Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the d...Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the development schemes of the harbor. Verification of spring and neap tidal currents and sediment in the winter and summer of 2006 shows that the calculated values of tidal stages as well as flow velocities, flow directions and sediment concentration of 15 synchronous vertical lines are in good agreement with the measured data. Also, deposition and erosion of the sea area in front of Caofeidian ore terminal induced by suspended load under tidal currents and waves are verified; it shows that the calculated values of depth of deposition and erosion as well as their distribution are close to the measured data. Furthermore, effects of reclamation scheme of island in front of the land behind Caofeidian harbor on the hydrodynamic environment are studied, including changes of flow velocities in the deep channels at the south side of Caofeidian foreland and Laolonggou and in various harbor basins, as well as changes of deposition and erosion of seabed induced by the project.展开更多
The Huanghe and Yongding rivers were formed before the early and middle Pliocene epoch. Then they became interior rivers because of the appearance of interior fault lake basins at the end of the Pliocene epoch. The in...The Huanghe and Yongding rivers were formed before the early and middle Pliocene epoch. Then they became interior rivers because of the appearance of interior fault lake basins at the end of the Pliocene epoch. The interior flow period continued until the end of the early Pleistocene or the middle pf the Middle Pleistocene, and then they changed into the exterior rivers again till today.展开更多
Black rockfish(Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process...Black rockfish(Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season(October 2011–November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.展开更多
Korla fragrant pear(KFP)with special fragrance is a unique cultivar in Xinjiang,China.In order to explore the biosynthesis molecular mechanism of chlorogenic acid(CGA)in KFP,the samples at different development period...Korla fragrant pear(KFP)with special fragrance is a unique cultivar in Xinjiang,China.In order to explore the biosynthesis molecular mechanism of chlorogenic acid(CGA)in KFP,the samples at different development periods were collected for transcriptome analysis.High performance liquid chromatography analysis showed that CGA contents of KFP at 88,118 and 163 days after full bloom were(20.96±1.84),(12.01±0.91)and(7.16±0.41)mg/100 g,respectively,and decreased with the fruit development.Pears from these typical 3 periods were selected for de novo transcriptome assemble and 68059 unigenes were assembled from 444037960 clean reads.One‘phenylpropanoid biosynthesis’pathway including 57 unigenes,11 PALs,1 PTAL,64CLs,9 C4Hs,25 HCTs and 5 C3’Hs related to CGA biosynthesis was determined.It was found that the expression levels of 11 differentially expressed genes including 1 PAL,2 C4Hs,34CLs and 5 HCTs were consistent with the change of CGA content.Quantitative polymerase chain reaction analysis further showed that 8 unigenes involved in CGA biosynthesis were consistent with the RNA-seq data.These findings will provide a comprehensive understanding and valuable information on the genetic engineering and molecular breeding in KFP.展开更多
Shale gas is a practical resource with great potential that could be economically explored and developed in the near future. It has been commercially developed in North America and other places. Featuring a vast distr...Shale gas is a practical resource with great potential that could be economically explored and developed in the near future. It has been commercially developed in North America and other places. Featuring a vast distribution, a low abundance,unfavorable reservoir conditions, ultra-low permeability and a fast production decline, shale gas is more difficult to develop than conventional natural gas, as it needs advanced drilling and completion technology to develop. During the early stage of shale gas exploration and development, the United States offered enterprises necessary incentives such as tax reductions and exemptions and subsidies to achieve sustainable shale gas development and encourage technological progresses. By comparing the state of China's shale gas development with that of the US' in terms of geological conditions, production technology,market price, tax relief, subsidy periods and amount, this paper intends to put forward related suggestions for the effective development of shale gas according to the current status of development.展开更多
Genetic Programming (GP) is an important approach to deal with complex problem analysis and modeling, and has been applied in a wide range of areas. The development of GP involves various aspects, including design of ...Genetic Programming (GP) is an important approach to deal with complex problem analysis and modeling, and has been applied in a wide range of areas. The development of GP involves various aspects, including design of genetic operators, evolutionary controls and implementations of heuristic strategy, evaluations and other mechanisms. When designing genetic operators, it is necessary to consider the possible limitations of encoding methods of individuals. And when selecting evolutionary control strategies, it is also necessary to balance search efficiency and diversity based on representation characteristics as well as the problem itself. More importantly, all of these matters, among others, have to be implemented through tedious coding work. Therefore, GP development is both complex and time-consuming. To overcome some of these difficulties that hinder the enhancement of GP development efficiency, we explore the feasibility of mutual assistance among GP variants, and then propose a rapid GP prototyping development method based on πGrammatical Evolution (πGE). It is demonstrated through regression analysis experiments that not only is this method beneficial for the GP developers to get rid of some tedious implementations, but also enables them to concentrate on the essence of the referred problem, such as individual representation, decoding means and evaluation. Additionally, it provides new insights into the roles of individual delineations in phenotypes and semantic research of individuals.展开更多
Under the background of digital transformation,the reform of the higher vocational mathematics curriculum faces urgent challenges and opportunities.This article explores the impact of digital transformation on the ref...Under the background of digital transformation,the reform of the higher vocational mathematics curriculum faces urgent challenges and opportunities.This article explores the impact of digital transformation on the reform of higher vocational mathematics curriculum and emphasizes the importance of improving teaching methods centered on learners.The article proposes specific reform methods and discusses the practical application of digital technology in the reform process.By combining digital technology with specific reform methods,further conducting innovative practice research,and continuously exploring the path of reform,we can effectively improve the quality of higher vocational mathematics classroom teaching and provide strong support for the cultivation of comprehensive qualities and employment abilities.展开更多
The rural commodity economy in the Edo period developed by leaps and bounds under the influence of institution,policy,technology and other factors. From the mid 17 th century,the specific area of cash crops gradually ...The rural commodity economy in the Edo period developed by leaps and bounds under the influence of institution,policy,technology and other factors. From the mid 17 th century,the specific area of cash crops gradually took shape in Japan and the largescale cultivation of cash crops greatly promoted the development of rural handicrafts,thereby creating the conditions for the initiation of the capitalist relations of production. The development of rural commodity economy not only changed the traditional mode of operation and production of Japanese farmers,but also accelerated the class differentiation,shook and disintegrated the economic foundation and class basis of Bakuhan society,and created the preconditions for the later Meiji Restoration.展开更多
This article discusses the important role of mathematical and physical sciences in, and their influence on, the development of natural science and modern technology, as well as social science and the humanities. On th...This article discusses the important role of mathematical and physical sciences in, and their influence on, the development of natural science and modern technology, as well as social science and the humanities. On the basis of the present situation in China, it calls for accelerating the development of the mathematical and physical sciences.展开更多
1.Products of the basic rawmaterials industry Products of the basic raw materialsindustry should improve product quality,make great efforts to realize diversification,serialization and specialization in productvariety...1.Products of the basic rawmaterials industry Products of the basic raw materialsindustry should improve product quality,make great efforts to realize diversification,serialization and specialization in productvariety,develop new varieties,and expandproduction so as to adapt to the demands forthe development of the food industry. Cereals:Develop high quality riceand wheat flour on a grade and class basis;develop special rice and wheat flour suitablefor the needs of processing various kinds offood;actively utilize coarse cereals such ascorn to open up various kinds of展开更多
Modern biotechnology booms in the molecular life science. It brings about a promising future for improving human health, foodstuff, environment and energy and is of significance to improve traditional agriculture, dru...Modern biotechnology booms in the molecular life science. It brings about a promising future for improving human health, foodstuff, environment and energy and is of significance to improve traditional agriculture, druamakins and other展开更多
This paper presents a methodology driven by database constraints for designing and developing(database)software applications.Much needed and with excellent results,this paradigm guarantees the highest possible quality...This paper presents a methodology driven by database constraints for designing and developing(database)software applications.Much needed and with excellent results,this paradigm guarantees the highest possible quality of the managed data.The proposed methodology is illustrated with an easy to understand,yet complex medium-sized genealogy software application driven by more than 200 database constraints,which fully meets such expectations.展开更多
[Objective] This study was conducted to investigate effects of different intercropping modes on growth, yields and economic benefit of cassava and peanut in symbiotic period. [Method] With sole cropping of cassava (M...[Objective] This study was conducted to investigate effects of different intercropping modes on growth, yields and economic benefit of cassava and peanut in symbiotic period. [Method] With sole cropping of cassava (M1) and sole cropping of peanut (M2) as control groups, effects of intercropping of cassava with 1 row, 2 rows and 3 rows of peanut (M3, M4 and M5)on crop growth, yields and economic benefit were studied. [Result] Intercropping affected both growth and yields of cassava and peanut. Growth competition existed between cassava and peanut, and plant heights of cassava and peanut changed similarly. In late stages of intercropping, treatments M1, M2 and M5 showed higher plant heights under no nitrogen application, while treatment M3 and M4 exhibited higher plant heights under nitrogen application; intercropping improved leaf temperature, but no obvious law could be observed among different intercropping treatments; and intercropping improved total dry matter amount, which was the highest in M5 in root expanding stage and on the 30th day of the expanding stage, and the highest in M4 on the 60th day of the expanding stage. Intercropping reduced the yield of single plant, but improved the economic benefit of red upland soil; and under no nitrogen application and nitrogen application, cassava yields decreased by 25.35% and 14.55%, respectively, peanut yields decreased by 28.76% and 52.60%, respectively, while economic benefit increased by 72.90% and 56.82%, respectively. [Conclusion] Compared with sole cropping, interplanting cassava with 1 row, 2 rows or 3 rows of peanut could all improve economic benefit, and the economic benefit increased with number of rows of interplanted peanut increasing.展开更多
From the process of sedimentation the mathematical relationships among deposition Volume and powder properties as well as sedimentation parameters were deduced. Based on the formula a mathematical model was set up and...From the process of sedimentation the mathematical relationships among deposition Volume and powder properties as well as sedimentation parameters were deduced. Based on the formula a mathematical model was set up and simulated through the computer. At last the validity of mathematical model was supported by the representative experiment on Ti-Mo system FGM prepared by co-sedimentation.展开更多
Based on the electric double layer (EDL) theory and the momentum equation governing the electroosmosis flow, this paper presents an analytical solution to the peri- odical electroosmosis with a parallel straight cap...Based on the electric double layer (EDL) theory and the momentum equation governing the electroosmosis flow, this paper presents an analytical solution to the peri- odical electroosmosis with a parallel straight capillary bundle model of reservoir rocks to reveal the microscopic mechanism of the electroosmotic flows in rocks. The theory shows that both the frequency dispersion characteristics of the ma^roscQpic electroosmotic Darcy velocity in unsealed rocks and the electroosmotic pressure coefficient in sealed rocks de- pend on the porosity and electrochemical properties of reservoir rocks. The mathematical simulation indicates that the distribution of the periodical electroosmotic velocity is wave- like in the rock pore. The greater the porosity is, the greater electroosmotic the Darcy velocity and the smaller electroosmotic pressure coefficient are generated. The module values of the electroosmotic Darcy velocity and the electroosmotic pressure coefficient increase with the decreasing solution concentration or the increasing cation exchange ca- pacity without affecting the phase of the electroosmotic Darcy velocity.展开更多
In order to develop high strength Mg-Gd-Y-Zn alloys,key experiments coupled with CALPHAD(CALculation of PHAse Diagrams)calculations were carried out in the current work to provide critical understanding of this import...In order to develop high strength Mg-Gd-Y-Zn alloys,key experiments coupled with CALPHAD(CALculation of PHAse Diagrams)calculations were carried out in the current work to provide critical understanding of this important alloy system.Three Mg-10 Gd-xY-yZn(x=4 or 5,y=3 or 5,wt.%) were mapped on Mg-Gd-Y-Zn phase diagrams for phase equilibria and microstructure investigation.Electron microscopy was performed for phase identification and phase fraction determination in as-cast and solution treated conditions.In all three alloys,the major phases were Mg-matrix and long period stacking order(LPSO) 14 H phase.With ST at 400 and 500℃,the phase fraction of LPSO 14 H increased,particularly the fine lamellar morphology in the Mg matrix.The as-cast and 400℃ Mg10 Gd5 Y3 Zn samples had Mg(Gd,Y) present.At 500℃,Mg(Gd,Y) is not stable and transforms into LPSO 14 H.The Mg 10 Gd5 Y5 Zn alloy included the WPhase,which showed a reduction in phase fraction with solution treatment.These experimental results were used to validate and improve the thermodynamic database of the Mg-Gd-Y-Zn system.Thermodynamic calculations using the improved database can well describe the available experimental results and make accurate predictions to guide the development of promising high-strength Mg-Gd-Y-Zn alloys.展开更多
Dongnong50 was overexpressing TaDREB3, a stress-tolerance gene, and transgenic progenies with TaDREB3 showing stable heredity characters were obtained in this study. The seeds of T4 generation were sowed on saline lan...Dongnong50 was overexpressing TaDREB3, a stress-tolerance gene, and transgenic progenies with TaDREB3 showing stable heredity characters were obtained in this study. The seeds of T4 generation were sowed on saline land of which salt concentration was 0.19% and pH was 8.43, and agronomic traits including growth period, plant height, numbers of main nodes, branching numbers, pods per plant, numbers of seeds per plant, and weight of 100-seed were collected and comparing to control plants Dongnong50 were made. The impacts of TaDREB3 gene on agronomic traits of soybeans under high concentration of salt were discussed. The results showed that the growth period was not altered in transgenic line with TaDREB3 under high concentration of saline and alkali, the extremely significant or significant increase in the numbers of main nodes, pods per plant and in branching numbers and other agronomic traits in transgenic lines in comparing with non-transgenic lines was an indicator of their resistance to saline-alkali stress展开更多
Avian embryos,which develop within eggs,exhibit remarkable tolerance to extremely low temperatures.Despite being a common trait among all birds,the mechanisms underlying this cold tolerance in avian embryos remain lar...Avian embryos,which develop within eggs,exhibit remarkable tolerance to extremely low temperatures.Despite being a common trait among all birds,the mechanisms underlying this cold tolerance in avian embryos remain largely unknown.To gain a better understanding of this phenomenon and the coping mechanisms involved,we reviewed the literature on severe cold tolerance in embryos of both wild and domestic birds.We found that embryos of different bird orders exhibit tolerance to severe cold during their development.In response to cold stress,embryos slow down their heartbeat rates and metabolism.In severe cold temperatures,embryos can suspend these processes,entering a torpid-like state of cardiac arrest.To compensate for these developmental delays,embryos extend their regular incubation periods.Depending on their embryonic age,embryos of all bird species can tolerate acute severe cold regimes;only a few tolerate chronic severe cold regimes.We also discussed various extrinsic and intrinsic factors that affect the tolerance of bird embryos to low temperatures before and after incubation.Cold tolerance appears to be a heritable trait shared by wild and domestic embryos of all bird classes,regardless of egg size or development(altricial/precocial).Driven by environmental variability,cold tolerance in avian embryos is an optimal physiological and ecological strategy to mitigate the adverse effects of cold conditions on their development in response to fluctuating environmental temperatures.展开更多
Oil field waterflooding is a complex man-controlled systematic behavior, and the related evaluation methods vary greatly. This paper put forward a fuzzy comprehensive method of evaluating controlled development level ...Oil field waterflooding is a complex man-controlled systematic behavior, and the related evaluation methods vary greatly. This paper put forward a fuzzy comprehensive method of evaluating controlled development level by analysis of the macroscopic evaluation to oil field waterflooding effect with combination of original reservoir geological state. This fuzzy evaluation technique bears unique advantages because there is little difference among evaluation indexes which represent the dynamic and static state of regional neighborhood of development units (blocks, Production Company<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> etc.). Not only the mathematical method for evaluating oil field waterflooding effect is set up, but also the method is applied in three blocks of D oil field. The calculated results show the effectiveness and practicability of the method.</span></span></span>展开更多
2020 is the final year of China’s 13th Five-Year Plan period and an intersection between the“two centennial goals.”It is also a vital year for drafting the 14th Five-year Plan and embarking on a new journey of soci...2020 is the final year of China’s 13th Five-Year Plan period and an intersection between the“two centennial goals.”It is also a vital year for drafting the 14th Five-year Plan and embarking on a new journey of socialist modernization.What socio-economic progress has China achieved during the 13th Five-Year Plan period and what are the opportunities,challenges and countermeasures for the 14th Five-Year Plan period?In May 2020,the China Economist conducted a questionnaire survey among economists.Results suggest that during the 13th Five-Year Plan period,China has achieved remarkable progress in the following areas:significant socio-economic development,deepening industry-ICT integration,and rapid growth of new economy;mass entrepreneurship and mass innovation,and enhanced R&D capabilities for cutting-edge technologies;green production and the abatement of air and water pollution;and poverty reduction.In the 14th Five-Year Plan period,opportunities co-exist with challenges for China’s socio-economic development,which brims with resiliency.Surveyed economists felt sanguine about China’s development outlook.Based on the results,surveyed economists believed that the Chinese government should focus on the following priorities during the 14th Five-Year Plan period:expediting industrial transition,strengthening the real economy,and exploring domestic consumption potentials;ramping up research in fundamental science,and accelerating the research of critical technologies;increasing equal access to basic public services;and promoting green development in all respects,including green consumption,production,distribution,innovation,and finance.展开更多
基金The project is financially supported by the National key Basic Research and Development Program(973 Program,No.2003CB415206)the National Natural Science Foundation of China (Grant No.50379027)
文摘Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the development schemes of the harbor. Verification of spring and neap tidal currents and sediment in the winter and summer of 2006 shows that the calculated values of tidal stages as well as flow velocities, flow directions and sediment concentration of 15 synchronous vertical lines are in good agreement with the measured data. Also, deposition and erosion of the sea area in front of Caofeidian ore terminal induced by suspended load under tidal currents and waves are verified; it shows that the calculated values of depth of deposition and erosion as well as their distribution are close to the measured data. Furthermore, effects of reclamation scheme of island in front of the land behind Caofeidian harbor on the hydrodynamic environment are studied, including changes of flow velocities in the deep channels at the south side of Caofeidian foreland and Laolonggou and in various harbor basins, as well as changes of deposition and erosion of seabed induced by the project.
文摘The Huanghe and Yongding rivers were formed before the early and middle Pliocene epoch. Then they became interior rivers because of the appearance of interior fault lake basins at the end of the Pliocene epoch. The interior flow period continued until the end of the early Pleistocene or the middle pf the Middle Pleistocene, and then they changed into the exterior rivers again till today.
基金supported financially by Grand Innovating Program of Agriculture Applying Technique in Shandong Province (No. 2008-109)Modern Agricultural Industry Technology System in Shandong Province and the Science and Technology Development Program of Yantai (No. 2013 ZH088)
文摘Black rockfish(Sebastes schlegeli) is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season(October 2011–November 2012) with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.
基金supported by Major scientific and technological projects of XPCC(2020KWZ-012)。
文摘Korla fragrant pear(KFP)with special fragrance is a unique cultivar in Xinjiang,China.In order to explore the biosynthesis molecular mechanism of chlorogenic acid(CGA)in KFP,the samples at different development periods were collected for transcriptome analysis.High performance liquid chromatography analysis showed that CGA contents of KFP at 88,118 and 163 days after full bloom were(20.96±1.84),(12.01±0.91)and(7.16±0.41)mg/100 g,respectively,and decreased with the fruit development.Pears from these typical 3 periods were selected for de novo transcriptome assemble and 68059 unigenes were assembled from 444037960 clean reads.One‘phenylpropanoid biosynthesis’pathway including 57 unigenes,11 PALs,1 PTAL,64CLs,9 C4Hs,25 HCTs and 5 C3’Hs related to CGA biosynthesis was determined.It was found that the expression levels of 11 differentially expressed genes including 1 PAL,2 C4Hs,34CLs and 5 HCTs were consistent with the change of CGA content.Quantitative polymerase chain reaction analysis further showed that 8 unigenes involved in CGA biosynthesis were consistent with the RNA-seq data.These findings will provide a comprehensive understanding and valuable information on the genetic engineering and molecular breeding in KFP.
文摘Shale gas is a practical resource with great potential that could be economically explored and developed in the near future. It has been commercially developed in North America and other places. Featuring a vast distribution, a low abundance,unfavorable reservoir conditions, ultra-low permeability and a fast production decline, shale gas is more difficult to develop than conventional natural gas, as it needs advanced drilling and completion technology to develop. During the early stage of shale gas exploration and development, the United States offered enterprises necessary incentives such as tax reductions and exemptions and subsidies to achieve sustainable shale gas development and encourage technological progresses. By comparing the state of China's shale gas development with that of the US' in terms of geological conditions, production technology,market price, tax relief, subsidy periods and amount, this paper intends to put forward related suggestions for the effective development of shale gas according to the current status of development.
文摘Genetic Programming (GP) is an important approach to deal with complex problem analysis and modeling, and has been applied in a wide range of areas. The development of GP involves various aspects, including design of genetic operators, evolutionary controls and implementations of heuristic strategy, evaluations and other mechanisms. When designing genetic operators, it is necessary to consider the possible limitations of encoding methods of individuals. And when selecting evolutionary control strategies, it is also necessary to balance search efficiency and diversity based on representation characteristics as well as the problem itself. More importantly, all of these matters, among others, have to be implemented through tedious coding work. Therefore, GP development is both complex and time-consuming. To overcome some of these difficulties that hinder the enhancement of GP development efficiency, we explore the feasibility of mutual assistance among GP variants, and then propose a rapid GP prototyping development method based on πGrammatical Evolution (πGE). It is demonstrated through regression analysis experiments that not only is this method beneficial for the GP developers to get rid of some tedious implementations, but also enables them to concentrate on the essence of the referred problem, such as individual representation, decoding means and evaluation. Additionally, it provides new insights into the roles of individual delineations in phenotypes and semantic research of individuals.
基金Classroom Revolution Special Project for Teaching Construction and Reform at Jiangsu Vocational College of Electronics and Information(JX-G-2023-04)。
文摘Under the background of digital transformation,the reform of the higher vocational mathematics curriculum faces urgent challenges and opportunities.This article explores the impact of digital transformation on the reform of higher vocational mathematics curriculum and emphasizes the importance of improving teaching methods centered on learners.The article proposes specific reform methods and discusses the practical application of digital technology in the reform process.By combining digital technology with specific reform methods,further conducting innovative practice research,and continuously exploring the path of reform,we can effectively improve the quality of higher vocational mathematics classroom teaching and provide strong support for the cultivation of comprehensive qualities and employment abilities.
基金Supported by Project of Introducing International Advanced Forestry Science and Technology(2014-4-45)
文摘The rural commodity economy in the Edo period developed by leaps and bounds under the influence of institution,policy,technology and other factors. From the mid 17 th century,the specific area of cash crops gradually took shape in Japan and the largescale cultivation of cash crops greatly promoted the development of rural handicrafts,thereby creating the conditions for the initiation of the capitalist relations of production. The development of rural commodity economy not only changed the traditional mode of operation and production of Japanese farmers,but also accelerated the class differentiation,shook and disintegrated the economic foundation and class basis of Bakuhan society,and created the preconditions for the later Meiji Restoration.
文摘This article discusses the important role of mathematical and physical sciences in, and their influence on, the development of natural science and modern technology, as well as social science and the humanities. On the basis of the present situation in China, it calls for accelerating the development of the mathematical and physical sciences.
文摘1.Products of the basic rawmaterials industry Products of the basic raw materialsindustry should improve product quality,make great efforts to realize diversification,serialization and specialization in productvariety,develop new varieties,and expandproduction so as to adapt to the demands forthe development of the food industry. Cereals:Develop high quality riceand wheat flour on a grade and class basis;develop special rice and wheat flour suitablefor the needs of processing various kinds offood;actively utilize coarse cereals such ascorn to open up various kinds of
文摘Modern biotechnology booms in the molecular life science. It brings about a promising future for improving human health, foodstuff, environment and energy and is of significance to improve traditional agriculture, druamakins and other
文摘This paper presents a methodology driven by database constraints for designing and developing(database)software applications.Much needed and with excellent results,this paradigm guarantees the highest possible quality of the managed data.The proposed methodology is illustrated with an easy to understand,yet complex medium-sized genealogy software application driven by more than 200 database constraints,which fully meets such expectations.
基金Supported by Youth Innovation Fund of Jiangxi Sciences of Agricultural Sciences(2013CQN010)Earmarked Fund for China Agriculture Research System(CARS-12-jxyzq)~~
文摘[Objective] This study was conducted to investigate effects of different intercropping modes on growth, yields and economic benefit of cassava and peanut in symbiotic period. [Method] With sole cropping of cassava (M1) and sole cropping of peanut (M2) as control groups, effects of intercropping of cassava with 1 row, 2 rows and 3 rows of peanut (M3, M4 and M5)on crop growth, yields and economic benefit were studied. [Result] Intercropping affected both growth and yields of cassava and peanut. Growth competition existed between cassava and peanut, and plant heights of cassava and peanut changed similarly. In late stages of intercropping, treatments M1, M2 and M5 showed higher plant heights under no nitrogen application, while treatment M3 and M4 exhibited higher plant heights under nitrogen application; intercropping improved leaf temperature, but no obvious law could be observed among different intercropping treatments; and intercropping improved total dry matter amount, which was the highest in M5 in root expanding stage and on the 30th day of the expanding stage, and the highest in M4 on the 60th day of the expanding stage. Intercropping reduced the yield of single plant, but improved the economic benefit of red upland soil; and under no nitrogen application and nitrogen application, cassava yields decreased by 25.35% and 14.55%, respectively, peanut yields decreased by 28.76% and 52.60%, respectively, while economic benefit increased by 72.90% and 56.82%, respectively. [Conclusion] Compared with sole cropping, interplanting cassava with 1 row, 2 rows or 3 rows of peanut could all improve economic benefit, and the economic benefit increased with number of rows of interplanted peanut increasing.
文摘From the process of sedimentation the mathematical relationships among deposition Volume and powder properties as well as sedimentation parameters were deduced. Based on the formula a mathematical model was set up and simulated through the computer. At last the validity of mathematical model was supported by the representative experiment on Ti-Mo system FGM prepared by co-sedimentation.
基金supported by the National Natural Science Foundation of China (No. 41174101)the Natural Science Foundation of Shandong Province of China (No. ZR2011DM002)
文摘Based on the electric double layer (EDL) theory and the momentum equation governing the electroosmosis flow, this paper presents an analytical solution to the peri- odical electroosmosis with a parallel straight capillary bundle model of reservoir rocks to reveal the microscopic mechanism of the electroosmotic flows in rocks. The theory shows that both the frequency dispersion characteristics of the ma^roscQpic electroosmotic Darcy velocity in unsealed rocks and the electroosmotic pressure coefficient in sealed rocks de- pend on the porosity and electrochemical properties of reservoir rocks. The mathematical simulation indicates that the distribution of the periodical electroosmotic velocity is wave- like in the rock pore. The greater the porosity is, the greater electroosmotic the Darcy velocity and the smaller electroosmotic pressure coefficient are generated. The module values of the electroosmotic Darcy velocity and the electroosmotic pressure coefficient increase with the decreasing solution concentration or the increasing cation exchange ca- pacity without affecting the phase of the electroosmotic Darcy velocity.
基金partially funded by the Army Research Laboratory (ARL) and Terves LLCsupported by the Army Contracting Command - Adelphi, MD under Contract No W911QX-18-P-0038
文摘In order to develop high strength Mg-Gd-Y-Zn alloys,key experiments coupled with CALPHAD(CALculation of PHAse Diagrams)calculations were carried out in the current work to provide critical understanding of this important alloy system.Three Mg-10 Gd-xY-yZn(x=4 or 5,y=3 or 5,wt.%) were mapped on Mg-Gd-Y-Zn phase diagrams for phase equilibria and microstructure investigation.Electron microscopy was performed for phase identification and phase fraction determination in as-cast and solution treated conditions.In all three alloys,the major phases were Mg-matrix and long period stacking order(LPSO) 14 H phase.With ST at 400 and 500℃,the phase fraction of LPSO 14 H increased,particularly the fine lamellar morphology in the Mg matrix.The as-cast and 400℃ Mg10 Gd5 Y3 Zn samples had Mg(Gd,Y) present.At 500℃,Mg(Gd,Y) is not stable and transforms into LPSO 14 H.The Mg 10 Gd5 Y5 Zn alloy included the WPhase,which showed a reduction in phase fraction with solution treatment.These experimental results were used to validate and improve the thermodynamic database of the Mg-Gd-Y-Zn system.Thermodynamic calculations using the improved database can well describe the available experimental results and make accurate predictions to guide the development of promising high-strength Mg-Gd-Y-Zn alloys.
基金Supported by Project of Education Department of Heilongjiang Province (11551048)
文摘Dongnong50 was overexpressing TaDREB3, a stress-tolerance gene, and transgenic progenies with TaDREB3 showing stable heredity characters were obtained in this study. The seeds of T4 generation were sowed on saline land of which salt concentration was 0.19% and pH was 8.43, and agronomic traits including growth period, plant height, numbers of main nodes, branching numbers, pods per plant, numbers of seeds per plant, and weight of 100-seed were collected and comparing to control plants Dongnong50 were made. The impacts of TaDREB3 gene on agronomic traits of soybeans under high concentration of salt were discussed. The results showed that the growth period was not altered in transgenic line with TaDREB3 under high concentration of saline and alkali, the extremely significant or significant increase in the numbers of main nodes, pods per plant and in branching numbers and other agronomic traits in transgenic lines in comparing with non-transgenic lines was an indicator of their resistance to saline-alkali stress
基金supported by the National Natural Science Foundation of China(NSFC,31971413)granted to DLthe Second Tibetan Plateau Scientific Expedition and Research Program(STEP,2019QZKK0501)granted to DL。
文摘Avian embryos,which develop within eggs,exhibit remarkable tolerance to extremely low temperatures.Despite being a common trait among all birds,the mechanisms underlying this cold tolerance in avian embryos remain largely unknown.To gain a better understanding of this phenomenon and the coping mechanisms involved,we reviewed the literature on severe cold tolerance in embryos of both wild and domestic birds.We found that embryos of different bird orders exhibit tolerance to severe cold during their development.In response to cold stress,embryos slow down their heartbeat rates and metabolism.In severe cold temperatures,embryos can suspend these processes,entering a torpid-like state of cardiac arrest.To compensate for these developmental delays,embryos extend their regular incubation periods.Depending on their embryonic age,embryos of all bird species can tolerate acute severe cold regimes;only a few tolerate chronic severe cold regimes.We also discussed various extrinsic and intrinsic factors that affect the tolerance of bird embryos to low temperatures before and after incubation.Cold tolerance appears to be a heritable trait shared by wild and domestic embryos of all bird classes,regardless of egg size or development(altricial/precocial).Driven by environmental variability,cold tolerance in avian embryos is an optimal physiological and ecological strategy to mitigate the adverse effects of cold conditions on their development in response to fluctuating environmental temperatures.
文摘Oil field waterflooding is a complex man-controlled systematic behavior, and the related evaluation methods vary greatly. This paper put forward a fuzzy comprehensive method of evaluating controlled development level by analysis of the macroscopic evaluation to oil field waterflooding effect with combination of original reservoir geological state. This fuzzy evaluation technique bears unique advantages because there is little difference among evaluation indexes which represent the dynamic and static state of regional neighborhood of development units (blocks, Production Company<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> etc.). Not only the mathematical method for evaluating oil field waterflooding effect is set up, but also the method is applied in three blocks of D oil field. The calculated results show the effectiveness and practicability of the method.</span></span></span>
文摘2020 is the final year of China’s 13th Five-Year Plan period and an intersection between the“two centennial goals.”It is also a vital year for drafting the 14th Five-year Plan and embarking on a new journey of socialist modernization.What socio-economic progress has China achieved during the 13th Five-Year Plan period and what are the opportunities,challenges and countermeasures for the 14th Five-Year Plan period?In May 2020,the China Economist conducted a questionnaire survey among economists.Results suggest that during the 13th Five-Year Plan period,China has achieved remarkable progress in the following areas:significant socio-economic development,deepening industry-ICT integration,and rapid growth of new economy;mass entrepreneurship and mass innovation,and enhanced R&D capabilities for cutting-edge technologies;green production and the abatement of air and water pollution;and poverty reduction.In the 14th Five-Year Plan period,opportunities co-exist with challenges for China’s socio-economic development,which brims with resiliency.Surveyed economists felt sanguine about China’s development outlook.Based on the results,surveyed economists believed that the Chinese government should focus on the following priorities during the 14th Five-Year Plan period:expediting industrial transition,strengthening the real economy,and exploring domestic consumption potentials;ramping up research in fundamental science,and accelerating the research of critical technologies;increasing equal access to basic public services;and promoting green development in all respects,including green consumption,production,distribution,innovation,and finance.