Purpose-Amidst an increasingly severe cybersecurity landscape,the widespread adoption of Xinchuang endpoints has become a strategic imperative.Governments and enterprises have established terminal localization as a cr...Purpose-Amidst an increasingly severe cybersecurity landscape,the widespread adoption of Xinchuang endpoints has become a strategic imperative.Governments and enterprises have established terminal localization as a critical objective,aiming for comprehensive indigenous replacement through rapid technological iteration.Consequently,Xinchuang systems and Windows platforms are expected to coexist over an extended period.This study seeks to establish an automated verification framework for multi-version operating systems and validate the efficacy of baseline hardening in mitigating security risks.Design/methodology/approach-Based on the Classified Protection 2.0 framework and relevant national standards for endpoint security,this study proposes an endpoint security baseline verification scheme applicable to multiple operating systems.The scheme addresses divergent security policies and implementation methodologies across heterogeneous environments.It automates the inspection of core baselines,including account password complexity,default shared service status and patch installation status.Furthermore,a comprehensive scoring model is established by incorporating differentiated weights for account security,patch management and log auditing,ultimately generating visualized risk reports to facilitate remediation prioritization.Findings-This study reveals that baseline configuration serves as the fundamental prerequisite in endpoint security practices.Through a scalable detection engine and quantitative scoring model,the system can promptly identify and remediate potential risks,thereby reducing the attack surface and mitigating intrusion risks.However,on certain domestic chip architectures,compatibility issues persist in detecting specific configuration items.Further improvement in hardware-software co-adaptation for domestic platforms is required to advance the development of localized security protection systems.Originality/value-Through in-depth research on security baseline configurations across multiple operating systems,this study implements an automated and visualized baseline verification methodology.This approach significantly strengthens the security posture of domestic operating systems and supports the establishment of a more robust,national-level cybersecurity defense framework.展开更多
This paper delves into the baseline design under the baseline parameterization model in experimental design, focusing on the relationship between the K-aberration criterion and the word length pattern (WLP) of regular...This paper delves into the baseline design under the baseline parameterization model in experimental design, focusing on the relationship between the K-aberration criterion and the word length pattern (WLP) of regular two-level designs. The paper provides a detailed analysis of the relationship between K5and the WLP for regular two-level designs with resolution t=3, and proposes corresponding theoretical results. These results not only theoretically reveal the connection between the orthogonal parameterization model and the baseline parameterization model but also provide theoretical support for finding the K-aberration optimal regular two-level baseline designs. It demonstrates how to apply these theories to evaluate and select the optimal experimental designs. In practical applications, experimental designers can utilize the theoretical results of this paper to quickly assess and select regular two-level baseline designs with minimal K-aberration by analyzing the WLP of the experimental design. This allows for the identification of key factors that significantly affect the experimental outcomes without frequently changing the factor levels, thereby maximizing the benefits of the experiment.展开更多
The rice stem borer,Chilo suppressalis(Walker)(Lepidoptera:Crambidae),is one of the most serious pests in rice-growing areas,and it has developed resistance to most insecticides currently used in the field.Cyproflanil...The rice stem borer,Chilo suppressalis(Walker)(Lepidoptera:Crambidae),is one of the most serious pests in rice-growing areas,and it has developed resistance to most insecticides currently used in the field.Cyproflanilide is a novel meta-diamide insecticide that has shown high activities to multiple pests.Evaluating the risk of resistance to cyproflanilide in C.suppressalis is necessary for its preventive resistance management.Here we established the baseline susceptibility of C.suppressalis to cyproflanilide by the rice-seedling dipping method and topical application,and the LC_(50) and LD_(50) values were 0.026 mg L^(-1) and 0.122 ng/larva,respectively.The LC_(50) values of cyproflanilide in 37 field populations ranged from 0.012 to 0.061 mg L^(-1),and 25 field populations exhibited resistance to chlorantraniliprole with the highest LC_(50) value of 3,770.059 mg L^(-1).In addition,a logistic distribution model analysis indicated that only 0.048 mg L^(-1) of cyproflanilide was required to kill 90% field chlorantraniliprole-resistant populations of C.suppressalis,compared to 2,087.764 mg L^(-1) of chlorantraniliprole for a similar level of control.Resistance screening over 19 generations did not result in resistance to cyproflanilide(RR=3.1-fold).The realized heritability(h^(2))of resistance was estimated as 0.067 by using threshold trait analysis,suggesting a low risk of cyproflanilide resistance development in susceptible strains.The Cypro-SEL population(F_(10))had no obvious fitness cost(relative fitness=0.96),and no significant changes in sensitivity to seven tested insecticides.These findings suggested that cyproflanilide is a promising insecticide for the management of chlorantraniliprole-resistant C.suppressalis.Moreover,this integrated risk assessment provides scientific application guidelines for the sustainable resistance management of cyproflanilide for controlling C.suppressalis.展开更多
The natural visibility graph method has been widely used in physiological signal analysis,but it fails to accurately handle signals with data points below the baseline.Such signals are common across various physiologi...The natural visibility graph method has been widely used in physiological signal analysis,but it fails to accurately handle signals with data points below the baseline.Such signals are common across various physiological measurements,including electroencephalograph(EEG)and functional magnetic resonance imaging(fMRI),and are crucial for insights into physiological phenomena.This study introduces a novel method,the baseline perspective visibility graph(BPVG),which can analyze time series by accurately capturing connectivity across data points both above and below the baseline.We present the BPVG construction process and validate its performance using simulated signals.Results demonstrate that BPVG accurately translates periodic,random,and fractal signals into regular,random,and scale-free networks respectively,exhibiting diverse degree distribution traits.Furthermore,we apply BPVG to classify Alzheimer’s disease(AD)patients from healthy controls using EEG data and identify non-demented adults at varying dementia risk using resting-state fMRI(rs-fMRI)data.Utilizing degree distribution entropy derived from BPVG networks,our results exceed the best accuracy benchmark(77.01%)in EEG analysis,especially at channels F4(78.46%)and O1(81.54%).Additionally,our rs-fMRI analysis achieves a statistically significant classification accuracy of 76.74%.These findings highlight the effectiveness of BPVG in distinguishing various time series types and its practical utility in EEG and rs-fMRI analysis for early AD detection and dementia risk assessment.In conclusion,BPVG’s validation across both simulated and real data confirms its capability to capture comprehensive information from time series,irrespective of baseline constraints,providing a novel method for studying neural physiological signals.展开更多
Toroidal torques,generated by the resonant magnetic perturbation(RMP)and acting on the plasma column,are numerically systematically investigated for an ITER baseline scenario.The neoclassical toroidal viscosity(NTV),i...Toroidal torques,generated by the resonant magnetic perturbation(RMP)and acting on the plasma column,are numerically systematically investigated for an ITER baseline scenario.The neoclassical toroidal viscosity(NTV),in particular the resonant portion,is found to provide the dominant contribution to the total toroidal torque under the slow plasma flow regime in ITER.While the electromagnetic torque always opposes the plasma flow,the toroidal torque associated with the Reynolds stress enhances the plasma flow independent of the flow direction.A peculiar double-peak structure for the net NTV torque is robustly computed for ITER,as the toroidal rotation frequency is scanned near the zero value.This structure is found to be ultimately due to a non-monotonic behavior of the wave-particle resonance integral(over the particle pitch angle)in the superbanana plateau NTV regime in ITER.These findings are qualitatively insensitive to variations of a range of factors including the wall resistivity,the plasma pedestal flow and the assumed frequency of the rotating RMP field.展开更多
The intertidal zone of mangroves has a significant impact on the ecological environment by serving as a crucial habitat for a wide range of organisms.When assessing heavy metal contamination in sediments within this z...The intertidal zone of mangroves has a significant impact on the ecological environment by serving as a crucial habitat for a wide range of organisms.When assessing heavy metal contamination in sediments within this zone,it is essential to establish a regional geochemical baseline that accounts for natural variations.In this study,regional geochemical baselines of heavy metals were established based on core sediment samples collected from Dongzhai Harbor in November 2015.Linear regression analysis was employed to examine the correlations between heavy metals and potential normalized elements.Subsequently,the sediment quality and intensity of pollutant input in the sediments of a mangrove intertidal zone were evaluated with enrichment factor(EF)and excessive influx of heavy metals.The EF values for Cr,Cd,Pb,Zn,and Ni in the study area were all below 1.5,indicating minimal levels of contamination;however,minor Cu contamination was observed in the high tidal flat area due to potential terrestrial inputs.These findings suggest that the overall environmental quality about heavy metals was good within the intertidal zone of mangroves.Moreover,as for the excess fluxes of heavy metals in intertidal sediments,there was consistency between influence and intervention of human activities on sedimentary environment during the selected period when examining variation trends.展开更多
The monument thermal effect(MTE)displacements could result in periodical signals with several mil-limeters magnitudes in the vertical and horizontal GPS position time series.However,the interaction ofvarious origins o...The monument thermal effect(MTE)displacements could result in periodical signals with several mil-limeters magnitudes in the vertical and horizontal GPS position time series.However,the interaction ofvarious origins of periodic signals in GPS observations makes it difficult to isolate the millimeter-levelMTE displacement from other signals and noises.In this study,to assess the diurnal and semidiurnalsignals induced by MTE,we processed 12 very short GPS baselines(VSGB)with length<150 m.Themonument pairs for each baseline differ in their heights,horizontal structure,or base foundations.Meanwhile,two zero-baselines were also processed as the control group.Results showed that the sea-sonal signals observed in VSGB time series in the horizontal and vertical directions,were mainly inducedby seasonal MTE.Time-varying diurnal and semidiurnal signals with amplitude up to 4 mm wereobserved in the vertical direction for baselines with monument height difference(MHD)larger than10 m.Horizontal diurnal signal with an amplitude of about 2 mm was also detected for baselines withnon-axisymmetric monument structure.The orientation of the detected horizontal displacement wascoherent with the direction of daily temperature variation(DTV)driven by direct solar radiation,whichindicates that the diurnal and semidiurnal signals are likely induced by MTE.The observed high-frequency MTE displacements,if not well modeled and removed,may propagate into spurious long-term signals and bias the velocity estimation in the daily GPS time series.展开更多
Sea topography information holds significant importance in oceanic research and the climate change detection.Radar imaging altimetry has emerged as the leading approach for global ocean observation,employing synthetic...Sea topography information holds significant importance in oceanic research and the climate change detection.Radar imaging altimetry has emerged as the leading approach for global ocean observation,employing synthetic aperture radar(SAR)interferometry to enhance the spatial resolution of Sea topography.Nevertheless,current payload capacity and satellite hardware limitations prevent the extension of the interferometric baseline by enlarging the physical antenna size.This constraint hinders achieving centimeter-level accuracy in interferometric altimetry.To address this challenge,we conducted a numerical simulation to assess the viability of a large baseline interferometric imaging altimeter(LB-IIA).By controlling the baseline within the range of 600-1000 m through spiral orbit design in two satellites and mitigating baseline de-correlation with the carrier frequency shift(CFS)technique,we aimed to overcome the above limitations.Our findings demonstrate the efficacy of the CFS technique in compensating for baseline decoherence,elevating coherence from less than 0.1 to over 0.85.Concurrently.The height difference accuracy between neighboring sea surfaces reaches 1 cm within a 1 km resolution.This study is anticipated to serve as a foundational reference for future interferometric imaging altimeter development,catering to the demand for high-precision sea topography data in accurate global bathymetry inversion.展开更多
[Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. T...[Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. The distribution of sensitivity variation of B. cinerea to boscalid in different regions was cleared, and the sen- sitivity baseline of B. cinerea from Liaoning Province to boscalid was established. [Result] The ECso values of B. cinerea strains from Liaoning Province ranged from 0.080 0 to 7.787 2μg/ml, and the highest ECho value was 97.34 times higher than the minimum. The average EC50 value （1.973μg/ml） of the 158 strains was treated as the baseline sensitivity of B. cinerea from Liaoning Province to boscalid. [Conclu- sion] It is essential to conduct a risk assessment of drug resistance in B. cinerea to boscalid.展开更多
A frequency-domain equalizer with a mixed-signal adaptive control loop and a novel baseline wander （BLW） canceller are proposed. The equalizer is independent of channel-modeling accuracy,and its control loop is intr...A frequency-domain equalizer with a mixed-signal adaptive control loop and a novel baseline wander （BLW） canceller are proposed. The equalizer is independent of channel-modeling accuracy,and its control loop is intrinsically stable. An AGC function is incorporated into the equalizer without an extra AGC circuit. The proposed BLW canceller uses a peak detector to monitor the BLW and full feedback method to accomplish BLW canceling. High canceling accuracy and robust performance are achieved. The circuits are tested in 0.25μm CMOS technology. Better performance and smaller silicon area are achieved compared with results in the literature.展开更多
When the cycle slips take place in the attitude determination of a moving platform, the precision of the attitude will be impaired badly. A method of cycle slip detection and correction is proposed, which is suitable ...When the cycle slips take place in the attitude determination of a moving platform, the precision of the attitude will be impaired badly. A method of cycle slip detection and correction is proposed, which is suitable to the dynamic measurement using GPS carrier phase： the cycle slips detection is first achieved by triple difference observables, then the cycle slips correction is performed with baseline length constraint. The simulation results show that the proposed method is effective to the dynamic cycle slips problem.展开更多
AIM: To characterize the baseline profiles of patients aged 70 years and above with hepatocellular carcinoma (HCC).METHODS: A series of 127 consecutive patients with HCC were enrolled between 2000 and 2004, and none o...AIM: To characterize the baseline profiles of patients aged 70 years and above with hepatocellular carcinoma (HCC).METHODS: A series of 127 consecutive patients with HCC were enrolled between 2000 and 2004, and none of them had been diagnosed as having HCC previously. Baseline profiles, including parameters of hepatic function such as serum transaminase and prothrombin time [PT (% activity)] were compared between patients aged ≥70 and ＜70 years.RESULTS: Patients ≥70 years old showed significantly lower levels of aspartate aminotransferase (P = 0.04)and alanine aminotransferase (P = 0.01), and significantly higher PTs (P= 0.04) and platelet counts (P = 0.02).Concomitantly, among ≥70-year-old patients, HCC was more common in non-cirrhotics, whereas among patients ＜70 years old, HCC was more common in cirrhotics. There was no significant difference between the groups in the number or size of tumors.CONCLUSION: Older HCC patients showed less inflammation and better preservation of hepatic function, indicating that not only cirrhotic patients but also noncirrhotic patients should be considered as a high-risk group among the elderly.展开更多
Urban topsoil is the most frequent interface between human society and natural environment.The accumulation of heavy metals in the urban topsoil has a direct effect on residents'life and health.The geochemical bas...Urban topsoil is the most frequent interface between human society and natural environment.The accumulation of heavy metals in the urban topsoil has a direct effect on residents'life and health.The geochemical baseline of heavy metals is an objective description of the general level of heavy metals in the urban topsoil.Meanwhile,the determination of geochemical baseline is necessary for regional environmental management,especially in coal cities prone to heavy metal pollution.Heavy metal pollution has become an environmental problem in Fuxin City,China for a long time.To establish the geochemical baseline of heavy metals in the topsoil of Fuxin City and to evaluate the ecological risk of the topsoil,we collected 75 topsoil samples(0–20 cm)and analyzed the concentrations of Cu,Ni,Zn,Pb,Cr,Cd,Hg and As through X-ray fluorescence spectrometry,atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry.We determined the geochemical baseline of heavy metals in the topsoil of Fuxin City by using iteration removal,box-whisker plot,cumulative frequency curve and reference metal normalization;evaluated the contamination risk and ecological risk of the topsoil by using the baseline factor index,Nemerow index and Hakanson potential ecological risk index;and identified the source category of heavy metals in the topsoil by using a pedigree clustering heatmap.Results showed that the geochemical baseline values were 42.86,89.34,92.23,60.55,145.21,0.09,0.08 and 4.17 mg/kg for Cu,Ni,Zn,Pb,Cr,Cd,Hg and As,respectively.The results of Nemerow index and Hakanson potential ecological risk index indicated that the urban topsoil in the study area was slightly contaminated and suffering low potential ecological risk.The main contaminated areas dominated in the middle part and northeast part of the study area,especially in the western Haizhou Strip Mine.The result of baseline factor index indicated that Hg and Cd were the major pollution elements.Using a pedigree clustering heatmap,we divided the sources of these heavy metals into three types:type I for Ni and Cr,largely represented the enrichment of heavy metals from natural sources;type II for Cu,Pb,Zn,Cd and As,mainly represented the enrichment of heavy metals from anthropogenic sources;and type III for Hg,represented the form of both natural and anthropogenic inputs.展开更多
Baseline offset in digital strong-motion acceleration record and initial velocity can produce unrealistic results for ground velocity and displacement derived from the acceleration by integration. A new method is prop...Baseline offset in digital strong-motion acceleration record and initial velocity can produce unrealistic results for ground velocity and displacement derived from the acceleration by integration. A new method is proposed for the baseline correction and initial velocity calculation. It is based on linear least-squares fitting of the pre-event portion of velocity derived from the uncorrected acceleration data. Compared with the conventional method,which is based on removing the mean values of the pre-event portions of the acceleration and velocity traces,this method has clearer physical meaning and better stability.展开更多
基金supported by scientific research projects of China Academy of Railway Sciences Co.,Ltd.(grant no.2024YJ117).
文摘Purpose-Amidst an increasingly severe cybersecurity landscape,the widespread adoption of Xinchuang endpoints has become a strategic imperative.Governments and enterprises have established terminal localization as a critical objective,aiming for comprehensive indigenous replacement through rapid technological iteration.Consequently,Xinchuang systems and Windows platforms are expected to coexist over an extended period.This study seeks to establish an automated verification framework for multi-version operating systems and validate the efficacy of baseline hardening in mitigating security risks.Design/methodology/approach-Based on the Classified Protection 2.0 framework and relevant national standards for endpoint security,this study proposes an endpoint security baseline verification scheme applicable to multiple operating systems.The scheme addresses divergent security policies and implementation methodologies across heterogeneous environments.It automates the inspection of core baselines,including account password complexity,default shared service status and patch installation status.Furthermore,a comprehensive scoring model is established by incorporating differentiated weights for account security,patch management and log auditing,ultimately generating visualized risk reports to facilitate remediation prioritization.Findings-This study reveals that baseline configuration serves as the fundamental prerequisite in endpoint security practices.Through a scalable detection engine and quantitative scoring model,the system can promptly identify and remediate potential risks,thereby reducing the attack surface and mitigating intrusion risks.However,on certain domestic chip architectures,compatibility issues persist in detecting specific configuration items.Further improvement in hardware-software co-adaptation for domestic platforms is required to advance the development of localized security protection systems.Originality/value-Through in-depth research on security baseline configurations across multiple operating systems,this study implements an automated and visualized baseline verification methodology.This approach significantly strengthens the security posture of domestic operating systems and supports the establishment of a more robust,national-level cybersecurity defense framework.
文摘This paper delves into the baseline design under the baseline parameterization model in experimental design, focusing on the relationship between the K-aberration criterion and the word length pattern (WLP) of regular two-level designs. The paper provides a detailed analysis of the relationship between K5and the WLP for regular two-level designs with resolution t=3, and proposes corresponding theoretical results. These results not only theoretically reveal the connection between the orthogonal parameterization model and the baseline parameterization model but also provide theoretical support for finding the K-aberration optimal regular two-level baseline designs. It demonstrates how to apply these theories to evaluate and select the optimal experimental designs. In practical applications, experimental designers can utilize the theoretical results of this paper to quickly assess and select regular two-level baseline designs with minimal K-aberration by analyzing the WLP of the experimental design. This allows for the identification of key factors that significantly affect the experimental outcomes without frequently changing the factor levels, thereby maximizing the benefits of the experiment.
基金funded by the National Key Research and Developmental Program of China(2022YFD1700200).
文摘The rice stem borer,Chilo suppressalis(Walker)(Lepidoptera:Crambidae),is one of the most serious pests in rice-growing areas,and it has developed resistance to most insecticides currently used in the field.Cyproflanilide is a novel meta-diamide insecticide that has shown high activities to multiple pests.Evaluating the risk of resistance to cyproflanilide in C.suppressalis is necessary for its preventive resistance management.Here we established the baseline susceptibility of C.suppressalis to cyproflanilide by the rice-seedling dipping method and topical application,and the LC_(50) and LD_(50) values were 0.026 mg L^(-1) and 0.122 ng/larva,respectively.The LC_(50) values of cyproflanilide in 37 field populations ranged from 0.012 to 0.061 mg L^(-1),and 25 field populations exhibited resistance to chlorantraniliprole with the highest LC_(50) value of 3,770.059 mg L^(-1).In addition,a logistic distribution model analysis indicated that only 0.048 mg L^(-1) of cyproflanilide was required to kill 90% field chlorantraniliprole-resistant populations of C.suppressalis,compared to 2,087.764 mg L^(-1) of chlorantraniliprole for a similar level of control.Resistance screening over 19 generations did not result in resistance to cyproflanilide(RR=3.1-fold).The realized heritability(h^(2))of resistance was estimated as 0.067 by using threshold trait analysis,suggesting a low risk of cyproflanilide resistance development in susceptible strains.The Cypro-SEL population(F_(10))had no obvious fitness cost(relative fitness=0.96),and no significant changes in sensitivity to seven tested insecticides.These findings suggested that cyproflanilide is a promising insecticide for the management of chlorantraniliprole-resistant C.suppressalis.Moreover,this integrated risk assessment provides scientific application guidelines for the sustainable resistance management of cyproflanilide for controlling C.suppressalis.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF1204803)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20190736)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.NJ2024029)the National Natural Science Foundation of China(Grant Nos.81701346 and 62201265).
文摘The natural visibility graph method has been widely used in physiological signal analysis,but it fails to accurately handle signals with data points below the baseline.Such signals are common across various physiological measurements,including electroencephalograph(EEG)and functional magnetic resonance imaging(fMRI),and are crucial for insights into physiological phenomena.This study introduces a novel method,the baseline perspective visibility graph(BPVG),which can analyze time series by accurately capturing connectivity across data points both above and below the baseline.We present the BPVG construction process and validate its performance using simulated signals.Results demonstrate that BPVG accurately translates periodic,random,and fractal signals into regular,random,and scale-free networks respectively,exhibiting diverse degree distribution traits.Furthermore,we apply BPVG to classify Alzheimer’s disease(AD)patients from healthy controls using EEG data and identify non-demented adults at varying dementia risk using resting-state fMRI(rs-fMRI)data.Utilizing degree distribution entropy derived from BPVG networks,our results exceed the best accuracy benchmark(77.01%)in EEG analysis,especially at channels F4(78.46%)and O1(81.54%).Additionally,our rs-fMRI analysis achieves a statistically significant classification accuracy of 76.74%.These findings highlight the effectiveness of BPVG in distinguishing various time series types and its practical utility in EEG and rs-fMRI analysis for early AD detection and dementia risk assessment.In conclusion,BPVG’s validation across both simulated and real data confirms its capability to capture comprehensive information from time series,irrespective of baseline constraints,providing a novel method for studying neural physiological signals.
基金funded by National Natural Science Foundation of China(NSFC)(Nos.12075053,11505021 and 11975068)by National Key R&D Program of China(No.2022YFE 03060002)+1 种基金by Fundamental Research Funds for the Central Universities(No.2232024G-10)supported by the U.S.DoE Office of Science(No.DE-FG02–95ER54309)。
文摘Toroidal torques,generated by the resonant magnetic perturbation(RMP)and acting on the plasma column,are numerically systematically investigated for an ITER baseline scenario.The neoclassical toroidal viscosity(NTV),in particular the resonant portion,is found to provide the dominant contribution to the total toroidal torque under the slow plasma flow regime in ITER.While the electromagnetic torque always opposes the plasma flow,the toroidal torque associated with the Reynolds stress enhances the plasma flow independent of the flow direction.A peculiar double-peak structure for the net NTV torque is robustly computed for ITER,as the toroidal rotation frequency is scanned near the zero value.This structure is found to be ultimately due to a non-monotonic behavior of the wave-particle resonance integral(over the particle pitch angle)in the superbanana plateau NTV regime in ITER.These findings are qualitatively insensitive to variations of a range of factors including the wall resistivity,the plasma pedestal flow and the assumed frequency of the rotating RMP field.
基金Supported by the Project of Investigation on the Background and Quality of Representative Intertidal Sediments in China and Compilation of Atlas,Ministry of Science and Technology of the People’s Republic of China(No.2014FY210600)the National Natural Science Foundation of China(No.41807247)。
文摘The intertidal zone of mangroves has a significant impact on the ecological environment by serving as a crucial habitat for a wide range of organisms.When assessing heavy metal contamination in sediments within this zone,it is essential to establish a regional geochemical baseline that accounts for natural variations.In this study,regional geochemical baselines of heavy metals were established based on core sediment samples collected from Dongzhai Harbor in November 2015.Linear regression analysis was employed to examine the correlations between heavy metals and potential normalized elements.Subsequently,the sediment quality and intensity of pollutant input in the sediments of a mangrove intertidal zone were evaluated with enrichment factor(EF)and excessive influx of heavy metals.The EF values for Cr,Cd,Pb,Zn,and Ni in the study area were all below 1.5,indicating minimal levels of contamination;however,minor Cu contamination was observed in the high tidal flat area due to potential terrestrial inputs.These findings suggest that the overall environmental quality about heavy metals was good within the intertidal zone of mangroves.Moreover,as for the excess fluxes of heavy metals in intertidal sediments,there was consistency between influence and intervention of human activities on sedimentary environment during the selected period when examining variation trends.
基金funded by the Independent Innovation Project of Changjiang Institute of Survey,Planning,Design and Research Corporation (CX2020Z32)supported by the National Natural Science Foundation of China (Grant Numbers42204006 and 42104028)the Open Fund of Hubei Luojia Laboratory (Grant Numbers 230100020 and 230100019)
文摘The monument thermal effect(MTE)displacements could result in periodical signals with several mil-limeters magnitudes in the vertical and horizontal GPS position time series.However,the interaction ofvarious origins of periodic signals in GPS observations makes it difficult to isolate the millimeter-levelMTE displacement from other signals and noises.In this study,to assess the diurnal and semidiurnalsignals induced by MTE,we processed 12 very short GPS baselines(VSGB)with length<150 m.Themonument pairs for each baseline differ in their heights,horizontal structure,or base foundations.Meanwhile,two zero-baselines were also processed as the control group.Results showed that the sea-sonal signals observed in VSGB time series in the horizontal and vertical directions,were mainly inducedby seasonal MTE.Time-varying diurnal and semidiurnal signals with amplitude up to 4 mm wereobserved in the vertical direction for baselines with monument height difference(MHD)larger than10 m.Horizontal diurnal signal with an amplitude of about 2 mm was also detected for baselines withnon-axisymmetric monument structure.The orientation of the detected horizontal displacement wascoherent with the direction of daily temperature variation(DTV)driven by direct solar radiation,whichindicates that the diurnal and semidiurnal signals are likely induced by MTE.The observed high-frequency MTE displacements,if not well modeled and removed,may propagate into spurious long-term signals and bias the velocity estimation in the daily GPS time series.
文摘Sea topography information holds significant importance in oceanic research and the climate change detection.Radar imaging altimetry has emerged as the leading approach for global ocean observation,employing synthetic aperture radar(SAR)interferometry to enhance the spatial resolution of Sea topography.Nevertheless,current payload capacity and satellite hardware limitations prevent the extension of the interferometric baseline by enlarging the physical antenna size.This constraint hinders achieving centimeter-level accuracy in interferometric altimetry.To address this challenge,we conducted a numerical simulation to assess the viability of a large baseline interferometric imaging altimeter(LB-IIA).By controlling the baseline within the range of 600-1000 m through spiral orbit design in two satellites and mitigating baseline de-correlation with the carrier frequency shift(CFS)technique,we aimed to overcome the above limitations.Our findings demonstrate the efficacy of the CFS technique in compensating for baseline decoherence,elevating coherence from less than 0.1 to over 0.85.Concurrently.The height difference accuracy between neighboring sea surfaces reaches 1 cm within a 1 km resolution.This study is anticipated to serve as a foundational reference for future interferometric imaging altimeter development,catering to the demand for high-precision sea topography data in accurate global bathymetry inversion.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest of China(201303025)~~
文摘[Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. The distribution of sensitivity variation of B. cinerea to boscalid in different regions was cleared, and the sen- sitivity baseline of B. cinerea from Liaoning Province to boscalid was established. [Result] The ECso values of B. cinerea strains from Liaoning Province ranged from 0.080 0 to 7.787 2μg/ml, and the highest ECho value was 97.34 times higher than the minimum. The average EC50 value （1.973μg/ml） of the 158 strains was treated as the baseline sensitivity of B. cinerea from Liaoning Province to boscalid. [Conclu- sion] It is essential to conduct a risk assessment of drug resistance in B. cinerea to boscalid.
文摘A frequency-domain equalizer with a mixed-signal adaptive control loop and a novel baseline wander （BLW） canceller are proposed. The equalizer is independent of channel-modeling accuracy,and its control loop is intrinsically stable. An AGC function is incorporated into the equalizer without an extra AGC circuit. The proposed BLW canceller uses a peak detector to monitor the BLW and full feedback method to accomplish BLW canceling. High canceling accuracy and robust performance are achieved. The circuits are tested in 0.25μm CMOS technology. Better performance and smaller silicon area are achieved compared with results in the literature.
文摘When the cycle slips take place in the attitude determination of a moving platform, the precision of the attitude will be impaired badly. A method of cycle slip detection and correction is proposed, which is suitable to the dynamic measurement using GPS carrier phase： the cycle slips detection is first achieved by triple difference observables, then the cycle slips correction is performed with baseline length constraint. The simulation results show that the proposed method is effective to the dynamic cycle slips problem.
文摘AIM: To characterize the baseline profiles of patients aged 70 years and above with hepatocellular carcinoma (HCC).METHODS: A series of 127 consecutive patients with HCC were enrolled between 2000 and 2004, and none of them had been diagnosed as having HCC previously. Baseline profiles, including parameters of hepatic function such as serum transaminase and prothrombin time [PT (% activity)] were compared between patients aged ≥70 and ＜70 years.RESULTS: Patients ≥70 years old showed significantly lower levels of aspartate aminotransferase (P = 0.04)and alanine aminotransferase (P = 0.01), and significantly higher PTs (P= 0.04) and platelet counts (P = 0.02).Concomitantly, among ≥70-year-old patients, HCC was more common in non-cirrhotics, whereas among patients ＜70 years old, HCC was more common in cirrhotics. There was no significant difference between the groups in the number or size of tumors.CONCLUSION: Older HCC patients showed less inflammation and better preservation of hepatic function, indicating that not only cirrhotic patients but also noncirrhotic patients should be considered as a high-risk group among the elderly.
基金the National Natural Science Foundation of China(41271064)the Foundation of Liaoning Educational Committee,China(L201783640)the PhD Research Startup Foundation of Liaoning University,China(BS2018L014)。
文摘Urban topsoil is the most frequent interface between human society and natural environment.The accumulation of heavy metals in the urban topsoil has a direct effect on residents'life and health.The geochemical baseline of heavy metals is an objective description of the general level of heavy metals in the urban topsoil.Meanwhile,the determination of geochemical baseline is necessary for regional environmental management,especially in coal cities prone to heavy metal pollution.Heavy metal pollution has become an environmental problem in Fuxin City,China for a long time.To establish the geochemical baseline of heavy metals in the topsoil of Fuxin City and to evaluate the ecological risk of the topsoil,we collected 75 topsoil samples(0–20 cm)and analyzed the concentrations of Cu,Ni,Zn,Pb,Cr,Cd,Hg and As through X-ray fluorescence spectrometry,atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry.We determined the geochemical baseline of heavy metals in the topsoil of Fuxin City by using iteration removal,box-whisker plot,cumulative frequency curve and reference metal normalization;evaluated the contamination risk and ecological risk of the topsoil by using the baseline factor index,Nemerow index and Hakanson potential ecological risk index;and identified the source category of heavy metals in the topsoil by using a pedigree clustering heatmap.Results showed that the geochemical baseline values were 42.86,89.34,92.23,60.55,145.21,0.09,0.08 and 4.17 mg/kg for Cu,Ni,Zn,Pb,Cr,Cd,Hg and As,respectively.The results of Nemerow index and Hakanson potential ecological risk index indicated that the urban topsoil in the study area was slightly contaminated and suffering low potential ecological risk.The main contaminated areas dominated in the middle part and northeast part of the study area,especially in the western Haizhou Strip Mine.The result of baseline factor index indicated that Hg and Cd were the major pollution elements.Using a pedigree clustering heatmap,we divided the sources of these heavy metals into three types:type I for Ni and Cr,largely represented the enrichment of heavy metals from natural sources;type II for Cu,Pb,Zn,Cd and As,mainly represented the enrichment of heavy metals from anthropogenic sources;and type III for Hg,represented the form of both natural and anthropogenic inputs.
基金supported by the National Natural Science Foundation of China( 41004020)the Director Foundation of Institute of Seismology,CEA(IS200926044)
文摘Baseline offset in digital strong-motion acceleration record and initial velocity can produce unrealistic results for ground velocity and displacement derived from the acceleration by integration. A new method is proposed for the baseline correction and initial velocity calculation. It is based on linear least-squares fitting of the pre-event portion of velocity derived from the uncorrected acceleration data. Compared with the conventional method,which is based on removing the mean values of the pre-event portions of the acceleration and velocity traces,this method has clearer physical meaning and better stability.
