Emerging research suggests a potential association of progression of Alzheimer's disease(AD)with alterations in synaptic currents and mitochondrial dynamics.However,the specific associations between these patholog...Emerging research suggests a potential association of progression of Alzheimer's disease(AD)with alterations in synaptic currents and mitochondrial dynamics.However,the specific associations between these pathological changes remain unclear.In this study,we utilized Aβ42-induced AD rats and primary neural cells as in vivo and in vitro models.The investigations included behavioural tests,brain magnetic resonance imaging(MRI),liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)analysis,Nissl staining,thioflavin-S staining,enzyme-linked immunosorbent assay,Golgi-Cox staining,transmission electron microscopy(TEM),immunofluorescence staining,proteomics,adenosine triphosphate(ATP)detection,mitochondrial membrane potential(MMP)and reactive oxygen species(ROS)assessment,mitochondrial morphology analysis,electrophysiological studies,Western blotting,and molecular docking.The results revealed changes in synaptic currents,mitophagy,and mitochondrial dynamics in the AD models.Remarkably,intervention with Dengzhan Shengmai(DZSM)capsules emerged as a pivotal element in this investigation.Aβ42-induced synaptic dysfunction was significantly mitigated by DZSM intervention,which notably amplified the frequency and amplitude of synaptic transmission.The cognitive impairment observed in AD rats was ameliorated and accompanied by robust protection against structural damage in key brain regions,including the hippocampal CA3,primary cingular cortex,prelimbic system,and dysgranular insular cortex.DZSM intervention led to increased IDE levels,augmented long-term potential(LTP)amplitude,and enhanced dendritic spine density and length.Moreover,DZSM intervention led to favourable changes in mitochondrial parameters,including ROS expression,MMP and ATP contents,and mitochondrial morphology.In conclusion,our findings delved into the realm of altered synaptic currents,mitophagy,and mitochondrial dynamics in AD,concurrently highlighting the therapeutic potential of DZSM intervention.展开更多
Background:Hand,foot and mouth disease(HFMD)is a common infectious disease caused by viral infection by a variety of enteroviruses,with coxsackievirus A 10(CA10)having become more prevalent in recent years.Methods:In ...Background:Hand,foot and mouth disease(HFMD)is a common infectious disease caused by viral infection by a variety of enteroviruses,with coxsackievirus A 10(CA10)having become more prevalent in recent years.Methods:In this study,models of CA10 infection were established in 7-day-old Institute of Cancer Research(ICR)mice by intraperitoneal injection to analyze the pathogenicity of the virus.RNA sequencing analysis was used to screen the differentially expressed genes(DEGs)after CA10 infection.Coxsackievirus A 16(CA16)and enterovirus 71(EV71)infections were also compared with CA10.Results:After CA10 virus infection,the mice showed paralysis of the hind limbs at 3 days post infection and weight loss at 5 days post infection.We observed viral replication in various tissues and severe inflammatory cell infiltration in skeletal muscle.The RNA-sequencing analysis showed that the DEGs in blood,muscle,thymus and spleen showed heterogeneity after CA10 infection and the most upregulated DEGs in muscle were enriched in immune-related pathways.Compared with CA16 and EV71 infection,CA10 may have an inhibitory effect on T helper(Th)cell differentiation and cell growth.Additionally,the common DEGs in the three viruses were most enriched in the immune system response,including the Toll-l ike receptor pathway and the nucleotide-binding and oligomerization domain(NOD)-l ike pathway.Conclusions:Our findings revealed a group of genes that coordinate in response to CA10 infection,which increases our understanding of the pathological mechanism of HFMD.展开更多
A moving submarine can generate internal waves,as well as extremely small free surface waves,in a fluid with density stratification.In this study,the internal and free surface wave wakes caused by a moving submarine i...A moving submarine can generate internal waves,as well as extremely small free surface waves,in a fluid with density stratification.In this study,the internal and free surface wave wakes caused by a moving submarine in two layers of constant density fluid were studied numerically using the commercial software STAR-CCM+.The realizable k–εturbulence model was used to solve the Reynolds-averaged Navier–Stokes equation,and the volume of the fluid method was used to monitor the fluctuations of the internal interface and free surface.Different cases of a moving submarine with different cruising speeds and relative diving depths were studied.Results showed that the maximum fluctuation amplitude of the free surface increased as the speed of the submarine increased;however,the maximum fluctuation amplitude of the internal interface first decreased and then increased.When the submarine moved at the maximum cruising speed,the maximum fluctuation amplitude of the free surface decreased as the diving depth increased,while the wavelength of the free surface wave was basically the same.If the submarine moved at the minimum cruising speed,then the wave elevation in the free surface was extremely small,but the internal surface had obviously large-amplitude internal waves,and the relative diving depth had a great influence on internal waves.展开更多
Owing to the large amplitude and nonlinearity of extreme sea waves,sailing ships exhibit obvious large-amplitude motion and green water.For a tumblehome vessel,a low-tumblehome freeboard and wave-piercing bow make gre...Owing to the large amplitude and nonlinearity of extreme sea waves,sailing ships exhibit obvious large-amplitude motion and green water.For a tumblehome vessel,a low-tumblehome freeboard and wave-piercing bow make green water more likely.To study the green water of a wave-facing sailing tumblehome vessel in strong nonlinear regular waves,the computational fluid dynamics software STAR-CCM+was used.The Reynolds-averaged Navier–Stokes method was used for the numerical simulation,and the k-epsilon model was adopted to deal with viscous turbulence.The volume of the fluid method was used to capture the free surface,and overset grids were utilized to simulate the large-amplitude ship motion.This study delves into the influence of wave height on the ship motion response and a tumblehome vessel green water under a large wave steepness(0.033≤H/λ≤0.067)at Fr=0.22.In addition,the dynamic process of green water and the“wave run-up”phenomenon were evaluated.The results suggest that when the wavelength is equal to the ship length and the wave steepness increases to 0.056,the increase in the water height on the deck is obvious.However,the wave height had little effect on the green water duration.The wave steepness and“backwater”have a great impact on the value and number of the peak of the water height on the deck.When the wave steepness exceeded 0.056,the water climbed up,and the plunging-type water body was formed at the top of the wave baffle,resulting in a large water area on the deck.展开更多
“Green–Naghdi Theory,Part A:Green–Naghdi(GN)Equations for Shallow Water Waves”have investigated the linear dispersion relations of high-level GN equations in shallow water.In this study,the GN equations for deep w...“Green–Naghdi Theory,Part A:Green–Naghdi(GN)Equations for Shallow Water Waves”have investigated the linear dispersion relations of high-level GN equations in shallow water.In this study,the GN equations for deep water waves are investigated.In the traditional GN equations for deep water waves,the velocity distribution assumption involves only one representative wave number.Herein,a new velocity distribution shape function with multiple representative wave numbers is employed.Further,we have derived the three-dimensional GN equations and analyzed the linear dispersion relations of the GN-3 and GN-5 equations.In this study,the finite difference method is used to simulate focus waves in the time domain.Additionally,the GN-5 equations are used to validate the wave profile and horizontal velocity distribution along water depth for different focused waves.展开更多
Concentration of elements or element groups in a geological body is the result of multiple stages of rockforming and ore-forming geological processes.An ore-forming element group can be identified by PCA(principal com...Concentration of elements or element groups in a geological body is the result of multiple stages of rockforming and ore-forming geological processes.An ore-forming element group can be identified by PCA(principal component analysis)and be separated into two components using BEMD(bi-dimensional empirical mode decomposition):(1)a high background component which represents the ore-forming background developed in rocks through various geological processes favorable for mineralization(i.e.magmatism,sedimentation and/or metamorphism);(2)the anomaly component which reflects the oreforming anomaly that is overprinted on the high background component developed during mineralization.Anomaly components are used to identify ore-finding targets more effectively than ore-forming element groups.Three steps of data analytical procedures are described in this paper;firstly,the application of PCA to establish the ore-forming element group;secondly,using BEMD on the o re-forming element group to identify the anomaly components created by different types of mineralization processes;and finally,identifying ore-finding targets based on the anomaly components.This method is applied to the Tengchong tin-polymetallic belt to delineate ore-finding targets,where four targets for Sn(W)and three targets for Pb-Zn-Ag-Fe polymetallic mineralization are identified and defined as new areas for further prospecting.It is shown that BEMD combined with PCA can be applied not only in extracting the anomaly component for delineating the ore-finding target,but also in extracting the residual component for identifying its high background zone favorable for mineralization from its oreforming element group.展开更多
In this work, Green-Naghdi （GN） equations with general weight functions were derived in a simple way. A wave-absorbing beach was also considered in the general GN equations. A numerical solution for a level higher t...In this work, Green-Naghdi （GN） equations with general weight functions were derived in a simple way. A wave-absorbing beach was also considered in the general GN equations. A numerical solution for a level higher than 4 was not feasible in the past with the original GN equations. The GN equations for shallow water waves were simplified here, which make the application of high level （higher than 4） equations feasible. The linear dispersion relationships of the first seven levels were presented. The accuracy of dispersion relationships increased as the level increased. Level 7 GN equations are capable of simulating waves out to wave number times depth kd 〈 26. Numerical simulation of nonlinear water waves was performed by use of Level 5 and 7 GN equations, which will be presented in the next paper.展开更多
The Green-Naghdi （GN） theory is used here to simulate two-dimensional （2D） underwater landslide-induce tsunamis. Finite difference method is used to solve the GN equations. GN theory has different levels. There ar...The Green-Naghdi （GN） theory is used here to simulate two-dimensional （2D） underwater landslide-induce tsunamis. Finite difference method is used to solve the GN equations. GN theory has different levels. There are GN-1, GN-2, .--, GN-K theory in GN theory. When K goes up, the GN equations will be more complicated, and the results will be more accurate. For the case simulated here, results of GN-5 theory are better than results of GN-3 theory. GN-7 results are almost the same as GN-5 results. That means GN-5 results are the converged results from GN theory. GN-5 results agree well with other＇s experimental results.展开更多
The chemoselective hydrogenation ofα,β-unsaturated aldehydes is a key strategy for the synthesis of fine chemicals.Herein,we developed an efficient method of depositing Pt particles on FeO_(x)/SBA-15.This strategy i...The chemoselective hydrogenation ofα,β-unsaturated aldehydes is a key strategy for the synthesis of fine chemicals.Herein,we developed an efficient method of depositing Pt particles on FeO_(x)/SBA-15.This strategy is dependent on using a platinumdivinyltetramethyldisiloxane complex(Pt^(0)-DVTMS)as the precursor,which we demonstrate can be removed through a H_(2)-treatment under mild conditions.This,in turn,allowed for the synthesis of catalysts with well dispersed Pt particles.The presence of FeO_(x) species also aided Pt dispersion;when coated onto SBA-15,FeO_(x) strongly interacted with dissociated Pt species,inhibiting both Pt aggregation and metal leaching.Using cinnamaldehyde as a modelα,β-unsaturated aldehyde,it was demonstrated that this catalyst was highly selective towards the unsaturated alcohol and no obvious loss in activity was observed over five recycles.This catalyst was determined to be significantly more effective than an analogous catalyst prepared using chloroplatinic acid as a precursor,evidencing the importance of using the Pt0-DVTMS precursor.We corroborate the excellent catalytic performance to highly dispersed Pt-species,whereby Pt0 and Pt^(2+) play a critical role in activating H_(2) and the C=O bond.This research demonstrates that the Pt precursor can have a significant impact on the physicochemical properties and thus,the performance of the final catalyst.It also evidences how metal support interactions can dramatically influence selectivity in such hydrogenation reactions.This novel catalyst preparation protocol,using a DVTMS ligand for Pt impregnation,offers a facile approach to the design of multi-component heterogeneous catalysts.展开更多
Crop breeding aims to generate pure in bred lines with multiple desired traits. Doubled haploid (DH) and genome editing using CRISPR/Cas9 are two powerful game-changing technologies in crop breeding. However, both of ...Crop breeding aims to generate pure in bred lines with multiple desired traits. Doubled haploid (DH) and genome editing using CRISPR/Cas9 are two powerful game-changing technologies in crop breeding. However, both of them still fall short for rapid generation of pure elite lines with integrated favorable traits. Here, we report the development of a Haploid-Inducer Mediated Genome Editing (IMGE) approach, which utilizes a maize haploid inducer line carrying a CRISPR/Cas9 cassette targeting for a desired agronomic trait to pollinate an elite maize in bred line and to generate genome-edited haploids in the elite maize background. Homozygous pure DH lines with the desired trait improvement could be generated within two generations, thus bypassing the lengthy procedure of repeated crossing and backcrossing used in conventional breeding for integrating a desirable trait into elite commercial backgrounds.展开更多
Nestedness has been a research focus in fields of island biogeography and community ecology in recent decades. Although nestedness of faunal assemblages has been investigated in natural wetlands, it remains largely un...Nestedness has been a research focus in fields of island biogeography and community ecology in recent decades. Although nestedness of faunal assemblages has been investigated in natural wetlands, it remains largely unknown whether and why waterbird communities in artificial wetlands follow n ested patter ns. We exami ned the existence of n ested ness and un derlyi ng drivers in waterbird comm un ities in subside nee wetlands that are recently created by large-scale un derground coal mining in the North China Plain. Twelve point-count surveys for waterbirds were undertaken approximately every 2 weeks in 55 subside nee wetla nds from September 2016 to April 2017. We used the metric WNODF to estimate nestedness of the assemblages. Partial Spearman rank correlations were performed to examine the association between the nestedness and habitat variables (wetland area, landscape connectivity, wetland age, and habitat diversity) as well as life-history traits (body size, clutch size, dispersal ratio, geographical range size, and migrant status) related to species exti notion risk and colon izati on rate. Waterbird assemblages in the subside nee wetla nds were significantly nested. After controlling for other independent variables, the magnitude of nestedness was significantly and negatively correlated with wetland area and species trait linked to extinction risk (i.e., geographical range size). Our results indicate that selective extinction may be the main driver of the nestedness of waterbird assemblages in our study system. However, the nestedness was not due to passive sampling, selective colonization, or habitat diversity. From a conservation viewpoint, both large wetlands and waterbirds with a small geographic range should be protected to maximize the preserved species richness.展开更多
The Bozhushan Ore Field,located at the western margin of the South China Block,is an important area for Ag-Pb-Zn-W polymetallic mineralization which may be associated with the Late Cretaceous granitic magmaism.In this...The Bozhushan Ore Field,located at the western margin of the South China Block,is an important area for Ag-Pb-Zn-W polymetallic mineralization which may be associated with the Late Cretaceous granitic magmaism.In this paper,the singular value decomposition(SVD)was effectively applied to decompose gravity data at scale of 1:50000 within the Bozhushan Ore Field to extract deep ore-finding information.Two gravity anomaly images displaying different scales of the ore-controlling factors were obtained.(1)The low-pass filtered image may reflect the deeply buried geological structures,hidden intrusions and concealed ore bodies.The negative gravity anomaly may reflect the overall distribution of granite bodies in the Bozhushan Ore Field.One negative gravity anomaly area may correspond to the exposed part of the Baozhushan granitic intrusion and the other corresponds to the concealed part of the granitic intrusion.The granitic intrusions are the main ore-controlling factors in this ore district.(2)The band-pass filtered image depicts the shallow concealed geological structures and geological bodies within this study area.There are two obvious negative gravity anomalies,which may be created by the hidden granites at different depths at both northwestern and southeastern sides of the exposed granitic intrusion.Thus the two negative gravity anomalies are favorable prospecting areas for various type of polymetallic ore deposits at depth.The gravity anomalies extracted by using the SVD exactly reflect the distribution of the ore deposits,structures and intrusions,which will give new insights for further mineral exploration in the study area.展开更多
Influenza A virus may circulate simultaneously with the SARS-CoV-2 virus,leading to more serious respiratory diseases during this winter.However,the influence of these viruses on disease outcome when both influenza A ...Influenza A virus may circulate simultaneously with the SARS-CoV-2 virus,leading to more serious respiratory diseases during this winter.However,the influence of these viruses on disease outcome when both influenza A and SARS-CoV-2 are present in the host remains unclear.Using a mammalian model,sequential infection was performed in ferrets and in K18-MCE2 mice,with SARS-CoV-2 infection following H1N1.We found that co-infection with H1N1 and SARS-CoV-2 extended the duration of clinical manifestation of COVID-19,and enhanced pulmonary damage,but reduced viral shedding of throat swabs and viral loads in the lungs of ferrets.Moreover,mortality was increased in sequentially infected mice compared with single-infection mice.Compared with singlevaccine inoculation,co-inoculation of PiCoVacc(a SARS-CoV-2 vaccine)and the flu vaccine showed no significant differences in neutralizing antibody titers or virus-specific immune responses.Combined immunization effectively protected K18-MCE2 mice against both H1N1 and SARS-CoV-2 infection.Our findings indicated the development of systematic models of co-infection of H1N1 and SARS-CoV-2,which together notably enhanced pneumonia in ferrets and mice,as well as demonstrated that simultaneous vaccination against HINT and SARS-CoV-2 may be an effective prevention strategy for the coming winter.展开更多
Current Zoology,Advance Access publication:23 April 2018.doi.org/10.1093/cz/zoy034 The original version of this article contained inaccuracies in the description of an author's work in the 4Species life-history tr...Current Zoology,Advance Access publication:23 April 2018.doi.org/10.1093/cz/zoy034 The original version of this article contained inaccuracies in the description of an author's work in the 4Species life-history traits5 sub-section.The original description was as follows.展开更多
Image captchas have recently become very popular and are widely deployed across the Internet to defend against abusive programs. However, the ever-advancing capabilities of computer vision have gradually diminished th...Image captchas have recently become very popular and are widely deployed across the Internet to defend against abusive programs. However, the ever-advancing capabilities of computer vision have gradually diminished the security of image captchas and made them vulnerable to attack. In this paper, we first classify the currently popular image captchas into three categories: selection-based captchas, slide-based captchas, and click-based captchas. Second, we propose simple yet powerful attack frameworks against each of these categories of image captchas. Third, we systematically evaluate our attack frameworks against 10 popular real-world image captchas,including captchas from tencent.com, google.com, and 12306.cn. Fourth, we compare our attacks against nine online image recognition services and against human labors from eight underground captcha-solving services. Our evaluation results show that(1) each of the popular image captchas that we study is vulnerable to our attacks;(2) our attacks yield the highest captcha-breaking success rate compared with state-of-the-art methods in almost all scenarios; and(3) our attacks achieve almost as high a success rate as human labor while being much faster.Based on our evaluation, we identify some design flaws in these popular schemes, along with some best practices and design principles for more secure captchas. We also examine the underground market for captcha-solving services, identifying 152 such services. We then seek to measure this underground market with data from these services. Our findings shed light on understanding the scale, impact, and commercial landscape of the underground market for captcha solving.展开更多
基金National Natural Science Foundation of China(Grant No.:82374317)State Key Program of National Natural Science of China(Grant Nos.:82130119 and 82130118)+4 种基金Postdoctoral Research Foundation of China(Grant No.:2021M690450)Traditional Chinese Medicine Research Project of Health Commission of Hubei Province(Grant No.:ZY2021M017)Hubei University of Chinese Medicine Funds for Distinguished Young Scholars(Grant No.:2022ZZXJ004)National Natural Science Foundation of China(Grant No.:82174210)Fundamental Research Funds for the Central Public Welfare Research Institutes(Grant No.:ZZ14-FL-005).
文摘Emerging research suggests a potential association of progression of Alzheimer's disease(AD)with alterations in synaptic currents and mitochondrial dynamics.However,the specific associations between these pathological changes remain unclear.In this study,we utilized Aβ42-induced AD rats and primary neural cells as in vivo and in vitro models.The investigations included behavioural tests,brain magnetic resonance imaging(MRI),liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)analysis,Nissl staining,thioflavin-S staining,enzyme-linked immunosorbent assay,Golgi-Cox staining,transmission electron microscopy(TEM),immunofluorescence staining,proteomics,adenosine triphosphate(ATP)detection,mitochondrial membrane potential(MMP)and reactive oxygen species(ROS)assessment,mitochondrial morphology analysis,electrophysiological studies,Western blotting,and molecular docking.The results revealed changes in synaptic currents,mitophagy,and mitochondrial dynamics in the AD models.Remarkably,intervention with Dengzhan Shengmai(DZSM)capsules emerged as a pivotal element in this investigation.Aβ42-induced synaptic dysfunction was significantly mitigated by DZSM intervention,which notably amplified the frequency and amplitude of synaptic transmission.The cognitive impairment observed in AD rats was ameliorated and accompanied by robust protection against structural damage in key brain regions,including the hippocampal CA3,primary cingular cortex,prelimbic system,and dysgranular insular cortex.DZSM intervention led to increased IDE levels,augmented long-term potential(LTP)amplitude,and enhanced dendritic spine density and length.Moreover,DZSM intervention led to favourable changes in mitochondrial parameters,including ROS expression,MMP and ATP contents,and mitochondrial morphology.In conclusion,our findings delved into the realm of altered synaptic currents,mitophagy,and mitochondrial dynamics in AD,concurrently highlighting the therapeutic potential of DZSM intervention.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC2303404)the CAMS Innovation Fund for Medical Sciences(CIFMS)grant(2021-1-I2 M-035,2022-I2M-1-020)。
文摘Background:Hand,foot and mouth disease(HFMD)is a common infectious disease caused by viral infection by a variety of enteroviruses,with coxsackievirus A 10(CA10)having become more prevalent in recent years.Methods:In this study,models of CA10 infection were established in 7-day-old Institute of Cancer Research(ICR)mice by intraperitoneal injection to analyze the pathogenicity of the virus.RNA sequencing analysis was used to screen the differentially expressed genes(DEGs)after CA10 infection.Coxsackievirus A 16(CA16)and enterovirus 71(EV71)infections were also compared with CA10.Results:After CA10 virus infection,the mice showed paralysis of the hind limbs at 3 days post infection and weight loss at 5 days post infection.We observed viral replication in various tissues and severe inflammatory cell infiltration in skeletal muscle.The RNA-sequencing analysis showed that the DEGs in blood,muscle,thymus and spleen showed heterogeneity after CA10 infection and the most upregulated DEGs in muscle were enriched in immune-related pathways.Compared with CA16 and EV71 infection,CA10 may have an inhibitory effect on T helper(Th)cell differentiation and cell growth.Additionally,the common DEGs in the three viruses were most enriched in the immune system response,including the Toll-l ike receptor pathway and the nucleotide-binding and oligomerization domain(NOD)-l ike pathway.Conclusions:Our findings revealed a group of genes that coordinate in response to CA10 infection,which increases our understanding of the pathological mechanism of HFMD.
基金Supported by the Frontier Science Center for Extreme Marine Environmental Fluctuation FieldsHeilongjiang Touyan Innovation Team Program
文摘A moving submarine can generate internal waves,as well as extremely small free surface waves,in a fluid with density stratification.In this study,the internal and free surface wave wakes caused by a moving submarine in two layers of constant density fluid were studied numerically using the commercial software STAR-CCM+.The realizable k–εturbulence model was used to solve the Reynolds-averaged Navier–Stokes equation,and the volume of the fluid method was used to monitor the fluctuations of the internal interface and free surface.Different cases of a moving submarine with different cruising speeds and relative diving depths were studied.Results showed that the maximum fluctuation amplitude of the free surface increased as the speed of the submarine increased;however,the maximum fluctuation amplitude of the internal interface first decreased and then increased.When the submarine moved at the maximum cruising speed,the maximum fluctuation amplitude of the free surface decreased as the diving depth increased,while the wavelength of the free surface wave was basically the same.If the submarine moved at the minimum cruising speed,then the wave elevation in the free surface was extremely small,but the internal surface had obviously large-amplitude internal waves,and the relative diving depth had a great influence on internal waves.
基金Supported by the Heilongjiang Touyan Project of Chinaand the Frontier Science Center of the Ministry of Education for Extreme Marine Environment Wave Fields
文摘Owing to the large amplitude and nonlinearity of extreme sea waves,sailing ships exhibit obvious large-amplitude motion and green water.For a tumblehome vessel,a low-tumblehome freeboard and wave-piercing bow make green water more likely.To study the green water of a wave-facing sailing tumblehome vessel in strong nonlinear regular waves,the computational fluid dynamics software STAR-CCM+was used.The Reynolds-averaged Navier–Stokes method was used for the numerical simulation,and the k-epsilon model was adopted to deal with viscous turbulence.The volume of the fluid method was used to capture the free surface,and overset grids were utilized to simulate the large-amplitude ship motion.This study delves into the influence of wave height on the ship motion response and a tumblehome vessel green water under a large wave steepness(0.033≤H/λ≤0.067)at Fr=0.22.In addition,the dynamic process of green water and the“wave run-up”phenomenon were evaluated.The results suggest that when the wavelength is equal to the ship length and the wave steepness increases to 0.056,the increase in the water height on the deck is obvious.However,the wave height had little effect on the green water duration.The wave steepness and“backwater”have a great impact on the value and number of the peak of the water height on the deck.When the wave steepness exceeded 0.056,the water climbed up,and the plunging-type water body was formed at the top of the wave baffle,resulting in a large water area on the deck.
文摘“Green–Naghdi Theory,Part A:Green–Naghdi(GN)Equations for Shallow Water Waves”have investigated the linear dispersion relations of high-level GN equations in shallow water.In this study,the GN equations for deep water waves are investigated.In the traditional GN equations for deep water waves,the velocity distribution assumption involves only one representative wave number.Herein,a new velocity distribution shape function with multiple representative wave numbers is employed.Further,we have derived the three-dimensional GN equations and analyzed the linear dispersion relations of the GN-3 and GN-5 equations.In this study,the finite difference method is used to simulate focus waves in the time domain.Additionally,the GN-5 equations are used to validate the wave profile and horizontal velocity distribution along water depth for different focused waves.
基金funded by the Na-tional Natural Science Foundation of China(Grant Nos.41672329,41272365)the National Key Research and Development Project of China(Grant No.2016YFC0600509)the Project of China Geological Survey(Grant No.1212011120341)
文摘Concentration of elements or element groups in a geological body is the result of multiple stages of rockforming and ore-forming geological processes.An ore-forming element group can be identified by PCA(principal component analysis)and be separated into two components using BEMD(bi-dimensional empirical mode decomposition):(1)a high background component which represents the ore-forming background developed in rocks through various geological processes favorable for mineralization(i.e.magmatism,sedimentation and/or metamorphism);(2)the anomaly component which reflects the oreforming anomaly that is overprinted on the high background component developed during mineralization.Anomaly components are used to identify ore-finding targets more effectively than ore-forming element groups.Three steps of data analytical procedures are described in this paper;firstly,the application of PCA to establish the ore-forming element group;secondly,using BEMD on the o re-forming element group to identify the anomaly components created by different types of mineralization processes;and finally,identifying ore-finding targets based on the anomaly components.This method is applied to the Tengchong tin-polymetallic belt to delineate ore-finding targets,where four targets for Sn(W)and three targets for Pb-Zn-Ag-Fe polymetallic mineralization are identified and defined as new areas for further prospecting.It is shown that BEMD combined with PCA can be applied not only in extracting the anomaly component for delineating the ore-finding target,but also in extracting the residual component for identifying its high background zone favorable for mineralization from its oreforming element group.
基金Supported by the Special Fund for Basic Scientific Research of Central Colleges Harbin Engineering University(Harbin)the National Natural Science Foundation of China+1 种基金Doctor Subject Foundation of the Ministry of Education of Chinathe"111"project(B07019)
文摘In this work, Green-Naghdi （GN） equations with general weight functions were derived in a simple way. A wave-absorbing beach was also considered in the general GN equations. A numerical solution for a level higher than 4 was not feasible in the past with the original GN equations. The GN equations for shallow water waves were simplified here, which make the application of high level （higher than 4） equations feasible. The linear dispersion relationships of the first seven levels were presented. The accuracy of dispersion relationships increased as the level increased. Level 7 GN equations are capable of simulating waves out to wave number times depth kd 〈 26. Numerical simulation of nonlinear water waves was performed by use of Level 5 and 7 GN equations, which will be presented in the next paper.
基金supported by the National Natural Science Foundation of China (11102049)the Specialized Research Fund for the Doctoral Program of Higher Education of China (SRFDP 20112304120021)
文摘The Green-Naghdi （GN） theory is used here to simulate two-dimensional （2D） underwater landslide-induce tsunamis. Finite difference method is used to solve the GN equations. GN theory has different levels. There are GN-1, GN-2, .--, GN-K theory in GN theory. When K goes up, the GN equations will be more complicated, and the results will be more accurate. For the case simulated here, results of GN-5 theory are better than results of GN-3 theory. GN-7 results are almost the same as GN-5 results. That means GN-5 results are the converged results from GN theory. GN-5 results agree well with other＇s experimental results.
基金the National Natural Science Foundation(Nos.U1910202 and 21978194)the Key Research and Development Program of Shanxi Province(No.202102090301005)the Fund for Shanxi“1331 Project”.
文摘The chemoselective hydrogenation ofα,β-unsaturated aldehydes is a key strategy for the synthesis of fine chemicals.Herein,we developed an efficient method of depositing Pt particles on FeO_(x)/SBA-15.This strategy is dependent on using a platinumdivinyltetramethyldisiloxane complex(Pt^(0)-DVTMS)as the precursor,which we demonstrate can be removed through a H_(2)-treatment under mild conditions.This,in turn,allowed for the synthesis of catalysts with well dispersed Pt particles.The presence of FeO_(x) species also aided Pt dispersion;when coated onto SBA-15,FeO_(x) strongly interacted with dissociated Pt species,inhibiting both Pt aggregation and metal leaching.Using cinnamaldehyde as a modelα,β-unsaturated aldehyde,it was demonstrated that this catalyst was highly selective towards the unsaturated alcohol and no obvious loss in activity was observed over five recycles.This catalyst was determined to be significantly more effective than an analogous catalyst prepared using chloroplatinic acid as a precursor,evidencing the importance of using the Pt0-DVTMS precursor.We corroborate the excellent catalytic performance to highly dispersed Pt-species,whereby Pt0 and Pt^(2+) play a critical role in activating H_(2) and the C=O bond.This research demonstrates that the Pt precursor can have a significant impact on the physicochemical properties and thus,the performance of the final catalyst.It also evidences how metal support interactions can dramatically influence selectivity in such hydrogenation reactions.This novel catalyst preparation protocol,using a DVTMS ligand for Pt impregnation,offers a facile approach to the design of multi-component heterogeneous catalysts.
基金National Key R&D Program of China (2016YFD0100303 and 2016YFD0101001)Beijing Natural Science Foundation (6172032).
文摘Crop breeding aims to generate pure in bred lines with multiple desired traits. Doubled haploid (DH) and genome editing using CRISPR/Cas9 are two powerful game-changing technologies in crop breeding. However, both of them still fall short for rapid generation of pure elite lines with integrated favorable traits. Here, we report the development of a Haploid-Inducer Mediated Genome Editing (IMGE) approach, which utilizes a maize haploid inducer line carrying a CRISPR/Cas9 cassette targeting for a desired agronomic trait to pollinate an elite maize in bred line and to generate genome-edited haploids in the elite maize background. Homozygous pure DH lines with the desired trait improvement could be generated within two generations, thus bypassing the lengthy procedure of repeated crossing and backcrossing used in conventional breeding for integrating a desirable trait into elite commercial backgrounds.
基金the National Natural Science Foundation of China [31770571, 31770462, and 31471981]the Fundamental Research Funds for the Central Universities [2016QNA6001]Zhejiang Provincial Natural Science Foundation [LZ18C030002).
文摘Nestedness has been a research focus in fields of island biogeography and community ecology in recent decades. Although nestedness of faunal assemblages has been investigated in natural wetlands, it remains largely unknown whether and why waterbird communities in artificial wetlands follow n ested patter ns. We exami ned the existence of n ested ness and un derlyi ng drivers in waterbird comm un ities in subside nee wetlands that are recently created by large-scale un derground coal mining in the North China Plain. Twelve point-count surveys for waterbirds were undertaken approximately every 2 weeks in 55 subside nee wetla nds from September 2016 to April 2017. We used the metric WNODF to estimate nestedness of the assemblages. Partial Spearman rank correlations were performed to examine the association between the nestedness and habitat variables (wetland area, landscape connectivity, wetland age, and habitat diversity) as well as life-history traits (body size, clutch size, dispersal ratio, geographical range size, and migrant status) related to species exti notion risk and colon izati on rate. Waterbird assemblages in the subside nee wetla nds were significantly nested. After controlling for other independent variables, the magnitude of nestedness was significantly and negatively correlated with wetland area and species trait linked to extinction risk (i.e., geographical range size). Our results indicate that selective extinction may be the main driver of the nestedness of waterbird assemblages in our study system. However, the nestedness was not due to passive sampling, selective colonization, or habitat diversity. From a conservation viewpoint, both large wetlands and waterbirds with a small geographic range should be protected to maximize the preserved species richness.
基金funded by the Chinese Research&Development Program for Probing into Deep Earth(No.2016YFC0600509)the National Natural Science Foundation of China(Nos.41672329,41972312)。
文摘The Bozhushan Ore Field,located at the western margin of the South China Block,is an important area for Ag-Pb-Zn-W polymetallic mineralization which may be associated with the Late Cretaceous granitic magmaism.In this paper,the singular value decomposition(SVD)was effectively applied to decompose gravity data at scale of 1:50000 within the Bozhushan Ore Field to extract deep ore-finding information.Two gravity anomaly images displaying different scales of the ore-controlling factors were obtained.(1)The low-pass filtered image may reflect the deeply buried geological structures,hidden intrusions and concealed ore bodies.The negative gravity anomaly may reflect the overall distribution of granite bodies in the Bozhushan Ore Field.One negative gravity anomaly area may correspond to the exposed part of the Baozhushan granitic intrusion and the other corresponds to the concealed part of the granitic intrusion.The granitic intrusions are the main ore-controlling factors in this ore district.(2)The band-pass filtered image depicts the shallow concealed geological structures and geological bodies within this study area.There are two obvious negative gravity anomalies,which may be created by the hidden granites at different depths at both northwestern and southeastern sides of the exposed granitic intrusion.Thus the two negative gravity anomalies are favorable prospecting areas for various type of polymetallic ore deposits at depth.The gravity anomalies extracted by using the SVD exactly reflect the distribution of the ore deposits,structures and intrusions,which will give new insights for further mineral exploration in the study area.
基金supported by the CAMS Initiative for Innovative Medicine of China(Grant Nos.2020-I2M-COV19-009,2016-I2M-2-006,2018-I2M-1-003)the Special Funds of the National Natural Science Foundation of China(Grant No.82041035)+3 种基金the National Research and Development Project of China(Grant No.2020YFC0841100)the National Mega projects of China for Major Infectious Diseases(Grant Nos.2017ZX10304402,2018ZX10301403)the National Key Research and Development Project of China(Grant No.2016YFD0500304)the Fundamental Research Funds for the Central Public Welfare Research Institutes(Grant No.ZZ13-035-03).
文摘Influenza A virus may circulate simultaneously with the SARS-CoV-2 virus,leading to more serious respiratory diseases during this winter.However,the influence of these viruses on disease outcome when both influenza A and SARS-CoV-2 are present in the host remains unclear.Using a mammalian model,sequential infection was performed in ferrets and in K18-MCE2 mice,with SARS-CoV-2 infection following H1N1.We found that co-infection with H1N1 and SARS-CoV-2 extended the duration of clinical manifestation of COVID-19,and enhanced pulmonary damage,but reduced viral shedding of throat swabs and viral loads in the lungs of ferrets.Moreover,mortality was increased in sequentially infected mice compared with single-infection mice.Compared with singlevaccine inoculation,co-inoculation of PiCoVacc(a SARS-CoV-2 vaccine)and the flu vaccine showed no significant differences in neutralizing antibody titers or virus-specific immune responses.Combined immunization effectively protected K18-MCE2 mice against both H1N1 and SARS-CoV-2 infection.Our findings indicated the development of systematic models of co-infection of H1N1 and SARS-CoV-2,which together notably enhanced pneumonia in ferrets and mice,as well as demonstrated that simultaneous vaccination against HINT and SARS-CoV-2 may be an effective prevention strategy for the coming winter.
文摘Current Zoology,Advance Access publication:23 April 2018.doi.org/10.1093/cz/zoy034 The original version of this article contained inaccuracies in the description of an author's work in the 4Species life-history traits5 sub-section.The original description was as follows.
基金supported by the National Natural Science Foundation of China (Nos. 61772466 and U1836202)the Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars (No. LR19F020003)+1 种基金the Provincial Key Research and Development Program of Zhejiang Province (No. 2017C01055)the Alibaba-ZJU Joint Research Institute of Frontier Technologies
文摘Image captchas have recently become very popular and are widely deployed across the Internet to defend against abusive programs. However, the ever-advancing capabilities of computer vision have gradually diminished the security of image captchas and made them vulnerable to attack. In this paper, we first classify the currently popular image captchas into three categories: selection-based captchas, slide-based captchas, and click-based captchas. Second, we propose simple yet powerful attack frameworks against each of these categories of image captchas. Third, we systematically evaluate our attack frameworks against 10 popular real-world image captchas,including captchas from tencent.com, google.com, and 12306.cn. Fourth, we compare our attacks against nine online image recognition services and against human labors from eight underground captcha-solving services. Our evaluation results show that(1) each of the popular image captchas that we study is vulnerable to our attacks;(2) our attacks yield the highest captcha-breaking success rate compared with state-of-the-art methods in almost all scenarios; and(3) our attacks achieve almost as high a success rate as human labor while being much faster.Based on our evaluation, we identify some design flaws in these popular schemes, along with some best practices and design principles for more secure captchas. We also examine the underground market for captcha-solving services, identifying 152 such services. We then seek to measure this underground market with data from these services. Our findings shed light on understanding the scale, impact, and commercial landscape of the underground market for captcha solving.
