In the increasingly competitive construction market,the engineering quantity list pricing model,as an important way of project cost management,is of crucial significance for construction enterprises to control costs a...In the increasingly competitive construction market,the engineering quantity list pricing model,as an important way of project cost management,is of crucial significance for construction enterprises to control costs and enhance benefits.This study deeply analyzes the characteristics of engineering quantity list pricing,and elaborates on the dilemmas faced by construction enterprises in project cost control,such as lagging concepts,imperfect mechanisms,weak risk management and control,and lack of construction-stage management.Based on this,from the dimensions of strengthening management and control concepts,improving supervision mechanisms,enhancing risk management and control capabilities,and attaching importance to construction-stage cost management,this study proposes project cost management and control strategies that are in line with the actual situation of construction enterprises,aiming to promote construction enterprises to achieve scientific management and optimization of project costs under the engineering quantity list pricing model.展开更多
Minimum quantity lubrication(MQL)is a technique that achieves effective lubrication and cooling of the cutting zone by using a minimal amount of cutting fluid.This results in a decrease in the cutting temperature,exte...Minimum quantity lubrication(MQL)is a technique that achieves effective lubrication and cooling of the cutting zone by using a minimal amount of cutting fluid.This results in a decrease in the cutting temperature,extending the cutting tool life and improving the surface quality of the workpiece.Optimizing the nozzle settings can enhance the cooling and lubrication performance of MQL,leading to increased processing efficiency and product quality.Nozzles with different shapes are fabricated,and different outlet diameters and wall thicknesses are set.The cutting process takes into account the impact of spindle speed and feed rate.An experimental study is conducted to investigate the atomization cone angle and particle size distribution of different nozzles.The circular nozzle is more conducive to the concentrated injection of an atomized liquid beam.The atomization cone angle is the largest when the nozzle outlet diameter is 1.2 mm.Enlarging the nozzle outlet diameter will increase the diameter of the atomized droplets.The atomization cone angle increases while the droplet diameter decreases with the increase of outlet wall thickness.Properly increasing the outlet wall thickness is beneficial to improving the atomization quality.The droplet diameter increases firstly and then decreases with the increase of spindle speed and feed rate.Increasing the MQL gas supply pressure and reducing the lubricating oil flow rate will improve the atomization quality of the nozzle.Studies on the influence of the MQL nozzle processing technology on the atomization effect can help to enhance the cooling and lubrication performance of the MQL technology,leading to improved processing efficiency and quality.展开更多
With the continuous application of new technologies in reconnaissance and attack, false camouflage plays a more important role in improving the survivability of targets, and the number of decoys plays a crucial role i...With the continuous application of new technologies in reconnaissance and attack, false camouflage plays a more important role in improving the survivability of targets, and the number of decoys plays a crucial role in the camouflaging effect. Based on the concept of cost-effectiveness ratio, according to the newly formulated Johnson criterion and the view of discovery and destruction, this paper proposes to take the identification probability as the probability of being destroyed and uses mathematical formulas to calculate the cost of a single use decoy. On this basis, a cost-effectiveness ratio model is established, with the product of the increase in the survival probability of the target and the cost of the target as the benefit, and the sum of the product of the probability of being destroyed and the cost of the decoy and the cost of a single use as the consumption cost. The model is calculated and analyzed, and the number of decoys that conform to the actual situation is obtained.展开更多
Minimum quantity Lubrication(MQL)is a sustainable lubrication system that is famous in many machining systems.It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes.The MQL ...Minimum quantity Lubrication(MQL)is a sustainable lubrication system that is famous in many machining systems.It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes.The MQL system is affirmed to exhibit an excellent machining performance,and it is highly economical.The nanofluids are understood to exhibit excellent lubricity and heat evacuation capability,compared to pure oil-based MQL system.Studies have shown that the surface quality and amount of energy expended in the grinding operations can be reduced considerably due to the positive effect of these nanofluids.This work presents an experimental study on the tribological performance of SiO_(2)nanofluid during grinding of Si_(3)N_(4)ceramic.The effect different grinding modes and lubrication systems during the grinding operation was also analyzed.Different concentrations of the SiO_(2)nanofluid was manufactured using canola,corn and sunflower oils.The quantitative evaluation of the grinding process was done based on the amount of grinding forces,specific grinding energy,frictional coefficient,and surface integrity.It was found that the canola oil exhibits optimal lubrication performance compared to corn oil,sunflower oil,and traditional lubrication systems.Additionally,the introduction of ultrasonic vibrations with the SiO_(2)nanofluid in MQL system was found to reduce the specific grinding energy,normal grinding forces,tangential grinding forces,and surface roughness by 65%,57%,65%,and 18%respectively.Finally,regression analysis was used to obtain an optimum parameter combinations.The observations from this work will aid the smooth transition towards ecofriendly and sustainable machining of engineering ceramics.展开更多
The ability to predict gas emissions accurately is pivotal in managing gas control and ensuring safe mining operations.Existing internationally acknowledged gas control and prediction software does not cater to the sp...The ability to predict gas emissions accurately is pivotal in managing gas control and ensuring safe mining operations.Existing internationally acknowledged gas control and prediction software does not cater to the specific conditions in Chinese coal mines.Hence,this paper introduces an object-oriented programming method to design a software tool for calculating the total gas emission quantity using the MATLAB application program designer runtime environment.The software incorporates an algorithm,data structure,framework,and module functions,all of which enable seamless integration and visualization of gas emission calculation software.This software tool mitigates the inefficiencies and inaccuracies associated with manual,different-source forecast methods.Based on the field data of the Hulonggou Coal Mine in Shanxi province,this technical software was used to predict the gas emission of the mine.The research results show that the predicted value of the technical software is close to the actual measured value.The differing estimates of the working face and coal mine output primarily account for the deviation between the tool's predicted gas emission value and the field-measured value.The underlying design logic of this technical software determines that it has good adaptability to mines with clear mining technology parameters and gas geological parameters.This study provides a valuable method for researchers and engineers seeking to improve gas emission calculation efficiency.展开更多
[Objectives]The paper was to further investigate the correlation between the presence of earthworms and the occurrence of Meloidogyne incognita.[Methods]The effect of earthworms on the population quantity of M.incogni...[Objectives]The paper was to further investigate the correlation between the presence of earthworms and the occurrence of Meloidogyne incognita.[Methods]The effect of earthworms on the population quantity of M.incognita and the growth of tomato plants was assessed through a potting experiment utilizing Eisenia fetida and M.incognita as the primary subjects of investigation.[Results]E.fetida exhibited an inhibitory effect on both the reproductive capacity and the prevalence of M.incognita.Additionally,it mitigated the adverse effects of M.incognita on the growth and development of tomato plants.[Conclusions]The findings of this study will establish a theoretical framework for utilizing earthworms and their metabolites to modulate the rhizosphere microecological environment,thereby facilitating the management of M.incognita.展开更多
Because of the various elements that come into play in natural soil formation, the impact of varied proportions of mineral composition and fines amount on Atterberg limits and compaction characteristics of soils is no...Because of the various elements that come into play in natural soil formation, the impact of varied proportions of mineral composition and fines amount on Atterberg limits and compaction characteristics of soils is not well known. Three distinct soil samples were used in this investigation. The findings indicated the effect of varied mineral composition proportions and fines amount on the liquid limit, plastic limit, and plasticity index as assessed by the Casagrande test and hand-rolling method. The fluctuation of maximum dry density and optimal moisture content with these three soils has also been studied. Furthermore, correlations were established to indicate the compaction parameters and the amount of minerals and particles in the soil. The data show that the mineral content of the soil has a direct impact on the Atterberg limits and compaction characteristics. Soils containing larger percentages of expansive minerals, such as montmorillonite, have more flexibility and volume change capability. Mineral composition influences compaction parameters such as maximum dry density, ideal water content, axial strain, and axial stress. Soils with a larger proportion of fines, such as Soil 2 and Soil 3, have stronger flexibility and lower compaction qualities, with higher ideal water content and lower maximum dry density. Soil 1 has moderate flexibility and intermediate compaction qualities due to its low fines percentage. The effect of different mineral compositions and fines on the Atterberg limits and compaction characteristics of soils can be used to predict the behavior of compacted soils encountered in engineering practices, reducing the time and effort required to assess soil suitability for engineering use.展开更多
Traditional methods for selecting models in experimental data analysis are susceptible to researcher bias, hindering exploration of alternative explanations and potentially leading to overfitting. The Finite Informati...Traditional methods for selecting models in experimental data analysis are susceptible to researcher bias, hindering exploration of alternative explanations and potentially leading to overfitting. The Finite Information Quantity (FIQ) approach offers a novel solution by acknowledging the inherent limitations in information processing capacity of physical systems. This framework facilitates the development of objective criteria for model selection (comparative uncertainty) and paves the way for a more comprehensive understanding of phenomena through exploring diverse explanations. This work presents a detailed comparison of the FIQ approach with ten established model selection methods, highlighting the advantages and limitations of each. We demonstrate the potential of FIQ to enhance the objectivity and robustness of scientific inquiry through three practical examples: selecting appropriate models for measuring fundamental constants, sound velocity, and underwater electrical discharges. Further research is warranted to explore the full applicability of FIQ across various scientific disciplines.展开更多
Regressive formulae to calculate the quantity of plant leaf area for 13 species of ornamental plants were set up based on investigation data of 30 species on 3 major public squares (Dongfeng square, Shengli square and...Regressive formulae to calculate the quantity of plant leaf area for 13 species of ornamental plants were set up based on investigation data of 30 species on 3 major public squares (Dongfeng square, Shengli square and Guandu square) in Kun-ming City, China, which were applied to calculate quantities of plant leaf area of these 13 species. The quantities of plant leaf area for the other 17 ornamental plant species on these squares were directly measured, and the total quantity of plant leaf area of each studied square was obtained individually. The results showed that the quantity of plant leaf area on Shengli square with ornamental plants structure composed of arbor tree species, shrub tree species and turf grass was highest among the three squares. It is believed that the design model of multi-storied vertical structure and proper tending of plant community could not only increase the quantity of plant leaf area, but also play an important role in generating ecological and landscaping benefits. Some corresponding suggestions were put forward on the basis of comprehensive analyses on the plant leaf area quantity of the three representative squares in Kunming urban area.展开更多
[Objective] The aim was to research the rules of nectar quantity and sugar concentration of perfect and staminate flowers in a day. [Method] Based on nine Tianguang Yan pomegranate trees, nectar quantity and sugar con...[Objective] The aim was to research the rules of nectar quantity and sugar concentration of perfect and staminate flowers in a day. [Method] Based on nine Tianguang Yan pomegranate trees, nectar quantity and sugar concentration of per- fect and staminate flowers were measured and analyzed in morning and afternoon. [Result] Average nectar quantity and sugar concentration differed insignificantly in morning and afternoon of perfect flowers, which could also be applied to staminate flowers. However, average nectar quantity of perfect flower was 64.09 μI and of staminate flower was 44.07 μl. It is obvious that the two were of extremely signifi- cant differences （t=4.642, P〈0.01）, and the former was significantly higher by 45,43%. On the other hand, average sugar concentration of perfect flower was 48.44% and of staminate flower was 37.16%. The two were of extremely significant differences and the former is higher by 30.36%, compared with the latter. These suggested that nectar quantity and sugar concentration would maintain unchanged in different periods for a day, if nectars are not consumed by pollinators, such as bees and butterflies. In the same period, nectar quantity and sugar concentration of per- fect flowers were higher than those of staminate flowers. [Conclusion] The research provides references for benefits increase of bee farmers and fruit farmers, as well as exploration of bee pollination.展开更多
[Objective] This study aimed to investigate the effects of different land use patterns on soil ecological environment. [Method] Total three representative land use patterns （corn field, cherry tree land, wood land） ...[Objective] This study aimed to investigate the effects of different land use patterns on soil ecological environment. [Method] Total three representative land use patterns （corn field, cherry tree land, wood land） were selected from Hongta District, Yuxi City, and under these three patterns, soil microbial quantity and activity were studied. [Result] Under the three land use patterns, soil microorganisms were domi- nated by bacteria; soil microbial quantity ranked as wood land＇s〉cheery tree land＇s〉 corn field＇s; and total microbial activity, catalase activity and urease activity all ranked as cherry tree land＇s〉wood land＇s〉corn field＇s. [Conclusion] Soil microbial activity and functions are related to farmland management measures, as well as land use pattern and soil nutrients.展开更多
OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia （ADH）, ductal carcinoma in situ （DCIS） and invasive ductal carcinoma （IDC） of the bre...OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia （ADH）, ductal carcinoma in situ （DCIS） and invasive ductal carcinoma （IDC） of the breast. The relationship between centrosome abnormalities and breast tumor development was further discussed. METHODS There were three groups including ADH, DCIS and IDC with 30 cases in each group. They were analyzed by immuno-fiuorescence quantity analysis. The expression levels of α-tubulin and γ-tubulin protein in these tissues were detected by flow cytometry immuno-fiuorescence analysis and compared with the results from normal tissues. Immunohistochemistry was also performed in this research. RESULTS The results showed significant differences of the average of the positive （FITC labeled） cells （P=0.000） among the four groups. The level of the IDC group was the highest, while normal breast tissue showed the lowest level. The results suggested that the expression levels of α-tubulin and γ-tubulin both increased as the grade of cellular proliferation and differentiation increased. The expressions showed significant differences among all the groups, except between the ADH and DCIS. There were no significant differences between α-tubulin and γ-tubulin expression in each group （P〈0.05）, as there was agreement in the immuno-fluorescence and immunohistochemical analysis for protein expression. CONCLUSION There is abnormal expression of centrosome tubulin as an early event in the development of breast tumor. Furthermore these aberrations may play a key role during oncogenesis and promote cellular transformation to malignancy. The immuno-fiuorescence quantitive analysis and immunohistochemistry can complement each other.展开更多
[Objective] The aim was to research the appropriate seeding quantities of double-season machine-transplanted rice in middle and low-yielding district of southern Jiangxi Province. [Method] The research set five differ...[Objective] The aim was to research the appropriate seeding quantities of double-season machine-transplanted rice in middle and low-yielding district of southern Jiangxi Province. [Method] The research set five different seeding quantities treatments, and compared with conventional seedling treatment, and the appropriate seeding quantities of double season machine-transplanted rice in middle and lowyielding district of southern Jiangxi Province was discussed. [Result] The yields were highest when the seeding quantity was 70 g per tray of early rice by mechanical transplanting and 60 g per tray of late rice. The yield of early rice by mechanical transplanting showed significantly positive correlation with the number of productive ear and the number of seed per ear, and late rice yield showed significant correlation with the number of productive ear by mechanical transplanting. It is key for improving high yields by guaranteeing the number of productive ear. [Conclusion] The issue of proper sowing quantity should be taken into consideration for double-cropping rice in the region, which is crucial for high yields.展开更多
Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze ...Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze yield. [Result] Both of N and P fertiIizers have significant effects on malze yield. When malze yield reached the highest, the quantities of N fertiIizers and P fertiIizers were 530.56 and 105.44 kg/hm2, respectiveIy. [Conclusion] Malze yield keeps growing upon N or P fertiIizers to certaln extent, and excessive quantities of N and P fertiIizer wouId reduce malze yield.展开更多
A non-Noether conserved quantity, i.e., Hojman conserved quantity, constructed by using Mei symmetry for the nonholonomic controllable mechanical system, is presented. Under general infinitesimal transformations, the ...A non-Noether conserved quantity, i.e., Hojman conserved quantity, constructed by using Mei symmetry for the nonholonomic controllable mechanical system, is presented. Under general infinitesimal transformations, the determining equations of the special Mei symmetry, the constrained restriction equations, the additional restriction equations, and the definitions of the weak Mei symmetry and the strong Mei symmetry of the nonholonomic controllable mechanical system are given. The condition under which Mei symmetry is a Lie symmetry is obtained. The form of the Hojman conserved quantity of the corresponding holonomic mechanical system, the weak Hojman conserved quantity and the strong Hojman conserved quantity of the nonholonomie controllable mechanical system are obtained. An example is given to illustrate the application of the results.展开更多
The development and deployment of privary preserving supply chain quantity discount contract design can allow supply chain collaborations to take place without revealing any participant＇s data to others, reaping the ...The development and deployment of privary preserving supply chain quantity discount contract design can allow supply chain collaborations to take place without revealing any participant＇s data to others, reaping the benefits of collaborations wbile avoiding the drawbacks of privacy information disclosure. First, secure multi-party computation protocols are applied in the joint-ordering policy between a single supplier and a single retailer, the joint-ordering policy can be conducted without disclosing private cost information of any of the other supply chain partners. Secondly, secure multi-party computation protocols are applied in the privacy preserving supply chain quantity discount contract design between a single supplier and a single retailer. The information disclosure analyses of the algorithm show that： the optimal quantity discount of the jointordering policy can be conducted without disclosing private cost information of any of the other supply chain partners; the above protocol can be implemented without mediators; the privacy preserving quantity discount algorithm can be mutually verifiable and has solved the problem of asymmetric information.展开更多
Urban peripheral green space (UPGS) plays more and more important rol e in sustaining urban physical and ecological environments. In this paper, a pre liminary classification of UPGS was presented for seven types and ...Urban peripheral green space (UPGS) plays more and more important rol e in sustaining urban physical and ecological environments. In this paper, a pre liminary classification of UPGS was presented for seven types and quantity index of UPGS was discussed tentatively. The quantity and layout problems in urban pe ripheral green space, and the several principles were mainly discussed in urban ventilation and sanitation, recreational opportunity and landscape ecological st ructure.展开更多
In nanofluid minimum quantity lubrication(NMQL)milling of aviation aluminum alloy,it is the bottleneck problem to adjust the position parameters(target distance,incidence angle,and elevation angle)of the nozzle to imp...In nanofluid minimum quantity lubrication(NMQL)milling of aviation aluminum alloy,it is the bottleneck problem to adjust the position parameters(target distance,incidence angle,and elevation angle)of the nozzle to improve the surface roughness of milling,which has large and uncontrollable errors.In this paper,the influence law of milling cutter speed,helical angle,and cavity shape on the flow field around the milling cutter was studied,and the optimal nozzle profile parameters were obtained.Using 7050 aluminum alloy as the workpiece material,the milling experiment of the NMQL cavity was conducted by utilizing cottonseed oil-based Al2 O3 nanofluid.Results show that the high velocity of the surrounding air flow field and the strong gas barrier could be attributed to high rotating velocities of the milling cutter.The incidence angle of the nozzle was consistent with the helical angle of the milling cutter,the target distance was appropriate at 25–30 mm,and the elevation angle was suitable at 60°–65°.The range and variance analyses of the signal-to-noise ratio of milling force and roughness were performed,and the chip morphology was observed and analyzed.The results show that the optimal combination of nozzle position parameters was the target distance of 30 mm,the incidence angle of 35°,and the elevation angle of 60°.Among these parameters,target distance had the largest impact on cutting performance with a contribution rate of more than 55%,followed by incidence angle and elevation contribution rate.Analysis by orthogonal experiment revealed that the nozzle position parameters were appropriate,and Ra(0.087 lm)was reduced by 30.4%from the maximum value(0.125 lm).Moreover,Rsm(0.05 mm)was minimum,which was 36%lower than that of the seventh group(Rsm=0.078 mm).展开更多
It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL)technology.Nevertheless,for aeronautical difficult-tomachine materials,MQL couldn’t meet...It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL)technology.Nevertheless,for aeronautical difficult-tomachine materials,MQL couldn’t meet the high demand of cooling and lubrication due to high heat generation during machining.Nano-biolubricants,especially non-toxic carbon group nano-enhancers(CGNs)are used,can solve this technical bottleneck.However,the machining mechanisms under lubrication of CGNs are unclear at complex interface between tool and workpiece,which characterized by high temperature,pressure,and speed,limited its application in factories and necessitates in-depth understanding.To fill this gap,this study concentrates on the comprehensive quantitative assessment of tribological characteristics based on force,tool wear,chip,and surface integrity in titanium alloy and nickel alloy machining and attempts to answer mechanisms systematically.First,to establish evaluation standard,the cutting mechanisms and performance improvement behavior covering antifriction,antiwear,tool failure,material removal,and surface formation of MQL were revealed.Second,the unique film formation and lubrication behaviors of CGNs in MQL turning,milling,and grinding are concluded.The influence law of molecular structure and micromorphology of CGNs was also answered and optimized options were recommended by considering diverse boundary conditions.Finally,in view of CGNs limitations in MQL,the future development direction is proposed,which needs to be improved in thermal stability of lubricant,activity of CGNs,controllable atomization and transportation methods,and intelligent formation of processing technology solutions.展开更多
文摘In the increasingly competitive construction market,the engineering quantity list pricing model,as an important way of project cost management,is of crucial significance for construction enterprises to control costs and enhance benefits.This study deeply analyzes the characteristics of engineering quantity list pricing,and elaborates on the dilemmas faced by construction enterprises in project cost control,such as lagging concepts,imperfect mechanisms,weak risk management and control,and lack of construction-stage management.Based on this,from the dimensions of strengthening management and control concepts,improving supervision mechanisms,enhancing risk management and control capabilities,and attaching importance to construction-stage cost management,this study proposes project cost management and control strategies that are in line with the actual situation of construction enterprises,aiming to promote construction enterprises to achieve scientific management and optimization of project costs under the engineering quantity list pricing model.
文摘Minimum quantity lubrication(MQL)is a technique that achieves effective lubrication and cooling of the cutting zone by using a minimal amount of cutting fluid.This results in a decrease in the cutting temperature,extending the cutting tool life and improving the surface quality of the workpiece.Optimizing the nozzle settings can enhance the cooling and lubrication performance of MQL,leading to increased processing efficiency and product quality.Nozzles with different shapes are fabricated,and different outlet diameters and wall thicknesses are set.The cutting process takes into account the impact of spindle speed and feed rate.An experimental study is conducted to investigate the atomization cone angle and particle size distribution of different nozzles.The circular nozzle is more conducive to the concentrated injection of an atomized liquid beam.The atomization cone angle is the largest when the nozzle outlet diameter is 1.2 mm.Enlarging the nozzle outlet diameter will increase the diameter of the atomized droplets.The atomization cone angle increases while the droplet diameter decreases with the increase of outlet wall thickness.Properly increasing the outlet wall thickness is beneficial to improving the atomization quality.The droplet diameter increases firstly and then decreases with the increase of spindle speed and feed rate.Increasing the MQL gas supply pressure and reducing the lubricating oil flow rate will improve the atomization quality of the nozzle.Studies on the influence of the MQL nozzle processing technology on the atomization effect can help to enhance the cooling and lubrication performance of the MQL technology,leading to improved processing efficiency and quality.
文摘With the continuous application of new technologies in reconnaissance and attack, false camouflage plays a more important role in improving the survivability of targets, and the number of decoys plays a crucial role in the camouflaging effect. Based on the concept of cost-effectiveness ratio, according to the newly formulated Johnson criterion and the view of discovery and destruction, this paper proposes to take the identification probability as the probability of being destroyed and uses mathematical formulas to calculate the cost of a single use decoy. On this basis, a cost-effectiveness ratio model is established, with the product of the increase in the survival probability of the target and the cost of the target as the benefit, and the sum of the product of the probability of being destroyed and the cost of the decoy and the cost of a single use as the consumption cost. The model is calculated and analyzed, and the number of decoys that conform to the actual situation is obtained.
文摘Minimum quantity Lubrication(MQL)is a sustainable lubrication system that is famous in many machining systems.It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes.The MQL system is affirmed to exhibit an excellent machining performance,and it is highly economical.The nanofluids are understood to exhibit excellent lubricity and heat evacuation capability,compared to pure oil-based MQL system.Studies have shown that the surface quality and amount of energy expended in the grinding operations can be reduced considerably due to the positive effect of these nanofluids.This work presents an experimental study on the tribological performance of SiO_(2)nanofluid during grinding of Si_(3)N_(4)ceramic.The effect different grinding modes and lubrication systems during the grinding operation was also analyzed.Different concentrations of the SiO_(2)nanofluid was manufactured using canola,corn and sunflower oils.The quantitative evaluation of the grinding process was done based on the amount of grinding forces,specific grinding energy,frictional coefficient,and surface integrity.It was found that the canola oil exhibits optimal lubrication performance compared to corn oil,sunflower oil,and traditional lubrication systems.Additionally,the introduction of ultrasonic vibrations with the SiO_(2)nanofluid in MQL system was found to reduce the specific grinding energy,normal grinding forces,tangential grinding forces,and surface roughness by 65%,57%,65%,and 18%respectively.Finally,regression analysis was used to obtain an optimum parameter combinations.The observations from this work will aid the smooth transition towards ecofriendly and sustainable machining of engineering ceramics.
基金support from the Beijing Natural Science Foundation(8222070)the National Natural Science Foundation of China(52374250,52121003,52130409)the Fundamental Research Funds for the Central Universities(2023ZKPYAQ01).
文摘The ability to predict gas emissions accurately is pivotal in managing gas control and ensuring safe mining operations.Existing internationally acknowledged gas control and prediction software does not cater to the specific conditions in Chinese coal mines.Hence,this paper introduces an object-oriented programming method to design a software tool for calculating the total gas emission quantity using the MATLAB application program designer runtime environment.The software incorporates an algorithm,data structure,framework,and module functions,all of which enable seamless integration and visualization of gas emission calculation software.This software tool mitigates the inefficiencies and inaccuracies associated with manual,different-source forecast methods.Based on the field data of the Hulonggou Coal Mine in Shanxi province,this technical software was used to predict the gas emission of the mine.The research results show that the predicted value of the technical software is close to the actual measured value.The differing estimates of the working face and coal mine output primarily account for the deviation between the tool's predicted gas emission value and the field-measured value.The underlying design logic of this technical software determines that it has good adaptability to mines with clear mining technology parameters and gas geological parameters.This study provides a valuable method for researchers and engineers seeking to improve gas emission calculation efficiency.
基金Supported by Key R&D Project of Science&Technology Department of Ningxia Hui Autonomous Region(2021BBF02013)Post-doctoral Program of Hebei Province(2019003011)Hebei Province Innovation Ability Enhancement Plan Project(225676109H).
文摘[Objectives]The paper was to further investigate the correlation between the presence of earthworms and the occurrence of Meloidogyne incognita.[Methods]The effect of earthworms on the population quantity of M.incognita and the growth of tomato plants was assessed through a potting experiment utilizing Eisenia fetida and M.incognita as the primary subjects of investigation.[Results]E.fetida exhibited an inhibitory effect on both the reproductive capacity and the prevalence of M.incognita.Additionally,it mitigated the adverse effects of M.incognita on the growth and development of tomato plants.[Conclusions]The findings of this study will establish a theoretical framework for utilizing earthworms and their metabolites to modulate the rhizosphere microecological environment,thereby facilitating the management of M.incognita.
文摘Because of the various elements that come into play in natural soil formation, the impact of varied proportions of mineral composition and fines amount on Atterberg limits and compaction characteristics of soils is not well known. Three distinct soil samples were used in this investigation. The findings indicated the effect of varied mineral composition proportions and fines amount on the liquid limit, plastic limit, and plasticity index as assessed by the Casagrande test and hand-rolling method. The fluctuation of maximum dry density and optimal moisture content with these three soils has also been studied. Furthermore, correlations were established to indicate the compaction parameters and the amount of minerals and particles in the soil. The data show that the mineral content of the soil has a direct impact on the Atterberg limits and compaction characteristics. Soils containing larger percentages of expansive minerals, such as montmorillonite, have more flexibility and volume change capability. Mineral composition influences compaction parameters such as maximum dry density, ideal water content, axial strain, and axial stress. Soils with a larger proportion of fines, such as Soil 2 and Soil 3, have stronger flexibility and lower compaction qualities, with higher ideal water content and lower maximum dry density. Soil 1 has moderate flexibility and intermediate compaction qualities due to its low fines percentage. The effect of different mineral compositions and fines on the Atterberg limits and compaction characteristics of soils can be used to predict the behavior of compacted soils encountered in engineering practices, reducing the time and effort required to assess soil suitability for engineering use.
文摘Traditional methods for selecting models in experimental data analysis are susceptible to researcher bias, hindering exploration of alternative explanations and potentially leading to overfitting. The Finite Information Quantity (FIQ) approach offers a novel solution by acknowledging the inherent limitations in information processing capacity of physical systems. This framework facilitates the development of objective criteria for model selection (comparative uncertainty) and paves the way for a more comprehensive understanding of phenomena through exploring diverse explanations. This work presents a detailed comparison of the FIQ approach with ten established model selection methods, highlighting the advantages and limitations of each. We demonstrate the potential of FIQ to enhance the objectivity and robustness of scientific inquiry through three practical examples: selecting appropriate models for measuring fundamental constants, sound velocity, and underwater electrical discharges. Further research is warranted to explore the full applicability of FIQ across various scientific disciplines.
基金This research was sponsored by Educational Department of Yunnan Province (No. 03Z583B).
文摘Regressive formulae to calculate the quantity of plant leaf area for 13 species of ornamental plants were set up based on investigation data of 30 species on 3 major public squares (Dongfeng square, Shengli square and Guandu square) in Kun-ming City, China, which were applied to calculate quantities of plant leaf area of these 13 species. The quantities of plant leaf area for the other 17 ornamental plant species on these squares were directly measured, and the total quantity of plant leaf area of each studied square was obtained individually. The results showed that the quantity of plant leaf area on Shengli square with ornamental plants structure composed of arbor tree species, shrub tree species and turf grass was highest among the three squares. It is believed that the design model of multi-storied vertical structure and proper tending of plant community could not only increase the quantity of plant leaf area, but also play an important role in generating ecological and landscaping benefits. Some corresponding suggestions were put forward on the basis of comprehensive analyses on the plant leaf area quantity of the three representative squares in Kunming urban area.
基金Supported by National Modern Agriculture (Bee Industry) Technolgy System (CARS-45-SYZ17)~~
文摘[Objective] The aim was to research the rules of nectar quantity and sugar concentration of perfect and staminate flowers in a day. [Method] Based on nine Tianguang Yan pomegranate trees, nectar quantity and sugar concentration of per- fect and staminate flowers were measured and analyzed in morning and afternoon. [Result] Average nectar quantity and sugar concentration differed insignificantly in morning and afternoon of perfect flowers, which could also be applied to staminate flowers. However, average nectar quantity of perfect flower was 64.09 μI and of staminate flower was 44.07 μl. It is obvious that the two were of extremely signifi- cant differences （t=4.642, P〈0.01）, and the former was significantly higher by 45,43%. On the other hand, average sugar concentration of perfect flower was 48.44% and of staminate flower was 37.16%. The two were of extremely significant differences and the former is higher by 30.36%, compared with the latter. These suggested that nectar quantity and sugar concentration would maintain unchanged in different periods for a day, if nectars are not consumed by pollinators, such as bees and butterflies. In the same period, nectar quantity and sugar concentration of per- fect flowers were higher than those of staminate flowers. [Conclusion] The research provides references for benefits increase of bee farmers and fruit farmers, as well as exploration of bee pollination.
文摘[Objective] This study aimed to investigate the effects of different land use patterns on soil ecological environment. [Method] Total three representative land use patterns （corn field, cherry tree land, wood land） were selected from Hongta District, Yuxi City, and under these three patterns, soil microbial quantity and activity were studied. [Result] Under the three land use patterns, soil microorganisms were domi- nated by bacteria; soil microbial quantity ranked as wood land＇s〉cheery tree land＇s〉 corn field＇s; and total microbial activity, catalase activity and urease activity all ranked as cherry tree land＇s〉wood land＇s〉corn field＇s. [Conclusion] Soil microbial activity and functions are related to farmland management measures, as well as land use pattern and soil nutrients.
文摘OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia （ADH）, ductal carcinoma in situ （DCIS） and invasive ductal carcinoma （IDC） of the breast. The relationship between centrosome abnormalities and breast tumor development was further discussed. METHODS There were three groups including ADH, DCIS and IDC with 30 cases in each group. They were analyzed by immuno-fiuorescence quantity analysis. The expression levels of α-tubulin and γ-tubulin protein in these tissues were detected by flow cytometry immuno-fiuorescence analysis and compared with the results from normal tissues. Immunohistochemistry was also performed in this research. RESULTS The results showed significant differences of the average of the positive （FITC labeled） cells （P=0.000） among the four groups. The level of the IDC group was the highest, while normal breast tissue showed the lowest level. The results suggested that the expression levels of α-tubulin and γ-tubulin both increased as the grade of cellular proliferation and differentiation increased. The expressions showed significant differences among all the groups, except between the ADH and DCIS. There were no significant differences between α-tubulin and γ-tubulin expression in each group （P〈0.05）, as there was agreement in the immuno-fluorescence and immunohistochemical analysis for protein expression. CONCLUSION There is abnormal expression of centrosome tubulin as an early event in the development of breast tumor. Furthermore these aberrations may play a key role during oncogenesis and promote cellular transformation to malignancy. The immuno-fiuorescence quantitive analysis and immunohistochemistry can complement each other.
基金National Key Technology R&D Program of the Ministry of Science and Technology(2011BAD16B04,(2012BAD04B11)~~
文摘[Objective] The aim was to research the appropriate seeding quantities of double-season machine-transplanted rice in middle and low-yielding district of southern Jiangxi Province. [Method] The research set five different seeding quantities treatments, and compared with conventional seedling treatment, and the appropriate seeding quantities of double season machine-transplanted rice in middle and lowyielding district of southern Jiangxi Province was discussed. [Result] The yields were highest when the seeding quantity was 70 g per tray of early rice by mechanical transplanting and 60 g per tray of late rice. The yield of early rice by mechanical transplanting showed significantly positive correlation with the number of productive ear and the number of seed per ear, and late rice yield showed significant correlation with the number of productive ear by mechanical transplanting. It is key for improving high yields by guaranteeing the number of productive ear. [Conclusion] The issue of proper sowing quantity should be taken into consideration for double-cropping rice in the region, which is crucial for high yields.
基金Supported by Yantai Science and Technology Development Program(2007155)~~
文摘Objective] The alm was to provide scientific references for determination of optimal N and P quantities of malze. [Method] The research conducted a test in field to expIore the effects of N and P fertiIizers on malze yield. [Result] Both of N and P fertiIizers have significant effects on malze yield. When malze yield reached the highest, the quantities of N fertiIizers and P fertiIizers were 530.56 and 105.44 kg/hm2, respectiveIy. [Conclusion] Malze yield keeps growing upon N or P fertiIizers to certaln extent, and excessive quantities of N and P fertiIizer wouId reduce malze yield.
基金supported by the Key Disciplines Building Foundation of Henan Institute of Education
文摘A non-Noether conserved quantity, i.e., Hojman conserved quantity, constructed by using Mei symmetry for the nonholonomic controllable mechanical system, is presented. Under general infinitesimal transformations, the determining equations of the special Mei symmetry, the constrained restriction equations, the additional restriction equations, and the definitions of the weak Mei symmetry and the strong Mei symmetry of the nonholonomic controllable mechanical system are given. The condition under which Mei symmetry is a Lie symmetry is obtained. The form of the Hojman conserved quantity of the corresponding holonomic mechanical system, the weak Hojman conserved quantity and the strong Hojman conserved quantity of the nonholonomie controllable mechanical system are obtained. An example is given to illustrate the application of the results.
基金The National Natural Science Foundation of China(No.70771026)
文摘The development and deployment of privary preserving supply chain quantity discount contract design can allow supply chain collaborations to take place without revealing any participant＇s data to others, reaping the benefits of collaborations wbile avoiding the drawbacks of privacy information disclosure. First, secure multi-party computation protocols are applied in the joint-ordering policy between a single supplier and a single retailer, the joint-ordering policy can be conducted without disclosing private cost information of any of the other supply chain partners. Secondly, secure multi-party computation protocols are applied in the privacy preserving supply chain quantity discount contract design between a single supplier and a single retailer. The information disclosure analyses of the algorithm show that： the optimal quantity discount of the jointordering policy can be conducted without disclosing private cost information of any of the other supply chain partners; the above protocol can be implemented without mediators; the privacy preserving quantity discount algorithm can be mutually verifiable and has solved the problem of asymmetric information.
文摘Urban peripheral green space (UPGS) plays more and more important rol e in sustaining urban physical and ecological environments. In this paper, a pre liminary classification of UPGS was presented for seven types and quantity index of UPGS was discussed tentatively. The quantity and layout problems in urban pe ripheral green space, and the several principles were mainly discussed in urban ventilation and sanitation, recreational opportunity and landscape ecological st ructure.
基金the National Natural Science Foundation of China(Nos.51975305,51806112and 51905289)the Major Research Project of Shandong Province of China(Nos.2019GGX104040 and 2019GSF108236)+2 种基金the Shandong Provincial Natural Science Foundation of China(No.ZR2019PEE008)Major Science and Technology Innovation Engineering Projects of Shandong Province of China(No.2019JZZY020111)Applied Basic Research Youth Project of Qingdao Science and Technology Plan of China(No.19-6-2-63-cg)。
文摘In nanofluid minimum quantity lubrication(NMQL)milling of aviation aluminum alloy,it is the bottleneck problem to adjust the position parameters(target distance,incidence angle,and elevation angle)of the nozzle to improve the surface roughness of milling,which has large and uncontrollable errors.In this paper,the influence law of milling cutter speed,helical angle,and cavity shape on the flow field around the milling cutter was studied,and the optimal nozzle profile parameters were obtained.Using 7050 aluminum alloy as the workpiece material,the milling experiment of the NMQL cavity was conducted by utilizing cottonseed oil-based Al2 O3 nanofluid.Results show that the high velocity of the surrounding air flow field and the strong gas barrier could be attributed to high rotating velocities of the milling cutter.The incidence angle of the nozzle was consistent with the helical angle of the milling cutter,the target distance was appropriate at 25–30 mm,and the elevation angle was suitable at 60°–65°.The range and variance analyses of the signal-to-noise ratio of milling force and roughness were performed,and the chip morphology was observed and analyzed.The results show that the optimal combination of nozzle position parameters was the target distance of 30 mm,the incidence angle of 35°,and the elevation angle of 60°.Among these parameters,target distance had the largest impact on cutting performance with a contribution rate of more than 55%,followed by incidence angle and elevation contribution rate.Analysis by orthogonal experiment revealed that the nozzle position parameters were appropriate,and Ra(0.087 lm)was reduced by 30.4%from the maximum value(0.125 lm).Moreover,Rsm(0.05 mm)was minimum,which was 36%lower than that of the seventh group(Rsm=0.078 mm).
基金supported by the National Natural Science Foundation of China(Nos.51975305 and 51905289)the Major Research Project of Shandong Province(No.2019GGX104040)+2 种基金the Major Science and Technology Innovation Engineering Projects of Shandong Province(No.2019JZZY020111)the Natural Science Foundation of Shandong Province(Nos.ZR2020KE027 and ZR2020ME158)the Applied Basic Research Youth Project of Qingdao science and technology plan(No.19-6-2-63-cg)。
文摘It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL)technology.Nevertheless,for aeronautical difficult-tomachine materials,MQL couldn’t meet the high demand of cooling and lubrication due to high heat generation during machining.Nano-biolubricants,especially non-toxic carbon group nano-enhancers(CGNs)are used,can solve this technical bottleneck.However,the machining mechanisms under lubrication of CGNs are unclear at complex interface between tool and workpiece,which characterized by high temperature,pressure,and speed,limited its application in factories and necessitates in-depth understanding.To fill this gap,this study concentrates on the comprehensive quantitative assessment of tribological characteristics based on force,tool wear,chip,and surface integrity in titanium alloy and nickel alloy machining and attempts to answer mechanisms systematically.First,to establish evaluation standard,the cutting mechanisms and performance improvement behavior covering antifriction,antiwear,tool failure,material removal,and surface formation of MQL were revealed.Second,the unique film formation and lubrication behaviors of CGNs in MQL turning,milling,and grinding are concluded.The influence law of molecular structure and micromorphology of CGNs was also answered and optimized options were recommended by considering diverse boundary conditions.Finally,in view of CGNs limitations in MQL,the future development direction is proposed,which needs to be improved in thermal stability of lubricant,activity of CGNs,controllable atomization and transportation methods,and intelligent formation of processing technology solutions.
