Pan gnammas occur across Australia, mainly in granites and sandstones. Their morphology and origins on Eyre Peninsula, South Australia are known, but this Twidale model is not applicable everywhere. I investigated the...Pan gnammas occur across Australia, mainly in granites and sandstones. Their morphology and origins on Eyre Peninsula, South Australia are known, but this Twidale model is not applicable everywhere. I investigated their morphology and theorized on their origins at eight sites across the continent, noting particularly their edge profiles, floors and depths in relation to their geological placement. The steep sides, flat floors, depths up to about 25 cm in laminated granites appl<span style="font-family:Verdana;">y</span><span style="font-family:Verdana;"> only in the hot climates of Western Australia and South Australia. Laminations are rare in Victorian granites, so their pan gnammas have sloped edges and are not as deep (ca.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">10 cm) and in the granitic uplands of southeast Queensland</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> corrosion at the edge </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">concentrated to a narrow zone and most gnammas are only ca. 5 cm deep. Gnammas in horizontal sandstones in New South Wales and Queensland have steep or sloping edges and reach ca 10 cm deep but in dipping sandstones of the Grampians, Victoria horizontality of corrosion has produced visors at pan edges. The vertically bedded Uluru sandstones ha</span><span style="font-family:Verdana;">ve</span><span style="font-family:Verdana;"> enabled deeper corrosion and pans of different morphology. Regional depth variation has biological consequences.</span>展开更多
This paper discusses the analysis and design of a very thin slotless permanent magnet （PM） brushless motor whose stator laminations are manufactured from a single strip of steel that is edge wound into a spiral （li...This paper discusses the analysis and design of a very thin slotless permanent magnet （PM） brushless motor whose stator laminations are manufactured from a single strip of steel that is edge wound into a spiral （like a ＂Slinky＂） and then fitted over the windings that are preformed on the outside surface of a non-conducting former. Analytical and finite element analysis （FEA） are used to determine the con- strained optimum dimensions of a motor used to drive a rim driven thruster in which the motor rotor is fit- ted onto the rim of the propeller and the stator is encapsulated in the thin Kort nozzle of the thruster. The paper describes the fabrication of a demonstrator motor and presents experimental results to validate the theoretical calculations. Experimental motor performance results are also reported and compared with those of a slotted motor that fits within the same active radial dimensions as the slotless motor. The slotless motor, which has longer active length and endwindings, and thicker magnets than the slotted motor, was found to be less efficient and more expensive （prototype cost） than the slotted machine.展开更多
Hongfeng Lake is an eutrophic freshwater atificial reservior.It began to restore water in 1960. Three sediment cores were taken from both about 25m of water in the center of Hongfeng bake in May 1991. The stratigraphy...Hongfeng Lake is an eutrophic freshwater atificial reservior.It began to restore water in 1960. Three sediment cores were taken from both about 25m of water in the center of Hongfeng bake in May 1991. The stratigraphy of the three cores was easily matched .by using prominent marking horizons and characteristic aqnences of laminations. In three layer Samples studied, diatom and other algae taxa appear in repeating apuences. The presence of laminations may reflect either the regular changes of physical-chemical conditions within the lake or the variation in the intensity of erosion and transport of material from the catchment, pat iculaly where instability in the lake-water system has occult as a result of human activities. The larninations were mainly cantal by seasonal variation of envionmental conditions,particularly climate.Unlike t of the previous examples, they have ben fo￣ at most recent Sediments, in a small freshwater lake in the eastern slOPe of the QinghaiXiZang Plateau, China in a subtropical climate, which is adenly controlled by ￣theastern and southwestern mon￣n. It is believed that it's the first reported instanceOf laminated lake sediments from China.展开更多
The combinatorial Mandelbrot set is a continuum in the plane, whose boundary is defined as the quotient space of the unit circle by an explicit equivalence relation. This equivalence relation was described by Douady(1...The combinatorial Mandelbrot set is a continuum in the plane, whose boundary is defined as the quotient space of the unit circle by an explicit equivalence relation. This equivalence relation was described by Douady(1984) and, separately, by Thurston(1985) who used quadratic invariant geolaminations as a major tool. We showed earlier that the combinatorial Mandelbrot set can be interpreted as a quotient of the space of all limit quadratic invariant geolaminations with the Hausdorff distance topology. In this paper, we describe two similar quotients. In the first case, the identifications are the same but the space is smaller than that used for the Mandelbrot set. The resulting quotient space is obtained from the Mandelbrot set by "unpinching" the transitions between adjacent hyperbolic components. In the second case we identify renormalizable geolaminations that can be "unrenormalized" to the same hyperbolic geolamination while no two non-renormalizable geolaminations are identified.展开更多
NOT until Gao Zhenzhong and Eriksson studied the Ordovician of Fincastle area, Appalachi-ans, the USA in 1990, did sedimentologist recognize internal-tide deposits in the ancientrecord and begin to use the term of ...NOT until Gao Zhenzhong and Eriksson studied the Ordovician of Fincastle area, Appalachi-ans, the USA in 1990, did sedimentologist recognize internal-tide deposits in the ancientrecord and begin to use the term of 'internal-tide deposit'. In the Ordovician of Fincastlearea, two facies are recognized: (i) bidirectional cross-laminated very fine grained展开更多
文摘Pan gnammas occur across Australia, mainly in granites and sandstones. Their morphology and origins on Eyre Peninsula, South Australia are known, but this Twidale model is not applicable everywhere. I investigated their morphology and theorized on their origins at eight sites across the continent, noting particularly their edge profiles, floors and depths in relation to their geological placement. The steep sides, flat floors, depths up to about 25 cm in laminated granites appl<span style="font-family:Verdana;">y</span><span style="font-family:Verdana;"> only in the hot climates of Western Australia and South Australia. Laminations are rare in Victorian granites, so their pan gnammas have sloped edges and are not as deep (ca.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">10 cm) and in the granitic uplands of southeast Queensland</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> corrosion at the edge </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">concentrated to a narrow zone and most gnammas are only ca. 5 cm deep. Gnammas in horizontal sandstones in New South Wales and Queensland have steep or sloping edges and reach ca 10 cm deep but in dipping sandstones of the Grampians, Victoria horizontality of corrosion has produced visors at pan edges. The vertically bedded Uluru sandstones ha</span><span style="font-family:Verdana;">ve</span><span style="font-family:Verdana;"> enabled deeper corrosion and pans of different morphology. Regional depth variation has biological consequences.</span>
文摘This paper discusses the analysis and design of a very thin slotless permanent magnet （PM） brushless motor whose stator laminations are manufactured from a single strip of steel that is edge wound into a spiral （like a ＂Slinky＂） and then fitted over the windings that are preformed on the outside surface of a non-conducting former. Analytical and finite element analysis （FEA） are used to determine the con- strained optimum dimensions of a motor used to drive a rim driven thruster in which the motor rotor is fit- ted onto the rim of the propeller and the stator is encapsulated in the thin Kort nozzle of the thruster. The paper describes the fabrication of a demonstrator motor and presents experimental results to validate the theoretical calculations. Experimental motor performance results are also reported and compared with those of a slotted motor that fits within the same active radial dimensions as the slotless motor. The slotless motor, which has longer active length and endwindings, and thicker magnets than the slotted motor, was found to be less efficient and more expensive （prototype cost） than the slotted machine.
文摘Hongfeng Lake is an eutrophic freshwater atificial reservior.It began to restore water in 1960. Three sediment cores were taken from both about 25m of water in the center of Hongfeng bake in May 1991. The stratigraphy of the three cores was easily matched .by using prominent marking horizons and characteristic aqnences of laminations. In three layer Samples studied, diatom and other algae taxa appear in repeating apuences. The presence of laminations may reflect either the regular changes of physical-chemical conditions within the lake or the variation in the intensity of erosion and transport of material from the catchment, pat iculaly where instability in the lake-water system has occult as a result of human activities. The larninations were mainly cantal by seasonal variation of envionmental conditions,particularly climate.Unlike t of the previous examples, they have ben fo￣ at most recent Sediments, in a small freshwater lake in the eastern slOPe of the QinghaiXiZang Plateau, China in a subtropical climate, which is adenly controlled by ￣theastern and southwestern mon￣n. It is believed that it's the first reported instanceOf laminated lake sediments from China.
基金supported by National Science Foundation of USA (Grant No. DMS-1201450)supported by National Science Foundation of USA (Grant No. DMS-1807558)supported by the Russian Academic Excellence Project ‘5-100’
文摘The combinatorial Mandelbrot set is a continuum in the plane, whose boundary is defined as the quotient space of the unit circle by an explicit equivalence relation. This equivalence relation was described by Douady(1984) and, separately, by Thurston(1985) who used quadratic invariant geolaminations as a major tool. We showed earlier that the combinatorial Mandelbrot set can be interpreted as a quotient of the space of all limit quadratic invariant geolaminations with the Hausdorff distance topology. In this paper, we describe two similar quotients. In the first case, the identifications are the same but the space is smaller than that used for the Mandelbrot set. The resulting quotient space is obtained from the Mandelbrot set by "unpinching" the transitions between adjacent hyperbolic components. In the second case we identify renormalizable geolaminations that can be "unrenormalized" to the same hyperbolic geolamination while no two non-renormalizable geolaminations are identified.
文摘NOT until Gao Zhenzhong and Eriksson studied the Ordovician of Fincastle area, Appalachi-ans, the USA in 1990, did sedimentologist recognize internal-tide deposits in the ancientrecord and begin to use the term of 'internal-tide deposit'. In the Ordovician of Fincastlearea, two facies are recognized: (i) bidirectional cross-laminated very fine grained
