With the advancement of agricultural modernization, agricultural machinery service organizations, as an important part of the rural operating entities, show an increasing trend year by year, and need new facilities la...With the advancement of agricultural modernization, agricultural machinery service organizations, as an important part of the rural operating entities, show an increasing trend year by year, and need new facilities land in the process of development and growth. Based on the written survey of 597 agricultural machinery service organizations in Guizhou Province, the demand and demand gap of various facilities land use in agricultural machinery service organizations were analyzed and compared. In addition, based on the field survey and policy background, the main practices and experiences of agricultural machinery service organizations in Guizhou Province in the approval and use of facility land were sorted out, and the problems and causes of large gap in facility agricultural land, lack of standards and difficulty in policy implementation were analyzed. Finally, it recommended that the site selection of agricultural machinery service organization facilities needs to be standardized, the land demand needs to be coordinated, the land scale needs to be scientifically demonstrated, and financial support should be sought to promote Guizhou agricultural machinery service organization to become bigger, better and stronger.展开更多
In order to solve the problems of low production efficiency,great loss and low yield,Millet Research Institute of Hebei Academy of Agriculture and Forestry Sciences integrated the plastic film mulching technique and m...In order to solve the problems of low production efficiency,great loss and low yield,Millet Research Institute of Hebei Academy of Agriculture and Forestry Sciences integrated the plastic film mulching technique and mechanized production technique,forming a foxtail millet production technique combining machinery and agronomy.The foxtail millet production technique combining machinery and agronomy regulates millet production from the links of soil preparation,fertilization,variety selection,seeding,intertillage and fertilization and harvest,so as to achieve the effects of promoting the matching between agro-machinery and agronomy,improving the level of millet production mechanization,realizing light simplified production and saving labor cost.This technical regulation has a broad application prospect.展开更多
With the continuous progress of agricultural technology, agricultural mechanization presents a good development trend after half a century development. But agricultural machinery equipment and the level of agricultura...With the continuous progress of agricultural technology, agricultural mechanization presents a good development trend after half a century development. But agricultural machinery equipment and the level of agricultural mechanization are imbalances in different regions</span><span style="font-family:Verdana;">;</span><span style="font-family:Verdana;"> the structure of agricultural machinery equipment is unreasonable</span><span style="font-family:Verdana;">;</span><span style="font-family:Verdana;"> there are great differences in agricultural mechanization level of different operations and different crops and the whole level of agricultural mechanization social service is not high. Through cross regional allocation of existing agricultural machinery</span><span style="font-family:Verdana;"> to</span><span style="font-family:Verdana;"> improve the working efficiency of agricultural machinery;we can extend the operation time of the agricultural machinery and improve the operation effect and income of agricultural machinery.展开更多
Mechanical construction will put influence on the biological characters of reclaimed soils,as well as the soil quality.In order to explore the changing rule of soil microbial quantity and respiratory capacity under di...Mechanical construction will put influence on the biological characters of reclaimed soils,as well as the soil quality.In order to explore the changing rule of soil microbial quantity and respiratory capacity under different construction machineries and rolling times,and find the optimal processing conditions,an experiment was set up and a simulation experimental area was chosen,in which we simulated the main types of reclamation in coal mine area.After 2 years’natural aging,we collected surface soil samples(0-20 cm)that can be used for experimental analysis.The result shows that changing rules of soil biological factors are different with different construction machineries,and soil properties are closest to the normal soil when adopting the combination of“crawler dozer×5 compaction times”and“dump truck×3 compaction times”,which shows that the soil quality is better under this condition.展开更多
In a hybrid system, the subsystems with discrete dynamics play a central role in a hybrid system. In the course of engineering machinery of cluster construction, the discrete control law is hard to obtain because the ...In a hybrid system, the subsystems with discrete dynamics play a central role in a hybrid system. In the course of engineering machinery of cluster construction, the discrete control law is hard to obtain because the construction environment is complex and there exist many affecting factors. In this paper, hierarchically intelligent control, expert control and fuzzy control are introduced into the discrete subsystems of engineering machinery of cluster hybrid system, so as to rebuild the hybrid system and make the discrete control law easily and effectively obtained. The structures, reasoning mechanism and arithmetic of intelligent control are replanted to discrete dynamic, conti- nuous process and the interface of the hybrid system. The structures of three types of intelligent hybrid system are presented and the human experiences summarized from engineering machinery of cluster are taken into account.展开更多
Compound fault,as a primary failure leading to unexpected downtime of rotating machinery,dramatically increases the difficulty in fault diagnosis.To deal with the difficulty encountered in implementing compound fault ...Compound fault,as a primary failure leading to unexpected downtime of rotating machinery,dramatically increases the difficulty in fault diagnosis.To deal with the difficulty encountered in implementing compound fault diagnosis(CFD),researchers and engineers from industry and academia have made numerous significant breakthroughs in recent years.Admittedly,many systematic surveys focused on fault diagnosis have been conducted by reputable researchers.Nevertheless,previous review articles paid more attention to fault diagnosis with several single or independent faults,resulting in that there is still lacking a comprehensive survey on CFD.Therefore,to fulfill the above requirements,it is necessary to provide an in-depth overview of fault diagnosis methods or algorithms for compound faults of rotating machinery and uncover potential challenges or opportunities that would guide and inspire readers to devote their efforts to promoting fault diagnosis technology more effective and practical.Specifically,the backgrounds,including the related definitions and a new taxonomy of CFD methods,are detailed according to the way of implementing compound fault recognition.Then,the stateof-the-art applications of CFD are overviewed based on relevant publications in the past decades.Finally,the challenges and opportunities associated with implementing CFD are concluded and followed by a conclusion for ending this survey.We believe that this review article can provide a systematic guideline of CFD from different aspects for potential readers and seasoned researchers.展开更多
AUTOMATION has come a long way since the early days of mechanization,i.e.,the process of working exclusively by hand or using animals to work with machinery.The rise of steam engines and water wheels represented the f...AUTOMATION has come a long way since the early days of mechanization,i.e.,the process of working exclusively by hand or using animals to work with machinery.The rise of steam engines and water wheels represented the first generation of industry,which is now called Industry Citation:L.Vlacic,H.Huang,M.Dotoli,Y.Wang,P.Ioanno,L.Fan,X.Wang,R.Carli,C.Lv,L.Li,X.Na,Q.-L.Han,and F.-Y.Wang,“Automation 5.0:The key to systems intelligence and Industry 5.0,”IEEE/CAA J.Autom.Sinica,vol.11,no.8,pp.1723-1727,Aug.2024.展开更多
Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accide...Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accidents leading to production shrinkage.The potential failure would negatively affect the profitability of the company,including production shut down,cost of spare parts,cost of labor,damage of reputation,risk of injury to people and the environment.In recent years,condition-based maintenance( CBM) and prognostic and health management( PHM) are developed and formed a strong connection among science,engineering,computer,reliability,communication,management,etc.Computerized maintenance management systems( CMMS) store a lot of data regarding the fault diagnosis and life prediction of the machinery equipment.It's too necessary to uncover useful knowledge from the huge amount of data.It's vital to find the ways to obtain useful and concise information from these data.This information can be of great influence in the decision making of managers.This article is a review of intelligent approaches in machinery faults diagnosis and prediction based on PHM and CBM.展开更多
Although HIWIN has been established for only 24years and went public just about four years ago,it has become the largest machinery manufacturer,in Taiwan and one of the world leading companies in linear motion control...Although HIWIN has been established for only 24years and went public just about four years ago,it has become the largest machinery manufacturer,in Taiwan and one of the world leading companies in linear motion control and system technology.HIWIN’s self-developed products,including ballscrews,linear guideways and industrial robots,have been widely applied to industries like bio-medical,semiconductor,optoelectronics,3C,automation,precision machinery,energy saving and transportation.With strong market performance。展开更多
【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡...【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡萄汁酵素最优接种发酵方式。进一步通过单因素试验及响应面试验,优化葡萄汁酵素最佳发酵工艺条件。【结果】植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵可以显著提高葡萄汁酵素中益生菌活菌数和DPPH清除率;植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵的最佳工艺条件为:按照1∶1比例接种,初始接种量5.00 lg CFU/mL、大豆蛋白胨添加量0.46%、34℃发酵18 h,植物乳杆菌Zhang-LL活菌数达6.60×10^(8)CFU/mL,马克斯克鲁维酵母M3活菌数达8.20×10^(7)CFU/mL,酵素DPPH清除率85.25%。【结论】乳酸菌与酵母菌协同发酵,在缩短发酵时间的同时还能达到较高的活菌数和DPPH清除率,可为葡萄汁酵素的工业化制备及后续多功能产品研发提供理论依据。展开更多
This paper explores the impact of agricultural machinery input on rural households’land transfers,which is conducive to the acceleration of agricultural modernization,agricultural production at scale,and rural revita...This paper explores the impact of agricultural machinery input on rural households’land transfers,which is conducive to the acceleration of agricultural modernization,agricultural production at scale,and rural revitalization.By using the micro-data on rural households(2014–2018)from China Family Panel Studies(CFPS),we made an empirical analysis of the impact of agricultural machinery input on land transfers and drew three conclusions.First,agricultural machinery input has a positive impact on land transfers,which means the more rural households invest in agricultural machinery,the more willing they are to participate in land transfers.Second,the impact of agricultural machinery input on land transfers is mainly exerted by adjusting the allocation of labor resources for rural households,or rather by increasing the number of farmers engaged in agriculture and reducing the number of farmers-turned traders and workers to facilitate land transfers.Third,the impact of agricultural machinery input on land transfers concerns both the positive transfers-in and the negative transfers-out,and such an impact stays stable across income groups.Accordingly,we should further increase agricultural machinery-related subsidies,improve the agricultural machinery service outsourcing market,and help rural households to reasonably allocate their labor resource endowments and invest in agricultural machinery to increase land transfers.展开更多
Aiming at the problems of low efficiency,poor anti-noise and robustness of transfer learning model in intelligent fault diagnosis of rotating machinery,a new method of intelligent fault diagnosis of rotating machinery...Aiming at the problems of low efficiency,poor anti-noise and robustness of transfer learning model in intelligent fault diagnosis of rotating machinery,a new method of intelligent fault diagnosis of rotating machinery based on single source and multi-target domain adversarial network model(WDMACN)and Gram Angle Product field(GAPF)was proposed.Firstly,the original one-dimensional vibration signal is preprocessed using GAPF to generate the image data including all time series.Secondly,the residual network is used to extract data features,and the features of the target domain without labels are pseudo-labeled,and the transferable features among the feature extractors are shared through the depth parameter,and the feature extractors of the multi-target domain are updated anatomically to generate the features that the discriminator cannot distinguish.The modelt through adversarial domain adaptation,thus achieving fault classification.Finally,a large number of validations were carried out on the bearing data set of Case Western Reserve University(CWRU)and the gear data.The results show that the proposed method can greatly improve the diagnostic efficiency of the model,and has good noise resistance and generalization.展开更多
The circulating water system is widely used as the cooling system in the process industry,which has the characteristics of high water and power consumption,and its energy consumption level has an important impact on t...The circulating water system is widely used as the cooling system in the process industry,which has the characteristics of high water and power consumption,and its energy consumption level has an important impact on the economic performance of the whole system.Pump network and water turbine network constitute the work network of the circulating water system,that is,the fluid machinery network.Based on the previous studies,this paper proposes a stepwise method to optimize the fluid machinery network,that is,to optimize the network structure by using the recoverable pressure-head curve of the branch,and consider the recovery of adjustable resistance at the valve of each branch,so as to further reduce energy consumption and water consumption.The calculation result of the case shows that the topology structure optimization can further reduce the operation cost and the annual capital cost on the basis of the fixed structure optimization,and the total annualized cost can be reduced by 30.04%.The optimization result of different flow shows that both the pump network and the water turbine network tend to series structure at a low flow rate whereas to parallel structure at a high flow rate.展开更多
Addressing the challenges posed by the nonlinear and non-stationary vibrations in rotating machinery,where weak fault characteristic signals hinder accurate fault state representation,we propose a novel feature extrac...Addressing the challenges posed by the nonlinear and non-stationary vibrations in rotating machinery,where weak fault characteristic signals hinder accurate fault state representation,we propose a novel feature extraction method that combines the Flexible Analytic Wavelet Transform(FAWT)with Nonlinear Quantum Permutation Entropy.FAWT,leveraging fractional orders and arbitrary scaling and translation factors,exhibits superior translational invariance and adjustable fundamental oscillatory characteristics.This flexibility enables FAWT to provide well-suited wavelet shapes,effectively matching subtle fault components and avoiding performance degradation associated with fixed frequency partitioning and low-oscillation bases in detecting weak faults.In our approach,gearbox vibration signals undergo FAWT to obtain sub-bands.Quantum theory is then introduced into permutation entropy to propose Nonlinear Quantum Permutation Entropy,a feature that more accurately characterizes the operational state of vibration simulation signals.The nonlinear quantum permutation entropy extracted from sub-bands is utilized to characterize the operating state of rotating machinery.A comprehensive analysis of vibration signals from rolling bearings and gearboxes validates the feasibility of the proposed method.Comparative assessments with parameters derived from traditional permutation entropy,sample entropy,wavelet transform(WT),and empirical mode decomposition(EMD)underscore the superior effectiveness of this approach in fault detection and classification for rotating machinery.展开更多
文摘With the advancement of agricultural modernization, agricultural machinery service organizations, as an important part of the rural operating entities, show an increasing trend year by year, and need new facilities land in the process of development and growth. Based on the written survey of 597 agricultural machinery service organizations in Guizhou Province, the demand and demand gap of various facilities land use in agricultural machinery service organizations were analyzed and compared. In addition, based on the field survey and policy background, the main practices and experiences of agricultural machinery service organizations in Guizhou Province in the approval and use of facility land were sorted out, and the problems and causes of large gap in facility agricultural land, lack of standards and difficulty in policy implementation were analyzed. Finally, it recommended that the site selection of agricultural machinery service organization facilities needs to be standardized, the land demand needs to be coordinated, the land scale needs to be scientifically demonstrated, and financial support should be sought to promote Guizhou agricultural machinery service organization to become bigger, better and stronger.
文摘目的探讨血清程序性死亡蛋白-1(programmed cell death 1,PD-1)、亮氨酸leucine-37(Leucine leucine-37,LL-37)、胸腺基质淋巴细胞生成素(Thymic stromal lymphopoietin,TSLP)与白细胞(white blood cell,WBC)、降钙素原(procalcitonin,PCT)的相关性以及在小儿细菌性肺炎中的诊断价值。方法回顾性分析2023年2月至2024年2月在本院儿科住院治疗和门诊健康体检儿童的临床资料,共700例。其中317例细菌性肺炎患儿(重症105例,轻症212例)作为细菌性肺炎组,236例病毒性肺炎作为病毒性肺炎组,147例健康体检儿童作为对照组。采用全自动血细胞分析仪检测血WBC计数;电化学发光法检测血清PCT的水平;酶联免疫吸附法(ELISA)检测血清PD-1、LL-37、TSLP的水平。Pearson相关性分析轻、重症细菌性肺炎患儿血清PD-1、LL-37、TSLP与WBC、PCT的相关性。使用受试者工作特征(receiver operating characteristic,ROC)曲线分析PD-1、LL-37、TSLP单独及三者联合对小儿细菌性肺炎的诊断效能。结果与对照组、病毒性肺炎组相比,细菌性肺炎组血清PD-1、LL-37、TSLP以及WBC、PCT的水平显著升高,差异有统计学意义(F=205.220、185.200、712.300、266.000、3432.000,P均<0.05)。与轻症组相比,重症组血清PD-1、LL-37、TSLP以及WBC、PCT水平显著升高(t=22.180、17.000、19.220、10.560、22.400,P均<0.05)。Pearson相关性分析显示,轻、重症细菌性肺炎患儿血清中PD-1、LL-37、TSLP与WBC计数呈正相关(r=0.328、0.351、0.179、0.187、0.472、0.486,P均<0.05),PD-1、TSLP与PCT呈正相关(r=0.581、0.603、0.503、0.524,P均<0.05),LL-37与PCT无明显相关性。ROC曲线分析显示,血清PD-1、LL-37、TSLP三者联合诊断小儿细菌性肺炎的曲线下面积(area under the curve,AUC)为0.940(0.917~0.963)、灵敏度为90.53%、特异度为84.46%,血清PD-1、LL-37、TSLP三者联合诊断的AUC高于三者单独检查,但差异无统计学意义(Z=1.325、1.033、1.278,P=0.188、0.113、0.159)。结论细菌性肺炎患儿血清PD-1、LL-37、TSLP水平显著升高,且与病情严重程度有关,可反映患儿炎症和细菌感染状态,三者联用可作为诊断细菌性肺炎的有价值生物标志物。
文摘In order to solve the problems of low production efficiency,great loss and low yield,Millet Research Institute of Hebei Academy of Agriculture and Forestry Sciences integrated the plastic film mulching technique and mechanized production technique,forming a foxtail millet production technique combining machinery and agronomy.The foxtail millet production technique combining machinery and agronomy regulates millet production from the links of soil preparation,fertilization,variety selection,seeding,intertillage and fertilization and harvest,so as to achieve the effects of promoting the matching between agro-machinery and agronomy,improving the level of millet production mechanization,realizing light simplified production and saving labor cost.This technical regulation has a broad application prospect.
文摘With the continuous progress of agricultural technology, agricultural mechanization presents a good development trend after half a century development. But agricultural machinery equipment and the level of agricultural mechanization are imbalances in different regions</span><span style="font-family:Verdana;">;</span><span style="font-family:Verdana;"> the structure of agricultural machinery equipment is unreasonable</span><span style="font-family:Verdana;">;</span><span style="font-family:Verdana;"> there are great differences in agricultural mechanization level of different operations and different crops and the whole level of agricultural mechanization social service is not high. Through cross regional allocation of existing agricultural machinery</span><span style="font-family:Verdana;"> to</span><span style="font-family:Verdana;"> improve the working efficiency of agricultural machinery;we can extend the operation time of the agricultural machinery and improve the operation effect and income of agricultural machinery.
基金This study was funded by Natural Science Foundation of China(D011004):Ecological Restoration and Its Environmental Effects.
文摘Mechanical construction will put influence on the biological characters of reclaimed soils,as well as the soil quality.In order to explore the changing rule of soil microbial quantity and respiratory capacity under different construction machineries and rolling times,and find the optimal processing conditions,an experiment was set up and a simulation experimental area was chosen,in which we simulated the main types of reclamation in coal mine area.After 2 years’natural aging,we collected surface soil samples(0-20 cm)that can be used for experimental analysis.The result shows that changing rules of soil biological factors are different with different construction machineries,and soil properties are closest to the normal soil when adopting the combination of“crawler dozer×5 compaction times”and“dump truck×3 compaction times”,which shows that the soil quality is better under this condition.
文摘In a hybrid system, the subsystems with discrete dynamics play a central role in a hybrid system. In the course of engineering machinery of cluster construction, the discrete control law is hard to obtain because the construction environment is complex and there exist many affecting factors. In this paper, hierarchically intelligent control, expert control and fuzzy control are introduced into the discrete subsystems of engineering machinery of cluster hybrid system, so as to rebuild the hybrid system and make the discrete control law easily and effectively obtained. The structures, reasoning mechanism and arithmetic of intelligent control are replanted to discrete dynamic, conti- nuous process and the interface of the hybrid system. The structures of three types of intelligent hybrid system are presented and the human experiences summarized from engineering machinery of cluster are taken into account.
基金This work was supported in part by the National Natural Science Foundation of China under Grants 52205100,52275111,and 52205101in part by the Natural Science Foundations of Guangdong Province-China under Grants 2023A1515012856in part by China Postdoctoral Science Foundation under Grant 2022M711197.
文摘Compound fault,as a primary failure leading to unexpected downtime of rotating machinery,dramatically increases the difficulty in fault diagnosis.To deal with the difficulty encountered in implementing compound fault diagnosis(CFD),researchers and engineers from industry and academia have made numerous significant breakthroughs in recent years.Admittedly,many systematic surveys focused on fault diagnosis have been conducted by reputable researchers.Nevertheless,previous review articles paid more attention to fault diagnosis with several single or independent faults,resulting in that there is still lacking a comprehensive survey on CFD.Therefore,to fulfill the above requirements,it is necessary to provide an in-depth overview of fault diagnosis methods or algorithms for compound faults of rotating machinery and uncover potential challenges or opportunities that would guide and inspire readers to devote their efforts to promoting fault diagnosis technology more effective and practical.Specifically,the backgrounds,including the related definitions and a new taxonomy of CFD methods,are detailed according to the way of implementing compound fault recognition.Then,the stateof-the-art applications of CFD are overviewed based on relevant publications in the past decades.Finally,the challenges and opportunities associated with implementing CFD are concluded and followed by a conclusion for ending this survey.We believe that this review article can provide a systematic guideline of CFD from different aspects for potential readers and seasoned researchers.
基金supported in part by the Hong Kong Polytechnic University via the project P0038447The Science and Technology Development Fund,Macao SAR(0093/2023/RIA2)The Science and Technology Development Fund,Macao SAR(0145/2023/RIA3).
文摘AUTOMATION has come a long way since the early days of mechanization,i.e.,the process of working exclusively by hand or using animals to work with machinery.The rise of steam engines and water wheels represented the first generation of industry,which is now called Industry Citation:L.Vlacic,H.Huang,M.Dotoli,Y.Wang,P.Ioanno,L.Fan,X.Wang,R.Carli,C.Lv,L.Li,X.Na,Q.-L.Han,and F.-Y.Wang,“Automation 5.0:The key to systems intelligence and Industry 5.0,”IEEE/CAA J.Autom.Sinica,vol.11,no.8,pp.1723-1727,Aug.2024.
基金Fundamental Research Funds for the Central Universities,China(No.DUT17GF214)
文摘Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accidents leading to production shrinkage.The potential failure would negatively affect the profitability of the company,including production shut down,cost of spare parts,cost of labor,damage of reputation,risk of injury to people and the environment.In recent years,condition-based maintenance( CBM) and prognostic and health management( PHM) are developed and formed a strong connection among science,engineering,computer,reliability,communication,management,etc.Computerized maintenance management systems( CMMS) store a lot of data regarding the fault diagnosis and life prediction of the machinery equipment.It's too necessary to uncover useful knowledge from the huge amount of data.It's vital to find the ways to obtain useful and concise information from these data.This information can be of great influence in the decision making of managers.This article is a review of intelligent approaches in machinery faults diagnosis and prediction based on PHM and CBM.
文摘Although HIWIN has been established for only 24years and went public just about four years ago,it has become the largest machinery manufacturer,in Taiwan and one of the world leading companies in linear motion control and system technology.HIWIN’s self-developed products,including ballscrews,linear guideways and industrial robots,have been widely applied to industries like bio-medical,semiconductor,optoelectronics,3C,automation,precision machinery,energy saving and transportation.With strong market performance。
文摘【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡萄汁酵素最优接种发酵方式。进一步通过单因素试验及响应面试验,优化葡萄汁酵素最佳发酵工艺条件。【结果】植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵可以显著提高葡萄汁酵素中益生菌活菌数和DPPH清除率;植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵的最佳工艺条件为:按照1∶1比例接种,初始接种量5.00 lg CFU/mL、大豆蛋白胨添加量0.46%、34℃发酵18 h,植物乳杆菌Zhang-LL活菌数达6.60×10^(8)CFU/mL,马克斯克鲁维酵母M3活菌数达8.20×10^(7)CFU/mL,酵素DPPH清除率85.25%。【结论】乳酸菌与酵母菌协同发酵,在缩短发酵时间的同时还能达到较高的活菌数和DPPH清除率,可为葡萄汁酵素的工业化制备及后续多功能产品研发提供理论依据。
基金“Research in the Sustainable Means of Livelihood and Relevant Supportive Policies for ‘Hydropower Migrants’ in Tibetan Ethnic Areas, Sichuan Province”(17CMZ035),a program funded by the National Social Science Fund of China [NSSFC]“Research in the Mechanism and Measures on Relative Poverty Alleviation through E-Commerce Development in Chengdu”(YY0520200702),a Chengdu municipal program of philosophy and social sciences“Research in the Identification of Poverty-stricken Rural Households in Sichuan Province from the Perspective of Vulnerability”(CR1420),a program funded by Sichuan Center for Rural Development Research
文摘This paper explores the impact of agricultural machinery input on rural households’land transfers,which is conducive to the acceleration of agricultural modernization,agricultural production at scale,and rural revitalization.By using the micro-data on rural households(2014–2018)from China Family Panel Studies(CFPS),we made an empirical analysis of the impact of agricultural machinery input on land transfers and drew three conclusions.First,agricultural machinery input has a positive impact on land transfers,which means the more rural households invest in agricultural machinery,the more willing they are to participate in land transfers.Second,the impact of agricultural machinery input on land transfers is mainly exerted by adjusting the allocation of labor resources for rural households,or rather by increasing the number of farmers engaged in agriculture and reducing the number of farmers-turned traders and workers to facilitate land transfers.Third,the impact of agricultural machinery input on land transfers concerns both the positive transfers-in and the negative transfers-out,and such an impact stays stable across income groups.Accordingly,we should further increase agricultural machinery-related subsidies,improve the agricultural machinery service outsourcing market,and help rural households to reasonably allocate their labor resource endowments and invest in agricultural machinery to increase land transfers.
基金Shaanxi Province key Research and Development Plan-Listed project(2022-JBGS-07)。
文摘Aiming at the problems of low efficiency,poor anti-noise and robustness of transfer learning model in intelligent fault diagnosis of rotating machinery,a new method of intelligent fault diagnosis of rotating machinery based on single source and multi-target domain adversarial network model(WDMACN)and Gram Angle Product field(GAPF)was proposed.Firstly,the original one-dimensional vibration signal is preprocessed using GAPF to generate the image data including all time series.Secondly,the residual network is used to extract data features,and the features of the target domain without labels are pseudo-labeled,and the transferable features among the feature extractors are shared through the depth parameter,and the feature extractors of the multi-target domain are updated anatomically to generate the features that the discriminator cannot distinguish.The modelt through adversarial domain adaptation,thus achieving fault classification.Finally,a large number of validations were carried out on the bearing data set of Case Western Reserve University(CWRU)and the gear data.The results show that the proposed method can greatly improve the diagnostic efficiency of the model,and has good noise resistance and generalization.
基金Financial support from Key Research and Development Projects of Shaanxi Province(2024GX-YBXM-508)Research Fund for Young Star of Science and Technology in Shaanxi Province(2023KJXX-124)are gratefully acknowledged.
文摘The circulating water system is widely used as the cooling system in the process industry,which has the characteristics of high water and power consumption,and its energy consumption level has an important impact on the economic performance of the whole system.Pump network and water turbine network constitute the work network of the circulating water system,that is,the fluid machinery network.Based on the previous studies,this paper proposes a stepwise method to optimize the fluid machinery network,that is,to optimize the network structure by using the recoverable pressure-head curve of the branch,and consider the recovery of adjustable resistance at the valve of each branch,so as to further reduce energy consumption and water consumption.The calculation result of the case shows that the topology structure optimization can further reduce the operation cost and the annual capital cost on the basis of the fixed structure optimization,and the total annualized cost can be reduced by 30.04%.The optimization result of different flow shows that both the pump network and the water turbine network tend to series structure at a low flow rate whereas to parallel structure at a high flow rate.
基金supported financially by FundamentalResearch Program of Shanxi Province(No.202103021223056).
文摘Addressing the challenges posed by the nonlinear and non-stationary vibrations in rotating machinery,where weak fault characteristic signals hinder accurate fault state representation,we propose a novel feature extraction method that combines the Flexible Analytic Wavelet Transform(FAWT)with Nonlinear Quantum Permutation Entropy.FAWT,leveraging fractional orders and arbitrary scaling and translation factors,exhibits superior translational invariance and adjustable fundamental oscillatory characteristics.This flexibility enables FAWT to provide well-suited wavelet shapes,effectively matching subtle fault components and avoiding performance degradation associated with fixed frequency partitioning and low-oscillation bases in detecting weak faults.In our approach,gearbox vibration signals undergo FAWT to obtain sub-bands.Quantum theory is then introduced into permutation entropy to propose Nonlinear Quantum Permutation Entropy,a feature that more accurately characterizes the operational state of vibration simulation signals.The nonlinear quantum permutation entropy extracted from sub-bands is utilized to characterize the operating state of rotating machinery.A comprehensive analysis of vibration signals from rolling bearings and gearboxes validates the feasibility of the proposed method.Comparative assessments with parameters derived from traditional permutation entropy,sample entropy,wavelet transform(WT),and empirical mode decomposition(EMD)underscore the superior effectiveness of this approach in fault detection and classification for rotating machinery.
