To study test stability of Advanced Fiber Information System(AFIS),card sliver produced in two experiments(12 plans in each experiment)were tested by AFIS.By a statistic analysis of the test results,the number of test...To study test stability of Advanced Fiber Information System(AFIS),card sliver produced in two experiments(12 plans in each experiment)were tested by AFIS.By a statistic analysis of the test results,the number of test times that can get a reliable test reliability(hereinafter this number of test times is referred to as Reliable Test Times,RTT)of test parameters and the coefficient of variation(CV%)values of 30 test results of each experiment plan were obtained.It's concluded that some parameters,such as length,seed coat nep(SCN)size,nep size and immature fiber content(IFC),etc.are very reliable by a test of ten or more times,but other parameters,such as SCN content,trash content,and visible foreign matter(VFM)content,etc.are not reliable until they are tested over 100 times.展开更多
Background and Objective:Heparanase-1 (HPA-1) can promote angiogenesis and metastasis of malignant tumors and plays an important role in the genesis and development of tumors.This study was to explore the effects of s...Background and Objective:Heparanase-1 (HPA-1) can promote angiogenesis and metastasis of malignant tumors and plays an important role in the genesis and development of tumors.This study was to explore the effects of specific small interfering RNA (siRNA) targeting HPA-1 combined with heparin on invasiveness of mouse hepatocellular carcinoma cells.Methods:The expression of HPA-1 in Hca-F, Hca-P, and Hepa1-6 cells, which have high, low, and no metastatic potential, respectively, was analyzed by reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis and enzyme-linked immunosorbent assay (ELISA).After transfection with two specific siRNAs targeting HPA-1, siRNA-1 and siRNA-2, and treatment with heparin, invasiveness of Hca-F cells was observed by Matrigel invasion assay.Results:HPA-1 was negative in Hepa1-6 cells while positive in both Hca-F and Hca-P cells.The expression levels of both HPA-1 mRNA and protein were obviously higher in Hca-F cells than in Hca-P cells.HPA-1 proteins could be secreted into culture supernatant of Hca-F and Hca-P cells, and the amount of secreted HPA-1 detected by Western blot analysis was larger in Hca-F cells than in Hca-P cells (1.34±0.02 vs.0.60±0.01, P<0.001), which was consistent with the results of ELISA.Both siRNA-1 and siRNA-2 downregulated the expression of HPA-1 and the siRNA-2 did more efficiently.The number of invasive Hca-F cells treated with siRNA-2 or heparin alone was larger than that of Hca-F cells treated with combination of them (9±1 vs.4±1, P=0.013; 15±2 vs.4±1, P=0.008), but smaller than that of untreated Hca-F cells (9±1 vs.22±2, P=0.006; 15±2 vs.22±2, P=0.026).Conclusion:The combined application of specific siRNA targeting HPA-1 and heparin is more effective in inhibiting the invasiveness of mouse hepatoma cells.展开更多
The bimodal size SiC particulates(SiCp)reinforced magnesium matrix composites with different ratios of micron SiCp and nano SiCp(M-SiCp:N-SiCp=14.5:0.5,14:1,and 13.5:1.5)were prepared by semisolid stirring assisted ul...The bimodal size SiC particulates(SiCp)reinforced magnesium matrix composites with different ratios of micron SiCp and nano SiCp(M-SiCp:N-SiCp=14.5:0.5,14:1,and 13.5:1.5)were prepared by semisolid stirring assisted ultrasonic vibration method.The AZ31B alloy and all as-cast SiCp/AZ31B composites were extruded at 350℃ with the ratio of 12:1.Microstructural characterization of the extruded M14+N1(M-SiCp:N-SiCp=14:1)composite revealed the uniform distribution of bimodal size SiCp and significant grain refinement.Optical Microscopy(OM)observation showed that,compared with the M14.5+N0.5(M-SiCp:N-SiCp=14.5:0.5)composite,there are more recrystallized grains in M14+N1(M-SiCp:N-SiCp=14:1)and M13.5+N1.5(M-SiCp:N-SiCp=13.5:1.5)composites,but in comparison to the M13.5+N1.5 composite,the average grain size of the M14+N1 composite is slightly decreased.The evaluation of mechanical properties indicated that the yield strength and ultimate tensile strength of the M14+N1 composite were obviously increased compared with other composites.展开更多
To analyze static pressure between back plate and cylinder in an A186 carding machine,a fluid model is established. The model takes into account static pressure of airflow near back plate with the numerical simulation...To analyze static pressure between back plate and cylinder in an A186 carding machine,a fluid model is established. The model takes into account static pressure of airflow near back plate with the numerical simulation method of Computational Fluid Dynamics (CFD) in FLUENT software. The result of the simulation in the model shows that static pressure in this area quickly increases to its maximum then rapidly decreases to a lower fixed value from inlet to outlet along a zone between back plate and cylinder. Both rotating speeds of the cylinder and the taker-in affect static pressure from the inlet to the outlet,of which the cylinder rotating speed has more influence than that of taker-in. Numerical simulations reveal that static pressure on surface of back plate are in good agreement with the former result of experimental analysis.展开更多
In order to provide manufacturers of carding machines and relevant accessories with theoretical references,how cylinder radius,setover and heel-toe difference affect cylinder-flat gauge of a carding machine was theore...In order to provide manufacturers of carding machines and relevant accessories with theoretical references,how cylinder radius,setover and heel-toe difference affect cylinder-flat gauge of a carding machine was theoretically studied.The relationship between cylinder-flat gauge and cylinder radius,setover and heel-toe difference was geometrically discussed.Numerical calculation and illustration about the relationship were made with MATLAB in accordance with practical settings.A general formula about the relationship is derived.A concept,the small-gauge zone length,has been defined for the first time,and some relevant results thus obtained.Given setover and heel-toe difference,the greater the cylinder radius,the greater the average gauge.If a smaller overall cylinder-flat gauge is desirable,it is not necessary to emphasize the tangential direction of the heel of clothed surface to the cylinder.Their intersection within a small zone is acceptable.In many cases,small-gauge zone can reduce average gauge which may be helpful to the carding action;given cylinder radius and setover,the smaller the heel-toe difference,the more helpful to reduce the overall gauge;given cylinder radius and heel-toe difference,the small-gauge zone length will increase with the increase of setover,so does the difference between the smallest gauge and outlet gauge.展开更多
During the construction of multifunctional landscape(MFL) actor-network, economic, social, and ecological functions presented significant differences, which resulted from the different roles and effects of various het...During the construction of multifunctional landscape(MFL) actor-network, economic, social, and ecological functions presented significant differences, which resulted from the different roles and effects of various heterogeneous actors according to the tourism experience. In Hekou Village at the border area between China and North Korea, the roles and effects of heterogeneous actors during the MFL actor-network construction were analyzed by means of the analytic network process(ANP), which verified the Groundings-Entrepreneurship-Markets(GEM) theoretical framework of the MFL actor-network that assumed tourism experiences were core actors, and economic, social, and ecological landscape actors acted as support. Research results showed that in the MFL actornetwork construction, social and economic functions of landscapes were strong, while ecological and tourism experience functions were weak and that folk customs and land utilization were key actors of the MFL actor-network construction. In the MFL actor-network construction, actors played different roles and had different effects on the network. Intelligence facilities and rurality were critical to drive the MFL actor network translation process and pass through "obligatory passage point". By changing the interaction mode and intensity of the actors, the MFL actor-network could be promoted.展开更多
Most cherry orchards in China have low organic carbon content,though carbon is very important for plant growth.The changes in soil carbon and bacterial diversity were determined after different amounts of 12C-glucose ...Most cherry orchards in China have low organic carbon content,though carbon is very important for plant growth.The changes in soil carbon and bacterial diversity were determined after different amounts of 12C-glucose were added to the rhizosphere of Cerasus sachalinensis.Soil bacteria diversity was measured using high throughput sequencing,and bacteria containing 13C-glucose were identified using DNA-SIP methods.The results demonstrated that soil microbial biomass carbon(MBC)content and the soil respiratory rate were increased at 3 and 7 days after adding glucose.The soil organic carbon(SOC)content was decreased on the 7th day in the treatment where the added glucose-C was equivalent to the MBC content.SOC content was decreased on the 15th day after adding glucose-C equivalent to five times that of the soil MBC.Compared to the controls,the relative abundance of taxa at the phylum level displayed no significant change in the treatments with glucose-C added as 10%and equal amount of soil MBC 3–30 days after treatment.However,the relative abundance of Proteobacteria increased significantly in the treatment with the addition of glucose-C equivalent to five times of soil MBC.The main changes were observed in the bacteria in several genera including A4,Flavisolibacter,Aquicella,and Candidatus Solibacter.DNA-SIP results indicated that the relative abundance of the Proteobacteria and Pseudomonas was the highest;these were the primary bacteria phylum and genus,respectively,from day 3 to day 15.In conclusion,the changing pattern demonstrated that with the addition of more glucose,the range of the bacterial communities changed more.Proteobacteria and Pseudomonas may be the bacteria promoting priming effect.展开更多
The problem of transforming autonomous systems into Birkhoffian systems is studied. A reasonable form of linear autonomous Birkhoff equations is given. By combining them with the undetermined tensor method, a necessar...The problem of transforming autonomous systems into Birkhoffian systems is studied. A reasonable form of linear autonomous Birkhoff equations is given. By combining them with the undetermined tensor method, a necessary and sufficient condition for an autonomous system to have a representation in terms of linear autonomous Birkhoff equations is obtained. The methods of constructing Birkhoffian dynamical functions are given. Two examples are given to illustrate the application of the results.展开更多
Using powder-sintering method,SiO2-Al2O3-CaO-ZnO-R2O porous glass-ceramics were produced for analysis. Five samples with different SiO2 /CaO ratios were used in the research. The mechanical properties, microstructures...Using powder-sintering method,SiO2-Al2O3-CaO-ZnO-R2O porous glass-ceramics were produced for analysis. Five samples with different SiO2 /CaO ratios were used in the research. The mechanical properties, microstructures and textures of porous glass-ceramics are investigated by using differential thermogravimetric analysis/differential thermal analysis ( TGA/SDTA) ,X-ray diffraction ( XRD) ,and scanning electron microsco- py ( SEM) . The activity energy of crystallization ( E) and crystallization kinetics parameter ( k) were calculated based on the modified JMA equation. The Avrami parameter n was obtained according to Augis-Bennett function. The results show that the k value of No. 1 sample ( SiO2 /CaO = 61∶ 18) is the largest among all samples, which tends to crystallize more easily,and crystallization processes of all samples are observed bulk crystallization. The main crystal phase observed is parawollastonite ( clinorhombic system) with puncheon shape. Poreforming agents decomposed at 100 - 500 ℃ form a large number of closed pores with micron dimension and several semi-open pores distribute uniformly in the glass-ceramics matrix. This work may be expected to be favorable for industrial scale applications of porous glass-ceramics in the field of building thermal insulation.展开更多
In order to find the effect of state device installed on a carding machine on card sliver quality, card slivers produced in conditions of different voltages and gauges were tested by USTER AFIS. The results show that,...In order to find the effect of state device installed on a carding machine on card sliver quality, card slivers produced in conditions of different voltages and gauges were tested by USTER AFIS. The results show that, when the gauge is 1 nun, most parameters of card sliver quality are better when voltage is 600 V than those when no voltage is applied. The contents of nep, trash, visible foreign matter (VFM) and short fiber content by number (SFCn), short fiber content by weight (SFCw), immature fiber content (IFC) of card sliver decrease by 5.9%, 16.7%, 12.5%, 5.3%, 4.8% and 1.6%, respectively, but seed coat nep (SCN) content of card sliver doesn't decrease. When the electrostatic plate gauge is 2 mm and electrostatic voltage is 4000 V, the removal efficiency of neps and SCN is remarkable, decreasing by 8.7% and 25% respectively. Card sliver quality is hardly improved under any voltage when the gauge between electrostatic plate and cylinder is 3mm.展开更多
Exogenous DNA expressing green fluorescent protein( GFP) and labeled with fluorescein isothiocyanate( FITC) was used to transform the Chinese oak silkmoth Antheraea pernyi( A. pernyi)via sperm-mediated gene transfer( ...Exogenous DNA expressing green fluorescent protein( GFP) and labeled with fluorescein isothiocyanate( FITC) was used to transform the Chinese oak silkmoth Antheraea pernyi( A. pernyi)via sperm-mediated gene transfer( SMGT). Sperms entry into the female reproductive system and eggs were observed using fluorescence microscopy. The ability of A. pernyi sperms to uptake exogenous DNA was confirmed,and transfer of the exogenous DNA was shown by GFP expression in the transgenic eggs. Our result suggested that SMGT could also be used to directly generate transgenic A. pernyi expressing functional genes of interest.展开更多
The woven glass fiber reinforced composites(GFRP)subjected to high-speed impact is investigated to identify the hygrothermal aging effect on the impact resistance.Both the hygrothermal aged and unaged glass/epoxy lami...The woven glass fiber reinforced composites(GFRP)subjected to high-speed impact is investigated to identify the hygrothermal aging effect on the impact resistance.Both the hygrothermal aged and unaged glass/epoxy laminates are subjected to different impact velocities,which is confirmed as a sensitive factor for the failure modes and mechanisms.The results show the hygrothermal aging effect decreases the ballistic limit by 14.9%,but the influence on ballistic performance is limited within the impact velocity closed to the ballistic limit.The failure modes and energy dissipation mechanisms are confirmed to be slightly influenced by the hygrothermal aging effect.The hygrothermal aging effect induced localization of structural deformation and degradation of mechanical properties are the main reasons for the composite undergoing the same failure modes at smaller impact velocities.Based on the energy absorption mechanisms,analytical expressions predict the ballistic limit and energy absorption to reasonable accuracy,the underestimated total energy absorption results in a relatively poor agreement between the measured and predicted energy absorption efficiency.展开更多
By using the discrete variational method,we study the numerical method of the general nonholonomic system in the generalized Birkhoffian framework,and construct a numerical method of generalized Birkhoffian equations ...By using the discrete variational method,we study the numerical method of the general nonholonomic system in the generalized Birkhoffian framework,and construct a numerical method of generalized Birkhoffian equations called a self-adjoint-preserving algorithm.Numerical results show that it is reasonable to study the nonholonomic system by the structure-preserving algorithm in the generalized Birkhoffian framework.展开更多
Impurity redistribution during cotton carding was investigated. The content and size of impurity in card sliver,takerin droppings,flat strips,and cylinder screen droppings (including droppings under cylinder screen an...Impurity redistribution during cotton carding was investigated. The content and size of impurity in card sliver,takerin droppings,flat strips,and cylinder screen droppings (including droppings under cylinder screen and cylinder-doffer triangle section)at four taker-in speeds were tested by using USTER AFIS. Results show that both total impurities and visible foreign matter (VFM)weights are increased. Impurities in cotton lap are carded and redistributed in card sliver, taker-in droppings, flat strips and cylinder screen droppings. Impurity percentage in taker-in droppings are the highest,followed by that in card sliver,that in flat strips and that in cylinder screen droppings. Cylinder screen has better dust-removing efficiency than flats. The average sizes of impurities in card sliver and cylinder screen droppings are decreased,whereas those of flat strips are increased and those of taker-in droppings is almost the same,in comparison with cotton lap. The impurity contents of card sliver,taker-in droppings,flat strips and cylinder screen droppings have tendencies to decrease with the increase of taker-in speed.展开更多
The effect of flats speed,especially higher flats speed,on card sliver quality was studied.Card sliver produced at seven flats speeds was tested with Uster AFIS.Test results show that over-high flats speed is not bene...The effect of flats speed,especially higher flats speed,on card sliver quality was studied.Card sliver produced at seven flats speeds was tested with Uster AFIS.Test results show that over-high flats speed is not beneficial to removing impurities and neps of card sliver.The flats speed from 450 to 550 mm/min is the best for removing impurity;while a speed of 450 or 650 mm/min is the best for removing neps of card sliver.The 1 050 mm/min flats speed is the best for removing short fibers.Accordingly,the flats speed of 450 mm/min is the most advantageous to improve the comprehensive quality of card sliver.It is also found that installing back-web-cleaner is very helpful to remove neps.It is also favorable to reduce short fibers,thus increasing the average length.But it is not helpful to reduce impurities in the sliver.展开更多
The sol-gel method is used to prepare a new nano-alumina aerogel structure and the thermal properties of this nanomaterial are investigated comprehensively using electron microscope scanning,thermal analysis,X-ray and...The sol-gel method is used to prepare a new nano-alumina aerogel structure and the thermal properties of this nanomaterial are investigated comprehensively using electron microscope scanning,thermal analysis,X-ray and infrared spectrometer analysis methods.It is found that the composite aerogel alumina material has a multi-level porous nano-network structure.When employed for the thermal insulation of high-rise buildings,the alumina nanocomposite aerogel material can lead to effective energy savings in winter.However,it has almost no energy-saving effect on buildings where energy is consumed for cooling in summer.展开更多
In this paper, we present a new method to obtain the Lie symmetries and conserved quantities of the discrete wave equation with the Ablowitz-Ladik-Lattice equations. Firstly, the wave equation is transformed into a si...In this paper, we present a new method to obtain the Lie symmetries and conserved quantities of the discrete wave equation with the Ablowitz-Ladik-Lattice equations. Firstly, the wave equation is transformed into a simple difference equation with the Ablowitz-Ladik-Lattice method. Secondly, according to the invariance of the discrete wave equation and the Ablowitz-Ladik-Lattice equations under infinitesimal transformation of dependent and independent variables, we derive the discrete determining equation and the discrete restricted equations. Thirdly, a series of the discrete analogs of conserved quantities, the discrete analogs of Lie groups, and the characteristic equations are obtained for the wave equation. Finally, we study a model of a biological macromolecule chain of mechanical behaviors, the Lie symmetry theory of discrete wave equation with the Ablowitz-Ladik-Lattice method is verified.展开更多
A triethylenetetramine epoxy mixture was synthesized through the reaction of a low-molecular-weight liquid epoxy resin with triethylenetetramine(TETA).Then triethyltetramine(TETA)was injected dropwise into a pro-pylen...A triethylenetetramine epoxy mixture was synthesized through the reaction of a low-molecular-weight liquid epoxy resin with triethylenetetramine(TETA).Then triethyltetramine(TETA)was injected dropwise into a pro-pylene glycol methyl ether(PM)solution for chain extension reaction.A hydrophilic andflexible polyether seg-ment was introduced into the hardener molecule.The effects of TETA/DGEPG,reaction temperature and reaction time on the epoxy conversion of polyethylene glycol diglycidyl ether(DGEPG)were studied.In addition,several alternate strategies to add epoxy resin to the high-speed dispersion machine and synthesize MEA DGEBA adduct(without catalyst and with bisphenol A diglycidyl ether epoxy resin)were compared.It was found that the higher the molecular weight of triethylenetetramine,the longer the chain segment of the surface active molecule.When the equivalence ratio of amine hydrogen and epoxy group is low,the stability of lotion is good.When the ratio of amine hydrogen to epoxy group is large,the content of triethylenetetramine is small.The main objective of this study is the provision of new data and knowledge for the development of new materials in the coating and electronic industry.展开更多
Effect of flat heel-toe difference (HTD) of a card on some parameters of yarn quality was studied by testing the yarn which was produced under different HTDs, doffer speed, and cylinder speed with yarn evenness tester...Effect of flat heel-toe difference (HTD) of a card on some parameters of yarn quality was studied by testing the yarn which was produced under different HTDs, doffer speed, and cylinder speed with yarn evenness tester of PT7000. The effect of HTD on yarn parameters was analyzed by using SPSS. The results show that HTD has significant influence on parameters of thickness fault and nep. As a whole, the HTDs of 0.42 and 0.56 mm are beneficial to improving yarn quality in comparison with the other HTDs.展开更多
A novel method is proposed for treating cylindrical probe characteristics to obtain plasma density. The method consists of exponential extrapolation of the transitional part of the I -V curve to the floating potential...A novel method is proposed for treating cylindrical probe characteristics to obtain plasma density. The method consists of exponential extrapolation of the transitional part of the I -V curve to the floating potential for the ion saturation current, other than the existing theories which use the ion branch, and an iterative sheath thickness correction procedure for improved accuracy. The method was tested by treating Langmuir probe I-V characteristics obtained from inductively coupled Ar discharges at various pressures, and comparing the present results with those deduced by existing theories. It was shown that the plasma densities obtained by the present method are in good agreement with those calculated by the Allen-Boyd-Reynolds (ABR) theory, suggesting the effectiveness of the proposed method. Without need of manual setting and adjustment of fitting parameters, the method may be suitable for automatic and real time processing of probe characteristics.展开更多
基金Key Technologies R&D Program of Liaoning Province of China(No.2003220026)Key Technologies R&D Program of Dandong,China(No.06133)
文摘To study test stability of Advanced Fiber Information System(AFIS),card sliver produced in two experiments(12 plans in each experiment)were tested by AFIS.By a statistic analysis of the test results,the number of test times that can get a reliable test reliability(hereinafter this number of test times is referred to as Reliable Test Times,RTT)of test parameters and the coefficient of variation(CV%)values of 30 test results of each experiment plan were obtained.It's concluded that some parameters,such as length,seed coat nep(SCN)size,nep size and immature fiber content(IFC),etc.are very reliable by a test of ten or more times,but other parameters,such as SCN content,trash content,and visible foreign matter(VFM)content,etc.are not reliable until they are tested over 100 times.
基金Natural Science Foundation of Liaoning Province (No.20072215)
文摘Background and Objective:Heparanase-1 (HPA-1) can promote angiogenesis and metastasis of malignant tumors and plays an important role in the genesis and development of tumors.This study was to explore the effects of specific small interfering RNA (siRNA) targeting HPA-1 combined with heparin on invasiveness of mouse hepatocellular carcinoma cells.Methods:The expression of HPA-1 in Hca-F, Hca-P, and Hepa1-6 cells, which have high, low, and no metastatic potential, respectively, was analyzed by reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis and enzyme-linked immunosorbent assay (ELISA).After transfection with two specific siRNAs targeting HPA-1, siRNA-1 and siRNA-2, and treatment with heparin, invasiveness of Hca-F cells was observed by Matrigel invasion assay.Results:HPA-1 was negative in Hepa1-6 cells while positive in both Hca-F and Hca-P cells.The expression levels of both HPA-1 mRNA and protein were obviously higher in Hca-F cells than in Hca-P cells.HPA-1 proteins could be secreted into culture supernatant of Hca-F and Hca-P cells, and the amount of secreted HPA-1 detected by Western blot analysis was larger in Hca-F cells than in Hca-P cells (1.34±0.02 vs.0.60±0.01, P<0.001), which was consistent with the results of ELISA.Both siRNA-1 and siRNA-2 downregulated the expression of HPA-1 and the siRNA-2 did more efficiently.The number of invasive Hca-F cells treated with siRNA-2 or heparin alone was larger than that of Hca-F cells treated with combination of them (9±1 vs.4±1, P=0.013; 15±2 vs.4±1, P=0.008), but smaller than that of untreated Hca-F cells (9±1 vs.22±2, P=0.006; 15±2 vs.22±2, P=0.026).Conclusion:The combined application of specific siRNA targeting HPA-1 and heparin is more effective in inhibiting the invasiveness of mouse hepatoma cells.
文摘The bimodal size SiC particulates(SiCp)reinforced magnesium matrix composites with different ratios of micron SiCp and nano SiCp(M-SiCp:N-SiCp=14.5:0.5,14:1,and 13.5:1.5)were prepared by semisolid stirring assisted ultrasonic vibration method.The AZ31B alloy and all as-cast SiCp/AZ31B composites were extruded at 350℃ with the ratio of 12:1.Microstructural characterization of the extruded M14+N1(M-SiCp:N-SiCp=14:1)composite revealed the uniform distribution of bimodal size SiCp and significant grain refinement.Optical Microscopy(OM)observation showed that,compared with the M14.5+N0.5(M-SiCp:N-SiCp=14.5:0.5)composite,there are more recrystallized grains in M14+N1(M-SiCp:N-SiCp=14:1)and M13.5+N1.5(M-SiCp:N-SiCp=13.5:1.5)composites,but in comparison to the M13.5+N1.5 composite,the average grain size of the M14+N1 composite is slightly decreased.The evaluation of mechanical properties indicated that the yield strength and ultimate tensile strength of the M14+N1 composite were obviously increased compared with other composites.
基金Project of Liaoning Provincial Science and Technology Department, China(No.200322026)
文摘To analyze static pressure between back plate and cylinder in an A186 carding machine,a fluid model is established. The model takes into account static pressure of airflow near back plate with the numerical simulation method of Computational Fluid Dynamics (CFD) in FLUENT software. The result of the simulation in the model shows that static pressure in this area quickly increases to its maximum then rapidly decreases to a lower fixed value from inlet to outlet along a zone between back plate and cylinder. Both rotating speeds of the cylinder and the taker-in affect static pressure from the inlet to the outlet,of which the cylinder rotating speed has more influence than that of taker-in. Numerical simulations reveal that static pressure on surface of back plate are in good agreement with the former result of experimental analysis.
基金Fund of Scientific and Technological Key Project Plan of Liaoning Province,China (No2003220026)
文摘In order to provide manufacturers of carding machines and relevant accessories with theoretical references,how cylinder radius,setover and heel-toe difference affect cylinder-flat gauge of a carding machine was theoretically studied.The relationship between cylinder-flat gauge and cylinder radius,setover and heel-toe difference was geometrically discussed.Numerical calculation and illustration about the relationship were made with MATLAB in accordance with practical settings.A general formula about the relationship is derived.A concept,the small-gauge zone length,has been defined for the first time,and some relevant results thus obtained.Given setover and heel-toe difference,the greater the cylinder radius,the greater the average gauge.If a smaller overall cylinder-flat gauge is desirable,it is not necessary to emphasize the tangential direction of the heel of clothed surface to the cylinder.Their intersection within a small zone is acceptable.In many cases,small-gauge zone can reduce average gauge which may be helpful to the carding action;given cylinder radius and setover,the smaller the heel-toe difference,the more helpful to reduce the overall gauge;given cylinder radius and heel-toe difference,the small-gauge zone length will increase with the increase of setover,so does the difference between the smallest gauge and outlet gauge.
基金Sponsored by the National Social Science Fund of China(15BGL118)
文摘During the construction of multifunctional landscape(MFL) actor-network, economic, social, and ecological functions presented significant differences, which resulted from the different roles and effects of various heterogeneous actors according to the tourism experience. In Hekou Village at the border area between China and North Korea, the roles and effects of heterogeneous actors during the MFL actor-network construction were analyzed by means of the analytic network process(ANP), which verified the Groundings-Entrepreneurship-Markets(GEM) theoretical framework of the MFL actor-network that assumed tourism experiences were core actors, and economic, social, and ecological landscape actors acted as support. Research results showed that in the MFL actornetwork construction, social and economic functions of landscapes were strong, while ecological and tourism experience functions were weak and that folk customs and land utilization were key actors of the MFL actor-network construction. In the MFL actor-network construction, actors played different roles and had different effects on the network. Intelligence facilities and rurality were critical to drive the MFL actor network translation process and pass through "obligatory passage point". By changing the interaction mode and intensity of the actors, the MFL actor-network could be promoted.
基金This work was supported by the National Natural Science Foundation(Grant Nos.30871688,30900967,and 31572077)Liaoning Provincial Natural Science Foundation of China(Grant No.201602665)the High Level and Innovative Talents Program of Shenyang(Grant No.RC170201).
文摘Most cherry orchards in China have low organic carbon content,though carbon is very important for plant growth.The changes in soil carbon and bacterial diversity were determined after different amounts of 12C-glucose were added to the rhizosphere of Cerasus sachalinensis.Soil bacteria diversity was measured using high throughput sequencing,and bacteria containing 13C-glucose were identified using DNA-SIP methods.The results demonstrated that soil microbial biomass carbon(MBC)content and the soil respiratory rate were increased at 3 and 7 days after adding glucose.The soil organic carbon(SOC)content was decreased on the 7th day in the treatment where the added glucose-C was equivalent to the MBC content.SOC content was decreased on the 15th day after adding glucose-C equivalent to five times that of the soil MBC.Compared to the controls,the relative abundance of taxa at the phylum level displayed no significant change in the treatments with glucose-C added as 10%and equal amount of soil MBC 3–30 days after treatment.However,the relative abundance of Proteobacteria increased significantly in the treatment with the addition of glucose-C equivalent to five times of soil MBC.The main changes were observed in the bacteria in several genera including A4,Flavisolibacter,Aquicella,and Candidatus Solibacter.DNA-SIP results indicated that the relative abundance of the Proteobacteria and Pseudomonas was the highest;these were the primary bacteria phylum and genus,respectively,from day 3 to day 15.In conclusion,the changing pattern demonstrated that with the addition of more glucose,the range of the bacterial communities changed more.Proteobacteria and Pseudomonas may be the bacteria promoting priming effect.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10932002,11172120,and 11202090)
文摘The problem of transforming autonomous systems into Birkhoffian systems is studied. A reasonable form of linear autonomous Birkhoff equations is given. By combining them with the undetermined tensor method, a necessary and sufficient condition for an autonomous system to have a representation in terms of linear autonomous Birkhoff equations is obtained. The methods of constructing Birkhoffian dynamical functions are given. Two examples are given to illustrate the application of the results.
基金Sponsored by the Ministry of Science & Technology of China During the 11th Five-year Plan (Grant No. 2006BAJ05B07)
文摘Using powder-sintering method,SiO2-Al2O3-CaO-ZnO-R2O porous glass-ceramics were produced for analysis. Five samples with different SiO2 /CaO ratios were used in the research. The mechanical properties, microstructures and textures of porous glass-ceramics are investigated by using differential thermogravimetric analysis/differential thermal analysis ( TGA/SDTA) ,X-ray diffraction ( XRD) ,and scanning electron microsco- py ( SEM) . The activity energy of crystallization ( E) and crystallization kinetics parameter ( k) were calculated based on the modified JMA equation. The Avrami parameter n was obtained according to Augis-Bennett function. The results show that the k value of No. 1 sample ( SiO2 /CaO = 61∶ 18) is the largest among all samples, which tends to crystallize more easily,and crystallization processes of all samples are observed bulk crystallization. The main crystal phase observed is parawollastonite ( clinorhombic system) with puncheon shape. Poreforming agents decomposed at 100 - 500 ℃ form a large number of closed pores with micron dimension and several semi-open pores distribute uniformly in the glass-ceramics matrix. This work may be expected to be favorable for industrial scale applications of porous glass-ceramics in the field of building thermal insulation.
基金Supported by Fund of Scientific and Technological Key Project Plan of Liaoning Province , China(No.2003220026)Fund of Education Depart ment of Liaoning Province,China(No.05L147)
文摘In order to find the effect of state device installed on a carding machine on card sliver quality, card slivers produced in conditions of different voltages and gauges were tested by USTER AFIS. The results show that, when the gauge is 1 nun, most parameters of card sliver quality are better when voltage is 600 V than those when no voltage is applied. The contents of nep, trash, visible foreign matter (VFM) and short fiber content by number (SFCn), short fiber content by weight (SFCw), immature fiber content (IFC) of card sliver decrease by 5.9%, 16.7%, 12.5%, 5.3%, 4.8% and 1.6%, respectively, but seed coat nep (SCN) content of card sliver doesn't decrease. When the electrostatic plate gauge is 2 mm and electrostatic voltage is 4000 V, the removal efficiency of neps and SCN is remarkable, decreasing by 8.7% and 25% respectively. Card sliver quality is hardly improved under any voltage when the gauge between electrostatic plate and cylinder is 3mm.
基金Scientific Research Project for High Schools of the Educational Department of Liaoning Province,China(No.2008643)
文摘Exogenous DNA expressing green fluorescent protein( GFP) and labeled with fluorescein isothiocyanate( FITC) was used to transform the Chinese oak silkmoth Antheraea pernyi( A. pernyi)via sperm-mediated gene transfer( SMGT). Sperms entry into the female reproductive system and eggs were observed using fluorescence microscopy. The ability of A. pernyi sperms to uptake exogenous DNA was confirmed,and transfer of the exogenous DNA was shown by GFP expression in the transgenic eggs. Our result suggested that SMGT could also be used to directly generate transgenic A. pernyi expressing functional genes of interest.
基金supported by the Ph.D.Research Startup Funding of Eastern Liaoning University(Grant no.2019BS009).
文摘The woven glass fiber reinforced composites(GFRP)subjected to high-speed impact is investigated to identify the hygrothermal aging effect on the impact resistance.Both the hygrothermal aged and unaged glass/epoxy laminates are subjected to different impact velocities,which is confirmed as a sensitive factor for the failure modes and mechanisms.The results show the hygrothermal aging effect decreases the ballistic limit by 14.9%,but the influence on ballistic performance is limited within the impact velocity closed to the ballistic limit.The failure modes and energy dissipation mechanisms are confirmed to be slightly influenced by the hygrothermal aging effect.The hygrothermal aging effect induced localization of structural deformation and degradation of mechanical properties are the main reasons for the composite undergoing the same failure modes at smaller impact velocities.Based on the energy absorption mechanisms,analytical expressions predict the ballistic limit and energy absorption to reasonable accuracy,the underestimated total energy absorption results in a relatively poor agreement between the measured and predicted energy absorption efficiency.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11472124,11572145,11202090,and 11301350)the Doctor Research Start-up Fund of Liaoning Province,China(Grant No.20141050)+1 种基金the China Postdoctoral Science Foundation(Grant No.2014M560203)the General Science and Technology Research Plans of Liaoning Educational Bureau,China(Grant No.L2013005)
文摘By using the discrete variational method,we study the numerical method of the general nonholonomic system in the generalized Birkhoffian framework,and construct a numerical method of generalized Birkhoffian equations called a self-adjoint-preserving algorithm.Numerical results show that it is reasonable to study the nonholonomic system by the structure-preserving algorithm in the generalized Birkhoffian framework.
文摘Impurity redistribution during cotton carding was investigated. The content and size of impurity in card sliver,takerin droppings,flat strips,and cylinder screen droppings (including droppings under cylinder screen and cylinder-doffer triangle section)at four taker-in speeds were tested by using USTER AFIS. Results show that both total impurities and visible foreign matter (VFM)weights are increased. Impurities in cotton lap are carded and redistributed in card sliver, taker-in droppings, flat strips and cylinder screen droppings. Impurity percentage in taker-in droppings are the highest,followed by that in card sliver,that in flat strips and that in cylinder screen droppings. Cylinder screen has better dust-removing efficiency than flats. The average sizes of impurities in card sliver and cylinder screen droppings are decreased,whereas those of flat strips are increased and those of taker-in droppings is almost the same,in comparison with cotton lap. The impurity contents of card sliver,taker-in droppings,flat strips and cylinder screen droppings have tendencies to decrease with the increase of taker-in speed.
基金Fund of Key Subject Project of Liaoning Education Department,China (No. 2009432)
文摘The effect of flats speed,especially higher flats speed,on card sliver quality was studied.Card sliver produced at seven flats speeds was tested with Uster AFIS.Test results show that over-high flats speed is not beneficial to removing impurities and neps of card sliver.The flats speed from 450 to 550 mm/min is the best for removing impurity;while a speed of 450 or 650 mm/min is the best for removing neps of card sliver.The 1 050 mm/min flats speed is the best for removing short fibers.Accordingly,the flats speed of 450 mm/min is the most advantageous to improve the comprehensive quality of card sliver.It is also found that installing back-web-cleaner is very helpful to remove neps.It is also favorable to reduce short fibers,thus increasing the average length.But it is not helpful to reduce impurities in the sliver.
文摘The sol-gel method is used to prepare a new nano-alumina aerogel structure and the thermal properties of this nanomaterial are investigated comprehensively using electron microscope scanning,thermal analysis,X-ray and infrared spectrometer analysis methods.It is found that the composite aerogel alumina material has a multi-level porous nano-network structure.When employed for the thermal insulation of high-rise buildings,the alumina nanocomposite aerogel material can lead to effective energy savings in winter.However,it has almost no energy-saving effect on buildings where energy is consumed for cooling in summer.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11072218 and 11272287)
文摘In this paper, we present a new method to obtain the Lie symmetries and conserved quantities of the discrete wave equation with the Ablowitz-Ladik-Lattice equations. Firstly, the wave equation is transformed into a simple difference equation with the Ablowitz-Ladik-Lattice method. Secondly, according to the invariance of the discrete wave equation and the Ablowitz-Ladik-Lattice equations under infinitesimal transformation of dependent and independent variables, we derive the discrete determining equation and the discrete restricted equations. Thirdly, a series of the discrete analogs of conserved quantities, the discrete analogs of Lie groups, and the characteristic equations are obtained for the wave equation. Finally, we study a model of a biological macromolecule chain of mechanical behaviors, the Lie symmetry theory of discrete wave equation with the Ablowitz-Ladik-Lattice method is verified.
基金This work is financially supported by a University-Level Doctoral Research Start-Up Fund in 2019.
文摘A triethylenetetramine epoxy mixture was synthesized through the reaction of a low-molecular-weight liquid epoxy resin with triethylenetetramine(TETA).Then triethyltetramine(TETA)was injected dropwise into a pro-pylene glycol methyl ether(PM)solution for chain extension reaction.A hydrophilic andflexible polyether seg-ment was introduced into the hardener molecule.The effects of TETA/DGEPG,reaction temperature and reaction time on the epoxy conversion of polyethylene glycol diglycidyl ether(DGEPG)were studied.In addition,several alternate strategies to add epoxy resin to the high-speed dispersion machine and synthesize MEA DGEBA adduct(without catalyst and with bisphenol A diglycidyl ether epoxy resin)were compared.It was found that the higher the molecular weight of triethylenetetramine,the longer the chain segment of the surface active molecule.When the equivalence ratio of amine hydrogen and epoxy group is low,the stability of lotion is good.When the ratio of amine hydrogen to epoxy group is large,the content of triethylenetetramine is small.The main objective of this study is the provision of new data and knowledge for the development of new materials in the coating and electronic industry.
基金Education Department of Liaoning Province,China ( No. 2009A262) Liaoning BaiQianWan Talents Program,ChinaKey Subject Project of Liaoning Education Department,China ( No. 2011103)
文摘Effect of flat heel-toe difference (HTD) of a card on some parameters of yarn quality was studied by testing the yarn which was produced under different HTDs, doffer speed, and cylinder speed with yarn evenness tester of PT7000. The effect of HTD on yarn parameters was analyzed by using SPSS. The results show that HTD has significant influence on parameters of thickness fault and nep. As a whole, the HTDs of 0.42 and 0.56 mm are beneficial to improving yarn quality in comparison with the other HTDs.
文摘A novel method is proposed for treating cylindrical probe characteristics to obtain plasma density. The method consists of exponential extrapolation of the transitional part of the I -V curve to the floating potential for the ion saturation current, other than the existing theories which use the ion branch, and an iterative sheath thickness correction procedure for improved accuracy. The method was tested by treating Langmuir probe I-V characteristics obtained from inductively coupled Ar discharges at various pressures, and comparing the present results with those deduced by existing theories. It was shown that the plasma densities obtained by the present method are in good agreement with those calculated by the Allen-Boyd-Reynolds (ABR) theory, suggesting the effectiveness of the proposed method. Without need of manual setting and adjustment of fitting parameters, the method may be suitable for automatic and real time processing of probe characteristics.