Pub Date : 1973-12-01DOI: 10.1017/S000192400004207X
J. W. Hardy
In recent years considerable advances in the field of “optimal control” have been made. The impetus behind many of these advances has been derived from a growing demand that not only is it desirable, but also essential, that the design of a control system be optimised. This is particularly true of the aerospace industry in which the specification laid before the control systems designer usually demands the best possible performance for minimum cost (be that cost financial, on fuel, or on weight). Short of a major technological innovation, the problem becomes one of finding some means of meeting an ever increasing demand for performance, using existing technology. More attention has therefore been given in recent years to the study of optimal control, particularly since the advent of high speed, sophisticated scientific digital computers. Two of the major areas which have been explored have been the optimal design of systems, according to a quadratic performance criterion, and non-linear programming techniques. These are briefly discussed in Section 3 of this paper.
{"title":"An application of some aspects of optimal control","authors":"J. W. Hardy","doi":"10.1017/S000192400004207X","DOIUrl":"https://doi.org/10.1017/S000192400004207X","url":null,"abstract":"In recent years considerable advances in the field of “optimal control” have been made. The impetus behind many of these advances has been derived from a growing demand that not only is it desirable, but also essential, that the design of a control system be optimised. This is particularly true of the aerospace industry in which the specification laid before the control systems designer usually demands the best possible performance for minimum cost (be that cost financial, on fuel, or on weight). Short of a major technological innovation, the problem becomes one of finding some means of meeting an ever increasing demand for performance, using existing technology. More attention has therefore been given in recent years to the study of optimal control, particularly since the advent of high speed, sophisticated scientific digital computers. Two of the major areas which have been explored have been the optimal design of systems, according to a quadratic performance criterion, and non-linear programming techniques. These are briefly discussed in Section 3 of this paper.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"77 1","pages":"625 - 633"},"PeriodicalIF":1.4,"publicationDate":"1973-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57253603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1970-09-01DOI: 10.1017/S0001924000048259
A. van der Neut
The elementary beam theory for shell structures yields the exact solution for normal and shear stress, if the three following conditions are fulfilled: (a) the shell must be prismatic; (b) the cross section must not deform in its plane; (c) the centres of rotation of the different cross sections must form an axis of rotation parallel to the longitudinal axis of the beam.
{"title":"An Extension of the Validity of Beam Theory Beyond its Classical Bounds","authors":"A. van der Neut","doi":"10.1017/S0001924000048259","DOIUrl":"https://doi.org/10.1017/S0001924000048259","url":null,"abstract":"The elementary beam theory for shell structures yields the exact solution for normal and shear stress, if the three following conditions are fulfilled: (a) the shell must be prismatic; (b) the cross section must not deform in its plane; (c) the centres of rotation of the different cross sections must form an axis of rotation parallel to the longitudinal axis of the beam.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"74 1","pages":"752 - 756"},"PeriodicalIF":1.4,"publicationDate":"1970-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57254090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1970-09-01DOI: 10.1017/S000192400004820X
Sebastian de Ferranti
For aviation to become commercially usable and reliable, in addition to the development of aerodynamics, of reliable structures and reliable engines, there had to be the development of instruments, communications, and navigational aids. Suppose, for example, that today one could not fly through cloud, or at night, then nothing remotely resembling a regular service would be possible. Flying would still be a sport. To illustrate what I mean I shall quote the example of another innovation with quite different properties in this respect. The first railway was immediately commercial and usable without any aids. It can be seen at once that the train running along rails is constrained compared with aircraft. It is obvious that the navigation problem here is very simple, and that there is not really a problem of control or stability—the first railway trains did not even have brakes. The mechanical skill of operating and maintaining the new device had to be learned; but very little else.
{"title":"Instruments and Electronics in Aviation","authors":"Sebastian de Ferranti","doi":"10.1017/S000192400004820X","DOIUrl":"https://doi.org/10.1017/S000192400004820X","url":null,"abstract":"For aviation to become commercially usable and reliable, in addition to the development of aerodynamics, of reliable structures and reliable engines, there had to be the development of instruments, communications, and navigational aids. Suppose, for example, that today one could not fly through cloud, or at night, then nothing remotely resembling a regular service would be possible. Flying would still be a sport. To illustrate what I mean I shall quote the example of another innovation with quite different properties in this respect. The first railway was immediately commercial and usable without any aids. It can be seen at once that the train running along rails is constrained compared with aircraft. It is obvious that the navigation problem here is very simple, and that there is not really a problem of control or stability—the first railway trains did not even have brakes. The mechanical skill of operating and maintaining the new device had to be learned; but very little else.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"74 1","pages":"718 - 723"},"PeriodicalIF":1.4,"publicationDate":"1970-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57254007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1970-06-01DOI: 10.1017/S0001924000114812
D. L. Birdsall
In a decade when aircraft design procedures involve analyses which display ever increasing accuracy to satisfy growing operational demands, it is not surprising that the boundaries of compromise rapidly converge upon the envelope of acceptability. A finished aircraft becomes the unique solution to a well-defined design problem–or what is even more frightening, it becomes a solution to a unique problem. If the problem changes after the solution has been produced… c'est la vie.
{"title":"A Non-Linear Solution to a Tab-Aileron Flutter Problem","authors":"D. L. Birdsall","doi":"10.1017/S0001924000114812","DOIUrl":"https://doi.org/10.1017/S0001924000114812","url":null,"abstract":"In a decade when aircraft design procedures involve analyses which display ever increasing accuracy to satisfy growing operational demands, it is not surprising that the boundaries of compromise rapidly converge upon the envelope of acceptability. A finished aircraft becomes the unique solution to a well-defined design problem–or what is even more frightening, it becomes a solution to a unique problem. If the problem changes after the solution has been produced… c'est la vie.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"74 1","pages":"509 - 512"},"PeriodicalIF":1.4,"publicationDate":"1970-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57256617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1970-04-01DOI: 10.1017/s0001924000047679
R. C. Edmonston Low
It is undoubtedly true to say that with the death of Archibald Reith Low on the 21st January 1969, there departed from the scene the last of the early pioneers of British aviation. Born in Aberdeen on 31st December 1878, he was brought up with four brothers and three .sisters at the Manse at Fountainbridge, Edinburgh, where his father was Minister of the Church of Scotland. His mother was Jane Stuart Reith, aunt of the present Lord Reith, who was thereby his first cousin.
{"title":"Major A. R. Low, RAF, MA, FRAeS 1878-1969","authors":"R. C. Edmonston Low","doi":"10.1017/s0001924000047679","DOIUrl":"https://doi.org/10.1017/s0001924000047679","url":null,"abstract":"It is undoubtedly true to say that with the death of Archibald Reith Low on the 21st January 1969, there departed from the scene the last of the early pioneers of British aviation. Born in Aberdeen on 31st December 1878, he was brought up with four brothers and three .sisters at the Manse at Fountainbridge, Edinburgh, where his father was Minister of the Church of Scotland. His mother was Jane Stuart Reith, aunt of the present Lord Reith, who was thereby his first cousin.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"74 1","pages":"337 - 338"},"PeriodicalIF":1.4,"publicationDate":"1970-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57253761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1969-10-01DOI: 10.1017/S0001924000086103
K. R. Van der Spuy
I Feel highly honoured at having been asked to deliver this inaugural lecture as a prelude to the bi-annual series of Memorial Lectures on the development of Civil Aviation in South Africa. This lecture will be devoted to the man—Major Allister Macintosh Miller. Much has come about in the field of Civil Aviation since the days I am going to speak about. Space and time have been telescoped. Colossal strides have been made. In this hall tonight I see a number of persons who, like myself, are able to make the comparison between the civil aircraft of vintage 1919 and the civil aircraft of today.
{"title":"Major Allister Macintosh Miller: 1892—1951","authors":"K. R. Van der Spuy","doi":"10.1017/S0001924000086103","DOIUrl":"https://doi.org/10.1017/S0001924000086103","url":null,"abstract":"I Feel highly honoured at having been asked to deliver this inaugural lecture as a prelude to the bi-annual series of Memorial Lectures on the development of Civil Aviation in South Africa. This lecture will be devoted to the man—Major Allister Macintosh Miller. Much has come about in the field of Civil Aviation since the days I am going to speak about. Space and time have been telescoped. Colossal strides have been made. In this hall tonight I see a number of persons who, like myself, are able to make the comparison between the civil aircraft of vintage 1919 and the civil aircraft of today.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"73 1","pages":"881 - 887"},"PeriodicalIF":1.4,"publicationDate":"1969-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S0001924000086103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57255811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1969-07-01DOI: 10.1017/S0001924000052167
J. Lockwood Taylor
Application of a method suggested by my technical note on equilateral and semi-equilateral triangles has yielded values for the buckling coefficients for isosceles triangles which in some cases differ appreciably from those given on Data Sheet 02.04.06. The technical note quoted gives exact solutions in the form of a terminating trigonometrical series. When the triangle becomes isosceles, the series no longer terminates, but the infinite series solution, on insertion of the boundary conditions, gives an infinite determinant for the buckling load or eigenvalue. Evaluation of the determinant, or of a sufficient number of terms, was computed on a Univac 1107, with the following results, which have been converted to the notation of Data Sheet 02.04.06.
{"title":"Buckling of Isosceles Triangular Plates","authors":"J. Lockwood Taylor","doi":"10.1017/S0001924000052167","DOIUrl":"https://doi.org/10.1017/S0001924000052167","url":null,"abstract":"Application of a method suggested by my technical note on equilateral and semi-equilateral triangles has yielded values for the buckling coefficients for isosceles triangles which in some cases differ appreciably from those given on Data Sheet 02.04.06. The technical note quoted gives exact solutions in the form of a terminating trigonometrical series. When the triangle becomes isosceles, the series no longer terminates, but the infinite series solution, on insertion of the boundary conditions, gives an infinite determinant for the buckling load or eigenvalue. Evaluation of the determinant, or of a sufficient number of terms, was computed on a Univac 1107, with the following results, which have been converted to the notation of Data Sheet 02.04.06.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"73 1","pages":"604 - 604"},"PeriodicalIF":1.4,"publicationDate":"1969-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S0001924000052167","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57254716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1969-07-01DOI: 10.1017/S0001924000052076
H. R. Cox, K. Norton
It is, and always will be, an honour to give the Handley Page Memorial Lecture, but for me the occasion has a special pietas because Sir Frederick Handley Page was a friend of mine for many years and I admired his extraordinary intelligence, pertinacity and independence of character. I had the honour to immediately follow him in two offices of high importance—as President of the RAeS and as Chairman of the Governors of this College, and as this is the last major lecture I intend to give, I am particularly happy that it is in his memory, just as the first major lecture I ever gave was in memory of that other great pioneer, Wilbur Wright. In October of last year I was asked, almost simultaneously, to provide a final and summary paper for the Second Century papers in the Aeronautical Journal and to give the 1969 Handley Page Memorial Lecture. I did not feel equal to the two tasks, but after it had been suggested that they should be rolled into one—that the Memorial Lecture should be the last Second Century paper —I finally agreed, on this basis, to write a paper. In 1940 I had the honour of giving the 28th Wilbur Wright Memorial Lecture. It was called "Looking Forward", and it was about the future of British civil aviation. In his paper introducing the Royal Aeronautical Society's Second Century Papers, Mr. Alien' was kind enough to include it among the prophetic writings he examined. "Looking Forward" was produced under difficult conditions. Had I not been afflicted in the spring of 1940 with German measles, I do not think it could possibly have been written. I could not, moreover, consider in my predictions the influence of the gas turbine, with the development of which I was already closely associated, because the work of Whittle and his friends was necessarily shrouded in secrecy. I do not mention these facts to excuse the paper, but to explain first how time could be found to create such a mass of verbiage in the midst of war, and second, to explain what might at first seem a curious omission. I delivered the paper almost exactly 29 years ago, but the occasion is clear in my mind. The Society's President, Mr. Griffith Brewer, was in the United States with his old friend Orville Wright, and in the chair was that wonderful character, Brab, at that time still Lt. Col. J. T. C. MooreBrabazon. London was under attack, but the lecture was held in the great hall of the Institution of Electrical Engineers. The possibility of a less attractive venue was, however, in the Chairman's mind, for he announced the determination of the Society to continue the Wilbur Wright lectures in the war "even if it became necessary to hold them, like the early Christians, underground in catacombs".
{"title":"Looking forward again : Notes on the needs, probabilities and possibilities in aeronautics","authors":"H. R. Cox, K. Norton","doi":"10.1017/S0001924000052076","DOIUrl":"https://doi.org/10.1017/S0001924000052076","url":null,"abstract":"It is, and always will be, an honour to give the Handley Page Memorial Lecture, but for me the occasion has a special pietas because Sir Frederick Handley Page was a friend of mine for many years and I admired his extraordinary intelligence, pertinacity and independence of character. I had the honour to immediately follow him in two offices of high importance—as President of the RAeS and as Chairman of the Governors of this College, and as this is the last major lecture I intend to give, I am particularly happy that it is in his memory, just as the first major lecture I ever gave was in memory of that other great pioneer, Wilbur Wright. In October of last year I was asked, almost simultaneously, to provide a final and summary paper for the Second Century papers in the Aeronautical Journal and to give the 1969 Handley Page Memorial Lecture. I did not feel equal to the two tasks, but after it had been suggested that they should be rolled into one—that the Memorial Lecture should be the last Second Century paper —I finally agreed, on this basis, to write a paper. In 1940 I had the honour of giving the 28th Wilbur Wright Memorial Lecture. It was called \"Looking Forward\", and it was about the future of British civil aviation. In his paper introducing the Royal Aeronautical Society's Second Century Papers, Mr. Alien' was kind enough to include it among the prophetic writings he examined. \"Looking Forward\" was produced under difficult conditions. Had I not been afflicted in the spring of 1940 with German measles, I do not think it could possibly have been written. I could not, moreover, consider in my predictions the influence of the gas turbine, with the development of which I was already closely associated, because the work of Whittle and his friends was necessarily shrouded in secrecy. I do not mention these facts to excuse the paper, but to explain first how time could be found to create such a mass of verbiage in the midst of war, and second, to explain what might at first seem a curious omission. I delivered the paper almost exactly 29 years ago, but the occasion is clear in my mind. The Society's President, Mr. Griffith Brewer, was in the United States with his old friend Orville Wright, and in the chair was that wonderful character, Brab, at that time still Lt. Col. J. T. C. MooreBrabazon. London was under attack, but the lecture was held in the great hall of the Institution of Electrical Engineers. The possibility of a less attractive venue was, however, in the Chairman's mind, for he announced the determination of the Society to continue the Wilbur Wright lectures in the war \"even if it became necessary to hold them, like the early Christians, underground in catacombs\".","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"103 1","pages":"215-220"},"PeriodicalIF":1.4,"publicationDate":"1969-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S0001924000052076","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57254573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1969-06-01DOI: 10.1017/S0001924000052623
H. W. Pout
Throughout this paper I shall be using the term Guided Weapon to describe a weapon which receives corrections to its direction of flight after leaving the launching device, the corrections being related in some way to the measured relative positions and behaviour of the target and weapon. With this definition some rocket weapons are guided, others are not; most of the so-called ballistic missiles are not. I must also emphasise that the opinions expressed are my own, although I gratefully acknowledge the permission of the Ministry of Defence, Navy Department, to publish the paper. I have drawn on UK Naval experience, in much of which I have been personally involved, but at various stages the evolution of Naval guided weapons has been mixed inextricably with that of the other Services’ weapons. For this reason I chose a more general title for the paper.
{"title":"The Evolution of Guided Weapons","authors":"H. W. Pout","doi":"10.1017/S0001924000052623","DOIUrl":"https://doi.org/10.1017/S0001924000052623","url":null,"abstract":"Throughout this paper I shall be using the term Guided Weapon to describe a weapon which receives corrections to its direction of flight after leaving the launching device, the corrections being related in some way to the measured relative positions and behaviour of the target and weapon. With this definition some rocket weapons are guided, others are not; most of the so-called ballistic missiles are not. I must also emphasise that the opinions expressed are my own, although I gratefully acknowledge the permission of the Ministry of Defence, Navy Department, to publish the paper. I have drawn on UK Naval experience, in much of which I have been personally involved, but at various stages the evolution of Naval guided weapons has been mixed inextricably with that of the other Services’ weapons. For this reason I chose a more general title for the paper.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"73 1","pages":"547 - 552"},"PeriodicalIF":1.4,"publicationDate":"1969-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S0001924000052623","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57254811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1969-04-01DOI: 10.1017/S0001924000053148
W. Euan Hooper
I will describe in this paper some features of current Boeing-Vertol production helicopters that I have selected as those which strike me personally as being of particular engineering interest. But first just to provide some perspective on the subject I would like to summarise the background of the present Vertol Division of The Boeing Company. The Company was formed in 1944 as the Piasecki Aircraft Corporation and its first product was the HRP Tandem Rotor Helicopter, which first flew in 1945. This was followed by the HUP in 1948, the H-21 in 1952 and the H-16 in 1953. In 1956 the Company was renamed Vertol and the next aircraft to fly was the Model 107 Prototype in 1958. In 1960 Vertol was acquired by Boeing and became the Vertol Division. The currently manufactured models about which I am going to talk, are the 107 series (now mostly in production as the US Marine Corps Model CH-46, Sea Knight) and the 114 series (in service with the US Army as the CH-47, Chinook) of helicopters.
{"title":"Some Technical Aspects of Boeing Helicopters","authors":"W. Euan Hooper","doi":"10.1017/S0001924000053148","DOIUrl":"https://doi.org/10.1017/S0001924000053148","url":null,"abstract":"I will describe in this paper some features of current Boeing-Vertol production helicopters that I have selected as those which strike me personally as being of particular engineering interest. But first just to provide some perspective on the subject I would like to summarise the background of the present Vertol Division of The Boeing Company. The Company was formed in 1944 as the Piasecki Aircraft Corporation and its first product was the HRP Tandem Rotor Helicopter, which first flew in 1945. This was followed by the HUP in 1948, the H-21 in 1952 and the H-16 in 1953. In 1956 the Company was renamed Vertol and the next aircraft to fly was the Model 107 Prototype in 1958. In 1960 Vertol was acquired by Boeing and became the Vertol Division. The currently manufactured models about which I am going to talk, are the 107 series (now mostly in production as the US Marine Corps Model CH-46, Sea Knight) and the 114 series (in service with the US Army as the CH-47, Chinook) of helicopters.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":"73 1","pages":"347 - 354"},"PeriodicalIF":1.4,"publicationDate":"1969-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S0001924000053148","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57254429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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