Microplastics(MPs)have garnered significant international scrutiny as an emerging environmental pollutant,constituting one of the four principal global environmental threats and posing potential health hazards to huma...Microplastics(MPs)have garnered significant international scrutiny as an emerging environmental pollutant,constituting one of the four principal global environmental threats and posing potential health hazards to humans.However,data on the impact of MPs on the early life of the commercially important fish remain limited.In this study,polystyrene microspheres(PS-MPs)(1 and 5μm)were used to investigate the effects of MPs on the growth,development,and metabolism in early life stages of large yellow croaker Pseudosciaena crocea.Results indicate that MPs were enriched in the gastrointestinal tract and gills of the fish.In addition,PS-MPs(1μm)exhibited no obvious effects on embryo hatching and heart rates,while increased the mortality rate(23.00%vs.control 14.99%)and decreased the body length(4098.61±447.03μm vs.control with 2827.04±254.75μm)of the larvae at the highest exposure concentration(5×10^(4)items/L).Metabolomics analysis revealed that PS-MPs(5μm)induced mild perturbations in phospholipid metabolism,specifically alterations in phosphatidylethanolamine(PE)levels.These changes influenced the cell membranes of juvenile fish,and consequently elicited inflammatory responses,disrupted lipid homeostasis,and affected other critical physiological processes.Ultimately,these effects may avoid the growth retardation and potential mortality.Therefore,PS-MPs could affect negatively the fish health in the early life stage,which has implications for aquatic ecosystems.展开更多
Engineering systems such as aero-engines have the characteristics of complex structural geometries,diverse material types and variable load spectra,which pose great challenges for predicting the service life of practi...Engineering systems such as aero-engines have the characteristics of complex structural geometries,diverse material types and variable load spectra,which pose great challenges for predicting the service life of practical engineering structures.In this regard,a novel stress fatigue life prediction model applicable to the whole life stage and complex stress states has been developed.The novel model and the widely used total strain life prediction model were used to predict the fatigue life of specimens with various alloys(TC4.TC17,FGH95,GH907.DZ125 and GH4169)and notch geometries(K_(t)=1 and K_(t)=3)as well as stress ratios(R=-1,R=0.1 and R=0.5).The results show that the novel model is applicable to the whole life stage with satisfactory life prediction accuracy,thus having greater potential in engineering applications.Furthermore,the novel model was also applied to predict the fatigue life of the bridge-type pad and plate specimen contact component within±2 dispersion band.展开更多
Effects of river water from the Yangtze River （Nanjing section） on fish development, vitellogenin （VTG） induction, gonado-somatic index （GSI） and sex ratio were investigated by exposing goldfish （Carassius aura...Effects of river water from the Yangtze River （Nanjing section） on fish development, vitellogenin （VTG） induction, gonado-somatic index （GSI） and sex ratio were investigated by exposing goldfish （Carassius auratus） in the early life stage （from fertilization to 28 days post-hatch） to water samples （25%, 50% and 100%） collected from three representative sections. The results showed that there was no significant effect on hatching success for any of the exposure groups, but survival was significantly reduced when compared with the control （P 0.05）. Body lengths, weights of all treated fish did not differ significantly from those of the control. Condition factors （CF） of larval fish exposed to 50% and 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section were significantly lower than that of the control （P 0.05）. VTG inductions were significant in larval fish exposed to all the dilution series of river water. No significant difference in CF value was observed in any exposure group after 150 days of depuration. VTG was fully eliminated after 75 days of depuration. For both female and male, GSI did not significantly differ between exposure groups and the control after 150 days of convalescence. The highest female：male ratios were observed in response to the treatment with 50% or 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section （53：47, 56：44 and 54：46, respectively）, but no significant difference in sex ratio was observed in any treated group when compared to the control. The results showed that early life stage exposure of river water from the Yangtze River （Nanjing section） had adverse effects on goldfish development and reproductive health, and the effects on CF and VTG were reversible after depuration in clean water.展开更多
Tree interactions are essential for the structure,dynamics,and function of forest ecosystems,but variations in the architecture of life-stage interaction networks(LSINs)across forests is unclear.Here,we constructed 16...Tree interactions are essential for the structure,dynamics,and function of forest ecosystems,but variations in the architecture of life-stage interaction networks(LSINs)across forests is unclear.Here,we constructed 16 LSINs in the mountainous forests of northwest Hebei,China based on crown overlap from four mixed forests with two dominant tree species.Our results show that LSINs decrease the complexity of stand densities and basal areas due to the interaction cluster differentiation.In addition,we found that mature trees and saplings play different roles,the first acting as“hub”life stages with high connectivity and the second,as“bridges”controlling information flow with high centrality.Across the forests,life stages with higher importance showed better parameter stability within LSINs.These results reveal that the structure of tree interactions among life stages is highly related to stand variables.Our efforts contribute to the understanding of LSIN complexity and provide a basis for further research on tree interactions in complex forest communities.展开更多
Natural secondary forest has a strong capacity to regrow naturally and recover biodiversity rapidly on abandoned lands.However,at the neighborhood scale,which can truly reflect the facilitative or competitive interact...Natural secondary forest has a strong capacity to regrow naturally and recover biodiversity rapidly on abandoned lands.However,at the neighborhood scale,which can truly reflect the facilitative or competitive interactions among individual plants,the local diversity spatial structure in secondary forest and the feedback effects of neighborhood diversity on natural regeneration remain unclear,and this may be the key to properly understand the mechanisms of natural secondary forest species diversity recovery.To this end,this study established a dynamic plot in a rehabilitated secondary forest after disturbance and conducted a comprehensive survey of 68,336 individual plants with repeated measurements at 5-year interval to assess the characteristics of neighborhood diversity structure across life history stages and link the neighborhood species richness(NSR)effect translated by species interactions at species diversity structure with individual trees recruitment/mortality in secondary forest regeneration.The results showed that,compared with tropical and temperate natural forests,a higher proportion of diversity accumulators and a lower proportion of repellers in subtropical secondary forests resulted in neighborhood diversity structures characterized by heterospecific or high-diversity patches,which are beneficial to the maintenance or restoration of biodiversity.As an important supplement to the research on the relationship between diversity and productivity,our findings show a positive diversity-survival relationship in subtropical secondary forests.Importantly,we observed that the neighborhood diversity structure exhibited a trend of accumulator-dominated to neutral-dominant changes with life stage from sapling to adult,which,in turn,determined the direction and strength of NSR effects on recruitment/mortality.Specifically,diverse local neighborhoods at a later successional stage characterized with‘neutral’species-species interactions can act as a‘welfare net’by offering favorable microhabitats for the most vulnerable recruitments or saplings,i.e.,the NSR effects that promoted individual recruitment/survival in our study.These results not only enrich our understanding of the biodiversity-productivity-survival relationship but also highlight the importance of retaining latesuccessional species of native trees in intensive forest production or in situ conservation policies.展开更多
Knowing the developmental states of stored grain insects, especially for the immature stages hidden in cereal kernel, such as Sitophilus zeamais, could be in favor of monitoring early and controlling effectively. Atla...Knowing the developmental states of stored grain insects, especially for the immature stages hidden in cereal kernel, such as Sitophilus zeamais, could be in favor of monitoring early and controlling effectively. Atlas and scale parameters on different developmental stages of S. zeamais in wheat kernel were captured and described by three-dimensional microscope of super depth of field observation. The four instars of larva, pre-pupa, pupa, new adult, old adult in kernel could be seen by dissecting the infested kernels. The length, height, and width of larva body increased with insect development and centralized the sizes corresponding to the four instars of larva. The length of larva body centralized near 554, 746, 1 462, and 2 147 μm. The height of larva body centralized about 388, 575, 847, and 1 651 μm. The width of larva body centralized near 340, 598, 798, and 1 568 μm. Head capsule width was in same size for each exuviating period, centralized near 203, 317, 535, and 603 μm, and got big sharply with the instar changed. Developmental duration of four larva instars was about 21 days reared in wheat, less than 28 days reared in maize as published. The atlas and description should be helpful for monitoring the S. zeamais development hidden in cereal kernels and designing control strategy.展开更多
Aggregation is suggested beneficial with foraging,defense,and other fitness for the group members.While long distance dispersal with kinship has been found in several marine fishes,similar cases have not been reported...Aggregation is suggested beneficial with foraging,defense,and other fitness for the group members.While long distance dispersal with kinship has been found in several marine fishes,similar cases have not been reported in inland waters.We utilized microsatellite genotype data of 397 eggs or juvenile silver carp(Hypophthalmichthys molitrix)born in 2017 from the middle and lower reaches of the Yangtze River in China to analyze their relatedness and infer the dispersal patterns during their early life stages and whether they dispersed with their kinship.There were 11–58 pairs of full siblings or half siblings between samples from the spawning ground(Yichang section)and other sites(34.1–1047.2 km)which showed the dispersal path.Particularly,the proportion of maternal siblings(mean:47.9%)was higher than random,indicating kinship aggregation,or that the fish traveled with their kinship during their early life stages.Such kin aggregation has profound implications for our understanding of early life stage dispersal in inland water fish populations.Our findings suggest that the preservation of habitats along the middle Yangtze River should be increased.In particular,the channelized river bank should be rebuilt with more heterogeneous habitat,and the lake-river connections should be restored to expand the amount of appropriate habitat.展开更多
A method is proposed to improve the accuracy of remaining useful life prediction for rolling element bearings,based on a state space model(SSM)with different degradation stages and a particle filter.The model is impro...A method is proposed to improve the accuracy of remaining useful life prediction for rolling element bearings,based on a state space model(SSM)with different degradation stages and a particle filter.The model is improved by a method based on the Paris formula and the Foreman formula allowing the establishment of different degradation stages.The remaining useful life of rolling element bearings can be predicted by the adjusted model with inputs of physical data and operating status information.The late operating trend is predicted by the use of the particle filter algorithm.The rolling bearing full life experimental data validate the proposed method.Further,the prediction result is compared with the single SSM and the Gamma model,and the results indicate that the predicted accuracy of the proposed method is higher with better practicability.展开更多
With improved overall survival of cervical cancer patients, the importance of the quality of life (QOL) is increasingly recognized. This study was conducted to compare the QOL of women with different stage cervical ca...With improved overall survival of cervical cancer patients, the importance of the quality of life (QOL) is increasingly recognized. This study was conducted to compare the QOL of women with different stage cervical cancer before and after treatment to facilitate improved cervical cancer prevention and treatment. We used the generic Medical Outcomes Study Short Form-36 (MOS SF-36) to collect QOL information. Based on SF-36, we interviewed cervical cancer patients at West China Second Affiliated Hospital and Sichuan Cancer Hospital between May 2010 and January 2011. A total of 92 patients with precancerous lesions, 93 with early cancer, and 35 with advanced cancer responded to our survey. Average physical component summary (PCS) scores were significantly different between the three groups at every time point (P < 0.05). Average mental component summary (MCS) scores were significantly different between the three groups after treatment (P < 0.05). Average PCS and MCS scores increased gradually from the pretreatment to posttreatment period for patients with precancerous lesions. However, they reached the lowest at 1 month after treatment for patients with early and advanced cancers and rebounded between 1 and 6 months after treatment. Our results indicate that patients with precancerous lesions and early cervical cancer show better overall QOL than do those with advanced cervical cancer. Additionally, patients with early cancer recover more quickly than do those with advanced cancer in terms of both physical and mental functions. Thus, early detection and treatment initiatives may improve the QOL for patients with precancerous lesions and cervical cancer.展开更多
Objective:To explore the effects of standardized rehabilitation on quality of life (QOL) of stroke patients at convalescence and sequelae stages. Method:A total of 251 stroke patients were randomly divided into a stan...Objective:To explore the effects of standardized rehabilitation on quality of life (QOL) of stroke patients at convalescence and sequelae stages. Method:A total of 251 stroke patients were randomly divided into a standardized rehabilitation group and a control group. The simplified Fugl-Meyer assessment(FMA) scale, the 36-item short-form health survey questionnaire (SF-36) and functional comprehensive assessment (FCA) were administered before as well as after 3, 6 and at 12 months a follow-up study respectively. Statistical analysis was conducted based on the evaluations at 4 testing time points. Result:There was no significant difference in FMA,SF-36 and FCA scores of the two groups before and after 3 months treatments, while FMA,SF-36 and FCA scores of the rehabilitation group were obviously higher than those of the control group either after 6 months treatments or of followup study. Moreover, after 6 months treatments FMA score was apparently higher than the score at the beginning and after 3 months treatments. The FMA, SF36 and FAC scores during the followup visit decreased when compared with scores after 6 months treatments, but increased significantly when compared with the scores at the beginning and after 3 months treatments. Conclusion:Standardized tertiary rehabilitation (STR) at convalescence and sequelae stages can significantly improve motor functions and QOL of stroke patients.展开更多
Suggests some calculating formulas and methods with respect to the damage evolvingrate da / dN|i and the fatigue life and in varied history from uncrack to microcrackinitiation until fracture for a crankshaft, which ...Suggests some calculating formulas and methods with respect to the damage evolvingrate da / dN|i and the fatigue life and in varied history from uncrack to microcrackinitiation until fracture for a crankshaft, which are suitable to stress concentration positionsabout its journal fillets and oil holes on a crankshaft, that it is undergone to bending, twistingand shearing loading and subjected to unsymmetric cyclic many-stage loading. Last the total lifein whole process is estimated by展开更多
空调负荷规模大且具备灵活的可控性,同时储能的充放电行为与其寿命紧密相关,针对配电网多主体如何实现在互动博弈中共赢的问题,提出了一种计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法。首先考虑墙体与外部环境的热交换,...空调负荷规模大且具备灵活的可控性,同时储能的充放电行为与其寿命紧密相关,针对配电网多主体如何实现在互动博弈中共赢的问题,提出了一种计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法。首先考虑墙体与外部环境的热交换,采用两参数热模型建立空调负荷热力学模型;其次,考虑放电深度、电池循环次数和温度对电池寿命的影响,建立储能寿命衰减模型;然后,基于配电网运行模型、空调负荷聚合商模型和储能寿命衰减模型,构建各主体收益最大的双层互动博弈模型;接着采用(Karush-KuhnTucker,KKT)条件将其转化为单层混合整数二阶锥问题,针对分布式光伏出力的不确定性,建立钻石型切割凸包不确定集合,并采用列与约束生成(column and constraint generation,C&CG)算法对两阶段鲁棒博弈问题进行求解;最后,在52节点的实际算例上进行仿真分析,验证了所提的计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法的有效性。展开更多
基金Supported by the Pioneer and Leading Goose R&D Program of Zhejiang(No.2023C03130)the National Key R&D Program of China(No.2019YFD0901101)+4 种基金the National Natural Science Foundation of China(No.42076169)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(Nos.SL2022ZD203,SL2022MS012)the Zhejiang Provincial Natural Science Founds for Distinguished Young Scientists(No.LR21D060001)the State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOEDZZ1902)the ChinaAPEC Cooperation Fund(No.2029901)。
文摘Microplastics(MPs)have garnered significant international scrutiny as an emerging environmental pollutant,constituting one of the four principal global environmental threats and posing potential health hazards to humans.However,data on the impact of MPs on the early life of the commercially important fish remain limited.In this study,polystyrene microspheres(PS-MPs)(1 and 5μm)were used to investigate the effects of MPs on the growth,development,and metabolism in early life stages of large yellow croaker Pseudosciaena crocea.Results indicate that MPs were enriched in the gastrointestinal tract and gills of the fish.In addition,PS-MPs(1μm)exhibited no obvious effects on embryo hatching and heart rates,while increased the mortality rate(23.00%vs.control 14.99%)and decreased the body length(4098.61±447.03μm vs.control with 2827.04±254.75μm)of the larvae at the highest exposure concentration(5×10^(4)items/L).Metabolomics analysis revealed that PS-MPs(5μm)induced mild perturbations in phospholipid metabolism,specifically alterations in phosphatidylethanolamine(PE)levels.These changes influenced the cell membranes of juvenile fish,and consequently elicited inflammatory responses,disrupted lipid homeostasis,and affected other critical physiological processes.Ultimately,these effects may avoid the growth retardation and potential mortality.Therefore,PS-MPs could affect negatively the fish health in the early life stage,which has implications for aquatic ecosystems.
基金funded by the National Natural Science Foundation of China(Nos.12202030,12472208)the National Science and Technology Major Project,China(No.J2019-IV-0012-0080)+3 种基金the Foundation of State Key Laboratory of Structural Analysis,Optimization and CAE Software for Industrial Equipment,China(No.GZ24122)the Foundation of the Opening Project of State Key Laboratory of Advanced Ceramics,China(No.SKL202408SIC)the Foundation of the State Key Laboratory for Strength and Vibration of Mechanical Structures,China(No.SV2024-KF-14)We also thank the equipment support from the Analysis&Testing Center in Beihang University.
文摘Engineering systems such as aero-engines have the characteristics of complex structural geometries,diverse material types and variable load spectra,which pose great challenges for predicting the service life of practical engineering structures.In this regard,a novel stress fatigue life prediction model applicable to the whole life stage and complex stress states has been developed.The novel model and the widely used total strain life prediction model were used to predict the fatigue life of specimens with various alloys(TC4.TC17,FGH95,GH907.DZ125 and GH4169)and notch geometries(K_(t)=1 and K_(t)=3)as well as stress ratios(R=-1,R=0.1 and R=0.5).The results show that the novel model is applicable to the whole life stage with satisfactory life prediction accuracy,thus having greater potential in engineering applications.Furthermore,the novel model was also applied to predict the fatigue life of the bridge-type pad and plate specimen contact component within±2 dispersion band.
基金supported by the National Natural Science Foundation of China (No. 51079049)the National Basic Research Program (973) of China (No. 2010CB429006)
文摘Effects of river water from the Yangtze River （Nanjing section） on fish development, vitellogenin （VTG） induction, gonado-somatic index （GSI） and sex ratio were investigated by exposing goldfish （Carassius auratus） in the early life stage （from fertilization to 28 days post-hatch） to water samples （25%, 50% and 100%） collected from three representative sections. The results showed that there was no significant effect on hatching success for any of the exposure groups, but survival was significantly reduced when compared with the control （P 0.05）. Body lengths, weights of all treated fish did not differ significantly from those of the control. Condition factors （CF） of larval fish exposed to 50% and 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section were significantly lower than that of the control （P 0.05）. VTG inductions were significant in larval fish exposed to all the dilution series of river water. No significant difference in CF value was observed in any exposure group after 150 days of depuration. VTG was fully eliminated after 75 days of depuration. For both female and male, GSI did not significantly differ between exposure groups and the control after 150 days of convalescence. The highest female：male ratios were observed in response to the treatment with 50% or 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section （53：47, 56：44 and 54：46, respectively）, but no significant difference in sex ratio was observed in any treated group when compared to the control. The results showed that early life stage exposure of river water from the Yangtze River （Nanjing section） had adverse effects on goldfish development and reproductive health, and the effects on CF and VTG were reversible after depuration in clean water.
基金This study was supported by the National Water Pollution Control and Treatment Science and Technology Major Project(2017ZX07101-002).
文摘Tree interactions are essential for the structure,dynamics,and function of forest ecosystems,but variations in the architecture of life-stage interaction networks(LSINs)across forests is unclear.Here,we constructed 16 LSINs in the mountainous forests of northwest Hebei,China based on crown overlap from four mixed forests with two dominant tree species.Our results show that LSINs decrease the complexity of stand densities and basal areas due to the interaction cluster differentiation.In addition,we found that mature trees and saplings play different roles,the first acting as“hub”life stages with high connectivity and the second,as“bridges”controlling information flow with high centrality.Across the forests,life stages with higher importance showed better parameter stability within LSINs.These results reveal that the structure of tree interactions among life stages is highly related to stand variables.Our efforts contribute to the understanding of LSIN complexity and provide a basis for further research on tree interactions in complex forest communities.
基金supported by the Innovative Team Project of Nanjing Institute of Environmental Sciences,MEECentral Public Welfare Scientific Institution Basal Research Fund,Ministry of Finance and Ministry of Ecology and Environment of China(Nos.GYZX210302,GYZX200203):Biodiversity Survey,Observation and Assessment Program of Ministry of Ecology and Environment of China+2 种基金The National Environmental Protection Public Welfare Industry Targeted Research Fund:Research and demonstration of key technologies for dynamic supervision of nature reserves(No.201509042)The Special Foundation for National Science and Technology Basic Resources Investigation of China(No.2019FY202300)The Jiangsu Postdoctoral Research Funding Program(No.2021K038A)。
文摘Natural secondary forest has a strong capacity to regrow naturally and recover biodiversity rapidly on abandoned lands.However,at the neighborhood scale,which can truly reflect the facilitative or competitive interactions among individual plants,the local diversity spatial structure in secondary forest and the feedback effects of neighborhood diversity on natural regeneration remain unclear,and this may be the key to properly understand the mechanisms of natural secondary forest species diversity recovery.To this end,this study established a dynamic plot in a rehabilitated secondary forest after disturbance and conducted a comprehensive survey of 68,336 individual plants with repeated measurements at 5-year interval to assess the characteristics of neighborhood diversity structure across life history stages and link the neighborhood species richness(NSR)effect translated by species interactions at species diversity structure with individual trees recruitment/mortality in secondary forest regeneration.The results showed that,compared with tropical and temperate natural forests,a higher proportion of diversity accumulators and a lower proportion of repellers in subtropical secondary forests resulted in neighborhood diversity structures characterized by heterospecific or high-diversity patches,which are beneficial to the maintenance or restoration of biodiversity.As an important supplement to the research on the relationship between diversity and productivity,our findings show a positive diversity-survival relationship in subtropical secondary forests.Importantly,we observed that the neighborhood diversity structure exhibited a trend of accumulator-dominated to neutral-dominant changes with life stage from sapling to adult,which,in turn,determined the direction and strength of NSR effects on recruitment/mortality.Specifically,diverse local neighborhoods at a later successional stage characterized with‘neutral’species-species interactions can act as a‘welfare net’by offering favorable microhabitats for the most vulnerable recruitments or saplings,i.e.,the NSR effects that promoted individual recruitment/survival in our study.These results not only enrich our understanding of the biodiversity-productivity-survival relationship but also highlight the importance of retaining latesuccessional species of native trees in intensive forest production or in situ conservation policies.
基金Supported by National Keypoint Research and Invention Program of the Thirteenth(2017YFC1600804)
文摘Knowing the developmental states of stored grain insects, especially for the immature stages hidden in cereal kernel, such as Sitophilus zeamais, could be in favor of monitoring early and controlling effectively. Atlas and scale parameters on different developmental stages of S. zeamais in wheat kernel were captured and described by three-dimensional microscope of super depth of field observation. The four instars of larva, pre-pupa, pupa, new adult, old adult in kernel could be seen by dissecting the infested kernels. The length, height, and width of larva body increased with insect development and centralized the sizes corresponding to the four instars of larva. The length of larva body centralized near 554, 746, 1 462, and 2 147 μm. The height of larva body centralized about 388, 575, 847, and 1 651 μm. The width of larva body centralized near 340, 598, 798, and 1 568 μm. Head capsule width was in same size for each exuviating period, centralized near 203, 317, 535, and 603 μm, and got big sharply with the instar changed. Developmental duration of four larva instars was about 21 days reared in wheat, less than 28 days reared in maize as published. The atlas and description should be helpful for monitoring the S. zeamais development hidden in cereal kernels and designing control strategy.
基金supported by Key R&D plan of Hubei Province[grant number 2023BCB039]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDB31000000]Science&Technology Fundamental Resources Investigation Program[grant number 2022FY100400].
文摘Aggregation is suggested beneficial with foraging,defense,and other fitness for the group members.While long distance dispersal with kinship has been found in several marine fishes,similar cases have not been reported in inland waters.We utilized microsatellite genotype data of 397 eggs or juvenile silver carp(Hypophthalmichthys molitrix)born in 2017 from the middle and lower reaches of the Yangtze River in China to analyze their relatedness and infer the dispersal patterns during their early life stages and whether they dispersed with their kinship.There were 11–58 pairs of full siblings or half siblings between samples from the spawning ground(Yichang section)and other sites(34.1–1047.2 km)which showed the dispersal path.Particularly,the proportion of maternal siblings(mean:47.9%)was higher than random,indicating kinship aggregation,or that the fish traveled with their kinship during their early life stages.Such kin aggregation has profound implications for our understanding of early life stage dispersal in inland water fish populations.Our findings suggest that the preservation of habitats along the middle Yangtze River should be increased.In particular,the channelized river bank should be rebuilt with more heterogeneous habitat,and the lake-river connections should be restored to expand the amount of appropriate habitat.
文摘A method is proposed to improve the accuracy of remaining useful life prediction for rolling element bearings,based on a state space model(SSM)with different degradation stages and a particle filter.The model is improved by a method based on the Paris formula and the Foreman formula allowing the establishment of different degradation stages.The remaining useful life of rolling element bearings can be predicted by the adjusted model with inputs of physical data and operating status information.The late operating trend is predicted by the use of the particle filter algorithm.The rolling bearing full life experimental data validate the proposed method.Further,the prediction result is compared with the single SSM and the Gamma model,and the results indicate that the predicted accuracy of the proposed method is higher with better practicability.
文摘With improved overall survival of cervical cancer patients, the importance of the quality of life (QOL) is increasingly recognized. This study was conducted to compare the QOL of women with different stage cervical cancer before and after treatment to facilitate improved cervical cancer prevention and treatment. We used the generic Medical Outcomes Study Short Form-36 (MOS SF-36) to collect QOL information. Based on SF-36, we interviewed cervical cancer patients at West China Second Affiliated Hospital and Sichuan Cancer Hospital between May 2010 and January 2011. A total of 92 patients with precancerous lesions, 93 with early cancer, and 35 with advanced cancer responded to our survey. Average physical component summary (PCS) scores were significantly different between the three groups at every time point (P < 0.05). Average mental component summary (MCS) scores were significantly different between the three groups after treatment (P < 0.05). Average PCS and MCS scores increased gradually from the pretreatment to posttreatment period for patients with precancerous lesions. However, they reached the lowest at 1 month after treatment for patients with early and advanced cancers and rebounded between 1 and 6 months after treatment. Our results indicate that patients with precancerous lesions and early cervical cancer show better overall QOL than do those with advanced cervical cancer. Additionally, patients with early cancer recover more quickly than do those with advanced cancer in terms of both physical and mental functions. Thus, early detection and treatment initiatives may improve the QOL for patients with precancerous lesions and cervical cancer.
基金supported by the Key Projects of Shanghai Science and Technology on Biomedicine(NO.10DZ1950800)the 12th Five-year Plan supporting project of Ministry of Science and Technology of the Peo-ple's Republic of China (NO: 2013BAI10B03)the Major project of Shanghai Zhabei District Health Bureau(No. 2011ZD01)
文摘Objective:To explore the effects of standardized rehabilitation on quality of life (QOL) of stroke patients at convalescence and sequelae stages. Method:A total of 251 stroke patients were randomly divided into a standardized rehabilitation group and a control group. The simplified Fugl-Meyer assessment(FMA) scale, the 36-item short-form health survey questionnaire (SF-36) and functional comprehensive assessment (FCA) were administered before as well as after 3, 6 and at 12 months a follow-up study respectively. Statistical analysis was conducted based on the evaluations at 4 testing time points. Result:There was no significant difference in FMA,SF-36 and FCA scores of the two groups before and after 3 months treatments, while FMA,SF-36 and FCA scores of the rehabilitation group were obviously higher than those of the control group either after 6 months treatments or of followup study. Moreover, after 6 months treatments FMA score was apparently higher than the score at the beginning and after 3 months treatments. The FMA, SF36 and FAC scores during the followup visit decreased when compared with scores after 6 months treatments, but increased significantly when compared with the scores at the beginning and after 3 months treatments. Conclusion:Standardized tertiary rehabilitation (STR) at convalescence and sequelae stages can significantly improve motor functions and QOL of stroke patients.
文摘Suggests some calculating formulas and methods with respect to the damage evolvingrate da / dN|i and the fatigue life and in varied history from uncrack to microcrackinitiation until fracture for a crankshaft, which are suitable to stress concentration positionsabout its journal fillets and oil holes on a crankshaft, that it is undergone to bending, twistingand shearing loading and subjected to unsymmetric cyclic many-stage loading. Last the total lifein whole process is estimated by
文摘空调负荷规模大且具备灵活的可控性,同时储能的充放电行为与其寿命紧密相关,针对配电网多主体如何实现在互动博弈中共赢的问题,提出了一种计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法。首先考虑墙体与外部环境的热交换,采用两参数热模型建立空调负荷热力学模型;其次,考虑放电深度、电池循环次数和温度对电池寿命的影响,建立储能寿命衰减模型;然后,基于配电网运行模型、空调负荷聚合商模型和储能寿命衰减模型,构建各主体收益最大的双层互动博弈模型;接着采用(Karush-KuhnTucker,KKT)条件将其转化为单层混合整数二阶锥问题,针对分布式光伏出力的不确定性,建立钻石型切割凸包不确定集合,并采用列与约束生成(column and constraint generation,C&CG)算法对两阶段鲁棒博弈问题进行求解;最后,在52节点的实际算例上进行仿真分析,验证了所提的计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法的有效性。
