At present,the research on the physical composition and properties of pineapple plants is scarce,and the uncertainty of fruit picking method is the key bottleneck factor hindering the research and development of pinea...At present,the research on the physical composition and properties of pineapple plants is scarce,and the uncertainty of fruit picking method is the key bottleneck factor hindering the research and development of pineapple harvesting machinery.Based on the statistics of survey data from many places,this paper analyzes the fruit-stem fracture mechanism and the theoretical conditions for optimal separation through structural modeling,mechanical behavior analysis and function judgment.On this basis,the“pineapple plant fixation bench”and“fruit-stem bending separation torque test equipment”were developed,and large-size,small-size tests and random optimization tests were carried out successively.The test results showed that the larger of the stem-stalk fixation distance,the more torque and fracture starting angle required for fruit fracture would increase,and the change range was small when the stem-stalk fixation distance was within 50 mm,and the probability of brittle fracture and complete separation was very high.When the space between the fracture section and the fruit-stem connecting point is about 5mm,the range of bending moment value required for the fruit-stem fracture is 1.88 to 2.77 N·m,the range of fracture starting angle is 12.2°to 18.1°,and the angular travel range during the separation process is 82.9°to 87.5°.When the stem-stalk fixation distance is about 15 mm,it is the best fruit-stem separation condition and the breaking torque measured in the verification test is about 2.76 N·m.The fracture starting angle is about 13.8°,the maximum prediction error is 13.1%,and the elastic modulus near the fruit-stem joint ranges from 16.1 to 23.9 MPa.This conclusion can provide an important design basis for the research and development of pineapple field picking robot and harvesting equipment.展开更多
Conditional access system (CAS) is a key technical component in digital TV broadcasting through which TV op-erators manage the appropriate rights of different subscribers in order to protect their commercial benefits....Conditional access system (CAS) is a key technical component in digital TV broadcasting through which TV op-erators manage the appropriate rights of different subscribers in order to protect their commercial benefits. The normal digital TV receiver can only receive and decode the pay TV programs scrambled by one specific CAS. In this paper, the authors proposed a smartcard conditional access interface (SCAI) scheme in order to make the digital TV receiver be a common receiving platform independent of any specific CAS employed at the broadcasting head-end. As a result, it only needs to include a common condi-tional access software package (CCAP) without any requirement of hardware modification in the receiver. Comparison between the two mentioned DVB-CI-based schemes showed that the cost of such kind receiver is greatly reduced. The main design points of the proposed scheme and its reference implementation’s architecture are presented in this paper. This scheme is also one of the candidate national standards for Chinese digital TV broadcasting industry.展开更多
In reversed-phase high performance liquid chromatography （RP-HPLC）, the mobile phase condition for separating eight isoflavones （daidzin, glycitin, genistin, 6＇-o-acetyl daidzin, 6＇-o-malonyl genistin, daidzein, ...In reversed-phase high performance liquid chromatography （RP-HPLC）, the mobile phase condition for separating eight isoflavones （daidzin, glycitin, genistin, 6＇-o-acetyl daidzin, 6＇-o-malonyl genistin, daidzein, glycitein and genistein） was optimized using the HCI （High-Purity Separation Laboratory, Department of Chemical Engineering, Inha University） program software. The optimum composition of mobile phase for the separation of the eight isoflavones was obtained. The elution profiles were calculated by the plate theory based on the equations of retention factor, In k=A＋BF＋CF2, where F was the volume percentage of acetonitrile with 0.1% acetic acid （AA）. The first mobile phase composition was water with 0.1% AA/acetonitrile with 0.1% AA （88%/12%, by volume）, followed at 9min later by the second composition of mobile phase which was step-changed to 85%/15%, at 19rain by the third composition which was step-changed to 73%/27%, at 30min when it was changed to 65%/35% and finally it was maintained in isocratic mode to the end of the run time at 50rain. Although, using step gradient mode to separate the isoflavones, the calculated and experimented data were not achieved very good agreement, we could estimate the closed retention time before experiment. And the agreement between the experimental data and the calculated values was relatively good using isocratic separation for eight isoflavones, but the retention time is very long.展开更多
Embedding direct reduction followed by magnetic separation was conducted to fully recover iron and titanium separately from beach titanomagnetite （TTM）. The influences of reduction conditions, such as molar ratio of...Embedding direct reduction followed by magnetic separation was conducted to fully recover iron and titanium separately from beach titanomagnetite （TTM）. The influences of reduction conditions, such as molar ratio of C to Fe, reduction time, and reduction temperature, were studied. The results showed that the TTM concentrate was reduced to iron and iron-titanium oxides, depending on the reduction time, and the reduction sequence at 1 200℃ was suggested as follows ： Fe2.75 Ti0.25O4→Fe2TiO4→FeTiO3→FeTi2O5. The reduction temperature played a considerable role in the reduction of TTM concentrates. Increasing temperature from 1 100 to 1 200℃ was beneficial to recovering titanium and iron, whereas the results deteriorated as temperature increased further. The results of X-ray diffraction and scanning electron microscopy analyses showed that low temperature （≤1100℃） was unfavorable for the gasification of reductant, resulting in insufficient reducing atmosphere in the reduction process. The molten phase was formed at high temperatures of 1250-1 300℃, which accelerated the migration rate of metallic particles and suppressed the diffusion of reduction gas, resulting in poor reduction. The optimum conditions for reducing TTM concentrate are as follows： molar ratio of C to Fe of 1.68, reduction time of 150 min, and reduction temperature of 1 200℃. Under these conditions, direct reduction iron powder, assaying 90.28 mass% TFe and 1.73 mass% TiO2 with iron recovery of 90.85%, and titanium concentrate, assaying 46.24 mass% TiO2 with TiO2 recovery of 91.15%, were obtained.展开更多
An excellent separation of xylene isomers is reported using 2, 6-O-di-pentyl-3-O-acetyl-beta-CD as capillary stationary phase. The optimum conditions for the separation are also discussed.
By using the approximate derivative-dependent functional variable separation approach, we study the quasi-linear diffusion equations with a weak source ut = （A（u）Ux）x ＋ eB（u, Ux）. A complete classification of t...By using the approximate derivative-dependent functional variable separation approach, we study the quasi-linear diffusion equations with a weak source ut = （A（u）Ux）x ＋ eB（u, Ux）. A complete classification of these perturbed equations which admit approximate derivative-dependent functional separable solutions is listed. As a consequence, some approxi- mate solutions to the resulting perturbed equations are constructed via examples.展开更多
This paper studies the self-similar fractals with overlaps from an algorithmic point of view.A decidable problem is a question such that there is an algorithm to answer"yes"or"no"to the question fo...This paper studies the self-similar fractals with overlaps from an algorithmic point of view.A decidable problem is a question such that there is an algorithm to answer"yes"or"no"to the question for every possible input.For a classical class of self-similar sets{E b.d}b,d where E b.d=Sn i=1(E b,d/d+b i)with b=(b1,...,b n)∈Qn and d∈N∩[n,∞),we prove that the following problems on the class are decidable:To test if the Hausdorff dimension of a given self-similar set is equal to its similarity dimension,and to test if a given self-similar set satisfies the open set condition(or the strong separation condition).In fact,based on graph algorithm,there are polynomial time algorithms for the above decidable problem.展开更多
基金supported by the Construction Project of PhD Workstation in Guangdong Province(Guangdong Provincial Financial Administration[2020]No.122)the Special Fund for Rural Vitalization Strategy in Guangdong Province(Guangdong Provincial Financial Administration[2022]No.92).
文摘At present,the research on the physical composition and properties of pineapple plants is scarce,and the uncertainty of fruit picking method is the key bottleneck factor hindering the research and development of pineapple harvesting machinery.Based on the statistics of survey data from many places,this paper analyzes the fruit-stem fracture mechanism and the theoretical conditions for optimal separation through structural modeling,mechanical behavior analysis and function judgment.On this basis,the“pineapple plant fixation bench”and“fruit-stem bending separation torque test equipment”were developed,and large-size,small-size tests and random optimization tests were carried out successively.The test results showed that the larger of the stem-stalk fixation distance,the more torque and fracture starting angle required for fruit fracture would increase,and the change range was small when the stem-stalk fixation distance was within 50 mm,and the probability of brittle fracture and complete separation was very high.When the space between the fracture section and the fruit-stem connecting point is about 5mm,the range of bending moment value required for the fruit-stem fracture is 1.88 to 2.77 N·m,the range of fracture starting angle is 12.2°to 18.1°,and the angular travel range during the separation process is 82.9°to 87.5°.When the stem-stalk fixation distance is about 15 mm,it is the best fruit-stem separation condition and the breaking torque measured in the verification test is about 2.76 N·m.The fracture starting angle is about 13.8°,the maximum prediction error is 13.1%,and the elastic modulus near the fruit-stem joint ranges from 16.1 to 23.9 MPa.This conclusion can provide an important design basis for the research and development of pineapple field picking robot and harvesting equipment.
基金Project (No. 200442) supported by the Electronics DevelopmentFoundation for the Key Industrialization Project of the Ministry of0Information Industry, China
文摘Conditional access system (CAS) is a key technical component in digital TV broadcasting through which TV op-erators manage the appropriate rights of different subscribers in order to protect their commercial benefits. The normal digital TV receiver can only receive and decode the pay TV programs scrambled by one specific CAS. In this paper, the authors proposed a smartcard conditional access interface (SCAI) scheme in order to make the digital TV receiver be a common receiving platform independent of any specific CAS employed at the broadcasting head-end. As a result, it only needs to include a common condi-tional access software package (CCAP) without any requirement of hardware modification in the receiver. Comparison between the two mentioned DVB-CI-based schemes showed that the cost of such kind receiver is greatly reduced. The main design points of the proposed scheme and its reference implementation’s architecture are presented in this paper. This scheme is also one of the candidate national standards for Chinese digital TV broadcasting industry.
文摘In reversed-phase high performance liquid chromatography （RP-HPLC）, the mobile phase condition for separating eight isoflavones （daidzin, glycitin, genistin, 6＇-o-acetyl daidzin, 6＇-o-malonyl genistin, daidzein, glycitein and genistein） was optimized using the HCI （High-Purity Separation Laboratory, Department of Chemical Engineering, Inha University） program software. The optimum composition of mobile phase for the separation of the eight isoflavones was obtained. The elution profiles were calculated by the plate theory based on the equations of retention factor, In k=A＋BF＋CF2, where F was the volume percentage of acetonitrile with 0.1% acetic acid （AA）. The first mobile phase composition was water with 0.1% AA/acetonitrile with 0.1% AA （88%/12%, by volume）, followed at 9min later by the second composition of mobile phase which was step-changed to 85%/15%, at 19rain by the third composition which was step-changed to 73%/27%, at 30min when it was changed to 65%/35% and finally it was maintained in isocratic mode to the end of the run time at 50rain. Although, using step gradient mode to separate the isoflavones, the calculated and experimented data were not achieved very good agreement, we could estimate the closed retention time before experiment. And the agreement between the experimental data and the calculated values was relatively good using isocratic separation for eight isoflavones, but the retention time is very long.
基金financially supported by the National Natural Science Foundation of China (Grant No.51474018)
文摘Embedding direct reduction followed by magnetic separation was conducted to fully recover iron and titanium separately from beach titanomagnetite （TTM）. The influences of reduction conditions, such as molar ratio of C to Fe, reduction time, and reduction temperature, were studied. The results showed that the TTM concentrate was reduced to iron and iron-titanium oxides, depending on the reduction time, and the reduction sequence at 1 200℃ was suggested as follows ： Fe2.75 Ti0.25O4→Fe2TiO4→FeTiO3→FeTi2O5. The reduction temperature played a considerable role in the reduction of TTM concentrates. Increasing temperature from 1 100 to 1 200℃ was beneficial to recovering titanium and iron, whereas the results deteriorated as temperature increased further. The results of X-ray diffraction and scanning electron microscopy analyses showed that low temperature （≤1100℃） was unfavorable for the gasification of reductant, resulting in insufficient reducing atmosphere in the reduction process. The molten phase was formed at high temperatures of 1250-1 300℃, which accelerated the migration rate of metallic particles and suppressed the diffusion of reduction gas, resulting in poor reduction. The optimum conditions for reducing TTM concentrate are as follows： molar ratio of C to Fe of 1.68, reduction time of 150 min, and reduction temperature of 1 200℃. Under these conditions, direct reduction iron powder, assaying 90.28 mass% TFe and 1.73 mass% TiO2 with iron recovery of 90.85%, and titanium concentrate, assaying 46.24 mass% TiO2 with TiO2 recovery of 91.15%, were obtained.
文摘An excellent separation of xylene isomers is reported using 2, 6-O-di-pentyl-3-O-acetyl-beta-CD as capillary stationary phase. The optimum conditions for the separation are also discussed.
基金Project supported by the National Natural Science Foundation of China(Grant No.10671156)the Natural Science Foundation of Shaanxi Province of China(Grant No.SJ08A05)
文摘By using the approximate derivative-dependent functional variable separation approach, we study the quasi-linear diffusion equations with a weak source ut = （A（u）Ux）x ＋ eB（u, Ux）. A complete classification of these perturbed equations which admit approximate derivative-dependent functional separable solutions is listed. As a consequence, some approxi- mate solutions to the resulting perturbed equations are constructed via examples.
基金supported by National Natural Science Foundation of China(Grants Nos.11071224 and 11371329)Program for New Century Excellent Talents in University+1 种基金Natural Science Foundation of Zhejiang Province(Grants Nos.LY12F02011 and LR13A1010001)Foundation of Zhejiang Educational Committee(Grant No.Y201226044)
文摘This paper studies the self-similar fractals with overlaps from an algorithmic point of view.A decidable problem is a question such that there is an algorithm to answer"yes"or"no"to the question for every possible input.For a classical class of self-similar sets{E b.d}b,d where E b.d=Sn i=1(E b,d/d+b i)with b=(b1,...,b n)∈Qn and d∈N∩[n,∞),we prove that the following problems on the class are decidable:To test if the Hausdorff dimension of a given self-similar set is equal to its similarity dimension,and to test if a given self-similar set satisfies the open set condition(or the strong separation condition).In fact,based on graph algorithm,there are polynomial time algorithms for the above decidable problem.
