Traditionally,universally used pelt bating technologies rely on the application of trypsin,neutral and alkaline microbial proteases but suffer from complicated operation,limited bating efficiency and unsatisfac-tory l...Traditionally,universally used pelt bating technologies rely on the application of trypsin,neutral and alkaline microbial proteases but suffer from complicated operation,limited bating efficiency and unsatisfac-tory leather performance.Therefore,devising a new pelt bating approach to achieve high bating efficiency and excellent leather performance has always been wished for by the leather industry.To pursue this goal,years of persistent research work enabled us to develop a novel approach for pelt bating by means of acidic proteases in pickling process.Initially,basic enzymatic characteristics and bating effectiveness of several typical acidic pro-teases in pelt pickling medium were investigated;then,the bating effectiveness through the quantitative charac-terization of protease activity of the optimal acidic protease was compared with that of the conventional bating enzyme.The results indicated that all of the selected acidic proteases had good salt-tolerance and exhibited optimum activity at pH 3.0–4.0.The novel pickling-bating method based on microbial origin acidic protease L80A led to an outstanding performance on pelt bating at the dosage of 150 U/mL of collagenolytic activity.The bating effectiveness of acidic protease L80A was comparable to and even better than that of trypsin BEM due to its mod-erate proteolytic ability.Moreover,the deep and even penetration of acidic protease in the pelt permitted it to produce soft,organoleptically stable and overall better quality crust leather than that of the conventional trypsin bating method.Additionally,pelt bating was performed along with the pickling process without extra inactiva-tion and washing operation,making the bating operation more efficient,economical,and environment friendly.Results had made us to conclude that this cutting-edge acidic proteases based pickling-bating method could be the first step/way forward to replace the decades-old traditional pelt bating technology.展开更多
Bating pelt with protease is an important process,which removes unwanted non-collagenous proteins from the pelt and moderately disperse hide collagen network.However,the grain surface,may be excessively hydrolyzed dur...Bating pelt with protease is an important process,which removes unwanted non-collagenous proteins from the pelt and moderately disperse hide collagen network.However,the grain surface,may be excessively hydrolyzed during bating due to the longer retention time of protease in the grain than in the middle layer caused by the low mass transfer rate of protease in pelt.Here,the effects of protease dosage,common auxiliaries and molecular weight of protease on protease transfer during bating were investigated so that we can find the key points to avoid excessive collagen damage,particularly in the grain.Observably,increasing protease dosage led to faster protease transfer and softer leather,but along with more considerable grain damage.Using penetrating agent JFC(fatty alcohol-polyoxyethylene ether)and ammonium sulfate enhanced protease transfer and simultaneously alleviated collagen damage due to the decrease in interfacial tension and electrostatic attraction between protease and pelt,respectively.Additionally,proteases with lower molecular weight transferred faster in pelt,which suggests that a potential strategy to solve the conflict between the mass transfer and the reaction of protease in pelt might be to produce/employ smaller bating proteases.展开更多
Marsupenaeusjaponicus Bate is one of the most valuable cultured shrimp species in China and outdoor earthen pond farming is the most common method of culturing this organism. The need to increase soil usage efficiency...Marsupenaeusjaponicus Bate is one of the most valuable cultured shrimp species in China and outdoor earthen pond farming is the most common method of culturing this organism. The need to increase soil usage efficiency in aquaculture has been recognized and a great deal of research effort has been directed toward development of super-intensive farming systems. However, current research and development in this field is largely devoted to Litopenaeus vannamei Boone, while to M.japonicus Bate it has been neglected. In this study, a layered fanning system was designed and a 66-day study was conducted in M.japonicus Bate culture. The system comprised bracket and sand layers that divided a shrimp tank filled to a depth of 1.2 m into four water layers. Conventional tank culture （unlayered） was used as a control. The results show that survival rate, feed conversion efficiency and production of M.japonicus Bate in the layered farming system were 68%, 18%, and 0.59 kg/m^2, respectively, all of which are significantly higher than in the unlayered fanning system （P〈0.01）. These findings confirmed the possibility of using a layered system to culture M. japonicus Bate.展开更多
Detailed topographic maps show multiple stream valleys and what are probably dismembered stream valleys that extend completely across Wyoming’s northern Laramie Mountains. Several of the most obvious valleys are desc...Detailed topographic maps show multiple stream valleys and what are probably dismembered stream valleys that extend completely across Wyoming’s northern Laramie Mountains. Several of the most obvious valleys are described with valley origins first explained (or attempted to be explained) from the commonly accepted regional geomorphology paradigm (accepted paradigm) perspective and second from a recently proposed regional geomorphology paradigm (new paradigm) perspective in an effort to determine which of the two paradigms provides the simplest explanations. Accepted paradigm explanations require at least some of the valley erosion to have occurred prior to deposition of Oligocene and Miocene sediments that once covered the northern Laramie Mountains (with some of the exhumed valleys now containing sediment cover remnants). In contrast the fundamentally different new paradigm requires immense south-oriented continental ice sheet melt water floods to have crossed the region as ice sheet related crustal warping raised the region and the Laramie Mountains (and implies sediments now partially filling some of the valleys are probably flood deposited materials). The new paradigm provides simpler explanations for the origins of the valleys now extending completely across the northern Laramie Mountains and also for their related barbed tributaries, truncated side valleys, and drainage route U-turns than the accepted paradigm, although the new paradigm also leads to a fundamentally different middle and late Cenozoic regional geologic history than is currently recognized. One paradigm cannot be used to judge a different paradigm, but the paradigms can be compared based on their ability to explain evidence and Occam’s Razor can determine which of the two paradigms provides the simplest explanations. New paradigm explanations for northern Laramie Mountains valley origins investigated here require fewer assumptions than the accepted paradigm explanations suggesting the new paradigm merits serious future consideration.展开更多
This paper considers pricing European options under the well-known of SVJ model of Bates and related computational methods. According to the no-arbitrage principle, we first derive a partial differential equation that...This paper considers pricing European options under the well-known of SVJ model of Bates and related computational methods. According to the no-arbitrage principle, we first derive a partial differential equation that the value of any European contingent claim should satisfy, where the asset price obeys the SVJ model. This equation is numerically solved by using the implicit- explicit backward difference method and time semi-discretization. In order to explain the validity of our method, the stability of time semi-discretization scheme is also proved. Finally, we use a simulation example to illustrate the efficiency of the method.展开更多
“Through our walk in Zhejiang,the kindness of the people,the beauty of the scenery and the richness of its culture have left many footprints on our heart and our soul.Our hope is that through our Walk of Friendship w...“Through our walk in Zhejiang,the kindness of the people,the beauty of the scenery and the richness of its culture have left many footprints on our heart and our soul.Our hope is that through our Walk of Friendship we may have left behind a few positive British footprints in the lives and understanding and contributed in a small way to the‘golden era’of friendship between the people of China and the United Kingdom,”remarked British Lord Michael Bates at the premiere of The New Stories of Zhejiang,a documentary following his recentlycompleted walk across China’s coastal province of Zhejiang.The documentary was released to celebrate the 70th anniversary of the founding of the People’s Republic of China.Bates’walk event and the accompanying documentary were intended to help people better understand Zhejiang and Chinese culture and build a bridge of friendship through cultural exchange.展开更多
基金This work was financially supported by the National Key Research and Devel-opment Program of China(2017YFB0308402).
文摘Traditionally,universally used pelt bating technologies rely on the application of trypsin,neutral and alkaline microbial proteases but suffer from complicated operation,limited bating efficiency and unsatisfac-tory leather performance.Therefore,devising a new pelt bating approach to achieve high bating efficiency and excellent leather performance has always been wished for by the leather industry.To pursue this goal,years of persistent research work enabled us to develop a novel approach for pelt bating by means of acidic proteases in pickling process.Initially,basic enzymatic characteristics and bating effectiveness of several typical acidic pro-teases in pelt pickling medium were investigated;then,the bating effectiveness through the quantitative charac-terization of protease activity of the optimal acidic protease was compared with that of the conventional bating enzyme.The results indicated that all of the selected acidic proteases had good salt-tolerance and exhibited optimum activity at pH 3.0–4.0.The novel pickling-bating method based on microbial origin acidic protease L80A led to an outstanding performance on pelt bating at the dosage of 150 U/mL of collagenolytic activity.The bating effectiveness of acidic protease L80A was comparable to and even better than that of trypsin BEM due to its mod-erate proteolytic ability.Moreover,the deep and even penetration of acidic protease in the pelt permitted it to produce soft,organoleptically stable and overall better quality crust leather than that of the conventional trypsin bating method.Additionally,pelt bating was performed along with the pickling process without extra inactiva-tion and washing operation,making the bating operation more efficient,economical,and environment friendly.Results had made us to conclude that this cutting-edge acidic proteases based pickling-bating method could be the first step/way forward to replace the decades-old traditional pelt bating technology.
基金supported by the National Natural Science Foundation of China(21878193,21406145)the Innovation Team Program of Science&Technology Department of Sichuan Province(2017TD0010)+1 种基金the Graduate Student’s Research and Innovation Fund of Sichuan University(2018YJSY086)the National Innovation and Entrepreneurship Training Program for Undergraduate(201810610140).
文摘Bating pelt with protease is an important process,which removes unwanted non-collagenous proteins from the pelt and moderately disperse hide collagen network.However,the grain surface,may be excessively hydrolyzed during bating due to the longer retention time of protease in the grain than in the middle layer caused by the low mass transfer rate of protease in pelt.Here,the effects of protease dosage,common auxiliaries and molecular weight of protease on protease transfer during bating were investigated so that we can find the key points to avoid excessive collagen damage,particularly in the grain.Observably,increasing protease dosage led to faster protease transfer and softer leather,but along with more considerable grain damage.Using penetrating agent JFC(fatty alcohol-polyoxyethylene ether)and ammonium sulfate enhanced protease transfer and simultaneously alleviated collagen damage due to the decrease in interfacial tension and electrostatic attraction between protease and pelt,respectively.Additionally,proteases with lower molecular weight transferred faster in pelt,which suggests that a potential strategy to solve the conflict between the mass transfer and the reaction of protease in pelt might be to produce/employ smaller bating proteases.
基金Supported by the Science and Technology Plan of Qingdao(No.103-4-5-6-jch)the National Natural Science Foundation of China(No.31101916)+1 种基金the Natural Science Foundation of Shandong Province,China(No.ZR2010CM060)the University Student Innovation Plan of Qingdao Agricultural University(No.201030)
文摘Marsupenaeusjaponicus Bate is one of the most valuable cultured shrimp species in China and outdoor earthen pond farming is the most common method of culturing this organism. The need to increase soil usage efficiency in aquaculture has been recognized and a great deal of research effort has been directed toward development of super-intensive farming systems. However, current research and development in this field is largely devoted to Litopenaeus vannamei Boone, while to M.japonicus Bate it has been neglected. In this study, a layered fanning system was designed and a 66-day study was conducted in M.japonicus Bate culture. The system comprised bracket and sand layers that divided a shrimp tank filled to a depth of 1.2 m into four water layers. Conventional tank culture （unlayered） was used as a control. The results show that survival rate, feed conversion efficiency and production of M.japonicus Bate in the layered farming system were 68%, 18%, and 0.59 kg/m^2, respectively, all of which are significantly higher than in the unlayered fanning system （P〈0.01）. These findings confirmed the possibility of using a layered system to culture M. japonicus Bate.
文摘Detailed topographic maps show multiple stream valleys and what are probably dismembered stream valleys that extend completely across Wyoming’s northern Laramie Mountains. Several of the most obvious valleys are described with valley origins first explained (or attempted to be explained) from the commonly accepted regional geomorphology paradigm (accepted paradigm) perspective and second from a recently proposed regional geomorphology paradigm (new paradigm) perspective in an effort to determine which of the two paradigms provides the simplest explanations. Accepted paradigm explanations require at least some of the valley erosion to have occurred prior to deposition of Oligocene and Miocene sediments that once covered the northern Laramie Mountains (with some of the exhumed valleys now containing sediment cover remnants). In contrast the fundamentally different new paradigm requires immense south-oriented continental ice sheet melt water floods to have crossed the region as ice sheet related crustal warping raised the region and the Laramie Mountains (and implies sediments now partially filling some of the valleys are probably flood deposited materials). The new paradigm provides simpler explanations for the origins of the valleys now extending completely across the northern Laramie Mountains and also for their related barbed tributaries, truncated side valleys, and drainage route U-turns than the accepted paradigm, although the new paradigm also leads to a fundamentally different middle and late Cenozoic regional geologic history than is currently recognized. One paradigm cannot be used to judge a different paradigm, but the paradigms can be compared based on their ability to explain evidence and Occam’s Razor can determine which of the two paradigms provides the simplest explanations. New paradigm explanations for northern Laramie Mountains valley origins investigated here require fewer assumptions than the accepted paradigm explanations suggesting the new paradigm merits serious future consideration.
文摘This paper considers pricing European options under the well-known of SVJ model of Bates and related computational methods. According to the no-arbitrage principle, we first derive a partial differential equation that the value of any European contingent claim should satisfy, where the asset price obeys the SVJ model. This equation is numerically solved by using the implicit- explicit backward difference method and time semi-discretization. In order to explain the validity of our method, the stability of time semi-discretization scheme is also proved. Finally, we use a simulation example to illustrate the efficiency of the method.
文摘“Through our walk in Zhejiang,the kindness of the people,the beauty of the scenery and the richness of its culture have left many footprints on our heart and our soul.Our hope is that through our Walk of Friendship we may have left behind a few positive British footprints in the lives and understanding and contributed in a small way to the‘golden era’of friendship between the people of China and the United Kingdom,”remarked British Lord Michael Bates at the premiere of The New Stories of Zhejiang,a documentary following his recentlycompleted walk across China’s coastal province of Zhejiang.The documentary was released to celebrate the 70th anniversary of the founding of the People’s Republic of China.Bates’walk event and the accompanying documentary were intended to help people better understand Zhejiang and Chinese culture and build a bridge of friendship through cultural exchange.
