Objective: Given the unique cultural background, way of life, and physical environment of the Tibetan Plateau, this study aims to investigate the effects of health education using problem-based learning (PBL) approach...Objective: Given the unique cultural background, way of life, and physical environment of the Tibetan Plateau, this study aims to investigate the effects of health education using problem-based learning (PBL) approaches on the knowledge, attitude, practice, and coping skills of women with high-risk pregnancies in this region. Methods: 76 high-risk pregnancy cases were enrolled at Tibet’s Linzhi People’s Hospital between September 2023 and April 2024. 30 patients admitted between September 2023 and December 2023 were selected as the control group and were performed with regular patient education. 46 patients admitted between January 2024 and April 2024 were selected as the observation group and were performed regular patient education with problem-based learning approaches. Two groups’ performance on their health knowledge, attitude, practice and coping skills before and after interventions were evaluated, and patient satisfaction were measured at the end of the study. Results: There was no statistical significance (P P P Conclusions: Health education with problem-based learning approaches is worth promoting as it can help high-risk pregnant women in plateau areas develop better health knowledge, attitude and practice and healthier coping skills. Also, it can improve patient sanctification.展开更多
Luzon Strait is the main channel connecting the South China Sea(SCS)and the western Pacific,with complex atmospheric and oceanic dynamic processes.Based on 44 days of glider measurements and satellite observations,we ...Luzon Strait is the main channel connecting the South China Sea(SCS)and the western Pacific,with complex atmospheric and oceanic dynamic processes.Based on 44 days of glider measurements and satellite observations,we investigated the temporal and vertical variations of chlorophyll-a(Chl-a)concentration in the Luzon Strait from July 25 to September 6,2019.The Chl a was mainly distributed above 200 m and concentrated in the subsurface chlorophyll maximum(SCM)layer.The depth of SCM ranged between 50 m and 110 m,and the magnitude of SCM varied from 0.42 mg/m3 to 1.12 mg/m3.The variation of Chl a was identified with three stages responding to different dynamic processes.Under the influence of Kuroshio intrusion,the SCM depth sharply deepened,and its magnitude decreased in Stage 1.Afterward,a prominent Chl-a bloom was observed in the SCM layer from August 6 to August 16.The Chl-a bloom in Stage 2 was related to the influence of a cyclonic eddy,which uplifted of the thermocline and thus the deep nutrients.During Stage 3,prolonged heavy rainfall in the northeastern SCS resulted in a significant salinity decrease in the upper ocean.The convergence of upper water deepened the thermocline and the mixed layer.Thus,the Chl a decreased in the SCM layer but increased in the surface layer.In particular,a typhoon passed through the Luzon Strait on August 24,which induced the Chl a increase in the upper 50 m.However,there was little change in the depth-integrated Chl a(0-200 m),indicating that the Chl a increase in the surface layer was likely associated with physical entrainment of SCM caused by strong mixing,rather than the phytoplankton bloom in the upper water column.Underwater gliders provide frequent autonomous observations that help us understand the regional ocean’s complex dynamic processes and biological responses.展开更多
Frequency diverse array(FDA)radar has been studied for more than 15 years and has attracted a lot of attention due to its potential advantages over the well-known phased array radar.The representative feature of FDA i...Frequency diverse array(FDA)radar has been studied for more than 15 years and has attracted a lot of attention due to its potential advantages over the well-known phased array radar.The representative feature of FDA is range-angle-time-dependent transmit beampattern and its underlying properties are continuously revealed in the research.The formulation and exploitation of the transmit diversity with a frequency increment is the fundamental principle,which brings extra degrees-of-freedom(DOFs)in the transmit dimension.As the FDA radar carries additional information in range,it provides more flexibility in signal processing and also brings in new technical issues.This article overviews the state-of-the-art in FDA radar area and its applications,mainly based on the progress in our group.There are two main catalogs in FDA radar area,namely coherent FDA and FDA-MIMO(multiple-input multiple-output)radars.Potential applications including target parameter estimation,ambiguous clutter suppression,and deceptive jammer suppression are discussed.展开更多
Palmatine is a valuable ingredient in Chinese medicine that is produced by Phellodendron amurense Rupr. The contents of palmatine content in root bark, trunk bark, perennial branch bark, annual branches, and leaves of...Palmatine is a valuable ingredient in Chinese medicine that is produced by Phellodendron amurense Rupr. The contents of palmatine content in root bark, trunk bark, perennial branch bark, annual branches, and leaves of the trees with different ages and geographies in Northeast China were measured by high-performance liquid chromatography. The contents of palmatine in the barks of root, trunk, and perennial branch were significantly higher than those in annual branches and leaves. The contents of palmatine in trunk bark and root bark from Lesser Khingan Mountains increased with age, which is significantly opposite to other three vegetation types. The contents of palmatine in perennial branch bark, annual bark and leaves had no significant reg- ularity. Moreover, the contents of palmatine in samples of root bark, trunk bark, perennial branch bark and annual bark varied significantly with latitude. The nature populations of P. amurense growing at low latitude contained significantly more palmatine than those growing at high latitude. These results provide a scientific basis for the reasonable cultivation and efficient utilization of P. amurense.展开更多
Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)have attracted considerable attention as solid-state electrolytes owing to their high ionic conductivities similar to those of liquid electrolytes,ex...Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)have attracted considerable attention as solid-state electrolytes owing to their high ionic conductivities similar to those of liquid electrolytes,excellent contacts with the electrodes,and good mechanic properties.As a crucial property of a solid-state electrolyte,the ionic conductivity of the PPCE directly depends on the interactions between the constituent parts including the polymer,lithium salt,and SN.A few studies have focused on the effects of polymer–lithium–salt and polymer–SN interactions on the PPCE ionic conductivity.Nevertheless,the impact of the lithium–salt–SN combination on the PPCE ionic conductivity has not been analyzed.In particular,tuning of the lithium-salt–SN interaction to fabricate a subzero PPCE with a high low-temperature ionic conductivity has not been reported.In this study,we design and fabricate five PPCE membranes with different weight ratios of Li N(SO2 CF3)2(Li TFSI)and SN to investigate the effect of the Li TFSI–SN interaction on the PPCE ionic conductivity.The ionic conductivities of the five PPCEs are investigated in the temperature range of–20 to 60°C by electro-chemical impedance spectroscopy.The interaction is analyzed by Fourier-transform infrared spectroscopy,Raman spectroscopy,and differential scanning calorimetry.The Li TFSI–SN interaction significantly influences the melting point of the PPCE,dissociation of the Li TFSI salt,and thus the PPCE ionic conductivity.By tuning the Li TFSI–SN interaction,a subzero workable PPCE membrane having an excellent low-temperature ionic conductivity(6×10-4 S cm–1 at 0°C)is obtained.The electro-chemical performance of the optimal PPCE is evaluated by using a Li Co O2/PPCE/Li4 Ti5 O12 cell,which confirms the application feasibility of the proposed quasisolid-state electrolyte in subzero workable lithium-ion batteries.展开更多
Recently,the effectiveness of neural networks,especially convolutional neural networks,has been validated in the field of natural language processing,in which,sentiment classification for online reviews is an importan...Recently,the effectiveness of neural networks,especially convolutional neural networks,has been validated in the field of natural language processing,in which,sentiment classification for online reviews is an important and challenging task.Existing convolutional neural networks extract important features of sentences without local features or the feature sequence.Thus,these models do not perform well,especially for transition sentences.To this end,we propose a Piecewise Pooling Convolutional Neural Network(PPCNN)for sentiment classification.Firstly,with a sentence presented by word vectors,convolution operation is introduced to obtain the convolution feature map vectors.Secondly,these vectors are segmented according to the positions of transition words in sentences.Thirdly,the most significant feature of each local segment is extracted using max pooling mechanism,and then the different aspects of features can be extracted.Specifically,the relative sequence of these features is preserved.Finally,after processed by the dropout algorithm,the softmax classifier is trained for sentiment classification.Experimental results show that the proposed method PPCNN is effective and superior to other baseline methods,especially for datasets with transition sentences.展开更多
To address the issue of climate change caused by the use of polluting, non-renewable energy sources, the use of renewable energy has gained momentum worldwide. Consequently, the increased integration of renewable ener...To address the issue of climate change caused by the use of polluting, non-renewable energy sources, the use of renewable energy has gained momentum worldwide. Consequently, the increased integration of renewable energy sources into power grids has necessitated the inclusion of flexible capacities in the power systems to solve problems of intermittent and fluctuating characteristics associated with renewable generation outputs. In this work, we study the regulating cost of a power system with high renewable penetration using an improved time-series system production simulation analysis method. The operational cost of the system is considered as the objective function. Three different methods to increase regulating capacities, including using interconnection lines, building additional flexible power capacities, and retrofitting existing thermal power plants, are adopted and simulated to compare the costs of accommodating renewable energy in the system in these cases. Our results indicate that increasing the flexibility of thermal power plants and developing crossregional connection lines are cost-effective methods of increasing renewable energy consumption.展开更多
A growing number of studies show that different countries and populations require different cut-off points for body mass index (BMI), and waist circumference (WC) leading to obesity. There are no data on optimal cut-o...A growing number of studies show that different countries and populations require different cut-off points for body mass index (BMI), and waist circumference (WC) leading to obesity. There are no data on optimal cut-off points to metabolic syndrome (MS) among urban residents in Ningxia. Our aim is to determine the appropriate cut-off points for BMI and WC associated with elevated prevalent MS risk among urban residents in Ningxia. A total of 2500 urban residents in Ningxia were examined from May 2008 to March 2009 in a community-based cross-sectional study. Height, body weight, waist circumference and hip circumference were measured to calculate BMI. Fasting blood glucose (FBG), plasma levels of triglyceride (TG), total cholesterol (TC), and high-density lipoprotein cholesterol (HDL-C) were examined using a blood glucose meter and the chromatographic enzyme method. BMI and WC were measured to assess overweight or obesity. Of these, 301 subjects were chosen according to metabolic syndrome diagnosis standards to form the case group. The control group comprised 301 healthy people without diabetes, hypertension, hyperlipemia, coronary heart disease, cerebrovascular disease, malignant tumors or chronic infections. Logistic regression and receiver-operating characteristic (ROC) curve analyses were used to determine optimal cut-off points for BMI and WC in relation to the area under the curve (AUC), sensitivity and specificity. The optimal cut-off points for male and female respectively were 24.78 kg/m2?(sensitivity = 0.879, specificity = 0.648) and 24.72 kg/m2?(sensitivity = 0.804, specificity = 0.767) for BMI, 85.95 cm (sensitivity = 0.701, specificity = 0.641) and 78.25 cm (sensitivity = 0.804, specificity = 0.528) for WC. Urban residents in Ningxia were at high risk of MS, and the cut-off points for BMI and WC were lower than the data currently recommended in Asian population.展开更多
Impaired iron homeostasis may cause damage to dopaminergic neurons and is critically involved in the pathogenesis of Parkinson’s disease. At present, very little is understood about the effect of neonatal iron intake...Impaired iron homeostasis may cause damage to dopaminergic neurons and is critically involved in the pathogenesis of Parkinson’s disease. At present, very little is understood about the effect of neonatal iron intake on behavior in aging animals. Therefore, we hypothesized that increased neonatal iron intake would result in signiifcant behavior abnormalities and striatal dopamine depletion during aging, and Sirtuin 2 contributes to the age-related neurotoxicity. In the present study, we observed that neonatal iron intake (120 μg/g per day) during postnatal days 10–17 resulted in significant behavior abnormalities and striatal dopamine depletion in aging rats. Furthermore, after AK-7 (a selective Sirtuin 2 inhibitor) was injected into the substantia nigra at postnatal 540 days and 570 days (5 μg/side per day), striatal dopamine depletion was signiifcant-ly diminished and behavior abnormality was improved in aging rats with neonatal iron intake. Experimental ifndings suggest that increased neonatal iron intake may result in Parkinson’s dis-ease-like neurochemical and behavioral deifcits with aging, and inhibition of Sirtuin 2 expression may be a neuroprotective measure in Parkinson’s disease.展开更多
We propose an energy-based stochastic model of wireless sensor networks (WSNs) where each sensor node is randomly and alternatively in an active and a sleep mode. We first investigate the sensor model and derive the f...We propose an energy-based stochastic model of wireless sensor networks (WSNs) where each sensor node is randomly and alternatively in an active and a sleep mode. We first investigate the sensor model and derive the formula of the steady-state probability when there are a number of data packets in different sensor modes. We then determine important sensor’s performance measures in terms of energy consumptions, average data delay and throughput. The novelty of this paper is in its development of a stochastic model in WSN with active/sleep feature and the explicit results obtained for above mentioned energy consumption and performance characteristics. These results are expected to be useful as the fundamental results in the theoretical analysis and design of various hybrid WSNs with power mode consideration.展开更多
The oxidative weathering of petrogenic organic carbon(OC_(petro)) is an important source of carbon dioxide(CO_(2)) into the atmosphere on geological timescales and significantly influences the carbon cycle and global ...The oxidative weathering of petrogenic organic carbon(OC_(petro)) is an important source of carbon dioxide(CO_(2)) into the atmosphere on geological timescales and significantly influences the carbon cycle and global climate change. However, at present, a robust proxy to assess OC_(petro)oxidation is lacking. Riverine rhenium(Re) has emerged as a potential proxy to trace OC_(petro)oxidation, but little is known about Re sources and its relationship with OC_(petro)oxidation. To better understand the robustness of this proxy, we analyzed a shale weathering profile from the early Cambrian Shuijingtuo Formation in Chengkou County, Chongqing City, to address the mobility of Re and selenium(Se) and their relationship with the oxidation of OC_(petro)by analyses of the elemental variation and sequential extraction. The results showed that the chemical index of alteration(CIA)increases from the fresh bedrock to the weathered sections, indicating enhanced weathering intensity. Based on the sequential extraction and mass transfer coefficients(τ), Re and Se mainly exist in the organic phase of shale and are paired lost with OC_(petro) during weathering, with no obvious correlation with sulfide minerals. Furthermore, the different proportions of Re and Se loss with OC_(petro) loss can be attributed to their different geochemical behaviors during weathering. Our study supports Re as a robust proxy to trace OC_(petro) oxidation, whereas Se is the potential one. In the future, combined studies on various sedimentary rock profiles with catchment basins are needed to determine the sources of riverine Re and Se and their relationships with OC_(petro) oxidation.展开更多
Domain adaptation aims to transfer knowledge from the labeled source domain to an unlabeled target domain that follows a similar but different distribution.Recently,adversarial-based methods have achieved remarkable s...Domain adaptation aims to transfer knowledge from the labeled source domain to an unlabeled target domain that follows a similar but different distribution.Recently,adversarial-based methods have achieved remarkable success due to the excellent performance of domain-invariant feature presentation learning.However,the adversarial methods learn the transferability at the expense of the discriminability in feature representation,leading to low generalization to the target domain.To this end,we propose a Multi-view Feature Learning method for the Over-penalty in Adversarial Domain Adaptation.Specifically,multi-view representation learning is proposed to enrich the discriminative information contained in domain-invariant feature representation,which will counter the over-penalty for discriminability in adversarial training.Besides,the class distribution in the intra-domain is proposed to replace that in the inter-domain to capture more discriminative information in the learning of transferrable features.Extensive experiments show that our method can improve the discriminability while maintaining transferability and exceeds the most advanced methods in the domain adaptation benchmark datasets.展开更多
Based on Argo sea surface salinity(SSS) and the related precipitation(P), evaporation(E), and sea surface height data sets, the climatological annual mean and low-frequency variability in SSS in the global ocean and t...Based on Argo sea surface salinity(SSS) and the related precipitation(P), evaporation(E), and sea surface height data sets, the climatological annual mean and low-frequency variability in SSS in the global ocean and their relationship with ocean circulation and climate change were analyzed. Meanwhile, together with previous studies, a brief retrospect and prospect of seawater salinity were given in this work. Freshwater flux(E-P) dominated the mean pattern of SSS, while the dynamics of ocean circulation modulated the spatial structure and low-frequency variability in SSS in most regions. Under global warming, the trend in SSS indicated the intensification of the global hydrological cycle, and featured a decreasing trend at low and high latitudes and an increasing trend in subtropical regions. In the most recent two decades, global warming has slowed down, which is called the"global warming hiatus". The trend in SSS during this phase, which was different to that under global warming, mainly indicated the response of the ocean surface to the decadal and multi-decadal variability in the climate system, referring to the intensification of the Walker Circulation. The significant contrast of SSS trends between the western Pacific and the southeastern Indian Ocean suggested the importance of oceanic dynamics in the cross-basin interaction in recent decades. Ocean Rossby waves and the Indonesian Throughflow contributed to the freshening trend in SSS in the southeastern Indian Ocean, while the increasing trend in the southeastern Pacific and the decreasing trend in the northern Atlantic implied a long-term linear trend under global warming. In the future, higher resolution SSS data observed by satellites, together with Argo observations, will help to extend our knowledge on the dynamics of mesoscale eddies, regional oceanography, and climate change.展开更多
Pathological cardiac hypertrophy serves as a significant foundation for cardiac dysfunction and heart failure. Recently, growing evidence has revealed that microRNAs(miRNAs) play multiple roles in biological processes...Pathological cardiac hypertrophy serves as a significant foundation for cardiac dysfunction and heart failure. Recently, growing evidence has revealed that microRNAs(miRNAs) play multiple roles in biological processes and participate in cardiovascular diseases. In the present research, we investigate the impact of miRNA-34 c-5 p on cardiac hypertrophy and the mechanism involved. The expression of miR-34 c-5 p was proved to be elevated in heart tissues from isoprenaline(ISO)-infused mice. ISO also promoted miR-34 c-5 p level in primary cultures of neonatal rat cardiomyocytes(NRCMs). Transfection with miR-34 c-5 p mimic enhanced cell surface area and expression levels of foetal-type genes atrial natriuretic factor(Anf) and β-myosin heavy chain(β-Mhc) in NRCMs. In contrast, treatment with miR-34 c-5 p inhibitor attenuated ISO-induced hypertrophic responses. Enforced expression of miR-34 c-5 p by tail intravenous injection of its agomir led to cardiac dysfunction and hypertrophy in mice, whereas inhibiting miR-34 c-5 p by specific antagomir could protect the animals against ISO-triggered hypertrophic abnormalities. Mechanistically, miR-34 c-5 p suppressed autophagic flux in cardiomyocytes, which contributed to the development of hypertrophy. Furthermore, the autophagy-related gene 4 B(ATG4 B) was identified as a direct target of miR-34 c-5 p, and miR-34 c-5 p was certified to interact with 3’untranslated region of Atg4 b mRNA by dual-luciferase reporter assay. miR-34 c-5 p reduced the expression of ATG4 B, thereby resulting in decreased autophagy activity and induction of hypertrophy. Inhibition of miR-34 c-5 p abolished the detrimental effects of ISO by restoring ATG4 B and increasing autophagy. In conclusion, our findings illuminate that miR-34 c-5 p participates in ISO-induced cardiac hypertrophy, at least partly through suppressing ATG4 B and autophagy. It suggests that regulation of miR-34 c-5 p may offer a new way for handling hypertrophy-related cardiac dysfunction.展开更多
The transmit antenna beampattern of the phased array radar is only a function of angle,limiting its ability to discriminate the targets from the same direction.Recently,the waveform diverse array radars expand the ang...The transmit antenna beampattern of the phased array radar is only a function of angle,limiting its ability to discriminate the targets from the same direction.Recently,the waveform diverse array radars expand the angle-dependent beampattern to an angle-time-range-dependent three-dimensional function by modulating the frequencies/time delays/phases across different transmit antenna elements.In this respect,extra Degrees-of-Freedom(DOFs)in the range domain are achieved,which opens up an innovative way to fulfil the tasks with enhanced system performance by jointly using the angle and range information.This paper summaries the developments of waveform diverse radars,including the Frequency Diverse Array(FDA),the Space-Time-CirculatingArray(STCA),and the Element-Pulse-Coding(EPC)frameworks,with emphasis on the analysis of the range-dependent beampattern from the basic properties upon how it is controlled.Moreover,the most recent advances of utilizing such a range-dependent beampattern in target detection,parameter estimation and identifiability,clutter suppression,jammer suppression and Synthetic Aperture Radar(SAR)imaging are discussed.展开更多
Phosphoenolpyruvate carboxykinase 1(PCK1),a step limiting enzyme of gluconeogenesis,is downregulated in hepatocellular carcinoma(HCC).Overexpression of PCK1 has been shown to suppress hepatoma cell growth,but the unde...Phosphoenolpyruvate carboxykinase 1(PCK1),a step limiting enzyme of gluconeogenesis,is downregulated in hepatocellular carcinoma(HCC).Overexpression of PCK1 has been shown to suppress hepatoma cell growth,but the underlying mechanism remains unclear.We used recombinant adenovirus overexpressing PCK1 or GFP in Huh7 cells,and the differentially expressed genes(DEGs)were identified by RNA-Seq.180 were upregulated by PCK1 overexpression,whereas 316 were downregulated.Pathway analysis illustrated that PCK1 was closely correlated with Wnt signaling pathway and TGF-beta signaling pathway.Hence,Wnt signaling pathway and its downstream component,FZD2,FZD6,FZD7 and b-catenin were confirmed by qRT-PCR and Western blot.In vivo we also observed that PCK1 had restrained tumor growth as a result of decreasing expression of b-catenin.Whole-transcriptomic profile analysis discovered that overexpression of PCK1 downregulates several oncogenic signaling pathways in HCC,providing potential therapeutic targets for improving HCC therapy.展开更多
Organic-inorganic metal halide perovskite solar cells have achieved high efficiency of 25.5%.Finding an effective means to suppress the formation of traps and correlate stability losses are thought to be a promising r...Organic-inorganic metal halide perovskite solar cells have achieved high efficiency of 25.5%.Finding an effective means to suppress the formation of traps and correlate stability losses are thought to be a promising route for further increasing the photovoltaic performance and commercialization potential of perovskite photovoltaic devices.Herein,we report a facile passivation model,which uses a multi-functional organic molecule to simultaneously realize the chemical passivation and field-effect passivation for the perovskite film by an upgraded anti-solvent coating method,which reduces the trap states density of the perovskite,improves interface charge transfer,and thus promotes device performance.In addition,the hydrophobic groups of the molecules can form a moisture-repelling barrier on the perovskite grains,which apparently promotes the humidity stability of the solar cells.Therefore,the optimal power conversion efficiency(PCE)of perovskite solar cells after synergistic passivation reaches 21.52%,and it can still retain 95%of the original PCE when stored in-40%humidity for 30 days.Our findings extend the scope for traps passivation to further promote both the photovoltaic performance and the stability of the perovskite solar cells.展开更多
文摘Objective: Given the unique cultural background, way of life, and physical environment of the Tibetan Plateau, this study aims to investigate the effects of health education using problem-based learning (PBL) approaches on the knowledge, attitude, practice, and coping skills of women with high-risk pregnancies in this region. Methods: 76 high-risk pregnancy cases were enrolled at Tibet’s Linzhi People’s Hospital between September 2023 and April 2024. 30 patients admitted between September 2023 and December 2023 were selected as the control group and were performed with regular patient education. 46 patients admitted between January 2024 and April 2024 were selected as the observation group and were performed regular patient education with problem-based learning approaches. Two groups’ performance on their health knowledge, attitude, practice and coping skills before and after interventions were evaluated, and patient satisfaction were measured at the end of the study. Results: There was no statistical significance (P P P Conclusions: Health education with problem-based learning approaches is worth promoting as it can help high-risk pregnant women in plateau areas develop better health knowledge, attitude and practice and healthier coping skills. Also, it can improve patient sanctification.
基金Supported by the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.2019BT02H594)the Chinese Academy of Sciences(Nos.XDB42010305,XDA15020901,133244KYSB20190031,SCSIO202201,SCSIO202204)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA13010500)the National Natural Science Foundation of China(No.41976024)the Independent Research Project Program of State Key Laboratory of Tropical Oceanography(No.LTOZZ2101)。
文摘Luzon Strait is the main channel connecting the South China Sea(SCS)and the western Pacific,with complex atmospheric and oceanic dynamic processes.Based on 44 days of glider measurements and satellite observations,we investigated the temporal and vertical variations of chlorophyll-a(Chl-a)concentration in the Luzon Strait from July 25 to September 6,2019.The Chl a was mainly distributed above 200 m and concentrated in the subsurface chlorophyll maximum(SCM)layer.The depth of SCM ranged between 50 m and 110 m,and the magnitude of SCM varied from 0.42 mg/m3 to 1.12 mg/m3.The variation of Chl a was identified with three stages responding to different dynamic processes.Under the influence of Kuroshio intrusion,the SCM depth sharply deepened,and its magnitude decreased in Stage 1.Afterward,a prominent Chl-a bloom was observed in the SCM layer from August 6 to August 16.The Chl-a bloom in Stage 2 was related to the influence of a cyclonic eddy,which uplifted of the thermocline and thus the deep nutrients.During Stage 3,prolonged heavy rainfall in the northeastern SCS resulted in a significant salinity decrease in the upper ocean.The convergence of upper water deepened the thermocline and the mixed layer.Thus,the Chl a decreased in the SCM layer but increased in the surface layer.In particular,a typhoon passed through the Luzon Strait on August 24,which induced the Chl a increase in the upper 50 m.However,there was little change in the depth-integrated Chl a(0-200 m),indicating that the Chl a increase in the surface layer was likely associated with physical entrainment of SCM caused by strong mixing,rather than the phytoplankton bloom in the upper water column.Underwater gliders provide frequent autonomous observations that help us understand the regional ocean’s complex dynamic processes and biological responses.
基金supported by the National Natural Science Foundation of China(21503100)Natural Science Foundation of Jiangxi Province(20161BAB213071,20151BAB213010)+1 种基金Project of Education Department of Jiangxi Province(GJJ150325)Sponsored Program for Cultivating Youths of Outstanding Ability in Jiangxi Normal University~~
基金This work was supported in part by the National Natural Science Foundation of China(NSFC)(Nos.61931016,62071344 and 61911530246)the Key Laboratory Equipment Advanced Research Fund(No.6142206200210).
文摘Frequency diverse array(FDA)radar has been studied for more than 15 years and has attracted a lot of attention due to its potential advantages over the well-known phased array radar.The representative feature of FDA is range-angle-time-dependent transmit beampattern and its underlying properties are continuously revealed in the research.The formulation and exploitation of the transmit diversity with a frequency increment is the fundamental principle,which brings extra degrees-of-freedom(DOFs)in the transmit dimension.As the FDA radar carries additional information in range,it provides more flexibility in signal processing and also brings in new technical issues.This article overviews the state-of-the-art in FDA radar area and its applications,mainly based on the progress in our group.There are two main catalogs in FDA radar area,namely coherent FDA and FDA-MIMO(multiple-input multiple-output)radars.Potential applications including target parameter estimation,ambiguous clutter suppression,and deceptive jammer suppression are discussed.
基金supported by Special Fund for ForestryScientific Research in the Public Interest(Grant No.201104066)
文摘Palmatine is a valuable ingredient in Chinese medicine that is produced by Phellodendron amurense Rupr. The contents of palmatine content in root bark, trunk bark, perennial branch bark, annual branches, and leaves of the trees with different ages and geographies in Northeast China were measured by high-performance liquid chromatography. The contents of palmatine in the barks of root, trunk, and perennial branch were significantly higher than those in annual branches and leaves. The contents of palmatine in trunk bark and root bark from Lesser Khingan Mountains increased with age, which is significantly opposite to other three vegetation types. The contents of palmatine in perennial branch bark, annual bark and leaves had no significant reg- ularity. Moreover, the contents of palmatine in samples of root bark, trunk bark, perennial branch bark and annual bark varied significantly with latitude. The nature populations of P. amurense growing at low latitude contained significantly more palmatine than those growing at high latitude. These results provide a scientific basis for the reasonable cultivation and efficient utilization of P. amurense.
基金financially supported by the National Natural Science Foundation of China[grant numbers:21503265,51603135,21473241]Ministry of Science and Technology[grant number:2016YFB0100102]Nantong Science and Technology Bureau[grant number:JC2018038]。
文摘Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)have attracted considerable attention as solid-state electrolytes owing to their high ionic conductivities similar to those of liquid electrolytes,excellent contacts with the electrodes,and good mechanic properties.As a crucial property of a solid-state electrolyte,the ionic conductivity of the PPCE directly depends on the interactions between the constituent parts including the polymer,lithium salt,and SN.A few studies have focused on the effects of polymer–lithium–salt and polymer–SN interactions on the PPCE ionic conductivity.Nevertheless,the impact of the lithium–salt–SN combination on the PPCE ionic conductivity has not been analyzed.In particular,tuning of the lithium-salt–SN interaction to fabricate a subzero PPCE with a high low-temperature ionic conductivity has not been reported.In this study,we design and fabricate five PPCE membranes with different weight ratios of Li N(SO2 CF3)2(Li TFSI)and SN to investigate the effect of the Li TFSI–SN interaction on the PPCE ionic conductivity.The ionic conductivities of the five PPCEs are investigated in the temperature range of–20 to 60°C by electro-chemical impedance spectroscopy.The interaction is analyzed by Fourier-transform infrared spectroscopy,Raman spectroscopy,and differential scanning calorimetry.The Li TFSI–SN interaction significantly influences the melting point of the PPCE,dissociation of the Li TFSI salt,and thus the PPCE ionic conductivity.By tuning the Li TFSI–SN interaction,a subzero workable PPCE membrane having an excellent low-temperature ionic conductivity(6×10-4 S cm–1 at 0°C)is obtained.The electro-chemical performance of the optimal PPCE is evaluated by using a Li Co O2/PPCE/Li4 Ti5 O12 cell,which confirms the application feasibility of the proposed quasisolid-state electrolyte in subzero workable lithium-ion batteries.
基金This work is supported in part by the Natural Science Foundation of China under grants(61503112,61673152 and 61503116).
文摘Recently,the effectiveness of neural networks,especially convolutional neural networks,has been validated in the field of natural language processing,in which,sentiment classification for online reviews is an important and challenging task.Existing convolutional neural networks extract important features of sentences without local features or the feature sequence.Thus,these models do not perform well,especially for transition sentences.To this end,we propose a Piecewise Pooling Convolutional Neural Network(PPCNN)for sentiment classification.Firstly,with a sentence presented by word vectors,convolution operation is introduced to obtain the convolution feature map vectors.Secondly,these vectors are segmented according to the positions of transition words in sentences.Thirdly,the most significant feature of each local segment is extracted using max pooling mechanism,and then the different aspects of features can be extracted.Specifically,the relative sequence of these features is preserved.Finally,after processed by the dropout algorithm,the softmax classifier is trained for sentiment classification.Experimental results show that the proposed method PPCNN is effective and superior to other baseline methods,especially for datasets with transition sentences.
基金supported by National Key Research and Development Programe of China (No.2018YFB0904000)the State Grid Science & Technology Project (Title: Northeast Asia Power Grid Interconnection Feasibility Study)
文摘To address the issue of climate change caused by the use of polluting, non-renewable energy sources, the use of renewable energy has gained momentum worldwide. Consequently, the increased integration of renewable energy sources into power grids has necessitated the inclusion of flexible capacities in the power systems to solve problems of intermittent and fluctuating characteristics associated with renewable generation outputs. In this work, we study the regulating cost of a power system with high renewable penetration using an improved time-series system production simulation analysis method. The operational cost of the system is considered as the objective function. Three different methods to increase regulating capacities, including using interconnection lines, building additional flexible power capacities, and retrofitting existing thermal power plants, are adopted and simulated to compare the costs of accommodating renewable energy in the system in these cases. Our results indicate that increasing the flexibility of thermal power plants and developing crossregional connection lines are cost-effective methods of increasing renewable energy consumption.
文摘A growing number of studies show that different countries and populations require different cut-off points for body mass index (BMI), and waist circumference (WC) leading to obesity. There are no data on optimal cut-off points to metabolic syndrome (MS) among urban residents in Ningxia. Our aim is to determine the appropriate cut-off points for BMI and WC associated with elevated prevalent MS risk among urban residents in Ningxia. A total of 2500 urban residents in Ningxia were examined from May 2008 to March 2009 in a community-based cross-sectional study. Height, body weight, waist circumference and hip circumference were measured to calculate BMI. Fasting blood glucose (FBG), plasma levels of triglyceride (TG), total cholesterol (TC), and high-density lipoprotein cholesterol (HDL-C) were examined using a blood glucose meter and the chromatographic enzyme method. BMI and WC were measured to assess overweight or obesity. Of these, 301 subjects were chosen according to metabolic syndrome diagnosis standards to form the case group. The control group comprised 301 healthy people without diabetes, hypertension, hyperlipemia, coronary heart disease, cerebrovascular disease, malignant tumors or chronic infections. Logistic regression and receiver-operating characteristic (ROC) curve analyses were used to determine optimal cut-off points for BMI and WC in relation to the area under the curve (AUC), sensitivity and specificity. The optimal cut-off points for male and female respectively were 24.78 kg/m2?(sensitivity = 0.879, specificity = 0.648) and 24.72 kg/m2?(sensitivity = 0.804, specificity = 0.767) for BMI, 85.95 cm (sensitivity = 0.701, specificity = 0.641) and 78.25 cm (sensitivity = 0.804, specificity = 0.528) for WC. Urban residents in Ningxia were at high risk of MS, and the cut-off points for BMI and WC were lower than the data currently recommended in Asian population.
基金supported by the National Natural Science Foundation of China,No.81171204,81171203,30772280,81200871,and 81200921a grant from the Project of Shanghai Municipal Education Commission of China,No.14YZ046+2 种基金a grant from the Project of Shanghai Municipal Health and Family Planning Commission of China,No.20134049a grant from the Project of Shanghai Jiao Tong University of China,No.YG2013MS22a grant from the Projects of Shanghai Committee of Science and Technology of China,No.11nm0503300 and 12XD1403800
文摘Impaired iron homeostasis may cause damage to dopaminergic neurons and is critically involved in the pathogenesis of Parkinson’s disease. At present, very little is understood about the effect of neonatal iron intake on behavior in aging animals. Therefore, we hypothesized that increased neonatal iron intake would result in signiifcant behavior abnormalities and striatal dopamine depletion during aging, and Sirtuin 2 contributes to the age-related neurotoxicity. In the present study, we observed that neonatal iron intake (120 μg/g per day) during postnatal days 10–17 resulted in significant behavior abnormalities and striatal dopamine depletion in aging rats. Furthermore, after AK-7 (a selective Sirtuin 2 inhibitor) was injected into the substantia nigra at postnatal 540 days and 570 days (5 μg/side per day), striatal dopamine depletion was signiifcant-ly diminished and behavior abnormality was improved in aging rats with neonatal iron intake. Experimental ifndings suggest that increased neonatal iron intake may result in Parkinson’s dis-ease-like neurochemical and behavioral deifcits with aging, and inhibition of Sirtuin 2 expression may be a neuroprotective measure in Parkinson’s disease.
文摘We propose an energy-based stochastic model of wireless sensor networks (WSNs) where each sensor node is randomly and alternatively in an active and a sleep mode. We first investigate the sensor model and derive the formula of the steady-state probability when there are a number of data packets in different sensor modes. We then determine important sensor’s performance measures in terms of energy consumptions, average data delay and throughput. The novelty of this paper is in its development of a stochastic model in WSN with active/sleep feature and the explicit results obtained for above mentioned energy consumption and performance characteristics. These results are expected to be useful as the fundamental results in the theoretical analysis and design of various hybrid WSNs with power mode consideration.
基金financially supported by the National Key Research and Development Program of China(Grant No.2022YFF0800500)the National Natural Science Foundation of China(Grant No.41991322)。
文摘The oxidative weathering of petrogenic organic carbon(OC_(petro)) is an important source of carbon dioxide(CO_(2)) into the atmosphere on geological timescales and significantly influences the carbon cycle and global climate change. However, at present, a robust proxy to assess OC_(petro)oxidation is lacking. Riverine rhenium(Re) has emerged as a potential proxy to trace OC_(petro)oxidation, but little is known about Re sources and its relationship with OC_(petro)oxidation. To better understand the robustness of this proxy, we analyzed a shale weathering profile from the early Cambrian Shuijingtuo Formation in Chengkou County, Chongqing City, to address the mobility of Re and selenium(Se) and their relationship with the oxidation of OC_(petro)by analyses of the elemental variation and sequential extraction. The results showed that the chemical index of alteration(CIA)increases from the fresh bedrock to the weathered sections, indicating enhanced weathering intensity. Based on the sequential extraction and mass transfer coefficients(τ), Re and Se mainly exist in the organic phase of shale and are paired lost with OC_(petro) during weathering, with no obvious correlation with sulfide minerals. Furthermore, the different proportions of Re and Se loss with OC_(petro) loss can be attributed to their different geochemical behaviors during weathering. Our study supports Re as a robust proxy to trace OC_(petro) oxidation, whereas Se is the potential one. In the future, combined studies on various sedimentary rock profiles with catchment basins are needed to determine the sources of riverine Re and Se and their relationships with OC_(petro) oxidation.
基金This work is supported in part by the National Natural Science Foundation of China under grants(62076087,61976077)Anhui Provincial Natural Science Foundation under grants(2208085MF170).
文摘Domain adaptation aims to transfer knowledge from the labeled source domain to an unlabeled target domain that follows a similar but different distribution.Recently,adversarial-based methods have achieved remarkable success due to the excellent performance of domain-invariant feature presentation learning.However,the adversarial methods learn the transferability at the expense of the discriminability in feature representation,leading to low generalization to the target domain.To this end,we propose a Multi-view Feature Learning method for the Over-penalty in Adversarial Domain Adaptation.Specifically,multi-view representation learning is proposed to enrich the discriminative information contained in domain-invariant feature representation,which will counter the over-penalty for discriminability in adversarial training.Besides,the class distribution in the intra-domain is proposed to replace that in the inter-domain to capture more discriminative information in the learning of transferrable features.Extensive experiments show that our method can improve the discriminability while maintaining transferability and exceeds the most advanced methods in the domain adaptation benchmark datasets.
基金supported by the Chinese Academy of Sciences(Grant No.XDA19060501)the State Oceanic Administration of China(Grant No.GASI-IPOV AI-02)the National Natural Science Foundation of China(Grant Nos.41525019,41506019&41830538)
文摘Based on Argo sea surface salinity(SSS) and the related precipitation(P), evaporation(E), and sea surface height data sets, the climatological annual mean and low-frequency variability in SSS in the global ocean and their relationship with ocean circulation and climate change were analyzed. Meanwhile, together with previous studies, a brief retrospect and prospect of seawater salinity were given in this work. Freshwater flux(E-P) dominated the mean pattern of SSS, while the dynamics of ocean circulation modulated the spatial structure and low-frequency variability in SSS in most regions. Under global warming, the trend in SSS indicated the intensification of the global hydrological cycle, and featured a decreasing trend at low and high latitudes and an increasing trend in subtropical regions. In the most recent two decades, global warming has slowed down, which is called the"global warming hiatus". The trend in SSS during this phase, which was different to that under global warming, mainly indicated the response of the ocean surface to the decadal and multi-decadal variability in the climate system, referring to the intensification of the Walker Circulation. The significant contrast of SSS trends between the western Pacific and the southeastern Indian Ocean suggested the importance of oceanic dynamics in the cross-basin interaction in recent decades. Ocean Rossby waves and the Indonesian Throughflow contributed to the freshening trend in SSS in the southeastern Indian Ocean, while the increasing trend in the southeastern Pacific and the decreasing trend in the northern Atlantic implied a long-term linear trend under global warming. In the future, higher resolution SSS data observed by satellites, together with Argo observations, will help to extend our knowledge on the dynamics of mesoscale eddies, regional oceanography, and climate change.
基金supported by grants from the National Natural Science Foundation of China (81872860,81673433,and82070268)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01Y093,China)+4 种基金National Major Special Projects for the Creation and Manufacture of New Drugs (2019ZX09301104,China)National Engineering and Technology Research Center for New drug Druggability Evaluation (Seed Program of Guangdong Province,2017B090903004,China)Special Program for Applied Science and Technology of Guangdong Province (2015B020232009,China)Guangdong Basic and Applied Basic Research Foundation(2020A1515011512,China)Young Teacher Training Program of Sun Yat-sen University (18ykpy26,China)。
文摘Pathological cardiac hypertrophy serves as a significant foundation for cardiac dysfunction and heart failure. Recently, growing evidence has revealed that microRNAs(miRNAs) play multiple roles in biological processes and participate in cardiovascular diseases. In the present research, we investigate the impact of miRNA-34 c-5 p on cardiac hypertrophy and the mechanism involved. The expression of miR-34 c-5 p was proved to be elevated in heart tissues from isoprenaline(ISO)-infused mice. ISO also promoted miR-34 c-5 p level in primary cultures of neonatal rat cardiomyocytes(NRCMs). Transfection with miR-34 c-5 p mimic enhanced cell surface area and expression levels of foetal-type genes atrial natriuretic factor(Anf) and β-myosin heavy chain(β-Mhc) in NRCMs. In contrast, treatment with miR-34 c-5 p inhibitor attenuated ISO-induced hypertrophic responses. Enforced expression of miR-34 c-5 p by tail intravenous injection of its agomir led to cardiac dysfunction and hypertrophy in mice, whereas inhibiting miR-34 c-5 p by specific antagomir could protect the animals against ISO-triggered hypertrophic abnormalities. Mechanistically, miR-34 c-5 p suppressed autophagic flux in cardiomyocytes, which contributed to the development of hypertrophy. Furthermore, the autophagy-related gene 4 B(ATG4 B) was identified as a direct target of miR-34 c-5 p, and miR-34 c-5 p was certified to interact with 3’untranslated region of Atg4 b mRNA by dual-luciferase reporter assay. miR-34 c-5 p reduced the expression of ATG4 B, thereby resulting in decreased autophagy activity and induction of hypertrophy. Inhibition of miR-34 c-5 p abolished the detrimental effects of ISO by restoring ATG4 B and increasing autophagy. In conclusion, our findings illuminate that miR-34 c-5 p participates in ISO-induced cardiac hypertrophy, at least partly through suppressing ATG4 B and autophagy. It suggests that regulation of miR-34 c-5 p may offer a new way for handling hypertrophy-related cardiac dysfunction.
基金supported in part by the National Nature Science Foundation of China(Nos.62101402,61931016,62071344)China Postdoctoral Science Foundation(Nos.2021TQ0261,2021M702547)Young Elite Scientists Sponsorship Program by CAST(2021QNRC001).
文摘The transmit antenna beampattern of the phased array radar is only a function of angle,limiting its ability to discriminate the targets from the same direction.Recently,the waveform diverse array radars expand the angle-dependent beampattern to an angle-time-range-dependent three-dimensional function by modulating the frequencies/time delays/phases across different transmit antenna elements.In this respect,extra Degrees-of-Freedom(DOFs)in the range domain are achieved,which opens up an innovative way to fulfil the tasks with enhanced system performance by jointly using the angle and range information.This paper summaries the developments of waveform diverse radars,including the Frequency Diverse Array(FDA),the Space-Time-CirculatingArray(STCA),and the Element-Pulse-Coding(EPC)frameworks,with emphasis on the analysis of the range-dependent beampattern from the basic properties upon how it is controlled.Moreover,the most recent advances of utilizing such a range-dependent beampattern in target detection,parameter estimation and identifiability,clutter suppression,jammer suppression and Synthetic Aperture Radar(SAR)imaging are discussed.
基金We would like to thank Dr.Tong-Chuan He(University of Chicago,USA)for providing the AdEasy system.This study was supported by research grants from China National Natural Science Foundation(grant nos.81602417 to KW,and 81872270 and 81572683 to NT),the Major National S&T program(2017ZX10202203-004 to NT)Natural Science Foundation Project of CQ CSTC(grant no.cstc2018jcyjAX0254 to NT)The Program for Innovation Team of Higher Education in Chongqing(grant no.CXTDX201601015).
文摘Phosphoenolpyruvate carboxykinase 1(PCK1),a step limiting enzyme of gluconeogenesis,is downregulated in hepatocellular carcinoma(HCC).Overexpression of PCK1 has been shown to suppress hepatoma cell growth,but the underlying mechanism remains unclear.We used recombinant adenovirus overexpressing PCK1 or GFP in Huh7 cells,and the differentially expressed genes(DEGs)were identified by RNA-Seq.180 were upregulated by PCK1 overexpression,whereas 316 were downregulated.Pathway analysis illustrated that PCK1 was closely correlated with Wnt signaling pathway and TGF-beta signaling pathway.Hence,Wnt signaling pathway and its downstream component,FZD2,FZD6,FZD7 and b-catenin were confirmed by qRT-PCR and Western blot.In vivo we also observed that PCK1 had restrained tumor growth as a result of decreasing expression of b-catenin.Whole-transcriptomic profile analysis discovered that overexpression of PCK1 downregulates several oncogenic signaling pathways in HCC,providing potential therapeutic targets for improving HCC therapy.
基金support from the National Natural Science Foundation of China(Nos.61775081,11904127,22075101,61904066,61705020)Program for the Development of Science and Technology of Jilin Province(Nos.20200801032GH and 20190103002JH)+2 种基金the Thirteenth Five-Year Program for Science and Technology of Education Department of Jilin Province(Nos.JJKH20200417KJ)Special Project of Industrial Technology Research and Development in Jilin Province(No.2019C042-2)Construction Program for Innovation Research Team of Jilin Normal University(No.201703).
文摘Organic-inorganic metal halide perovskite solar cells have achieved high efficiency of 25.5%.Finding an effective means to suppress the formation of traps and correlate stability losses are thought to be a promising route for further increasing the photovoltaic performance and commercialization potential of perovskite photovoltaic devices.Herein,we report a facile passivation model,which uses a multi-functional organic molecule to simultaneously realize the chemical passivation and field-effect passivation for the perovskite film by an upgraded anti-solvent coating method,which reduces the trap states density of the perovskite,improves interface charge transfer,and thus promotes device performance.In addition,the hydrophobic groups of the molecules can form a moisture-repelling barrier on the perovskite grains,which apparently promotes the humidity stability of the solar cells.Therefore,the optimal power conversion efficiency(PCE)of perovskite solar cells after synergistic passivation reaches 21.52%,and it can still retain 95%of the original PCE when stored in-40%humidity for 30 days.Our findings extend the scope for traps passivation to further promote both the photovoltaic performance and the stability of the perovskite solar cells.