The authors developed a prototype of a warship maintenance system. The process started by defining the maintenance requirements of warship equipment. Next, a planning scheme was development for a maintenance network. ...The authors developed a prototype of a warship maintenance system. The process started by defining the maintenance requirements of warship equipment. Next, a planning scheme was development for a maintenance network. An optimization target for the plan and indexes for assessment were established. Based on the above work, a simulation model was proposed with two layers: a base and a workshop. Dispatching rules were then formulated for the simulation. Experimental results proved the validity of the model and the dispatching algorithm. It was found that the model can solve the capacity evaluation problem for maintenance systems and provides a scientific basis for decision-maker to make decisions regarding equipment maintenance.展开更多
To scientifically evaluate the equipment system of systems(SoS)contribution rate,a contribution rate calculation method based on a structural equation model(SEM)is proposed in this paper.The connotation and evaluation...To scientifically evaluate the equipment system of systems(SoS)contribution rate,a contribution rate calculation method based on a structural equation model(SEM)is proposed in this paper.The connotation and evaluation process of the equipment SoS contribution rate were redefined and standardized.To solve the existing problems in the application of the original contribution rate formula,a modified contribution rate calculation formula is proposed.Finally,the contribution rate evaluation index was divided into latent and explicit variables.The measurement and structural equations in the SEM were used to calculate and analyze the latent variables.The simulation results show that the number of defense lines of air defense weapon equipment has a greater impact on the linear configuration than the group configuration.When the number of K-type air defense weapons is sufficient,the two-layer linear configuration should be adopted with 20 air defense weapon systems.When the number of K-type air defense weapons is insufficient,the single-layer group configuration should be adopted with 12 air defense weapon systems.展开更多
Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the se...Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis (SGCS) method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% (by volume) C02. The mass ratio of CaO to CaZr03 as 8:2 (designated as CasZr2) was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area (SA) ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles.展开更多
It is a challenge to select an optimal set of devices to accomplish a graph-based ubiquitous service and execute it continuously under the circumstances of dynamic environments and limited device capability. We elabor...It is a challenge to select an optimal set of devices to accomplish a graph-based ubiquitous service and execute it continuously under the circumstances of dynamic environments and limited device capability. We elaborate a Synergy- aware Selection Mechanism (SSM) considering synergetic among devices. In the SSM, we design a distributed algorithm to integrate the devices and a dynamic updating weight method. The simulation results show that SSM can make devices composed together to ensure the continuity and smoothness of service展开更多
A cobalt-enriching crust mining vehicle with four independent driven wheels was proposed. The influence of center-of-gravity position of mining vehicle on obstacle performance was studied. The results show that the mi...A cobalt-enriching crust mining vehicle with four independent driven wheels was proposed. The influence of center-of-gravity position of mining vehicle on obstacle performance was studied. The results show that the mining vehicle has optimal obstacle performance with center-of-gravity position in the middle of suspension. A virtual prototype based on ADAMS software was built and its obstacle performance was simulated. Simulation results show that the mining vehicle with four independent driven wheels has excellent obstacle performance, the maximum climbing capacity is no less than 30°, the maximal ditch width and shoulder height are no less than wheel radius of mining vehicle. Thus wheeled mining vehicle is feasible for cobalt-enriching crust commercial mining.展开更多
10%(volume fraction) SiCp/Al-Mg composites with different Mg contents were successfully fabricated by semi-solid mechanical stirring technique under optimum processing conditions.Effects of Mg content on microstructur...10%(volume fraction) SiCp/Al-Mg composites with different Mg contents were successfully fabricated by semi-solid mechanical stirring technique under optimum processing conditions.Effects of Mg content on microstructure and mechanical properties were studied by scanning electron microscopy(SEM),X-ray diffractometry(XRD) and transmission electron microscopy(TEM).The results indicate that SiC particles disperse homogeneously in Al-Mg matrix and interfacial reaction between Al matrix and SiC particles is effectively controlled.Distribution of SiCp reinforcement and interfacial bonding are improved by adding Mg.Additionally,the mechanical properties of composites are remarkably improved with the Mg content increasing.展开更多
Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon (AC) samples after thermal modification were prepared by using muffle furnace. The phen...Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon (AC) samples after thermal modification were prepared by using muffle furnace. The phenol ad- sorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 ~C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC sam- ples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 ~C, the pseudo-second order kinetics and Langmuir models are found to fit the exper- imental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach 144,93 mg.g ~ which is higher than that of the raw sample, i.e. 119.53 mg.g 1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.展开更多
The microstructure and mechanical properties of Mg-xCe-0.5Zn (x=0.5, 1.5, 2.5, molar fraction, %) alloys were examined using a nano-indentation technique. The alloys were fabricated using a vacuum induction melting ...The microstructure and mechanical properties of Mg-xCe-0.5Zn (x=0.5, 1.5, 2.5, molar fraction, %) alloys were examined using a nano-indentation technique. The alloys were fabricated using a vacuum induction melting method under an argon atmosphere The microstruetures of Mg-xCe-0.5Zn alloys mainly consist ofa-Mg and eutectic Mg12Ce phase. The volume fraction and size of the eutectic Mgl2Ce phase increase with increasing Ce contents. Nano-indentation test results show that the indentation hardness and elastic modulus of the eutectic Mg12Ce phase are higher than those of the a-Mg matrix. In addition, the mean indentation hardness and elastic modulus of the Mg-xCe-0.5Zn alloys increase with the Ce addition amount increasing.展开更多
For small devices like the PDAs and mobile phones, formulation of relational database queries is not as simple as using conventional devices such as the personal computers and laptops. Due to the restricted size and r...For small devices like the PDAs and mobile phones, formulation of relational database queries is not as simple as using conventional devices such as the personal computers and laptops. Due to the restricted size and resources of these smaller devices, current works mostly limit the queries that can be posed by users by having them predetermined by the developers. This limits the capability of these devices in supporting robust queries. Hence, this paper proposes a universal relation based database querying language which is targeted for small devices. The language allows formulation of relational database queries that uses minimal query terms. The formulation of the language and its structure will be described and usability test results will be presented to support the effectiveness of the language.展开更多
Isothermal decomposition process of chemically transforming indium tin oxide(ITO) powders into indium(III) hydroxide powders was investigated. Two types of powders were analyzed, i.e., non-activated and mechanical...Isothermal decomposition process of chemically transforming indium tin oxide(ITO) powders into indium(III) hydroxide powders was investigated. Two types of powders were analyzed, i.e., non-activated and mechanically activated. It has been found that in the case of activated sample, shorter induction periods appear, which permits growth of smaller crystals, while in the case of non-activated sample, long induction periods appear, characterized by the growth of larger crystals. DAEM approach has shown that decomposition processes of non-activated and mechanically activated samples can be described by contracting volume model with a linear combination of two different density distribution functions of apparent activation energies(Ea), and with first-order model, with a single symmetrical density distribution function of Ea, respectively. It was established that specific characteristics of particles not only affect the mechanism of decomposition processes, but also have the significant impact on thermodynamic properties.展开更多
Equipment manufacturing industry is an important symbol to measure the industrial strength, scientific and technological innovation ability and international competitiveness of a country or region. Firstly, this paper...Equipment manufacturing industry is an important symbol to measure the industrial strength, scientific and technological innovation ability and international competitiveness of a country or region. Firstly, this paper analyzes the development status of equipment manufacturing industry in Shanghai, and then uses DEA to analyze the efficiency of technology innovation capability of equipment manufacturing industry in Shanghai. The results show that the equipment manufacturing industry in Shanghai has stronger overall drawing ability, and besides, the technology innovation ability of the transportation equipment manufacturing industry is weak, other equipment manufacturing sub industries have relatively strong ability of technological innovation. This paper analyzes the shortcomings of the transportation equipment manufacturing industry and gives guidance and puts forward corresponding suggestions and measures.展开更多
The operation of IT systems is a sine qua non condition in precision agriculture. In the traditional approach, professional competencies of a farmer comprise the ability to operate machines and technical equipment in ...The operation of IT systems is a sine qua non condition in precision agriculture. In the traditional approach, professional competencies of a farmer comprise the ability to operate machines and technical equipment in production technologies for biological raw materials. Precision agriculture increases this range of professional competencies with the ability to use computer IT systems that are complex and, by their very nature, much differing in their content and scope from typical farming knowledge. The ergonomic problem can be brought down to determination whether the operation of IT systems in precision agriculture is adjusted to the predispositions, needs and skills of the farmers. Generally, in the IT system of precision agriculture, three phases can be differentiated: data collection, processing and application. To what extent should they be operated by the farmer, and to what extent by the IT specialist, is the problem that determines effective functioning of precision farming. The ergonomic assessment of some software for equipment operation, generation of harvesting maps and applications points to: (1) the need for standardisation in construction and operation of IT systems; (2) the division of the function-farmer and IT specialist (e.g. from an agriculture consulting institution) in the precision agriculture system.展开更多
In order to study on the water purification ability of coriander, according to the material of Iris pseudacorus, Pontederia cordata, Thalia dealbata, coriander, Lythrum salicaria as the research object, the paper carr...In order to study on the water purification ability of coriander, according to the material of Iris pseudacorus, Pontederia cordata, Thalia dealbata, coriander, Lythrum salicaria as the research object, the paper carries on the analysis and comparison of water purification ability under greenhouse conditions in the 3~6 month period. The results showed: N, P content of coriander organizational changes before and after the test. Physiological responses of different plants, coriander is not sensitive to the physiological responses to stress of sewage, sewage adaptability is relatively strong. Judging from the effect of different plants to the water, then spent force has highest the removal rate for TN, coriander has the strongest absorption capacity for TP, water purification plant is excellent展开更多
Geopolymer-lightweight aggregate refractory concrete (GLARC) was prepared with geopolymer and lightweight aggregate. The mechanical property and heat-resistance (950 ℃) of GLARC were investigated. The effects of size...Geopolymer-lightweight aggregate refractory concrete (GLARC) was prepared with geopolymer and lightweight aggregate. The mechanical property and heat-resistance (950 ℃) of GLARC were investigated. The effects of size of aggregate and mass ratio of geopolymer to aggregate on mechanical and thermal properties were also studied. The results show that the highest compressive strength of the heated refractory concrete is 43.3 MPa,and the strength loss is only 42%. The mechanical property and heat-resistance are influenced by the thickness of geopolymer covered with aggregate,which can be expressed as the quantity of geopolymer on per surface area of aggregate. In order to show the relationship between the thickness of geopolymer covered with aggregate and the thermal property of concrete,equal thickness model is presented,which provides a reference for the mix design of GLARC. For the haydite sand with size of 1.18-4.75 mm,the best amount of geopolymer per surface area of aggregate should be in the range of 0.300-0.500 mg/mm2.展开更多
Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite ...Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite into graphite nanoplatelets with high efficiency. The obtained graphite nanoplatelets are highly crystalline, and the thickness is less than 10 nm. Moreover, the surface area could reached 738.1 m^2/g with a grinding time of 4 h. Silanized graphite nanoplatelets can disperse well in SG 15W-40 engine oil and serve as lubricant additive. Tribological results indicate that the friction coefficient and wear-scar of the friction pairs are lower than 76% and 41%, respectively, by adding 1.5‰(mass fraction) of silanized graphite nanoplatelets. Notably, the functionalized graphite nanoplatelets can realize large-scale production and commercial application.展开更多
Conducting hydrodynamic and physical motion simulation tests using a large-scale self-propelled model under actual wave conditions is an important means for researching environmental adaptability of ships. During the ...Conducting hydrodynamic and physical motion simulation tests using a large-scale self-propelled model under actual wave conditions is an important means for researching environmental adaptability of ships. During the navigation test of the self-propelled model, the complex environment including various port facilities, navigation facilities, and the ships nearby must be considered carefully, because in this dense environment the impact of sea waves and winds on the model is particularly significant. In order to improve the security of the self-propelled model, this paper introduces the Q learning based on reinforcement learning combined with chaotic ideas for the model's collision avoidance, in order to improve the reliability of the local path planning. Simulation and sea test results show that this algorithm is a better solution for collision avoidance of the self navigation model under the interference of sea winds and waves with good adaptability.展开更多
Distribution systems operators are often confronted with declined power quality, which can cause substantial economical losses. The problem analyzed in paper concerns thyristor controlled direct current motor used for...Distribution systems operators are often confronted with declined power quality, which can cause substantial economical losses. The problem analyzed in paper concerns thyristor controlled direct current motor used for ski-lift in ski resort as a source of disturbances with negative impact on sensitive electric equipment, which is then unable to operate correctly. To solve mentioned problems, series of measurements of voltage quality parameters were carried out according to the respective valid standards. Crucial power quality parameters necessary for parallel power active filter design were then analyzed. Power active filter compensates power factor and filters characteristic current harmonics. After power active filter was put into operation, power quality problems were eliminated. Payback period is estimated up to four years.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.60774036
文摘The authors developed a prototype of a warship maintenance system. The process started by defining the maintenance requirements of warship equipment. Next, a planning scheme was development for a maintenance network. An optimization target for the plan and indexes for assessment were established. Based on the above work, a simulation model was proposed with two layers: a base and a workshop. Dispatching rules were then formulated for the simulation. Experimental results proved the validity of the model and the dispatching algorithm. It was found that the model can solve the capacity evaluation problem for maintenance systems and provides a scientific basis for decision-maker to make decisions regarding equipment maintenance.
基金The National Social Science Foundation Military Science Project(No.16GJ003-068).
文摘To scientifically evaluate the equipment system of systems(SoS)contribution rate,a contribution rate calculation method based on a structural equation model(SEM)is proposed in this paper.The connotation and evaluation process of the equipment SoS contribution rate were redefined and standardized.To solve the existing problems in the application of the original contribution rate formula,a modified contribution rate calculation formula is proposed.Finally,the contribution rate evaluation index was divided into latent and explicit variables.The measurement and structural equations in the SEM were used to calculate and analyze the latent variables.The simulation results show that the number of defense lines of air defense weapon equipment has a greater impact on the linear configuration than the group configuration.When the number of K-type air defense weapons is sufficient,the two-layer linear configuration should be adopted with 20 air defense weapon systems.When the number of K-type air defense weapons is insufficient,the single-layer group configuration should be adopted with 12 air defense weapon systems.
基金Supported by the National Natural Science Foundation of China(51276210,50906030,31301586)the Partial Financial Grant of North China University of Water Resources and Electric Power(201012)the National Basic Research Program of China(2011CB707301)
文摘Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis (SGCS) method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% (by volume) C02. The mass ratio of CaO to CaZr03 as 8:2 (designated as CasZr2) was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area (SA) ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles.
文摘It is a challenge to select an optimal set of devices to accomplish a graph-based ubiquitous service and execute it continuously under the circumstances of dynamic environments and limited device capability. We elaborate a Synergy- aware Selection Mechanism (SSM) considering synergetic among devices. In the SSM, we design a distributed algorithm to integrate the devices and a dynamic updating weight method. The simulation results show that SSM can make devices composed together to ensure the continuity and smoothness of service
基金Project(DY105-03-02) supported by the State Council Ocean Special Foundation of China
文摘A cobalt-enriching crust mining vehicle with four independent driven wheels was proposed. The influence of center-of-gravity position of mining vehicle on obstacle performance was studied. The results show that the mining vehicle has optimal obstacle performance with center-of-gravity position in the middle of suspension. A virtual prototype based on ADAMS software was built and its obstacle performance was simulated. Simulation results show that the mining vehicle with four independent driven wheels has excellent obstacle performance, the maximum climbing capacity is no less than 30°, the maximal ditch width and shoulder height are no less than wheel radius of mining vehicle. Thus wheeled mining vehicle is feasible for cobalt-enriching crust commercial mining.
基金Project(2006CB605203-3) supported by the National Basic Research Program of China
文摘10%(volume fraction) SiCp/Al-Mg composites with different Mg contents were successfully fabricated by semi-solid mechanical stirring technique under optimum processing conditions.Effects of Mg content on microstructure and mechanical properties were studied by scanning electron microscopy(SEM),X-ray diffractometry(XRD) and transmission electron microscopy(TEM).The results indicate that SiC particles disperse homogeneously in Al-Mg matrix and interfacial reaction between Al matrix and SiC particles is effectively controlled.Distribution of SiCp reinforcement and interfacial bonding are improved by adding Mg.Additionally,the mechanical properties of composites are remarkably improved with the Mg content increasing.
基金Supported by the National Natural Science Foundation of China(41302132)Training Programmes of Innovation and Entrepreneurship for Undergraduates of Yunnan Province(Grant No.201510674042)the Introduced Talents Foundation of Kunming University of Science and Technology(KKSY201205160)
文摘Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon (AC) samples after thermal modification were prepared by using muffle furnace. The phenol ad- sorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 ~C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC sam- ples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 ~C, the pseudo-second order kinetics and Langmuir models are found to fit the exper- imental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach 144,93 mg.g ~ which is higher than that of the raw sample, i.e. 119.53 mg.g 1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.
基金supported by a grant-in-aid for the National Core Research Center Program(No.R15-2006-022-02001-0)the Metals Bank project of the Korea Ministry of Knowledge Economy
文摘The microstructure and mechanical properties of Mg-xCe-0.5Zn (x=0.5, 1.5, 2.5, molar fraction, %) alloys were examined using a nano-indentation technique. The alloys were fabricated using a vacuum induction melting method under an argon atmosphere The microstruetures of Mg-xCe-0.5Zn alloys mainly consist ofa-Mg and eutectic Mg12Ce phase. The volume fraction and size of the eutectic Mgl2Ce phase increase with increasing Ce contents. Nano-indentation test results show that the indentation hardness and elastic modulus of the eutectic Mg12Ce phase are higher than those of the a-Mg matrix. In addition, the mean indentation hardness and elastic modulus of the Mg-xCe-0.5Zn alloys increase with the Ce addition amount increasing.
文摘For small devices like the PDAs and mobile phones, formulation of relational database queries is not as simple as using conventional devices such as the personal computers and laptops. Due to the restricted size and resources of these smaller devices, current works mostly limit the queries that can be posed by users by having them predetermined by the developers. This limits the capability of these devices in supporting robust queries. Hence, this paper proposes a universal relation based database querying language which is targeted for small devices. The language allows formulation of relational database queries that uses minimal query terms. The formulation of the language and its structure will be described and usability test results will be presented to support the effectiveness of the language.
基金partially supported by the Ministry of Science and Environmental Protection of Serbia under the Project 172015
文摘Isothermal decomposition process of chemically transforming indium tin oxide(ITO) powders into indium(III) hydroxide powders was investigated. Two types of powders were analyzed, i.e., non-activated and mechanically activated. It has been found that in the case of activated sample, shorter induction periods appear, which permits growth of smaller crystals, while in the case of non-activated sample, long induction periods appear, characterized by the growth of larger crystals. DAEM approach has shown that decomposition processes of non-activated and mechanically activated samples can be described by contracting volume model with a linear combination of two different density distribution functions of apparent activation energies(Ea), and with first-order model, with a single symmetrical density distribution function of Ea, respectively. It was established that specific characteristics of particles not only affect the mechanism of decomposition processes, but also have the significant impact on thermodynamic properties.
文摘Equipment manufacturing industry is an important symbol to measure the industrial strength, scientific and technological innovation ability and international competitiveness of a country or region. Firstly, this paper analyzes the development status of equipment manufacturing industry in Shanghai, and then uses DEA to analyze the efficiency of technology innovation capability of equipment manufacturing industry in Shanghai. The results show that the equipment manufacturing industry in Shanghai has stronger overall drawing ability, and besides, the technology innovation ability of the transportation equipment manufacturing industry is weak, other equipment manufacturing sub industries have relatively strong ability of technological innovation. This paper analyzes the shortcomings of the transportation equipment manufacturing industry and gives guidance and puts forward corresponding suggestions and measures.
文摘The operation of IT systems is a sine qua non condition in precision agriculture. In the traditional approach, professional competencies of a farmer comprise the ability to operate machines and technical equipment in production technologies for biological raw materials. Precision agriculture increases this range of professional competencies with the ability to use computer IT systems that are complex and, by their very nature, much differing in their content and scope from typical farming knowledge. The ergonomic problem can be brought down to determination whether the operation of IT systems in precision agriculture is adjusted to the predispositions, needs and skills of the farmers. Generally, in the IT system of precision agriculture, three phases can be differentiated: data collection, processing and application. To what extent should they be operated by the farmer, and to what extent by the IT specialist, is the problem that determines effective functioning of precision farming. The ergonomic assessment of some software for equipment operation, generation of harvesting maps and applications points to: (1) the need for standardisation in construction and operation of IT systems; (2) the division of the function-farmer and IT specialist (e.g. from an agriculture consulting institution) in the precision agriculture system.
文摘In order to study on the water purification ability of coriander, according to the material of Iris pseudacorus, Pontederia cordata, Thalia dealbata, coriander, Lythrum salicaria as the research object, the paper carries on the analysis and comparison of water purification ability under greenhouse conditions in the 3~6 month period. The results showed: N, P content of coriander organizational changes before and after the test. Physiological responses of different plants, coriander is not sensitive to the physiological responses to stress of sewage, sewage adaptability is relatively strong. Judging from the effect of different plants to the water, then spent force has highest the removal rate for TN, coriander has the strongest absorption capacity for TP, water purification plant is excellent
基金Project(2009CB623201) supported by the National Basic Research Program of ChinaProject(G0510) supported by the Key Laboratory for Refractories and High-temperature Ceramics of Hubei Province, China
文摘Geopolymer-lightweight aggregate refractory concrete (GLARC) was prepared with geopolymer and lightweight aggregate. The mechanical property and heat-resistance (950 ℃) of GLARC were investigated. The effects of size of aggregate and mass ratio of geopolymer to aggregate on mechanical and thermal properties were also studied. The results show that the highest compressive strength of the heated refractory concrete is 43.3 MPa,and the strength loss is only 42%. The mechanical property and heat-resistance are influenced by the thickness of geopolymer covered with aggregate,which can be expressed as the quantity of geopolymer on per surface area of aggregate. In order to show the relationship between the thickness of geopolymer covered with aggregate and the thermal property of concrete,equal thickness model is presented,which provides a reference for the mix design of GLARC. For the haydite sand with size of 1.18-4.75 mm,the best amount of geopolymer per surface area of aggregate should be in the range of 0.300-0.500 mg/mm2.
基金Project(ZR2011BL005)supported by the Natural Science Foundation of Shandong Province,China
文摘Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite into graphite nanoplatelets with high efficiency. The obtained graphite nanoplatelets are highly crystalline, and the thickness is less than 10 nm. Moreover, the surface area could reached 738.1 m^2/g with a grinding time of 4 h. Silanized graphite nanoplatelets can disperse well in SG 15W-40 engine oil and serve as lubricant additive. Tribological results indicate that the friction coefficient and wear-scar of the friction pairs are lower than 76% and 41%, respectively, by adding 1.5‰(mass fraction) of silanized graphite nanoplatelets. Notably, the functionalized graphite nanoplatelets can realize large-scale production and commercial application.
基金Foundation item: Supported by the National Natural Science Foundation of China under Grant No.61100005.
文摘Conducting hydrodynamic and physical motion simulation tests using a large-scale self-propelled model under actual wave conditions is an important means for researching environmental adaptability of ships. During the navigation test of the self-propelled model, the complex environment including various port facilities, navigation facilities, and the ships nearby must be considered carefully, because in this dense environment the impact of sea waves and winds on the model is particularly significant. In order to improve the security of the self-propelled model, this paper introduces the Q learning based on reinforcement learning combined with chaotic ideas for the model's collision avoidance, in order to improve the reliability of the local path planning. Simulation and sea test results show that this algorithm is a better solution for collision avoidance of the self navigation model under the interference of sea winds and waves with good adaptability.
文摘Distribution systems operators are often confronted with declined power quality, which can cause substantial economical losses. The problem analyzed in paper concerns thyristor controlled direct current motor used for ski-lift in ski resort as a source of disturbances with negative impact on sensitive electric equipment, which is then unable to operate correctly. To solve mentioned problems, series of measurements of voltage quality parameters were carried out according to the respective valid standards. Crucial power quality parameters necessary for parallel power active filter design were then analyzed. Power active filter compensates power factor and filters characteristic current harmonics. After power active filter was put into operation, power quality problems were eliminated. Payback period is estimated up to four years.