based on major(Fe-Mg) and trace elements(REE—rare earth elements).The patchy zoning of pyroxenes has been interpreted as reflecting a two-stage crystallization history: 1) crystallization of Mg-rich pyroxene cores at depth(50 km, the base of Martian crust), 2) crystallization of Fe-rich pyroxene rims at the shallow depth near the Martian surface with a fast cooling history. The crystallization of Fe-rich pyroxenes and the existence of different symplectites indicate that NWA 8656 underwent eruption. The oxygen fugacity of NWA 8656(QFM –0.9±0.5) suggests an oxidized condition at the late-stage crystallization process, and the CI-normalized REE patterns of different minerals show enrichment in LREE, compared to that of depleted shergottites. Both of these observations suggest a relatively ITE(incompatible trace elements)-enriched signature of NWA 8656, similar to those of other enriched shergottites. The REE compositions of augite core and rim and plagioclase can be successfully reproduced by progressive crystallization without exogenous components, which indicates a closed magmatic system for NWA 8656. Consequently, we conclude that the ITE-enriched signature of NWA 8656 is inherited from an enriched mantle source rather than caused by crustal assimilation. Moreover, partial melting of depleted Martian mantle could not directly yield magmas that have geochemical characteristics similar to enriched shergottite parent magmas, so the enriched and depleted shergottites are derived from distinct mantle sources, and the mantle source of enriched shergottites would be expected to contain ilmenite.展开更多
Shallow carbonate deposits(Tarbur Formation)were formed in the Zagros foreland basin with dynamic tectonics during the Maastrichtian age.From the viewpoint of reconstruction of depositional conditions in these deposit...Shallow carbonate deposits(Tarbur Formation)were formed in the Zagros foreland basin with dynamic tectonics during the Maastrichtian age.From the viewpoint of reconstruction of depositional conditions in these deposits,studies of biostratigraphy,microfacies,microtaphofacies,and sequence stratigraphy were performed in a single area at Tang-e Shabi Khoon,northwest of Zagros.Based on the identification of two assemblage zones consisting of benthic foraminifera in these strata,the formation was deposited during the middle to late Maastrichtian.The number of cycles in test size and type of coiling in Loftusia decreased from the study area toward the northwest of the Neotethys basin.The input of clastic sediments affected the distribution of Loftusia and rudists in the study area.Nine microfacies,six microtaphofacies,and one terrigenous facies(shale)were identified based on the sedimentary features.These deposits of the middle-late Maastrichtian were deposited on a homoclinal carbonate ramp.The platform can be divided into restricted and semi-restricted lagoon,shoal,and open marine environments.In the study area,the deposits of the Tarbur Formation were deposited during four third-order depositional sequences.Local fault activities affected the formation of depositional sequences in the study area.展开更多
Wave-induced flow is observed as the domi- nated factor for P wave propagation at seismic frequencies. This mechanism has a mesoscopic scale nature. The inhomogeneous unsaturated patches are regarded larger than the p...Wave-induced flow is observed as the domi- nated factor for P wave propagation at seismic frequencies. This mechanism has a mesoscopic scale nature. The inhomogeneous unsaturated patches are regarded larger than the pore size, but smaller than the wavelength. Surface wave, e.g., Rayleigh wave, which propagates along the free surface, generated by the interfering of body waves is also affected by the mesoscopic loss mechanisms. Recent studies have reported that the effect of the wave-induced flow in wave propagation shows a relaxation behavior. Viscoelastic equivalent relaxation function associated with the wave mode can describe the kinetic nature of the attenuation. In this paper, the equivalent viscoelastic relaxation functions are extended to take into account the free surface for the Rayleigh surface wave propagation inpatchy saturated poroelastic media. Numerical results for the frequency-dependent velocity and attenuation and the time-dependent dynamical responses for the equivalent Rayleigh surface wave propagation along an interface between vacuum and patchy saturated porous media are reported in the low-frequency range (0.1-1,000 Hz). The results show that the dispersion and attenuation and kinetic characteristics of the mesoscopic loss effect for the surface wave can be effectively represented in the equivalent vis- coelastic media. The simulation of surface wave propaga- tion within mesoscopic patches requires solving Blot's differential equations in very small grid spaces, involving the conversion of the fast P wave energy diffusion into the Blot slow wave. This procedure requires a very large amount of computer consumption. An efficient equivalent approach for this patchy saturated poroelastic media shows a more convenient way to solve the single phase visco- elastic differential equations.展开更多
BACKGROUND Sinusoidal obstructive syndrome(SOS)is a disease that damages hepatic sinusoidal endothelial cells,resulting in progressive occlusion and fibrosis of the lobular central vein and the occurrence of intrahepa...BACKGROUND Sinusoidal obstructive syndrome(SOS)is a disease that damages hepatic sinusoidal endothelial cells,resulting in progressive occlusion and fibrosis of the lobular central vein and the occurrence of intrahepatic sinusoidal portal hypertension.However,SOS after liver transplantation(LT)is uncommon and potentially fatal.Here,we report a rare case of second-time recurrence of SOS after liver retransplantation(rLT).CASE SUMMARY A 22-year-old woman received a living donor LT due to SOS.Four years later,she developed abdominal distention and ascites with no apparent cause.She was diagnosed with recurrence of SOS and underwent rLT.But 2 mo post rLT,the patient suffered from aggravated jaundice and ascites again.She was diagnosed with second-time recurrence of SOS post-rLT according to computed tomography and liver pathology.After treatment with warfarin anticoagulation and immunosuppressant conversion,she gradually recovered with improvement of liver function and liver pathology.During the 17-mo follow-up period,she was in good condition with normal liver function and no ascites.CONCLUSION SOS can be a recurrent disease after LT,and autoimmune antibody and genetic sequencing should be screened before LT.For susceptible patients,anticoagulant drugs should be used for an extended period,and tacrolimus or other pathogenic agents should be avoided.Early diagnosis and treatment can improve the prognosis of patients and avoid graft failure or death.展开更多
Samples of phytoplankton were obtained in February, 1985, in Great Wall Bay, Antarctica. Among the 31 species of phytoplankton identified, the cold - water species rank highest in proportion. The cell number of phytop...Samples of phytoplankton were obtained in February, 1985, in Great Wall Bay, Antarctica. Among the 31 species of phytoplankton identified, the cold - water species rank highest in proportion. The cell number of phytoplankton averaged 162. 5×104 cells/m3 in the bay. The most dominant species are Chaetoceros socialis Lauder, Rhizosolenia. alata f. inermis (Castr. ) Hustedt and Biddulphia striatas Karsten. The former species mainly appeared in the bay and the latter two species aggregated at the bay mounth.展开更多
ObjectiveTo report a rare case of ALCL (Anaplastic Large Cell Lymphoma) with abundant neutrophils and necrosis and to analyse the histomorphologic subtypes and immunohistologic characteristics of ALCL. MethodsA biopsy...ObjectiveTo report a rare case of ALCL (Anaplastic Large Cell Lymphoma) with abundant neutrophils and necrosis and to analyse the histomorphologic subtypes and immunohistologic characteristics of ALCL. MethodsA biopsy of a painless tumor on a 26 year old male′s neck was taken for morphologic and immunohistochemical analyse. ResultsJudging from the morphologic feature of ALCL,the prognosis of the patient is good. ConclusionIt is necessary to do immunohistochemical staining in diagnosing an ALCL since p80 NPM/ALK or ALK is the best antibody to distinguish ALCL from other lymphomas.展开更多
文摘Phytoplankton patchiness ubiquitously obser- ved in marine ecosystems is a simple phy- sical phenomenon. Only two factors are required for its formation: one is persistent variations of inhomogeneous distributions in the phytopl- ankton population and the other is turbulent stirring by eddies. It is not necessary to assume continuous oscillations such as limit cycles for realization of the first factor. Instead, a certain amount of noise is enough. Random fluctua-tions by environmental noise and turbulent ad-vection by eddies seem to be common in open oceans. Based on these hypotheses, we pro-pose seemingly the simplest method to simulate patchiness formation that can create realistic images. Sufficient noise and turbulence can induce patchiness formation even though the system lies on the stable equilibrium conditions. We tentatively adopt the two-component model with nutrients and phytoplankton, however, the choice of the mathematical model is not essen-tial. The simulation method proposed in this study can be applied to whatever model with stable equilibrium states including one-com-ponent ones.
基金Key Program of the National Natural Science Foundation of China (30330130, 30500070), the National Natural Science Foundation of China for Distinguished Youth Scholar (39825106).
文摘Interconnected ramets of clonal plants can functionally specialize in the uptake of resources from aboveground and/or underground sources. Ramet pairs of the clonal stoloniferous herb Glechoma Iongltuba L. were grown In spatially heterogeneous environments with complementary availability of light and nutrients. Plasticity with respect to root-shoot ratio, fitness-related traits (biomass, number of ramets and dry weight per ramet), morphological traits (lamina area, root length) were experimentally examined. The aim was to understand the adaptation of G. Iongltuba to an environment with reciprocal patchiness of light and soil nutrients by plasticity In Its root-shoot ratio and clonal morphology. The results showed that the performance of ramets growing In patches with high light Intensity and low soil nutrients into the adjacent opposite patches was Increased in terms of fitness-related traits. However, the performance of those from patches with low light Intensity and high soil nutrients into the adjacent opposite patches was not changed. The root-shoot ratio and clonal morphology were plastic. Morphological traits such as lamina area and root length were altered In a way that enhanced the capture of light resources and soil nutrients. Apparent reciprocal resource transport between the ramets In an environment of reciprocal patchiness of resources can enhance the growth of ramets with complementary resource deficiencies.
基金National Natural Science Foundation of China(40435014).
文摘Aims Most plants are clonal in nature.Clonal ramets can share water,nutrients and photosynthate,especially when they experience patchy resources.Patch contrast(i.e.a difference in resources among patches)and patch direction(i.e.source–sink relations)are among the basic attributes of spatial patchiness.Here,I hypothesize that young established ramets in nutrient-rich patches support old ramets in nutrient-poor patches when ramets are subjected to different patch contrasts and patch directions.Methods In a greenhouse experiment,old and young ramets of Glechoma longituba were grown in four combinations consisting of patch contrast and patch direction.Minus patch direction refers to a patch combination in which parent ramets grow in nutrient-rich patches while connected daughter ramets grow in nutrient-poor ones and plus patch direction is the opposite direction.Imeasured photosynthesis and fluorescence traits,harvested all ramets,took morphological measures,weighed their dry mass and determined their nutrient uptake and use.Important Findings For parental ramets of G.longituba,patch contrast and patch direction and their interactions had no significant effects on net photosynthetic rate,maximal fluorescence yield,photochemical quenching(quenching refers to any process which decreases the fluorescence intensity of a given substance),non-photochemical quenching,nutrient uptake,biomass and stolon weight ratio.Patch direction alone significantly affected root weight ratio.Large patch contrast enhanced N use efficiency(NUE)and P use efficiency(PUE);plus patch direction decreased NUE,but increased PUE;the patch contrast by patch direction interaction affected PUE and K use efficiency(KUE).There were significant interactions between patch direction and patch contrast on PUE and KUE.It is concluded that soil nutrient patchiness may influence nutrient use strategies,but not nutrient uptake,photosynthesis and growth of parent ramets of G.longituba connected to daughter ramets,and that patch contrast and patch direction jointly affect PUE and KUE.
基金supported by the National Natural Science Foundation of China(No.21374028 and No.21306034)the Natural Science Foundation of Hebei Province(No.B2014201103)+2 种基金the Project for Talent Engineering of Hebei Province(No.A2016015001)the Project for Top Young Talent of Hebei Provincethe Project for Top Young Talent of General Colleges of Hebei Province(No.BJ2017017)
基金supported by the National Nature Science Foundation of China (Grant NSFC41374179)supported by NASA (NNX16AJ83G)
文摘The ion-to-electron temperature ratio is a good indicator of the processes involved in the plasma sheet.Observations have suggested that patchy reconnection and the resulting earthward bursty bulk flows(BBFs)transport may be involved in causing the lower temperature ratios at smaller radial distances during southward IMF periods.In this paper,we estimate theoretically how a patchy magnetic reconnection electric field can accelerate ions and electrons differently.If both ions and electrons are non-adiabatically accelerated only once within each reconnection,the temperature ratio would be preserved.However,when reconnection occurs closer to the Earth where magnetic field lines are shorter,particles mirrored back from the ionosphere can cross the reconnection region more than once within one reconnection;and electrons,moving faster than ions,can have more crossings than do ions,leading to electrons being accelerated more than ions.Thus as particles are transported from tail to the near-Earth by BBFs through multiple reconnection,electrons should be accelerated by the reconnection electric field more times than are ions,which can explain the lower temperature ratios observed closer to the Earth.
文摘The ion-to-electron temperature ratio is a good indicator of the processes involved in solar wind plasma entering and being transported inside Earth’s plasma sheet.In this study,we have demonstrated that patchy magnetic reconnection has the potential to preserve the ion-to-electron temperature ratio under certain conditions.If the charged particles are non-adiabatically accelerated no more than once in a single reconnection,the temperature ratio would be preserved;on the other hand,this ratio would not be preserved if they are accelerated multiple times.Consequently,under a northward interplanetary magnetic field(IMF)condition,the reconnection in the nonlinear phase of the Kelvin-Helmholtz instability is the dominant process for solar-originated plasma entering the Earth’s magnetosphere,and the ion-to-electron temperature ratio is preserved inside the plasma sheet.When the direction of the IMF is southward,the reflection of electrons from the magnetic mirror point,and subsequent multiple non-adiabatic accelerations at the reconnection site,are the primary reasons for the observed low ion-to-electron temperature ratio close to the Earth at midnight.While reconnections that occur in the night-side far tail might preserve the ratio,turbulence on the boundaries of the bursty bulk flows(BBFs)could change the ratio in the far tail through the violation of the frozen-in condition of the ions.The plateau in the contour of the calculated ion-to-electron temperature ratio in the down tail distance between 40 and 60 Earth radii may explain the strong correlation between the ion and electron temperatures in the outer central plasma sheet,which has not been clearly understood till date.
基金The National Natural Science Foundation of China under contract Nos 51579036 and 51779039the Fundamental Research Funds for the Central Universities of China under contract No.DUT19LAB13。
文摘Coastal vegetation is capable of decreasing wave run-up.However,because of regrowth,decay or man-made damage,coastal vegetation is always distributed in patches,and its internal distribution is often non-uniform.This study investigates the effects of patchy vegetation on solitary wave run-up by using a numerical simulation.A numerical model based on fully nonlinear Boussinesq equations is established to simulate the wave propagation on a slope with patchy vegetation.By using the model,the process of solitary wave run-up attenuation due to patchy vegetation is numerically analysed.The numerical results reveal that patchy vegetation can considerably attenuate the wave run-up in an effective manner.In addition,high-density patched vegetation can attenuate the solitary wave run-up more effectively than low-density patched vegetation can.For the same density,patchy vegetation with a uniform distribution has a better attenuation effect on wave run-up compared to that of patchy vegetation with a non-uniform distribution.
文摘Most basaltic shergottites are too Mg-rich to represent parent melt compositions because they contain some cumulus pyroxenes. However, basaltic shergottite Northwest Africa(NWA) 8656 with subophitic texture can be used as the parent melt composition in petrogenetic studies because it contains no or rare cumulus pyroxenes. Its pyroxene cores(Mg# 66-68, the most magnesian) are in equilibrium with the bulk rock composition based on major(Fe-Mg) and trace elements(REE—rare earth elements).The patchy zoning of pyroxenes has been interpreted as reflecting a two-stage crystallization history: 1) crystallization of Mg-rich pyroxene cores at depth(50 km, the base of Martian crust), 2) crystallization of Fe-rich pyroxene rims at the shallow depth near the Martian surface with a fast cooling history. The crystallization of Fe-rich pyroxenes and the existence of different symplectites indicate that NWA 8656 underwent eruption. The oxygen fugacity of NWA 8656(QFM –0.9±0.5) suggests an oxidized condition at the late-stage crystallization process, and the CI-normalized REE patterns of different minerals show enrichment in LREE, compared to that of depleted shergottites. Both of these observations suggest a relatively ITE(incompatible trace elements)-enriched signature of NWA 8656, similar to those of other enriched shergottites. The REE compositions of augite core and rim and plagioclase can be successfully reproduced by progressive crystallization without exogenous components, which indicates a closed magmatic system for NWA 8656. Consequently, we conclude that the ITE-enriched signature of NWA 8656 is inherited from an enriched mantle source rather than caused by crustal assimilation. Moreover, partial melting of depleted Martian mantle could not directly yield magmas that have geochemical characteristics similar to enriched shergottite parent magmas, so the enriched and depleted shergottites are derived from distinct mantle sources, and the mantle source of enriched shergottites would be expected to contain ilmenite.
基金the University of Isfahan for the financial support。
文摘Shallow carbonate deposits(Tarbur Formation)were formed in the Zagros foreland basin with dynamic tectonics during the Maastrichtian age.From the viewpoint of reconstruction of depositional conditions in these deposits,studies of biostratigraphy,microfacies,microtaphofacies,and sequence stratigraphy were performed in a single area at Tang-e Shabi Khoon,northwest of Zagros.Based on the identification of two assemblage zones consisting of benthic foraminifera in these strata,the formation was deposited during the middle to late Maastrichtian.The number of cycles in test size and type of coiling in Loftusia decreased from the study area toward the northwest of the Neotethys basin.The input of clastic sediments affected the distribution of Loftusia and rudists in the study area.Nine microfacies,six microtaphofacies,and one terrigenous facies(shale)were identified based on the sedimentary features.These deposits of the middle-late Maastrichtian were deposited on a homoclinal carbonate ramp.The platform can be divided into restricted and semi-restricted lagoon,shoal,and open marine environments.In the study area,the deposits of the Tarbur Formation were deposited during four third-order depositional sequences.Local fault activities affected the formation of depositional sequences in the study area.
基金support by the Natural Basic Research Program of China (the ‘‘973 Project’’,Grant No. 2013CB733303)the National Natural Science Foundation of China (Grant Nos. 41304077, 40974079)+1 种基金Postdoctoral Science Foundation of China (Grant No. 2013M531744)Key Laboratory of Geospace Environment and Geodesy (Grant Nos. 12-02-03)
文摘Wave-induced flow is observed as the domi- nated factor for P wave propagation at seismic frequencies. This mechanism has a mesoscopic scale nature. The inhomogeneous unsaturated patches are regarded larger than the pore size, but smaller than the wavelength. Surface wave, e.g., Rayleigh wave, which propagates along the free surface, generated by the interfering of body waves is also affected by the mesoscopic loss mechanisms. Recent studies have reported that the effect of the wave-induced flow in wave propagation shows a relaxation behavior. Viscoelastic equivalent relaxation function associated with the wave mode can describe the kinetic nature of the attenuation. In this paper, the equivalent viscoelastic relaxation functions are extended to take into account the free surface for the Rayleigh surface wave propagation inpatchy saturated poroelastic media. Numerical results for the frequency-dependent velocity and attenuation and the time-dependent dynamical responses for the equivalent Rayleigh surface wave propagation along an interface between vacuum and patchy saturated porous media are reported in the low-frequency range (0.1-1,000 Hz). The results show that the dispersion and attenuation and kinetic characteristics of the mesoscopic loss effect for the surface wave can be effectively represented in the equivalent vis- coelastic media. The simulation of surface wave propaga- tion within mesoscopic patches requires solving Blot's differential equations in very small grid spaces, involving the conversion of the fast P wave energy diffusion into the Blot slow wave. This procedure requires a very large amount of computer consumption. An efficient equivalent approach for this patchy saturated poroelastic media shows a more convenient way to solve the single phase visco- elastic differential equations.
基金Beijing Municipal Science&Technology Commission,No.Z181100001718220.
文摘BACKGROUND Sinusoidal obstructive syndrome(SOS)is a disease that damages hepatic sinusoidal endothelial cells,resulting in progressive occlusion and fibrosis of the lobular central vein and the occurrence of intrahepatic sinusoidal portal hypertension.However,SOS after liver transplantation(LT)is uncommon and potentially fatal.Here,we report a rare case of second-time recurrence of SOS after liver retransplantation(rLT).CASE SUMMARY A 22-year-old woman received a living donor LT due to SOS.Four years later,she developed abdominal distention and ascites with no apparent cause.She was diagnosed with recurrence of SOS and underwent rLT.But 2 mo post rLT,the patient suffered from aggravated jaundice and ascites again.She was diagnosed with second-time recurrence of SOS post-rLT according to computed tomography and liver pathology.After treatment with warfarin anticoagulation and immunosuppressant conversion,she gradually recovered with improvement of liver function and liver pathology.During the 17-mo follow-up period,she was in good condition with normal liver function and no ascites.CONCLUSION SOS can be a recurrent disease after LT,and autoimmune antibody and genetic sequencing should be screened before LT.For susceptible patients,anticoagulant drugs should be used for an extended period,and tacrolimus or other pathogenic agents should be avoided.Early diagnosis and treatment can improve the prognosis of patients and avoid graft failure or death.
文摘Samples of phytoplankton were obtained in February, 1985, in Great Wall Bay, Antarctica. Among the 31 species of phytoplankton identified, the cold - water species rank highest in proportion. The cell number of phytoplankton averaged 162. 5×104 cells/m3 in the bay. The most dominant species are Chaetoceros socialis Lauder, Rhizosolenia. alata f. inermis (Castr. ) Hustedt and Biddulphia striatas Karsten. The former species mainly appeared in the bay and the latter two species aggregated at the bay mounth.
文摘ObjectiveTo report a rare case of ALCL (Anaplastic Large Cell Lymphoma) with abundant neutrophils and necrosis and to analyse the histomorphologic subtypes and immunohistologic characteristics of ALCL. MethodsA biopsy of a painless tumor on a 26 year old male′s neck was taken for morphologic and immunohistochemical analyse. ResultsJudging from the morphologic feature of ALCL,the prognosis of the patient is good. ConclusionIt is necessary to do immunohistochemical staining in diagnosing an ALCL since p80 NPM/ALK or ALK is the best antibody to distinguish ALCL from other lymphomas.