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Energy Efficiency Operating Indicator Forecasting and Speed Design Optimization for Polar Ice Class Merchant Vessels
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作者 LU Yu LI Chen−ran +3 位作者 ZHU Xiang−hang LI Shi−an GU Zhu−hao LIU She−wen 《船舶力学》 北大核心 2025年第6期901-911,共11页
In order to accurately forecast the main engine fuel consumption and reduce the Energy Efficiency Operational Indicator(EEOI)of merchant ships in polar ice areas,the energy transfer relationship between ship-machine-p... In order to accurately forecast the main engine fuel consumption and reduce the Energy Efficiency Operational Indicator(EEOI)of merchant ships in polar ice areas,the energy transfer relationship between ship-machine-propeller is studied by analyzing the complex force situation during ship navigation and building a MATLAB/Simulink simulation platform based on multi-environmental resistance,propeller efficiency,main engine power,fuel consumption,fuel consumption rate and EEOI calculation module.Considering the environmental factors of wind,wave and ice,the route is divided into sections,the calculation of main engine power,main engine fuel consumption and EEOI for each section is completed,and the speed design is optimized based on the simulation model for each section.Under the requirements of the voyage plan,the optimization results show that the energy efficiency operation index of the whole route is reduced by 3.114%and the fuel consumption is reduced by 9.17 t. 展开更多
关键词 Energy Efficiency Operational indicator ice-class ships segment division design optimization
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Critical quality indicators of high-performance polyetherimide(ULTEM)over the MEX 3D printing key generic control parameters:Prospects for personalized equipment in the defense industry
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作者 Nectarios Vidakis Markos Petousis +6 位作者 Constantine David Nektarios K.Nasikas Dimitrios Sagris Nikolaos Mountakis Mariza Spiridaki Amalia Moutsopoulou Emmanuel Stratakis 《Defence Technology(防务技术)》 2025年第1期150-167,共18页
Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)proc... Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)procedure.This can be very important in defense-related applications,where optimum performance needs to be guaranteed.The quality of the Polyetherimide 3D-P specimens was examined by considering six control parameters,namely,infill percentage,layer height,deposition angle,travel speed,nozzle,and bed temperature.The quality indicators were the root mean square(Rq)and average(Ra)roughness,porosity,and the actual to nominal dimensional deviation.The examination was performed with optical profilometry,optical microscopy,and micro-computed tomography scanning.The Taguchi design of experiments was applied,with twenty-five runs,five levels for each control parameter,on five replicas.Two additional confirmation runs were conducted,to ensure reliability.Prediction equations were constructed to express the quality indicators in terms of the control parameters.Three modeling approaches were applied to the experimental data,to compare their efficiency,i.e.,Linear Regression Model(LRM),Reduced Quadratic Regression Model,and Quadratic Regression Model(QRM).QRM was the most accurate one,still the differences were not high even considering the simpler LRM model. 展开更多
关键词 Polyetherimide(PEI) Material extrusion(MEX) Three-dimensional printing(3D-P) Critical quality indicators(CQIs) Quadratic regression model(QRM) Taguchi
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Prediction on compression indicators of clay soils using XGBoost with Bayesian optimization
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作者 WU Hong-tao ZHANG Zi-long Daniel DIAS 《Journal of Central South University》 CSCD 2024年第11期3914-3929,共16页
The determination of the compressibility of clay soils is a major concern during the design and construction of geotechnical engineering projects.Directly acquiring precise values of compression indicators from consol... The determination of the compressibility of clay soils is a major concern during the design and construction of geotechnical engineering projects.Directly acquiring precise values of compression indicators from consolidation tests is cumbersome and time-consuming.Based on experimental results from a series of index tests,this study presents a hybrid method that combines the extreme gradient boosting(XGBoost)model with the Bayesian optimization strategy to show the potential for achieving higher accuracy in predicting the compressibility indicators of clay soils.The results show that the proposed XGBoost model selected by Bayesian optimization can predict compression indicators more accurately and reliably than the artificial neural network(ANN)and support vector machine(SVM)models.In addition to the lowest prediction error,the proposed XGBoost-based method enhances the interpretability by feature importance analysis,which indicates that the void ratio is the most important factor when predicting the compressibility of clay soils.This paper highlights the promising prospect of the XGBoost model with Bayesian optimization for predicting unknown property parameters of clay soils and its capability to benefit the entire life cycle of engineering projects. 展开更多
关键词 machine learning clay soils compression indicators XGBoost Bayesian optimization
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Construction of composite indicator system based on simulation data mining 被引量:3
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作者 Jianfei Ding Guangya Si +2 位作者 Baoqiang Li Jingyu Yang Yu Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第1期81-87,共7页
The indicator system is the foundation and emphasis in the effectiveness evaluation of system of systems(SoS). In the past, indicator systems were founded based on qualitative methods, and every indicator was mainly d... The indicator system is the foundation and emphasis in the effectiveness evaluation of system of systems(SoS). In the past, indicator systems were founded based on qualitative methods, and every indicator was mainly determined by the expert with experience. This paper proposed a brand-new method to construct indicator systems based on the repeated simulation of the scenario space, and calculated by quantitative data. Firstly, the selection of key indicators using the Gini indicator importance measure(IIM)is calculated by random forests(RFs). Then, principal component analysis(PCA) is applied when we use the selected indicators to construct the composite indicator system of SoS. Furthermore,a set of rulesare is developed to verify the practicability of the indicator system such as correlation, robustness, accuracy and convergence. Experiment shows that the algorithm achieves good results for the construction of composite indicators of So S. 展开更多
关键词 system of systems(SoS) indicator system random forests(RFs) principal component analysis(PCA)
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Application of a novel detection approach based on non-dispersive infrared theory to the in-situ analysis on indicator gases from underground coal fire 被引量:12
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作者 TIAN Fu-chao LIANG Yun-tao +2 位作者 ZHU Hong-qing CHEN Ming-yi WANG Jin-cheng 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第6期1840-1855,共16页
Coal mine fires,which can cause heavy casualties,environmental damages and a waste of coal resources,have become a worldwide problem.Aiming at overcoming the drawbacks,such as a low analysis efficiency,poor stability ... Coal mine fires,which can cause heavy casualties,environmental damages and a waste of coal resources,have become a worldwide problem.Aiming at overcoming the drawbacks,such as a low analysis efficiency,poor stability and large monitoring error,of the existing underground coal fire monitoring technology,a novel monitoring system based on non-dispersive infrared(NDIR)spectroscopy is developed.In this study,first,the measurement principle of NDIR sensor,the gas concentration calculation and its temperature compensation algorithms were expounded.Next,taking CO and CH_(4) as examples,the liner correlation coefficients of absorbance and the temperature correction factors of the two indicator gases were calculated,and then the errors of concentration measurement for CO,CO_(2),CH_(4) and C_(2)H_(4) were further analyzed.The results disclose that the designed NDIR sensors can satisfy the requirements of industrial standards for monitoring the indicator gases for coal fire hazards.For the established NDIR-based monitoring system,the NDIRbased spectrum analyzer and its auxiliary equipment boast intrinsically safe and explosion-proof performances and can achieve real-time and in-situ detection of indicator gases when installed close to the coal fire risk area underground.Furthermore,a field application of the NDIR-based monitoring system in a coal mine shows that the NDIR-based spectrum analyzer has a permissible difference from the chromatography in measuring the concentrations of various indicator gases.Besides,the advantages of high accuracy,quick analysis and excellent security of the NDIR-based monitoring system have promoted its application in many coal mines. 展开更多
关键词 indicator gas coal spontaneous combustion infrared spectrometry bundle tube monitoring intrinsically safe
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Visualization analysis of the capability of weapon system of systems for multi-dimensional indicators 被引量:1
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作者 Jianfei Ding Guangya Si +2 位作者 Guoqiang Yang Yang Liu Xiao Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期292-300,共9页
In the field of weapon system of systems (WSOS) simulation, various indicators are widely used to describe the capability of WSOS, but it is always difficult to describe the comprehensive capability of WSOS quickly an... In the field of weapon system of systems (WSOS) simulation, various indicators are widely used to describe the capability of WSOS, but it is always difficult to describe the comprehensive capability of WSOS quickly and intuitively by visualization of multi-dimensional indicators. A method of machine learning and visualization is proposed, which can display and analyze the capabilities of different WSOS in a two-dimensional plane. The analysis and comparison of the comprehensive capability of different components of WSOS is realized by the method, which consists of six parts: multiple simulations, key indicators mining, three spatial distance calculation, fusion project calculation, calculation of individual capability density, and calculation of multiple capability ranges overlay. Binding a simulation experiment, the collaborative analysis of six indicators and 100 possible kinds of red WSOS are achieved. The experimental results show that this method can effectively improve the quality and speed of capabilities analysis, reveal a large number of potential information, and provide a visual support for the qualitative and quantitative analysis model. 展开更多
关键词 weapon system of systems (WSOS) comprehensive capability visualization of multi-dimensional indicators machine learning
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Risk reduction in Sechahun iron ore deposit by geological boundary modification using multiple indicator Kriging 被引量:1
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作者 S.Kasmaee F.M.Torab 《Journal of Central South University》 SCIE EI CAS 2014年第5期2011-2017,共7页
Uncertainty on the geological contacts and the block volumes of the models along boundaries is often a major part of the global uncertainty of reserve estimation.This work introduces a geostatistical technique that ha... Uncertainty on the geological contacts and the block volumes of the models along boundaries is often a major part of the global uncertainty of reserve estimation.This work introduces a geostatistical technique that has been developed and tested in an iron ore deposit at Bafq mining district,in central Iran,and that,based on a probability criterion,helps to objectively model the geometry of this iron ore deposit.The main problem in reserve estimation of this ore body is its geometrical modeling and uncertainty in geological boundaries.This work deals with the geostatistical method of multiple indicator kriging,which is used to determine the real boundaries of ore body in different categories.This approach has potential to improve project performance and decrease operational risk.For this purpose,the ore body is separated into two categories including rich iron zone(w(Fe)>45%)and poor iron zone(20%<w(Fe)<45%).It significantly benefits to decrease the risk of reserve evaluation in the deposit.This case study also highlights the value of multiple indicator kriging as a tool for estimates the position of grade boundaries within the deposit.Comparison of the resultant probability maps with the real ore/waste contacts on the extracted levels shows that the first indicator model could separate the whole ore body(poor plus rich)from the waste zone by probability of more than 0.35,which concludes the total reserve of 53 million tons.The second indicator model applied to separate the rich and poor domains and the results show that the blocks with the estimated probability of equal to or more than 0.4 lay within the rich ore zone consisting of 15.8 million tons reserve. 展开更多
关键词 geological boundaries multiple indicator kriging risk assessment block model uncertainty Sechahun deposit
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The Influence of Lairage Conditions for Finishing Pigs on Behavior,Biochemical Indicators and Meat Quality
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作者 CHAI Jin PENG Jian +5 位作者 XIONG Qi ZHANG Chang-xin MIAO Wen LI Feng-e ZHENG Rong JIANG Si-wen 《畜牧兽医学报》 CAS CSCD 北大核心 2010年第S1期58-62,共5页
A total of 60 crossbred(Large White×Landrace) pigs of halothane genotype NN(castrated males and females) were allotted to three treatments:3 h lairage with toys,3 h lairage and 0 h lairage in a randomized complet... A total of 60 crossbred(Large White×Landrace) pigs of halothane genotype NN(castrated males and females) were allotted to three treatments:3 h lairage with toys,3 h lairage and 0 h lairage in a randomized complete block design and used to evaluate the influence of lairage conditions on behavior, biochemical indicators and meat quality for finishing pigs at slaughter.Behavior of the pigs was scored subjectively during lairage.Blood samples were taken at exsanguination s to measure blood temperature, plasma Cortisol,ACTH,glucose,lactate,plasma enzymes and hematological indices.Post-mortem meat quality measurements included muscle colour value(MCV),electrical conductivity(EC),pH at 45 min and 24 h from Longissimus thoracis(LM) and Semimembranosus(SM) mucles and drip loss from LM. The results showed that 3 h lairage group with toys demonstrated significantly improved behavior than the group without toys at 3 sampling times.All the pigs showed increasing calmness as the time of lairage progressed.The omission of lairage increased plasma Cortisol,ACTH,glucose and lactate(P【0.05),and decreased plasma lactate dehydrogenase(LDH),and creatine kinase(CK)(P【0.05).No biochemical index was influenced by the presence or absence of toys during lairage(P【0.05).Muscle colour value, electrical conductivity,pH at 45 min and 24 h from LM and SM and drip loss were not affected by any treatment(P【0.05).Pigs provided 3 h lairage,with or without toys,exhibited lower red blood cell(RBC), hemoglobin(HGB),and haematocrit(HCT) when compared to 0 h lairage.3 h lairage with or without toys resulted in higher white blood cell(WBC) and lymphocyte(W-SCC) levels than 0 h lairage.None of the hemocytic indices in pigs given lairage was affected by the presence or absence of toys.We conclude from this pilot study that in local commercial conditions,from the point of view of animal welfare and meat quality,lairage time of 3 h after short travel was beneficial.Pigs resting showed increased relief from stress and a recovery in immune competence.Holding pigs in lairage with toys for a few hours after arrival at the abattoir may be beneficial for the animal’s well-being. 展开更多
关键词 finishing pigs lairage conditions BEHAVIOR biochemical indices meat quality
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Research on Uncertainties in Evaluation Indicator System for Ecological Residential Community
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作者 JIAO Sheng1,GUAN Chen-yin2,ZENG Guang-ming3,LIU Jian-long1,Zhou Jian-fei3(1.College of Architecture,Hunan University,Changsha,Hunan 410082,China 2.Beijin School,Hunan University of Commerce,Changsha,Hunan 410209,China 3.College of Environmental Science and Engineering,Hunan University,Changsha,Hunan 410082,China) 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2009年第S1期177-181,共5页
In the process of evaluating,the weights of indicators are firstly determined by AHP and Delphi methods;and the values of indicators are normalized by grey correlative coefficient method.A suit of means were put forwa... In the process of evaluating,the weights of indicators are firstly determined by AHP and Delphi methods;and the values of indicators are normalized by grey correlative coefficient method.A suit of means were put forward,by which a qualitative and quantitative evaluation indicator system suitable for the situation of China and uncertainties can be established.Both idiographic and operable methods and process were presented.Following the principle of elasticity,hiberarchy and maneuverability,a three-layer evaluation indicator system was established by AHP in Jiuyi ecological residential community,which includes 5 subsystems and 24 indicatiors.The weights of indicators are measured by AHP and expert estimate and their best indicators values up to par were determined by fuzzy mathematics and optimization.The whole evaluation indicator system not only has an active and practical effect on estimating ecological residential community,but also guides ecological residential community planning. 展开更多
关键词 ECOLOGICAL RESIDENTIAL community EVALUATION indicator system ECOLOGICAL risk EVALUATION uncertainty fuzzy mathematics GREY correlative coefficient
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Effects of Fermented Puffed Feather Meal on Growth Performance,Serum Biochemical Indices,Meat Quality,and Intestinal Microbiota in Broilers
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作者 Lin Yu Chen Zhihui +9 位作者 Wu Hongzhi Ji Fengjie Liu Yang Li Jianing Yu Xilong Dou Renkai Yuan Hua Yang Qinghui Li Zhongyu Xu Liangmei 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第3期42-58,共17页
This study aimed to investigate the effects of fermented puffed feather meal(FPFM)on growth performance,serum biochemical indices,meat quality,and intestinal microbiota in Arbor Acres(AA)broilers.A single-factor desig... This study aimed to investigate the effects of fermented puffed feather meal(FPFM)on growth performance,serum biochemical indices,meat quality,and intestinal microbiota in Arbor Acres(AA)broilers.A single-factor design was adopted,and four treatments were administered with five replicates to 240 one-day-old AA broilers.The control group(group A)received a basal diet,while the experimental groups received a basal diet plus 33%(group B),67%(group C)and 100%(group D)FPFM,respectively.Compared with group A,(1)the average daily gain(ADG)in group C decreased(P<0.05),and the feed conversion ratio(FCR)in group D increased(P<0.05);(2)the level of serum urea nitrogen in treatment groups decreased(P<0.05),and the levels of triglyceride,high density lipoprotein,low density lipoprotein,cholesterol,and glucose contents in group D increased(P<0.05)at day 21;(3)the serum immunoglobulin M and immunoglobulin G in group B and the immunoglobulin A in group C increased(P<0.05)at day 21,and the serum immunoglobulin M and immunoglobulin G in group D decreased(P<0.05)at day 42;(4)the share force of breast muscle and thigh muscle in group D increased(P<0.05);(5)the villus height to crypt depth ratio in the jejunum of group B increased(P<0.05)at day 21,and the villus height in group C and D increased(P<0.05)at day 42;(6)the proteobacteria counts in the cecum digesta in treatment groups decreased(P<0.05)at day 21.The basal diet supplemented with 33%FPFM promoted protein metabolism,enhanced immunity and improved meat quality,promoted the digestion and absorption of nutrients,increased intestinal microbial diversity,and improved the content of beneficial bacteria without affecting the growth performance,it was possible to be used as a good substitute for fish meal. 展开更多
关键词 fermented puffed feather meal(FPFM) growth performance serum biochemical indices meat quality intestinal microbiota
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复方中草药对热应激肉羊生理指标、生长性能及血清生化指标的影响 被引量:1
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作者 郎利敏 张青娴 +5 位作者 王亚洲 施巧婷 赵彩艳 王二耀 辛晓玲 师志海 《中国饲料》 北大核心 2025年第5期89-95,共7页
为探讨复方中草药对热应激条件下肉羊生理指标、生长性能及血清生化指标的影响,选取体况良好、体重相近的育肥期杂交肉羊,随机分为4组,每组3个重复,每个重复15只。试验组日粮中分别添加0.5%、1.0%和1.5%的复方中草药,对照组饲喂基础日... 为探讨复方中草药对热应激条件下肉羊生理指标、生长性能及血清生化指标的影响,选取体况良好、体重相近的育肥期杂交肉羊,随机分为4组,每组3个重复,每个重复15只。试验组日粮中分别添加0.5%、1.0%和1.5%的复方中草药,对照组饲喂基础日粮。试验期30 d。结果表明:整个试验期间羊舍内环境温湿度指数(THI)>76,处于中度热应激状态。试验第20天,1.0%组羊的呼吸频率与对照组相比降低了4.3%,差异显著(P<0.05);第30天,1.0%和1.5%组羊的呼吸频率与对照组相比分别降低了6.07%和5.67%,差异显著(P<0.05)。与对照组相比,1.0%组羊的平均日采食量、平均日增重分别提高了10.27%、12.46%,差异显著(P<0.05)。与对照组相比,1.0%组羊的总蛋白(TP)、白蛋白(ALB)、球蛋白(GLB)、谷胱甘肽过氧化物酶(GSH-Px)、总抗氧化能力(T-AOC)和超氧化物歧化酶(SOD)含量分别提高了10.26%、12.24%、8.56%、5.19%、12.38%和8.50%,差异显著(P<0.05);总胆固醇(T-CHO)、甘油三酯(TG)、尿素氮(BUN)、葡萄糖(GLU)和丙二醛(MDA)的含量分别降低了6.05%、10.52%、8.98%、7.73%和7.88%,差异显著(P<0.05)。与对照组相比1.0%和1.5%组的免疫球蛋白G(IgG)含量分别提高了10.07%、9.56%,差异显著(P<0.05),1.0%组免疫球蛋白A(IgA)和白细胞介素6(IL-6)含量分别提高了10.60%、11.46%,差异显著(P<0.05)。综上,饲粮中添加复方中草药可以显著改善肉羊的热应激反应,添加量以1.0%效果最好。 展开更多
关键词 复方中草药 热应激 肉羊 生理指标 生长性能 血清生化指标
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A ε-indicator-based shuffled frog leaping algorithm for many-objective optimization problems
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作者 WANG Na SU Yuchao +2 位作者 CHEN Xiaohong LI Xia LIU Dui 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第1期142-155,共14页
Many-objective optimization problems take challenges to multi-objective evolutionary algorithms.A number of nondominated solutions in population cause a difficult selection towards the Pareto front.To tackle this issu... Many-objective optimization problems take challenges to multi-objective evolutionary algorithms.A number of nondominated solutions in population cause a difficult selection towards the Pareto front.To tackle this issue,a series of indicatorbased multi-objective evolutionary algorithms(MOEAs)have been proposed to guide the evolution progress and shown promising performance.This paper proposes an indicator-based manyobjective evolutionary algorithm calledε-indicator-based shuffled frog leaping algorithm(ε-MaOSFLA),which adopts the shuffled frog leaping algorithm as an evolutionary strategy and a simple and effectiveε-indicator as a fitness assignment scheme to press the population towards the Pareto front.Compared with four stateof-the-art MOEAs on several standard test problems with up to 50 objectives,the experimental results show thatε-MaOSFLA outperforms the competitors. 展开更多
关键词 evolutionary algorithm many-objective optimization shuffled frog leaping algorithm(SFLA) ε-indicator
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海洋生态系统健康评估:机遇、困难与挑战 被引量:2
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作者 孙晓霞 冷疏影 +4 位作者 张亮 庄志猛 沙忠利 魏皓 孙松 《海洋与湖沼》 北大核心 2025年第1期126-132,共7页
经济社会的发展需要一个健康的海洋生态系统,对海洋生态系统健康状态进行有效评估是全球关注的重大科学问题。人类不居住在海洋中,所以不可能通过我们自身的感受和观察来了解海洋的状态,我们对海洋的深入了解只能来自对海洋的观测。开... 经济社会的发展需要一个健康的海洋生态系统,对海洋生态系统健康状态进行有效评估是全球关注的重大科学问题。人类不居住在海洋中,所以不可能通过我们自身的感受和观察来了解海洋的状态,我们对海洋的深入了解只能来自对海洋的观测。开展海洋生态系统健康评估这一重大科学目标驱动下的海洋生态系统观测,是支撑健康海洋与可持续发展的重要举措。如何对中国近海生态系统健康状态进行评估、如何建立支撑生态系统健康状态评估的海洋综合观测方案是我们当前亟待解决的重大科学问题。在综合分析海洋生态系统现状、存在问题与健康评估需求的基础上,建议基于近海生态系统健康评估重大科学考察航次方案,选取中国近海重点区域和断面,基于历史观测资料整合研究,提出中国近海生态系统健康评估关键指标,构建生态系统健康评估技术体系和模式,确定明晰近海生态特征所需观测的空间范围、典型断面和时间频率,在中国近海选定的固定断面观测,精准获取相关资料并开展验证;评估中国近海生态系统健康状况,为健康海洋与可持续发展提供科学依据。 展开更多
关键词 海洋生态系统 海洋观测 健康评估 健康指标
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稻蛙种养模式下放养密度对黑斑蛙生长性能、血清激素和抗氧化指标及肠道菌群的影响 被引量:2
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作者 韩光明 覃宝利 +5 位作者 吴雷明 张家宏 寇祥明 王守红 徐荣 马林杰 《动物营养学报》 北大核心 2025年第2期1162-1172,共11页
本试验旨在研究稻蛙种养模式下放养密度对黑斑蛙生长性能、血清激素和抗氧化指标及肠道菌群的影响。以初始体重为(8.12±0.03)g的黑斑蛙幼蛙为研究对象,设置5个放养密度,M1、M2、M3、M4、M5组放养密度分别为6、12、24、48和96只/m^(... 本试验旨在研究稻蛙种养模式下放养密度对黑斑蛙生长性能、血清激素和抗氧化指标及肠道菌群的影响。以初始体重为(8.12±0.03)g的黑斑蛙幼蛙为研究对象,设置5个放养密度,M1、M2、M3、M4、M5组放养密度分别为6、12、24、48和96只/m^(2)(即0.4万、0.8万、1.6万、3.2万和6.4万只/亩),每组3个重复,养殖80 d。结果显示:1)放养密度超过24只/m^(2)时,黑斑蛙的成活率出现显著下降(P<0.05);M3组黑斑蛙的末均重、增重率和特定生长率最高,且饲料系数显著低于M4和M5组(P<0.05)。2)各组之间血清皮质醇、胰岛素样生长因子-Ⅰ、甲状腺素含量以及超氧化物歧化酶、谷胱甘肽过氧化物酶、过氧化氢酶活性与丙二醛含量无显著差异(P>0.05),但M3组的血清总抗氧化能力显著高于M5组(P<0.05)。3)随着黑斑蛙放养密度的增加,肠道菌群的Chao1、Faith_pd、Observed_species、Shannon指数均出现上升的趋势,其中M5组显著高于M1组(P<0.05)。4)在门水平上,与M1和M2组比较,M4组肠道菌群中厚壁菌门(Firmicutes)的相对丰度显著下降(P<0.05),拟杆菌门(Bacteroidetes)的相对丰度显著升高(P<0.05);在属水平上,随着黑斑蛙放养密度的增加,肠道菌群中拟杆菌属(Bacteroides)的相对丰度呈上升趋势,乳球菌属(Lactococcus)的相对丰度呈下降趋势,罗姆布茨菌属(Romboutsia)和阿克曼菌属(Akkermansia)的相对丰度呈先上升后下降的趋势。综上可知,在本试验条件下,黑斑蛙放养密度过高不利于个体生长,适当增加放养密度可以提高肠道菌群多样性;在稻蛙种养模式下,建议黑斑蛙的放养密度为12~24只/m^(2)(即0.8万~1.6万只/亩)。 展开更多
关键词 黑斑蛙 放养密度 血清激素 抗氧化指标 肠道菌群
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石家庄地区浅层地下水化学特征及形成机制 被引量:1
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作者 王丽娟 王哲 +3 位作者 李晓媛 宋胜华 刘敏 刘鹏飞 《地质通报》 北大核心 2025年第5期837-847,共11页
[研究目的]为了全面了解石家庄地区浅层地下水化学特征及其成因机制,为水环境管理部门提供科学参考。[研究方法]基于2019—2020年石家庄地区浅层地下水水质监测数据,综合运用地理统计学、Piper图、Gibbs模型和离子比等方法,分析了石家... [研究目的]为了全面了解石家庄地区浅层地下水化学特征及其成因机制,为水环境管理部门提供科学参考。[研究方法]基于2019—2020年石家庄地区浅层地下水水质监测数据,综合运用地理统计学、Piper图、Gibbs模型和离子比等方法,分析了石家庄地区不同水文地质单元浅层地下水化学特征、影响水质的主要化学指标及其形成机制。[研究结果]石家庄地区浅层地下水pH值在7.13~8.48之间,介于中性水和弱碱性水之间;TH(总硬度)和TDS(溶解性总固体)均值分别为391.03 mg/l和590.60 mg/1,沿地下水径流方向呈逐渐降低趋势;全区和各水文地质单元阴、阳离子基本以HCO_(3)-、SO_(4)^(2−)、Ca^(2+)和Na^(+)为主,台地、河谷平原区阳离子表现为以Ca^(2+)和Mg^(2+)为主,且Na^(+)、Cl^(−)、SO_(4)^(2−)、NO_(3)^(-)等离子空间变异系数相对较大;浅层地下水化学类型以HCO_(3)·SO_(4)-Ca·Mg为主,其次为SO_(4)·HCO_(3)-Ca·Mg型,且从台地区到冲洪积平原区水化学类型逐渐变得复杂;浅层地下水化学组分形成主要受岩石风化作用影响,冲洪积平原和台地区部分地下水化学组分形成受到人类活动影响显著。研究区浅层地下水主要超标指标为TH、SO_(4)^(2−)和NO_(3)^(-),河谷平原区3项指标综合超标率最高,达到62.5%。TH、SO_(4)^(2−)和NO_(3)^(-)三项指标超标的地下水样品的化学组分除受碳酸盐矿物溶解影响外,也受到硫酸盐矿物溶解和人类活动(农业活动和市政污水排放)影响。[结论]石家庄地区浅层地下水化学特征呈明显的分带性,从台地区到冲洪积平原区地下水的TH和TDS浓度逐渐降低,水化学类型逐渐复杂化,水质超标率逐渐降低,且水质超标现象是自然因素和人类活动共同作用的结果。本次对石家庄地区浅层不同水文地质单元的水化学特征及其成因机制研究,为水环境管理部门提供了重要科学依据。 展开更多
关键词 地下水 化学特征 超标指标 形成机制 石家庄地区
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职业教育高质量发展指标体系创建研究 被引量:5
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作者 李兴洲 龙语兮 《教育与经济》 北大核心 2025年第1期3-13,共11页
科学合理的职业教育高质量发展指标体系对于支持和引领职业教育高质量发展,推进教育强国建设有重要支撑作用。遵循指标体系创建的普遍原则和常规做法,职业教育高质量发展指标体系创建应当以基本概念为逻辑起点,抓住“可比”“领先”“... 科学合理的职业教育高质量发展指标体系对于支持和引领职业教育高质量发展,推进教育强国建设有重要支撑作用。遵循指标体系创建的普遍原则和常规做法,职业教育高质量发展指标体系创建应当以基本概念为逻辑起点,抓住“可比”“领先”“特色”三个衡量要点,在一定质量观、教育观和评价观的指导下,依据职业教育高质量发展的内涵意蕴、政策规定、评估经验进行创建。职业教育高质量发展指标体系应当全面评估职业教育发展在背景、输入、过程、输出各维度的高质量,具体可分解为基础条件、核心机制、内生能力、办学成效、社会贡献5个一级指标和20个二级指标、65个三级观测点,突出“充裕度”“协调性”“类型化”“认可性”“服务力”等多元评估关注点,体现量化和质性相结合、分值评定与等级判定相综合的评价范式。 展开更多
关键词 职业教育 高质量发展 指标体系
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花椒精油和牛至精油对不同生长阶段母羊生长性能、血清生化和免疫指标的影响 被引量:1
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作者 金茜 景照明 +3 位作者 康芳娥 刘海波 刘立山 宫旭胤 《饲料研究》 北大核心 2025年第4期1-6,共6页
试验旨在研究饲粮中添加花椒精油和牛至精油对不同生长阶段母羊生长性能、血清生化和免疫指标的影响。试验选取体重相近、体况良好的3月龄母羔和成年母羊各24只,将母羔和成年母羊各随机分为3组,每组8个重复,每个重复1只羊。对照组饲喂... 试验旨在研究饲粮中添加花椒精油和牛至精油对不同生长阶段母羊生长性能、血清生化和免疫指标的影响。试验选取体重相近、体况良好的3月龄母羔和成年母羊各24只,将母羔和成年母羊各随机分为3组,每组8个重复,每个重复1只羊。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加7 g/(只·d)牛至精油和10mL/(只·d)花椒精油。预试期10d,正式试验期90d。结果显示:与对照组相比,牛至精油和花椒精油均能显著提高母羊的末重、1~30 d平均日增重及平均日采食量(P<0.05);牛至精油能够显著提升血清中总蛋白(TP)、白蛋白(ALB)、葡萄糖(GLU)含量和谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性、总抗氧化能力(T-AOC),以及免疫球蛋白G(IgG)、免疫球蛋白M(IgM)、干扰素-γ(IFN-γ)含量(P<0.05),显著降低血清中胆固醇(CHO)和甘油三酯(TG)含量(P<0.05);花椒精油能够显著提高母羊血清中ALB含量、T-AOC及CAT活性(P<0.05),显著降低CHO含量(P<0.05),提升成年母羊血清中IgM、IFN-γ及母羔羊血清中IgG、IFN-γ含量(P<0.05)。研究表明,牛至精油和花椒精油均能有效改善成年母羊及母羔羊的生长性能,增强机体抗氧化能力和免疫力。 展开更多
关键词 花椒精油 牛至精油 母羊 生长阶段 生长性能 血清生化指标 抗氧化能力 免疫指标
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非洲猪瘟弱毒疫苗效力评价研究进展 被引量:1
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作者 戈胜强 沙洲 +10 位作者 崔进 房琳琳 王潇葳 于家荣 胡永新 张永强 李瑞红 左媛媛 郑辉 魏荣 王志亮 《中国动物检疫》 2025年第2期51-56,共6页
非洲猪瘟(African swine fever,ASF)是由非洲猪瘟病毒(African swine fever virus,ASFV)感染引起的烈性传染病。目前在研的ASF疫苗仍难以兼顾安全绝对保证及效力确实可靠。本文对已报道的ASF弱毒疫苗相关研究数据进行总结分析,分别从攻... 非洲猪瘟(African swine fever,ASF)是由非洲猪瘟病毒(African swine fever virus,ASFV)感染引起的烈性传染病。目前在研的ASF疫苗仍难以兼顾安全绝对保证及效力确实可靠。本文对已报道的ASF弱毒疫苗相关研究数据进行总结分析,分别从攻毒剂量及途径、攻毒后评价指标等方面进行综述。总结分析发现:ASF弱毒疫苗研究主要以免疫攻毒方式探究其效力;肌内注射剂量多为102~104 HAD50/TCID50,而与自然感染相似的口鼻接种途径不同感染方式采用的剂量差异较大;疫苗免疫后攻毒常以体温反应、临床表现、死亡情况、病毒血症、排毒水平等作为评价指标,并结合临床评分标准科学展示临床指标。未来在技术层面,ASF弱毒疫苗效力评价还应进一步探索模拟自然感染途径的疫苗攻毒保护试验。 展开更多
关键词 非洲猪瘟 弱毒疫苗 评价指标 效力评价
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不同季节“中药醋曲”理化指标与微生物菌群结构的相关性研究 被引量:1
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作者 黄静 袁英豪 +7 位作者 付金慧 李晓薇 木克尔·克力木江 刘书亮 胡凯弟 郭明烨 王松 李建龙 《食品与发酵工业》 北大核心 2025年第3期81-88,共8页
以不同季节保宁醋“中药醋曲”为研究对象,采用高通量测序技术结合常规理化指标测定,探究不同季节中药醋曲理化指标和微生物菌群的关联性。高通量测序结果显示,从属水平上看,保宁醋中药醋曲的优势细菌菌属为链霉菌属(Streptomyces)、火... 以不同季节保宁醋“中药醋曲”为研究对象,采用高通量测序技术结合常规理化指标测定,探究不同季节中药醋曲理化指标和微生物菌群的关联性。高通量测序结果显示,从属水平上看,保宁醋中药醋曲的优势细菌菌属为链霉菌属(Streptomyces)、火山渣芽孢杆菌属(Scopulibacillus)、泛菌属(Pantoea)、糖多孢菌属(Saccharopolyspora)、葡萄球菌属(Staphylococcus)、克罗彭斯特菌属(Kroppenstedtia),优势真菌菌属为曲霉菌属(Aspergillus)、嗜热真菌属(Thermomyces)、根毛霉菌属(Rhizomucor)和毕赤酵母属(Hyphopichia)。4个季节成品曲的理化指标均存在显著性差异,水分含量在15%左右,高于行业标准;pH值在7.0左右;淀粉含量约70 g/100 g,其中夏季淀粉含量最高;还原糖含量在春季最高;春季的糖化力水平最高;冬季酯化力和液化力水平最高。微生物菌群中泛菌属、糖多孢菌、克罗彭斯特菌属和根毛霉属与醋曲的糖化力、液化力关系密切,而泛菌属、链霉菌属、根毛霉属和毕赤酵母属可增强醋曲的酯化力。根毛霉属和毕赤酵母属强相关。该文揭示了不同季节中药醋曲理化指标和微生物菌群的关联性,为提高中药醋曲的品质奠定了理论基础。 展开更多
关键词 保宁醋 中药醋曲 微生物菌群 理化性质 不同季节
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复合微生物发酵饲料在母猪饲粮中的应用 被引量:1
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作者 王旭 颜国华 +5 位作者 杨玉增 贾楠 张伟涛 孟宪华 魏晓艳 胡栋 《饲料工业》 北大核心 2025年第6期88-94,共7页
试验旨在研究饲粮中添加复合微生物发酵饲料对妊娠后期及哺乳期母猪生产性能、初乳、血清指标及饲料中氮素转化利用的影响。选取48头预产期接近、胎次相近、体质健康的妊娠后期二元母猪,随机分为4组,每组12个重复,每个重复1头母猪。对... 试验旨在研究饲粮中添加复合微生物发酵饲料对妊娠后期及哺乳期母猪生产性能、初乳、血清指标及饲料中氮素转化利用的影响。选取48头预产期接近、胎次相近、体质健康的妊娠后期二元母猪,随机分为4组,每组12个重复,每个重复1头母猪。对照组饲喂常规饲粮,试验Ⅰ、Ⅱ、Ⅲ组在常规饲粮基础上分别添加1%、3%、5%的复合微生物发酵饲料。试验从母猪妊娠第90天开始,产后第21天结束。结果表明,与对照组相比:①试验Ⅲ组哺乳仔猪初生个体均重和21 d平均个体重分别提高25.00%和14.96%;试验Ⅱ、Ⅲ组哺乳仔猪日增重分别提高8.42%、11.88%。②试验Ⅱ组母猪初乳中乳糖含量提高26.64%,试验Ⅰ、Ⅱ、Ⅲ组母猪初乳中尿素氮含量分别下降10.74%、19.74%和17.64%,均与对照组差异显著(P<0.05)。③试验Ⅲ组母猪血清尿素氮含量下降最明显,降低33.93%;试验Ⅰ、Ⅱ、Ⅲ组母猪血清总胆固醇含量分别下降32.78%、35.79%和37.38%,均与对照组差异显著(P<0.05)。④试验Ⅱ、Ⅲ组母猪血清白细胞介素-1β含量分别下降16.19%、24.47%,均与对照组差异显著(P<0.05)。⑤试验Ⅲ组母猪产后21 d尿液氨氮含量降低18.60%,与对照组差异显著(P<0.05);试验Ⅰ、Ⅱ、Ⅲ组母猪产后21 d尿液总氮含量分别降低14.63%、25.27%、30.81%,均与对照组差异显著(P<0.05);试验Ⅰ、Ⅱ、Ⅲ组母猪产后21 d尿液pH均显著降低(P<0.05)。综上所述,母猪饲粮中添加3%~5%复合微生物发酵饲料可以显著改善母猪生产性能,提升母猪初乳质量,改善血液生化指标,提高母猪免疫力,同时可以显著降低初乳和尿液中的氮元素含量,从而提高妊娠母猪对饲料中氮素的利用率,为降低氮的排放量和绿色生态养殖提供数据支撑。 展开更多
关键词 妊娠后期母猪 发酵饲料 生产性能 初乳 血清指标 氮素转化
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