In this paper, a new method named as the gradually descent method was proposed to solve the discrete global optimization problem. With the aid of an auxiliary function, this method enables to convert the problem of fi...In this paper, a new method named as the gradually descent method was proposed to solve the discrete global optimization problem. With the aid of an auxiliary function, this method enables to convert the problem of finding one discrete minimizer of the objective function f to that of finding another at each cycle. The auxiliary function can ensure that a point, except a prescribed point, is not its integer stationary point if the value of objective function at the point is greater than the scalar which is chosen properly. This property leads to a better minimizer of f found more easily by some classical local search methods. The computational results show that this algorithm is quite efficient and reliable for solving nonlinear integer programming problems.展开更多
In order to ensure the steady development of our science, the Chinese government has continuously increased input in the last ten years. Information from the State Statistics Bureau shows that by the end of 1994, the ...In order to ensure the steady development of our science, the Chinese government has continuously increased input in the last ten years. Information from the State Statistics Bureau shows that by the end of 1994, the national institutions and enterprises boasted 18.659 million technical experts, 4.3 times the number in 1978, or 1258 technical experts every ten thousand people, redoubling that of 1978. The whole country has 5860 independent scientific research and development (R & D) institutions,展开更多
The effects of warm-rolling process on the microstructure, ordering, mechanical properties and cold- rolling workability of Fe-6.Swt%Si alloy were investigated, where three processes of warm-rolling with the same tota...The effects of warm-rolling process on the microstructure, ordering, mechanical properties and cold- rolling workability of Fe-6.Swt%Si alloy were investigated, where three processes of warm-rolling with the same total reduction of 93% were used, including (1) 500 ℃/12 passes/total reduction of 93%, (2) 500 ℃13 passes/total reduction of 50% + 400 ℃19 passes/total reduction of 86%, and (3) 500 ℃13 passes/total reduction of 50% + 400 ℃15 passes/total reduction of 60% + 300 ℃14 passes/total reduction of 64%. The results show that compared with process (1) warm-rolling with constant temperature of 500 ℃, process (2) and process (3) warm-rolling with gradually decreasing temperature can significantly improve the room temperature plasticity and cold-rolling workability of the Fe-6.5wt%Si alloy. For example, the three point bending fracture deflections are increased by 54.5% and 81.8% for processes (2) and (3), respectively, and the maximum reductions of single pass cold-rolling without edge crack are increased from 50% of process (1) to 55% of process (2) and 62% of process (3), respectively. The plasticity improvement of the Fe- 6.5wt%Si alloy can be attributed to both reductions of surface oxidation degree and order degree of the alloy by warm-rolling with gradually decreasing temperature.展开更多
Let D be a digital manifold, J the subset of non-empty of D; and let A<sub>1</sub>, A<sub>2</sub>, …, A<sub>m</sub> be m real numbers with A<sub>1</sub>【A<sub>2&...Let D be a digital manifold, J the subset of non-empty of D; and let A<sub>1</sub>, A<sub>2</sub>, …, A<sub>m</sub> be m real numbers with A<sub>1</sub>【A<sub>2</sub>【…【A<sub>m</sub>. Supposing function f<sub>J</sub>: J → A<sub>1</sub>,…, A<sub>m</sub>, we want to find a function f<sub>D</sub>: D→{A<sub>1</sub>…, A<sub>m</sub>}, such that f<sub>D</sub> is gradual variation on D, having f<sub>D</sub>(x)=f<sub>J</sub>(x), x∈J. Such f<sub>D</sub> is called the gradually varied extension or interpolation of f<sub>J</sub>.展开更多
Filling is an important part in pattern recognition and computer vision. In the discrete plane (grid of plane)∑<sub>2</sub>, fill means 'determination of the region D enclosed by the simple closed c...Filling is an important part in pattern recognition and computer vision. In the discrete plane (grid of plane)∑<sub>2</sub>, fill means 'determination of the region D enclosed by the simple closed curve J which is given beforehand'. In other words, if the valuation of the point on the contour J is 1, we want to do a valuation for ∑<sub>2</sub> to make the valuation of the point p be 1 iff point p belongs to D.展开更多
In the wake of the financial crisis, any signs of a slowdown will trigger fears. China, although its economy has resumed double-digit growth, is no exception. China’s first-half economicfigures released in mid-July s...In the wake of the financial crisis, any signs of a slowdown will trigger fears. China, although its economy has resumed double-digit growth, is no exception. China’s first-half economicfigures released in mid-July show its GDP grew 10.3展开更多
In 2016,China’s tungsten concentrate output declined,domestic and foreign downstream enterprises’tungsten raw material stocks were at a historical low,and the current market supply is stable but slightly tight;outpu...In 2016,China’s tungsten concentrate output declined,domestic and foreign downstream enterprises’tungsten raw material stocks were at a historical low,and the current market supply is stable but slightly tight;output of carbide alloy and other downstream products increased,while that of some elementary展开更多
The turbulence characteristics of both decelerating and accelerating flows under a gradually varying flume are investigated by using a three-dimensional down-looking acoustic Doppler velocimeter (ADV). The time-aver...The turbulence characteristics of both decelerating and accelerating flows under a gradually varying flume are investigated by using a three-dimensional down-looking acoustic Doppler velocimeter (ADV). The time-averaged velocity profiles are flatened except for the central parts, and fairly fit into logarithmic laws and those in the plane circulation under the gradual expansion are more likely to be negative. The complex secondary currents are identified under the present gradual transition attributed to the combination of driving forces induced by both the boundary configuration variation and the tmbalanced turbulence: a circulation on each side of the expansion and a pair of circulations on each side of the contraction. One sees an anisotropy in the turbulence intensities, the turbulence intensities increase or level out with the flow depth except those under expansion, and the V component of the turbulence intensity typically outweighs that in the streamwise direction. Apart from the above results, the respective particular distributions of the primary Reynolds shear stresses ( rxy and rxz ) under the gradual expansion and contraction can account for the patterns of the secondary currents in this investigation.展开更多
The advantages of blue InGaN light-emitting diodes (LED) with the active region of gradually increased barrier heights from n- to p-layers are studied. The energy band diagram, hole concentration, electrostatic fiel...The advantages of blue InGaN light-emitting diodes (LED) with the active region of gradually increased barrier heights from n- to p-layers are studied. The energy band diagram, hole concentration, electrostatic field near the electron blocking layer (EBL), and the internal quantum efficiency (IQE) are investigated by Crosslight simulation program. The simulation results show that the structure with gradually increased barrier heights has better performance over the equal one, which can be attributed to the mitigated polarization effect near the interface of the last barrier/EBL due to less interface polarization charges. Moreover, reduced barrier height toward the n-layers is beneficial for holes injection and transportation in the active region. As a result, holes are injected into the active region more efficiently and distributed uniformly in the quantum wells, with which both the IQE and the total lighting power are increased. Although it can lead to the broadening of the spontaneous emission spectrum, the increase is slight such that it has little effect on the application in solid-state lighting.展开更多
Micro-grinding with a spherical grinding head has been deemed an indispensable method in high-risk surgeries, such as neurosurgery and spine surgery, where bone grinding has long been plagued by the technical bottlene...Micro-grinding with a spherical grinding head has been deemed an indispensable method in high-risk surgeries, such as neurosurgery and spine surgery, where bone grinding has long been plagued by the technical bottleneck of mechanical stress-induced crack damage. In response to this challenge, the ultrasound-assisted biological bone micro-grinding novel process with a spherical grinding head has been proposed by researchers. Force modeling is a prerequisite for process parameter determination in orthopedic surgery, and the difculty in establishing and accurately predicting bone micro-grinding force prediction models is due to the geometric distribution of abrasive grains and the dynamic changes in geometry and kinematics during the cutting process. In addressing these critical needs and technical problems, the shape and protrusion heights of the wear particle of the spherical grinding head were frst studied, and the gradual rule of the contact arc length under the action of high-speed rotating ultrasonic vibration was proposed. Second, the mathematical model of the maximum thickness of undeformed chips under ultrasonic vibration of the spherical grinding head was established. Results showed that ultrasonic vibration can reduce the maximum thickness of undeformed chips and increase the range of ductile and bone meal removals, revealing the mechanism of reducing grinding force. Further, the dynamic grinding behavior of diferent layers of abrasive particles under diferent instantaneous interaction states was studied. Finally, a prediction model of micro-grinding force was established in accordance with the relationship between grinding force and cutting depth, revealing the mechanism of micro-grinding force transfer under ultrasonic vibration. The theoretical model’s average deviations are 10.37% in x-axis direction, 6.85% in y-axis direction, and 7.81% in z-axis direction compared with the experimental results. This study provides theoretical guidance and technical support for clinical bone micro-grinding.展开更多
This study involved outcrop,drilling,seismic,gravity,and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea(PSCS)and establish its evolution model.The re...This study involved outcrop,drilling,seismic,gravity,and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea(PSCS)and establish its evolution model.The results indicate that a series of arc-shaped ophiolite belts and calcalkaline magmatic rocks are developed in northern Borneo,both of which have the characteristics of gradually changing younger from west to east,and are direct signs of subduction and collision of PSCS.At the same time,the subduction of PSCS led to the formation of three accretion zones from the south to the north in Borneo,the Kuching belt,Sibu belt,and Miri belt.The sedimentary formation of northern Borneo is characterized by a three-layer structure,with the oceanic basement at the bottom,overlying the deep-sea flysch deposits of the Rajang–Crocker group,and the molasse sedimentary sequence that is dominated by river-delta and shallow marine facies at the top,recording the whole subduction–collision–orogeny process of PSCS.Further,seismic reflection and tomography also confirmed the subduction and collision of PSCS.Based on the geological records of the subduction and collision of PSCS,combined with the comprehensive analysis of segmented expansion and key tectonic events in the South China Sea,we establish the“gradual”subduction-collision evolution model of PSCS.During the late Eocene to middle Miocene,the Zengmu,Nansha,and Liyue–Palawan blocks were separated by West Baram Line and Balabac Fault,which collided with the Borneo block and Kagayan Ridge successively from the west to the east,forming several foreland basin systems,and PSCS subducted and closed from the west to the east.The subduction and extinction of PSCS controlled the oil and gas distribution pattern of southern South China Sea(SSCS)mainly in three aspects.First,the“gradual”closure process of PSCS led to the continuous development of many large deltas in SSCS.Second,the deltas formed during the subduction–collision of PSCS controlled the development of source rocks in the basins of SSCS.Macroscopically,the distribution and scale of deltas controlled the distribution and scale of source rocks,forming two types of source rocks,namely,coal measures and terrestrial marine facies.Microscopically,the difference of terrestrial higher plants carried by the delta controlled the proportion of macerals of source rocks.Third,the difference of source rocks mainly controlled the distribution pattern of oil and gas in SSCS.Meanwhile,the difference in the scale of source rocks mainly controlled the difference in the amount of oil and gas discoveries,resulting in a huge amount of oil and gas discoveries in the basin of SSCS.Meanwhile,the difference of macerals of source rocks mainly controlled the difference of oil and gas generation,forming the oil and gas distribution pattern of“nearshore oil and far-shore gas”.展开更多
Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus i...Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus in response to short-term low salinity stress,the experiments of gradually decline and recovery as well as abrupt decline in salinity were carried out.The results showed that P.trituberculatus could survive in a certain low salinity range in the short term,and salinity 12 was the lowest tolerable salinity under the present experimental conditions.The change of the hemolymph osmotic pressure displayed significant positive correlations with water salinity,and the pressure was always higher than seawater osmotic pressure.Short-term low salinity stress changed the structure and morphology of gill tissue.The expansion of gill filament ends and epithelial cell shedding were conducive to osmotic adjustment.The activities of key ion transport enzymes such as Na^(+)-K^(+)-ATPase,carbonic anhydrase and V-ATPase also changed with the osmotic regulation,while Na^(+)-K^(+)-ATPase played a dominant role.In summary,as an osmotic adjustment species,P.trituberculatus rapidly adapt to the short-term low-salinity environment by osmotic adjustment in vivo,but salinity below salinity 12 is not conducive to its survival.Our result enriched the theoretical mechanism of osmotic regulation of P.trituberculatus,providing reference for the development of aquaculture technology of P.trituberculatus.展开更多
Introduction: Gastroschisis is one of the neonatal pathologies with bad prognosis in developing countries due to a lack of equipment. We aim to report one way of managing this malformation that could be practised ever...Introduction: Gastroschisis is one of the neonatal pathologies with bad prognosis in developing countries due to a lack of equipment. We aim to report one way of managing this malformation that could be practised everywhere, constituting an alternative approach to surgery in poor areas. Patients and Methods: This observational and descriptive study included newborn babies with gastroschisis who underwent gradual bedside reduction at the Paediatric Surgery Department of the Yaounde Central Hospital. Results: Our cohort was constituted by 32 newborn babies with a mean age of 18.12 hours on admission. The Lefort type 2 was the most frequent in 81.25% of cases. The mean time for oral feeding after complete reduction was 17.4 days and the duration of hospital stay was 24.91 days. Survival rates were at 40.63%, with a residual hernia after healing in 38.46% of cases. Conclusion: Despite the high rate of mortality, gradual reduction of gastroschisis at the bedside seems to be an opportunity for resource constrained areas and can be an alternative solution to surgery.展开更多
[Objective] The large-scale single-column fattening pig house with fermen- tation bed could hold 1 500 heads of fattening pigs. Since the number of pigs in piggery is too large, the management is difficult. The behavi...[Objective] The large-scale single-column fattening pig house with fermen- tation bed could hold 1 500 heads of fattening pigs. Since the number of pigs in piggery is too large, the management is difficult. The behavior of feeding, drinking, movement, sleeping, fighting of pigs is difficult to handle. The pigs cannot be man- aged well, resulting in the enhanced weakness of piglets, enhanced illness of weak pigs and missing treatment of ill pigs. The management for the pig populations is not satisfactory, and thus, it is needed to improve timely. [Method] The barriers for the fattening pigs in the large-scale pig house with fermentation bed were designed. The single management for single fattening pig was proposed. The large-scale fat- tening pig house was divided into 8 regions. Among them, 4 regions were located in both sides of the fermentation bed. Their main function was to separate ill, weak, small and bad pigs. In addition, the main column was divided into 4 gradual barri- ers. They were used to separate different-size fattening pigs. In view of manage- ment, the different-type pigs were managed dividedly with the gradual barriers. The equally-sized pigs were concentrated into one column. The ill, weak, small and bad pigs were isolated into barriers. Thus, the dynamic management was adopted. Until the fattening pigs grew up to 75 kg and their health was stable, the barriers among the columns were canceled to mix the pigs again and guarantee the pigs more gymnastic space. [Result] This design would improve the disease resistance of ill pigs, health status of weak pigs and management level of pig populations. This study would also provide a basis for the healthy running of large-scale fattening pig house with fermentation bed. [Conclusion] The pig-raising model with fermentation bed would improve the environment of pig house and the welfare of pigs. In addi- tion, the performance of pigs and quality of pork were also improved. The fermen- tation bed had an obvious advantage in safety and economics, and it had a broad application prospect.展开更多
The purpose of this study was to find out the spatial-temporal rules and driving force of cultivated land quality in Henan Province in the last ten years. Agricultural land grading factor evaluation was used to evalua...The purpose of this study was to find out the spatial-temporal rules and driving force of cultivated land quality in Henan Province in the last ten years. Agricultural land grading factor evaluation was used to evaluate the cultivated land quality of 2002 and 2012 in Henan Province, and to research the change laws. Method of correlation coefficient was employed to select the driving forces affecting cultivated land quality evolution. The results indicated that the cultivated land quality in Henan Province increased slightly in the last ten years in general, and in spatial there were unchanged regions, increased regions and decreased regions. The cultivated land quality in spatial presented the trend of good becoming better, bad becoming worse, which should be highly valued in cultivated land quality protection and management. Land development and consolidation projects had significant contributions to increasing the cultivated land quality. Driving forces between the sudden change regions and gradual change regions were significantly different. The paper concluded that the research on the spatial-temporal evolution and driving force of cultivated land quality based on cultivated land quality evolution had important academic significance and practical value.展开更多
Aimed at the problem that the traditional ART-2 neural network can not recognize a gradually changing course, an eternal term memory (ETM) vector is introduced into ART-2 to simulate the function of human brain, i.e. ...Aimed at the problem that the traditional ART-2 neural network can not recognize a gradually changing course, an eternal term memory (ETM) vector is introduced into ART-2 to simulate the function of human brain, i.e. the deep remembrance for the initial impression.. The eternal term memory vector is determined only by the initial vector that establishes category neuron node and is used to keep the remembrance for this vector for ever. Two times of vigilance algorithm are put forward, and the posterior input vector must first pass the first vigilance of this eternal term memory vector, only succeeded has it the qualification to begin the second vigilance of long term memory vector. The long term memory vector can be revised only when both of the vigilances are passed. Results of recognition examples show that the improved ART-2 overcomes the defect of traditional ART-2 and can recognize a gradually changing course effectively.展开更多
In this paper, we propose a siliconbased highspeed plasmonic modulator. The modulator has a double-layer structure with a 16 The long metaldielectricmetal plasmonic waveguide at the upper layer and two silicon singlem...In this paper, we propose a siliconbased highspeed plasmonic modulator. The modulator has a double-layer structure with a 16 The long metaldielectricmetal plasmonic waveguide at the upper layer and two silicon singlemode waveguides at the bottom layer. The upperlayer plasmonic waveguide acts as a phase shifter and has a dielectric slot that is 30 nm wide. Two taper structures that have gradually varied widths are introduced at the bottom layer to convert the photonic mode into plasmonicslot mode with improved coupling efficiency. For a modulator with two 1 mlong mode couplers, simulation shows that there is an insertion loss of less than 11 dB and a halfwave voltage of 3.65 V. The modulation bandwidth of the proposed modulator can be more than 100 GHz without the carrier effect being a limiting factor in silicon. The fabrication process is also discussed, and the proposed design is shown to be feasible with a hybrid of CMOS and polymer technology.展开更多
The China Classification Society has established its office at Perth in Australia with 1680 ships and total tonnages of 136 million. It plans to organize other offices in Spanish, west coast of United State and North ...The China Classification Society has established its office at Perth in Australia with 1680 ships and total tonnages of 136 million. It plans to organize other offices in Spanish, west coast of United State and North Europe. It had already created offlees in Hamburg, Stuttgrt Osaka, Tokyo, Hongkong, New York, Rotterdam, Port Said, London and Singapore on the other day.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.10271073)
文摘In this paper, a new method named as the gradually descent method was proposed to solve the discrete global optimization problem. With the aid of an auxiliary function, this method enables to convert the problem of finding one discrete minimizer of the objective function f to that of finding another at each cycle. The auxiliary function can ensure that a point, except a prescribed point, is not its integer stationary point if the value of objective function at the point is greater than the scalar which is chosen properly. This property leads to a better minimizer of f found more easily by some classical local search methods. The computational results show that this algorithm is quite efficient and reliable for solving nonlinear integer programming problems.
文摘In order to ensure the steady development of our science, the Chinese government has continuously increased input in the last ten years. Information from the State Statistics Bureau shows that by the end of 1994, the national institutions and enterprises boasted 18.659 million technical experts, 4.3 times the number in 1978, or 1258 technical experts every ten thousand people, redoubling that of 1978. The whole country has 5860 independent scientific research and development (R & D) institutions,
基金financially supported by the National Basic Research Program of China(No.2011CB606300)the National HighTech Research and Development Program of China(No.2012AA03A505)
文摘The effects of warm-rolling process on the microstructure, ordering, mechanical properties and cold- rolling workability of Fe-6.Swt%Si alloy were investigated, where three processes of warm-rolling with the same total reduction of 93% were used, including (1) 500 ℃/12 passes/total reduction of 93%, (2) 500 ℃13 passes/total reduction of 50% + 400 ℃19 passes/total reduction of 86%, and (3) 500 ℃13 passes/total reduction of 50% + 400 ℃15 passes/total reduction of 60% + 300 ℃14 passes/total reduction of 64%. The results show that compared with process (1) warm-rolling with constant temperature of 500 ℃, process (2) and process (3) warm-rolling with gradually decreasing temperature can significantly improve the room temperature plasticity and cold-rolling workability of the Fe-6.5wt%Si alloy. For example, the three point bending fracture deflections are increased by 54.5% and 81.8% for processes (2) and (3), respectively, and the maximum reductions of single pass cold-rolling without edge crack are increased from 50% of process (1) to 55% of process (2) and 62% of process (3), respectively. The plasticity improvement of the Fe- 6.5wt%Si alloy can be attributed to both reductions of surface oxidation degree and order degree of the alloy by warm-rolling with gradually decreasing temperature.
基金Project supported by the Science Fund of the Chinese Academy of Sciences for Young Scientists.
文摘Let D be a digital manifold, J the subset of non-empty of D; and let A<sub>1</sub>, A<sub>2</sub>, …, A<sub>m</sub> be m real numbers with A<sub>1</sub>【A<sub>2</sub>【…【A<sub>m</sub>. Supposing function f<sub>J</sub>: J → A<sub>1</sub>,…, A<sub>m</sub>, we want to find a function f<sub>D</sub>: D→{A<sub>1</sub>…, A<sub>m</sub>}, such that f<sub>D</sub> is gradual variation on D, having f<sub>D</sub>(x)=f<sub>J</sub>(x), x∈J. Such f<sub>D</sub> is called the gradually varied extension or interpolation of f<sub>J</sub>.
基金Project supported by the Science Fund of the Chinese Academy of Sciences for Young Scientists
文摘Filling is an important part in pattern recognition and computer vision. In the discrete plane (grid of plane)∑<sub>2</sub>, fill means 'determination of the region D enclosed by the simple closed curve J which is given beforehand'. In other words, if the valuation of the point on the contour J is 1, we want to do a valuation for ∑<sub>2</sub> to make the valuation of the point p be 1 iff point p belongs to D.
文摘In the wake of the financial crisis, any signs of a slowdown will trigger fears. China, although its economy has resumed double-digit growth, is no exception. China’s first-half economicfigures released in mid-July show its GDP grew 10.3
文摘In 2016,China’s tungsten concentrate output declined,domestic and foreign downstream enterprises’tungsten raw material stocks were at a historical low,and the current market supply is stable but slightly tight;output of carbide alloy and other downstream products increased,while that of some elementary
基金supported by the National Natural Science Foundation of China(Grant No.41171016)the Sichuan Province Science and Technology Support Program(Grant No.2014SZ0163)
文摘The turbulence characteristics of both decelerating and accelerating flows under a gradually varying flume are investigated by using a three-dimensional down-looking acoustic Doppler velocimeter (ADV). The time-averaged velocity profiles are flatened except for the central parts, and fairly fit into logarithmic laws and those in the plane circulation under the gradual expansion are more likely to be negative. The complex secondary currents are identified under the present gradual transition attributed to the combination of driving forces induced by both the boundary configuration variation and the tmbalanced turbulence: a circulation on each side of the expansion and a pair of circulations on each side of the contraction. One sees an anisotropy in the turbulence intensities, the turbulence intensities increase or level out with the flow depth except those under expansion, and the V component of the turbulence intensity typically outweighs that in the streamwise direction. Apart from the above results, the respective particular distributions of the primary Reynolds shear stresses ( rxy and rxz ) under the gradual expansion and contraction can account for the patterns of the secondary currents in this investigation.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China (Grant Nos. 60976042 and 10990103), the National Basic Research Program of China (Nos. 2010CB923204 and 2012CB619302), and the China Postdoctoral Science Foundation (No. 20100480064). The authors are also grateful to Mr. M. Yang from Crosslight Software Inc. for technical assistance.
文摘The advantages of blue InGaN light-emitting diodes (LED) with the active region of gradually increased barrier heights from n- to p-layers are studied. The energy band diagram, hole concentration, electrostatic field near the electron blocking layer (EBL), and the internal quantum efficiency (IQE) are investigated by Crosslight simulation program. The simulation results show that the structure with gradually increased barrier heights has better performance over the equal one, which can be attributed to the mitigated polarization effect near the interface of the last barrier/EBL due to less interface polarization charges. Moreover, reduced barrier height toward the n-layers is beneficial for holes injection and transportation in the active region. As a result, holes are injected into the active region more efficiently and distributed uniformly in the quantum wells, with which both the IQE and the total lighting power are increased. Although it can lead to the broadening of the spontaneous emission spectrum, the increase is slight such that it has little effect on the application in solid-state lighting.
基金Supported by National Natural Science Foundation of China(Grant Nos.51975305,52105457,and 52205481)the Special Fund of Taishan Scholars Project(Grant No.tsqn202211179)+1 种基金Shandong Provincial Youth Talent Promotion Project(Grant No.SDAST2021qt12)Shandong Provincial Natural Science Foundation(Grant Nos.ZR2023QE057,ZR2022QE028,ZR2021QE116,and ZR2020KE027).
文摘Micro-grinding with a spherical grinding head has been deemed an indispensable method in high-risk surgeries, such as neurosurgery and spine surgery, where bone grinding has long been plagued by the technical bottleneck of mechanical stress-induced crack damage. In response to this challenge, the ultrasound-assisted biological bone micro-grinding novel process with a spherical grinding head has been proposed by researchers. Force modeling is a prerequisite for process parameter determination in orthopedic surgery, and the difculty in establishing and accurately predicting bone micro-grinding force prediction models is due to the geometric distribution of abrasive grains and the dynamic changes in geometry and kinematics during the cutting process. In addressing these critical needs and technical problems, the shape and protrusion heights of the wear particle of the spherical grinding head were frst studied, and the gradual rule of the contact arc length under the action of high-speed rotating ultrasonic vibration was proposed. Second, the mathematical model of the maximum thickness of undeformed chips under ultrasonic vibration of the spherical grinding head was established. Results showed that ultrasonic vibration can reduce the maximum thickness of undeformed chips and increase the range of ductile and bone meal removals, revealing the mechanism of reducing grinding force. Further, the dynamic grinding behavior of diferent layers of abrasive particles under diferent instantaneous interaction states was studied. Finally, a prediction model of micro-grinding force was established in accordance with the relationship between grinding force and cutting depth, revealing the mechanism of micro-grinding force transfer under ultrasonic vibration. The theoretical model’s average deviations are 10.37% in x-axis direction, 6.85% in y-axis direction, and 7.81% in z-axis direction compared with the experimental results. This study provides theoretical guidance and technical support for clinical bone micro-grinding.
基金The National Natural Science Foundation of China under contract No.91528303the National Science and Technology Major Project under contract No.2016ZX05026-004the CNOOC Basic Geology and Exploration Strategy of Natural Gas in the South China Sea under contract No.2021-KT-YXKY-05。
文摘This study involved outcrop,drilling,seismic,gravity,and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea(PSCS)and establish its evolution model.The results indicate that a series of arc-shaped ophiolite belts and calcalkaline magmatic rocks are developed in northern Borneo,both of which have the characteristics of gradually changing younger from west to east,and are direct signs of subduction and collision of PSCS.At the same time,the subduction of PSCS led to the formation of three accretion zones from the south to the north in Borneo,the Kuching belt,Sibu belt,and Miri belt.The sedimentary formation of northern Borneo is characterized by a three-layer structure,with the oceanic basement at the bottom,overlying the deep-sea flysch deposits of the Rajang–Crocker group,and the molasse sedimentary sequence that is dominated by river-delta and shallow marine facies at the top,recording the whole subduction–collision–orogeny process of PSCS.Further,seismic reflection and tomography also confirmed the subduction and collision of PSCS.Based on the geological records of the subduction and collision of PSCS,combined with the comprehensive analysis of segmented expansion and key tectonic events in the South China Sea,we establish the“gradual”subduction-collision evolution model of PSCS.During the late Eocene to middle Miocene,the Zengmu,Nansha,and Liyue–Palawan blocks were separated by West Baram Line and Balabac Fault,which collided with the Borneo block and Kagayan Ridge successively from the west to the east,forming several foreland basin systems,and PSCS subducted and closed from the west to the east.The subduction and extinction of PSCS controlled the oil and gas distribution pattern of southern South China Sea(SSCS)mainly in three aspects.First,the“gradual”closure process of PSCS led to the continuous development of many large deltas in SSCS.Second,the deltas formed during the subduction–collision of PSCS controlled the development of source rocks in the basins of SSCS.Macroscopically,the distribution and scale of deltas controlled the distribution and scale of source rocks,forming two types of source rocks,namely,coal measures and terrestrial marine facies.Microscopically,the difference of terrestrial higher plants carried by the delta controlled the proportion of macerals of source rocks.Third,the difference of source rocks mainly controlled the distribution pattern of oil and gas in SSCS.Meanwhile,the difference in the scale of source rocks mainly controlled the difference in the amount of oil and gas discoveries,resulting in a huge amount of oil and gas discoveries in the basin of SSCS.Meanwhile,the difference of macerals of source rocks mainly controlled the difference of oil and gas generation,forming the oil and gas distribution pattern of“nearshore oil and far-shore gas”.
基金supported by the National Key R&D Pro-gram of China(No.2020YFD0900203)the China Agricul-ture Research System of MOF and MARAthe K.C.Wong Magna Fund in Ningbo University。
文摘Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus in response to short-term low salinity stress,the experiments of gradually decline and recovery as well as abrupt decline in salinity were carried out.The results showed that P.trituberculatus could survive in a certain low salinity range in the short term,and salinity 12 was the lowest tolerable salinity under the present experimental conditions.The change of the hemolymph osmotic pressure displayed significant positive correlations with water salinity,and the pressure was always higher than seawater osmotic pressure.Short-term low salinity stress changed the structure and morphology of gill tissue.The expansion of gill filament ends and epithelial cell shedding were conducive to osmotic adjustment.The activities of key ion transport enzymes such as Na^(+)-K^(+)-ATPase,carbonic anhydrase and V-ATPase also changed with the osmotic regulation,while Na^(+)-K^(+)-ATPase played a dominant role.In summary,as an osmotic adjustment species,P.trituberculatus rapidly adapt to the short-term low-salinity environment by osmotic adjustment in vivo,but salinity below salinity 12 is not conducive to its survival.Our result enriched the theoretical mechanism of osmotic regulation of P.trituberculatus,providing reference for the development of aquaculture technology of P.trituberculatus.
文摘Introduction: Gastroschisis is one of the neonatal pathologies with bad prognosis in developing countries due to a lack of equipment. We aim to report one way of managing this malformation that could be practised everywhere, constituting an alternative approach to surgery in poor areas. Patients and Methods: This observational and descriptive study included newborn babies with gastroschisis who underwent gradual bedside reduction at the Paediatric Surgery Department of the Yaounde Central Hospital. Results: Our cohort was constituted by 32 newborn babies with a mean age of 18.12 hours on admission. The Lefort type 2 was the most frequent in 81.25% of cases. The mean time for oral feeding after complete reduction was 17.4 days and the duration of hospital stay was 24.91 days. Survival rates were at 40.63%, with a residual hernia after healing in 38.46% of cases. Conclusion: Despite the high rate of mortality, gradual reduction of gastroschisis at the bedside seems to be an opportunity for resource constrained areas and can be an alternative solution to surgery.
基金Supported by International Science and Technology Cooperation Project of China(2012DFA31120)Special Fund for Agro-scientific Research in the Public Interest(201303094)National Key Technology Research and Development Program(2012BAD14B15)~~
文摘[Objective] The large-scale single-column fattening pig house with fermen- tation bed could hold 1 500 heads of fattening pigs. Since the number of pigs in piggery is too large, the management is difficult. The behavior of feeding, drinking, movement, sleeping, fighting of pigs is difficult to handle. The pigs cannot be man- aged well, resulting in the enhanced weakness of piglets, enhanced illness of weak pigs and missing treatment of ill pigs. The management for the pig populations is not satisfactory, and thus, it is needed to improve timely. [Method] The barriers for the fattening pigs in the large-scale pig house with fermentation bed were designed. The single management for single fattening pig was proposed. The large-scale fat- tening pig house was divided into 8 regions. Among them, 4 regions were located in both sides of the fermentation bed. Their main function was to separate ill, weak, small and bad pigs. In addition, the main column was divided into 4 gradual barri- ers. They were used to separate different-size fattening pigs. In view of manage- ment, the different-type pigs were managed dividedly with the gradual barriers. The equally-sized pigs were concentrated into one column. The ill, weak, small and bad pigs were isolated into barriers. Thus, the dynamic management was adopted. Until the fattening pigs grew up to 75 kg and their health was stable, the barriers among the columns were canceled to mix the pigs again and guarantee the pigs more gymnastic space. [Result] This design would improve the disease resistance of ill pigs, health status of weak pigs and management level of pig populations. This study would also provide a basis for the healthy running of large-scale fattening pig house with fermentation bed. [Conclusion] The pig-raising model with fermentation bed would improve the environment of pig house and the welfare of pigs. In addi- tion, the performance of pigs and quality of pork were also improved. The fermen- tation bed had an obvious advantage in safety and economics, and it had a broad application prospect.
文摘The purpose of this study was to find out the spatial-temporal rules and driving force of cultivated land quality in Henan Province in the last ten years. Agricultural land grading factor evaluation was used to evaluate the cultivated land quality of 2002 and 2012 in Henan Province, and to research the change laws. Method of correlation coefficient was employed to select the driving forces affecting cultivated land quality evolution. The results indicated that the cultivated land quality in Henan Province increased slightly in the last ten years in general, and in spatial there were unchanged regions, increased regions and decreased regions. The cultivated land quality in spatial presented the trend of good becoming better, bad becoming worse, which should be highly valued in cultivated land quality protection and management. Land development and consolidation projects had significant contributions to increasing the cultivated land quality. Driving forces between the sudden change regions and gradual change regions were significantly different. The paper concluded that the research on the spatial-temporal evolution and driving force of cultivated land quality based on cultivated land quality evolution had important academic significance and practical value.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 50305005)
文摘Aimed at the problem that the traditional ART-2 neural network can not recognize a gradually changing course, an eternal term memory (ETM) vector is introduced into ART-2 to simulate the function of human brain, i.e. the deep remembrance for the initial impression.. The eternal term memory vector is determined only by the initial vector that establishes category neuron node and is used to keep the remembrance for this vector for ever. Two times of vigilance algorithm are put forward, and the posterior input vector must first pass the first vigilance of this eternal term memory vector, only succeeded has it the qualification to begin the second vigilance of long term memory vector. The long term memory vector can be revised only when both of the vigilances are passed. Results of recognition examples show that the improved ART-2 overcomes the defect of traditional ART-2 and can recognize a gradually changing course effectively.
基金supported in part by National Natural Science Foundation of China (61077052/61125504)Science and Technology Commission of Shanghai Municipality (11530700400)
文摘In this paper, we propose a siliconbased highspeed plasmonic modulator. The modulator has a double-layer structure with a 16 The long metaldielectricmetal plasmonic waveguide at the upper layer and two silicon singlemode waveguides at the bottom layer. The upperlayer plasmonic waveguide acts as a phase shifter and has a dielectric slot that is 30 nm wide. Two taper structures that have gradually varied widths are introduced at the bottom layer to convert the photonic mode into plasmonicslot mode with improved coupling efficiency. For a modulator with two 1 mlong mode couplers, simulation shows that there is an insertion loss of less than 11 dB and a halfwave voltage of 3.65 V. The modulation bandwidth of the proposed modulator can be more than 100 GHz without the carrier effect being a limiting factor in silicon. The fabrication process is also discussed, and the proposed design is shown to be feasible with a hybrid of CMOS and polymer technology.
文摘The China Classification Society has established its office at Perth in Australia with 1680 ships and total tonnages of 136 million. It plans to organize other offices in Spanish, west coast of United State and North Europe. It had already created offlees in Hamburg, Stuttgrt Osaka, Tokyo, Hongkong, New York, Rotterdam, Port Said, London and Singapore on the other day.