As the main geomaterials for coral reefs oil or gas extraction and underground infrastructure construction,coral reef limestone demonstrates significantly distinct mechanical responses compared to terrigenous rocks.To...As the main geomaterials for coral reefs oil or gas extraction and underground infrastructure construction,coral reef limestone demonstrates significantly distinct mechanical responses compared to terrigenous rocks.To investigate the mechanical behaviour of coral reef limestone under the coupling impact of size and strain rate,the uniaxial compression tests were conducted on reef limestone samples with length-to-diameter(L/D)ratio ranging from 0.5 to 2.0 at strain rate ranging from 10^(−5)·s^(−1)to 10^(−2)·s^(−1).It is revealed that the uniaxial compressive strength(UCS)and residual compressive strength(RCS)of coral reef limestone exhibits a decreasing trend with L/D ratio increasing.The dynamic increase factor(DIF)of UCS is linearly correlated with the logarithm of strain rate,while increasing the L/D ratio further enhances the DIF.The elastic modulus increases with strain rate or L/D ratio increasing,whereas the Poisson’s ratio approximates to a constant value of 0.24.The failure strain increases with strain rate increasing or L/D ratio decreasing,while the increase in L/D ratio will inhibit the enhancing effect of the strain rate.The high porosity and low mineral strength are the primary factors contributing to a high RCS of 16.7%–64.9%of UCS,a lower brittleness index and multiple irregular fracture planes.The failure pattern of coral reef limestone transits from the shear-dominated to the splitting-dominated failure with strain rate increasing or L/D ratio decreasing,which is mainly governed by the constrained zones induced by end friction and the strain rate-dependent crack propagation.Moreover,a predictive formula incorporating coupling effect of size and strain rate for the UCS of reef limestone was established and verified to effectively capture the trend of UCS.展开更多
目的探讨中学生睡眠质量与心肺耐力的关系,为促进中国青少年身心健康全面发展提供参考。方法于2023年9—12月,在上海、苏州、太原、婺源、兴义、乌鲁木齐分别采用分层整群随机抽样法抽取5713名13~18岁中学生,采用匹兹堡睡眠质量指数量表...目的探讨中学生睡眠质量与心肺耐力的关系,为促进中国青少年身心健康全面发展提供参考。方法于2023年9—12月,在上海、苏州、太原、婺源、兴义、乌鲁木齐分别采用分层整群随机抽样法抽取5713名13~18岁中学生,采用匹兹堡睡眠质量指数量表(PSQI)结合心肺耐力测试的方法对中学生的睡眠质量和心肺耐力水平进行评估,采用Pearson相关和多元线性回归分析睡眠质量与心肺耐力的关系。结果中学生睡眠质量差的报告率为33.7%(1926/5713),13~18岁女生的PSQI评分均高于男生(χ^(2)值分别为1.60,12.78,15.62,3.04,10.09,13.65,P值均<0.05)。中学生20 m往返跑(20 m SRT)为40(27,51)次,VO2max为46.27(40.84,51.30)mL/(kg·min),各年龄段女生20 m SRT与VO2max均低于男生(Z=-15.27~-6.41,-18.06~-14.07,P值均<0.05)。男生心肺耐力(VO2max)与睡眠时间和催眠药物评分呈负相关(r值分别为-0.032,-0.005),女生VO2max与睡眠时间、日间功能障碍评分均呈负相关(r值分别为-0.028,-0.008)(P值均<0.05)。控制相关变量后,线性回归分析显示,中学生PSQI总分与VO2max呈负相关(β=-0.347,P<0.01)。结论中学生睡眠质量越好,心肺耐力水平越高。促进中学生睡眠质量有利于改善其心肺耐力水平。展开更多
Root-knot nematodes(RKNs) cause huge yield losses to agricultural crops worldwide. Meanwhile, livestock manure is often improperly managed by farmers, which leads to serious environmental pollution. To resolve these t...Root-knot nematodes(RKNs) cause huge yield losses to agricultural crops worldwide. Meanwhile, livestock manure is often improperly managed by farmers, which leads to serious environmental pollution. To resolve these two problems, this study developed a procedure for the conversion of chicken manure to organic fertilizer by larvae of Hermetia illucens L. and Bacillus subtilis BSF-CL. Chicken manure organic fertilizer was then mixed thoroughly with Paenibacillus polymyxa KM2501-1 to a final concentration of 1.5×10^(8)CFU g^(-1). The efficacy of KM2501-1 microbial organic fertilizer in controlling root-knot nematodes was evaluated in pot and field experiments. In pot experiments, applying KM2501-1 microbial organic fertilizer either as a base fertilizer or as a fumigant at the dose of 40 g/pot suppressed root-knot disease by 61.76 and 69.05% compared to the corresponding control treatments, respectively. When applied as a fumigant at the dose of 1 kg m;in field experiments, KM2501-1 microbial organic fertilizer enhanced the growth of tomato plants, suppressed root-knot disease by 49.97%, and reduced second stage juveniles of RKN in soil by 88.68%. KM2501-1 microbial organic fertilizer controlled RKNs better than commercial bio-organic fertilizer in both pot and field experiments. These results demonstrate that this co-conversion process efficiently transforms chicken manure into high value-added larvae biomass and KM2501-1 microbial organic fertilizer with potential application as a novel nematode control agent.展开更多
A new approach to the facile synthesis of 2-substituted-quinazolin-4（3H）-ones and its derivatives using the condensation reaction of substituted 2-aminobenzamide and orthoesters is reported.
This paper deals with the mean-square exponential input-to-state stability(exp-ISS)of Euler-Maruyama(EM)method applied to stochastic control systems(SCSs).The aim is to find out the conditions of the exact and EM meth...This paper deals with the mean-square exponential input-to-state stability(exp-ISS)of Euler-Maruyama(EM)method applied to stochastic control systems(SCSs).The aim is to find out the conditions of the exact and EM method solutions to an SCS having the property of mean-square exp-ISS without involving control Lyapunov functions.Second moment boundedness and an appropriate form of strong convergence are achieved under global Lipschitz coeffcients and mean-square continuous random inputs.Under the strong convergent condition,it is shown that the mean-square exp-ISS of an SCS holds if and only if that of the EM method is preserved for suffciently small step size.展开更多
Objeαive： To determine whether Interferon-alpha-2b （IFN-α2b） can modulate the autophagic response in hepatocellular carcinoma cells. Methods： Hepatocellular carcinoma cells were treated with IFN-α2b. Autophagy ...Objeαive： To determine whether Interferon-alpha-2b （IFN-α2b） can modulate the autophagic response in hepatocellular carcinoma cells. Methods： Hepatocellular carcinoma cells were treated with IFN-α2b. Autophagy was assessed by acridine orange staining, GFP-LC3 dotted assay, transmission eleαron microscopy and immunoblotting. Results： Acridine orange staining showed that IFN-α2b triggered the accumulation of acidic vesicular and autolysosomes in HepG2 cells. The acridine orange HepG2 cell ratios were （4.3±1.0）%, （6.9±1.4）%, and （13.1±2.3）%, respeαively, after treatment with 100, 1,000, and 10,000 IU/mL IFN-α2b for 48 h. A markedly punαate pattern was observed in HepG2 cells treated with 10,000 IU/mL [FN-α2b for 48 h, but only diffuse and weakly fluorescent GFP-LC3 punαa was observed in control cells. HepG2 cells treated with 10,000 IU/mL IFN-α2b for 48 h developed autophagosome-like charaαeristics, including single- or double-membrane vacuoles containing intaα and degraded cellular debris. The Beclinl and LC3-II protein expression was up-regulated by IFN-α2b treatment. Conclusion： Autophagy can be induced in a dose-dependent manner by treatment with IFN-α2b in HepG2 cells, and the Beclinl signaling pathway was stimulated by IFN-α2b.展开更多
A micro-displacement sensor based on fiber Bragg grating(FBG) is proposed. The device consists of a pair of FBGs with different central wavelengths fabricated by femtosecond laser phase mask method and a metal substra...A micro-displacement sensor based on fiber Bragg grating(FBG) is proposed. The device consists of a pair of FBGs with different central wavelengths fabricated by femtosecond laser phase mask method and a metal substrate with lever structure. The displacement is amplified by lever structure and it converts into axial tension of FBG, which has a high displacement sensitivity. The amplification factors obtained by theoretical analysis and finite element simulation are 2.67 and 2.50, respectively. The experimental results show that in the range of 0-50 μm the shift of FBG center wavelength is linearly related to the displacement of measured object and displacement sensitivity reaches 121 pm/μm. In addition, the cascaded FBG is used to compensate the temperature.展开更多
Water conservation is one of the most important ecosystem services of terrestrial ecosystems. Identifying the optimization regions of water conservation using Bayesian belief networks not only helps develop a better u...Water conservation is one of the most important ecosystem services of terrestrial ecosystems. Identifying the optimization regions of water conservation using Bayesian belief networks not only helps develop a better understanding of water conservation processes but also increases the rationality of scenario design and pattern optimization. This study establishes a water conservation network model. The model, based on Bayesian belief networks, forecasts the distribution probability of the water conservation projected under different land use scenarios for the year 2050 with the CA-Markov model. A key variable subset method is proposed to optimize the spatial pattern of the water conservation. Three key findings were obtained. First, among the three scenarios, the probability of high water conservation value was the largest under the protection scenario, and the design of this scenario was conducive to the formulation of future land use policies. Second, the key influencing factors impacting the water conservation included precipitation, evapotranspiration and land use, and the state set corresponding to the highest state of water conservation was mainly distributed in areas with high annual average rainfall and evapotranspiration and high vegetation coverage. Third, the regions suitable for optimizing water conservation were mainly distributed in the southern part of Maiji District in Tianshui, southwest of Longxian and south of Weibin District in Baoji, northeast of Xunyi County and northwest of Yongshou County in Xianyang, and west of Yaozhou District in Tongchuan.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52222110,52401354,and 52301353).
文摘As the main geomaterials for coral reefs oil or gas extraction and underground infrastructure construction,coral reef limestone demonstrates significantly distinct mechanical responses compared to terrigenous rocks.To investigate the mechanical behaviour of coral reef limestone under the coupling impact of size and strain rate,the uniaxial compression tests were conducted on reef limestone samples with length-to-diameter(L/D)ratio ranging from 0.5 to 2.0 at strain rate ranging from 10^(−5)·s^(−1)to 10^(−2)·s^(−1).It is revealed that the uniaxial compressive strength(UCS)and residual compressive strength(RCS)of coral reef limestone exhibits a decreasing trend with L/D ratio increasing.The dynamic increase factor(DIF)of UCS is linearly correlated with the logarithm of strain rate,while increasing the L/D ratio further enhances the DIF.The elastic modulus increases with strain rate or L/D ratio increasing,whereas the Poisson’s ratio approximates to a constant value of 0.24.The failure strain increases with strain rate increasing or L/D ratio decreasing,while the increase in L/D ratio will inhibit the enhancing effect of the strain rate.The high porosity and low mineral strength are the primary factors contributing to a high RCS of 16.7%–64.9%of UCS,a lower brittleness index and multiple irregular fracture planes.The failure pattern of coral reef limestone transits from the shear-dominated to the splitting-dominated failure with strain rate increasing or L/D ratio decreasing,which is mainly governed by the constrained zones induced by end friction and the strain rate-dependent crack propagation.Moreover,a predictive formula incorporating coupling effect of size and strain rate for the UCS of reef limestone was established and verified to effectively capture the trend of UCS.
文摘目的探讨中学生睡眠质量与心肺耐力的关系,为促进中国青少年身心健康全面发展提供参考。方法于2023年9—12月,在上海、苏州、太原、婺源、兴义、乌鲁木齐分别采用分层整群随机抽样法抽取5713名13~18岁中学生,采用匹兹堡睡眠质量指数量表(PSQI)结合心肺耐力测试的方法对中学生的睡眠质量和心肺耐力水平进行评估,采用Pearson相关和多元线性回归分析睡眠质量与心肺耐力的关系。结果中学生睡眠质量差的报告率为33.7%(1926/5713),13~18岁女生的PSQI评分均高于男生(χ^(2)值分别为1.60,12.78,15.62,3.04,10.09,13.65,P值均<0.05)。中学生20 m往返跑(20 m SRT)为40(27,51)次,VO2max为46.27(40.84,51.30)mL/(kg·min),各年龄段女生20 m SRT与VO2max均低于男生(Z=-15.27~-6.41,-18.06~-14.07,P值均<0.05)。男生心肺耐力(VO2max)与睡眠时间和催眠药物评分呈负相关(r值分别为-0.032,-0.005),女生VO2max与睡眠时间、日间功能障碍评分均呈负相关(r值分别为-0.028,-0.008)(P值均<0.05)。控制相关变量后,线性回归分析显示,中学生PSQI总分与VO2max呈负相关(β=-0.347,P<0.01)。结论中学生睡眠质量越好,心肺耐力水平越高。促进中学生睡眠质量有利于改善其心肺耐力水平。
基金supported by the project from China Ocean Mineral Resources R&D Association(COMRADY135-B2-17)+1 种基金the National Key Technologies R&D Program of China(2018YFD0500203 and 2018YFF0213503)the Major Projects of Technological Innovation in Hubei Province,China(2017ABA072)。
文摘Root-knot nematodes(RKNs) cause huge yield losses to agricultural crops worldwide. Meanwhile, livestock manure is often improperly managed by farmers, which leads to serious environmental pollution. To resolve these two problems, this study developed a procedure for the conversion of chicken manure to organic fertilizer by larvae of Hermetia illucens L. and Bacillus subtilis BSF-CL. Chicken manure organic fertilizer was then mixed thoroughly with Paenibacillus polymyxa KM2501-1 to a final concentration of 1.5×10^(8)CFU g^(-1). The efficacy of KM2501-1 microbial organic fertilizer in controlling root-knot nematodes was evaluated in pot and field experiments. In pot experiments, applying KM2501-1 microbial organic fertilizer either as a base fertilizer or as a fumigant at the dose of 40 g/pot suppressed root-knot disease by 61.76 and 69.05% compared to the corresponding control treatments, respectively. When applied as a fumigant at the dose of 1 kg m;in field experiments, KM2501-1 microbial organic fertilizer enhanced the growth of tomato plants, suppressed root-knot disease by 49.97%, and reduced second stage juveniles of RKN in soil by 88.68%. KM2501-1 microbial organic fertilizer controlled RKNs better than commercial bio-organic fertilizer in both pot and field experiments. These results demonstrate that this co-conversion process efficiently transforms chicken manure into high value-added larvae biomass and KM2501-1 microbial organic fertilizer with potential application as a novel nematode control agent.
基金the Natural Science Foundation of China(Nos.U0832005,90813011,20772159,30801436)the Ministry of Education of the People's Republic of China(No.200805581163)+1 种基金the Guangdong Natural Science Foundation(No.8451008901000214)the Science Foundation of Guangzhou(No.2009A1-E011-6)for financial support of this study.
文摘A new approach to the facile synthesis of 2-substituted-quinazolin-4（3H）-ones and its derivatives using the condensation reaction of substituted 2-aminobenzamide and orthoesters is reported.
基金Supported by National Natural Science Foundation of China(10571036)the Key Discipline Development Program of Beijing Municipal Commission(XK100080537)
文摘This paper deals with the mean-square exponential input-to-state stability(exp-ISS)of Euler-Maruyama(EM)method applied to stochastic control systems(SCSs).The aim is to find out the conditions of the exact and EM method solutions to an SCS having the property of mean-square exp-ISS without involving control Lyapunov functions.Second moment boundedness and an appropriate form of strong convergence are achieved under global Lipschitz coeffcients and mean-square continuous random inputs.Under the strong convergent condition,it is shown that the mean-square exp-ISS of an SCS holds if and only if that of the EM method is preserved for suffciently small step size.
基金supported by grants from the Scientific Support Project of Anhui Province Education Department of China (Grant No. KJ2012ZD08 and KJ2012Z162)the National Scientific and Technological Support Projects of China (Grant No. 81101273)the National Natural Science Foundation of China (Grant No. 30872253)
文摘Objeαive： To determine whether Interferon-alpha-2b （IFN-α2b） can modulate the autophagic response in hepatocellular carcinoma cells. Methods： Hepatocellular carcinoma cells were treated with IFN-α2b. Autophagy was assessed by acridine orange staining, GFP-LC3 dotted assay, transmission eleαron microscopy and immunoblotting. Results： Acridine orange staining showed that IFN-α2b triggered the accumulation of acidic vesicular and autolysosomes in HepG2 cells. The acridine orange HepG2 cell ratios were （4.3±1.0）%, （6.9±1.4）%, and （13.1±2.3）%, respeαively, after treatment with 100, 1,000, and 10,000 IU/mL IFN-α2b for 48 h. A markedly punαate pattern was observed in HepG2 cells treated with 10,000 IU/mL [FN-α2b for 48 h, but only diffuse and weakly fluorescent GFP-LC3 punαa was observed in control cells. HepG2 cells treated with 10,000 IU/mL IFN-α2b for 48 h developed autophagosome-like charaαeristics, including single- or double-membrane vacuoles containing intaα and degraded cellular debris. The Beclinl and LC3-II protein expression was up-regulated by IFN-α2b treatment. Conclusion： Autophagy can be induced in a dose-dependent manner by treatment with IFN-α2b in HepG2 cells, and the Beclinl signaling pathway was stimulated by IFN-α2b.
基金Projects(51875585, 51875584, 51935013) supported by the National Natural Science Foundation of ChinaProject(2020JJ4247) supported by the Natural Science Foundation of Hunan Province,ChinaProject(ZHD202001) supported by the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory,China。
文摘A micro-displacement sensor based on fiber Bragg grating(FBG) is proposed. The device consists of a pair of FBGs with different central wavelengths fabricated by femtosecond laser phase mask method and a metal substrate with lever structure. The displacement is amplified by lever structure and it converts into axial tension of FBG, which has a high displacement sensitivity. The amplification factors obtained by theoretical analysis and finite element simulation are 2.67 and 2.50, respectively. The experimental results show that in the range of 0-50 μm the shift of FBG center wavelength is linearly related to the displacement of measured object and displacement sensitivity reaches 121 pm/μm. In addition, the cascaded FBG is used to compensate the temperature.
基金National Natural Science Foundation of China,No.41771198,No.41771576The Fundamental Research Funds For the Central Universities,Shaanxi Normal University,No.2017CSY011
文摘Water conservation is one of the most important ecosystem services of terrestrial ecosystems. Identifying the optimization regions of water conservation using Bayesian belief networks not only helps develop a better understanding of water conservation processes but also increases the rationality of scenario design and pattern optimization. This study establishes a water conservation network model. The model, based on Bayesian belief networks, forecasts the distribution probability of the water conservation projected under different land use scenarios for the year 2050 with the CA-Markov model. A key variable subset method is proposed to optimize the spatial pattern of the water conservation. Three key findings were obtained. First, among the three scenarios, the probability of high water conservation value was the largest under the protection scenario, and the design of this scenario was conducive to the formulation of future land use policies. Second, the key influencing factors impacting the water conservation included precipitation, evapotranspiration and land use, and the state set corresponding to the highest state of water conservation was mainly distributed in areas with high annual average rainfall and evapotranspiration and high vegetation coverage. Third, the regions suitable for optimizing water conservation were mainly distributed in the southern part of Maiji District in Tianshui, southwest of Longxian and south of Weibin District in Baoji, northeast of Xunyi County and northwest of Yongshou County in Xianyang, and west of Yaozhou District in Tongchuan.
