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91.
92.
EXPRESSION CLONING OF A PROTECTIVE LEISHMANIA ANTIGEN 总被引:5,自引:0,他引:5
郑时春 《西安交通大学学报(英文版)》1995,(2)
EXPRESSIONCLONINGOFAPROTECTIVELEISHMANIAANTIGENE.Mougneau,F.Altars,A.E.Wakil,ZhengShichun;T.Coppola,Z.Wang,R.Waldmann,R.M.Loc... 相似文献
93.
High-speed rail operations have the potential to reduce the long-term decline in rail passenger travel demand for the medium to long distance inter-urban markets. Such decline has been evident through most of the industrialized countries where air and road transport tend to be the dominant modes. In China, the operations of long distance high-speed rail on fully dedicated track is not very easy to implement, due to the high proportion of passengers who travel between high-speed and conventional railways. An alternative approach would be to allow for mixed operations with trains of various speeds on the same track. This article puts forward a simulation model designed to allow an evaluation of the most efficient distance for high-speed rail operations under mixed train speed scenarios. The model takes into account the main operating parameters such as passenger volumes, train speeds, capital and maintenance costs, train operating costs and energy consumption. The distance of high-speed train running on conventional rail that will yield the most economic benefit can be estimated using the model. The article includes the results of using the model for a specific example. It is concluded that large-scale high-speed trains have the potential to be successfully operated on conventional rail networks. 相似文献
94.
The North American Free Trade Agreement (NAFTA) signed by Canada, the U.S.A. and Mexico and which came into effect on 1 January 1994, is a significant move towards further integration of the North American economies. This paper examines the likely impact of NAFTA on Canadian ports. Three channels of impact are identified. First, there are direct impacts on trade flows between Canada and its North American trading partners. In this regard we find that ports do not typically handle the types of products that are likely to be affected by NAFTA, and so the direct impacts may be minimal. Second, and more significantly, port catchment areas are likely to undergo substantial changes as they respond to a more competitive environment within the free trade area. Third, the transportation sector has itself been included in NAFTA, and Canadian ports will face increased competition from land based transportation modes. We conclude that ports in Canada must learn to work more consciously as agents of regional economic development. 相似文献
95.
van der Kolk N. J. Akkerman I. Keuning J. A. Huijsmans R. H. M. 《Journal of Marine Science and Technology》2021,26(4):1126-1143
Journal of Marine Science and Technology - Wind propulsion for commercial ships has been identified as a key component in the energy transition for the maritime industry. The sailing hybrid ship... 相似文献
96.
The response of the Black Sea mean level to atmospheric pressure (AP) and wind forcing is investigated using 5 years of TOPEX/POSEIDON (T/P hereafter) data. A coherence analysis is first applied to mean sea level and pressure to examine the validity of the inverse barometer (IB) approximation over this area. As expected, it reveals very significant deviations from an IB response attributed to the narrowness of the Bosphorus Strait and its limiting role in water exchanges. A comparison is drawn with the Mediterranean Sea case. A single basin version of the Candela analytical model [Candela, J., 1991. The Gibraltar Strait and its role in the dynamics of the Mediterranean Sea. Dyn. Atmos. Oceans 15, 267–300], which takes linear friction at the strait into account, is then used. The model explains a significant part of the T/P mean sea level variance (about 30%, while the IB correction only explains 5% of its variance) and provides a means to correct the altimeter data for the pressure effect much better than the standard IB effect. The response of the mean sea level to wind forcing is then analysed. Coherence analysis between sea level and along-strait wind stress (WS) reveals a significant coherence at periods ranging from 40 to 100 days, with an almost steady phase of 270°. This result is confirmed with a multiple coherence analysis (mean sea level vs. WS and AP). A plausible mechanism is a piling-up of water at the northern or southern end of the strait due to along-strait wind forcing. The associated along-strait pressure gradient would modify the barotropic flow in the strait and then the mean sea level. Using an extension of the Candela model, we show that this mechanism is consistent with T/P mean sea level observations. 相似文献
97.
P. Sundarraman S. K. Saha N. J. Vasa R. Baskaran V. Sunilkumar K. Raghavendra 《International Journal of Automotive Technology》2012,13(2):193-203
The Fuel-Injection Pump (FIP) used in diesel engine has a higher-pair cam-mechanism to pressurize the fuel for injection.
This paper proposes a methodology to model FIP from a multibody Dynamics (MBD) perspective. The results from the model include
the temporal behavior of driving torque, contact Hertz stress and reaction forces at various joints. The model helps the designer
to assess the effect of various cam profiles, link parameters and other design variables. It is necessary that these parameters
be optimized for future high pressure applications. For this purpose, a cam-mechanism with offset follower axis is analysed.
Decoupled Natural Orthogonal Complement (DeNOC) matrices based algorithm is used to model FIP without and with offset cam-mechanism.
The study shows that, the offset cam-mechanism allows reduction in the side-thrust, reaction forces, and the contact Hertz
stress acting on the cam-follower interface. As a typical case, for an FIP working around a pressure value of 600 bar, an
optimum offset value is found to be 9.5 mm and it shows a reduction of about 45% in side thrust values. To validate the modeling
approach, experimental studies are performed on pump without and with offset cam-mechanism. Experimental results are in qualitative
agreement with the theoretical model results. 相似文献
98.
北京地铁14号线跨丰沙铁路节点桥位于右线曲线半径为470 m的曲线上,桥梁主体结构为84+84 m的T构。桥梁转体跨度71+71 m,转体重量7 130 t,转体时球铰中心相对下盘中心向曲线内侧预设偏心1.152 m,转体角度33.46°,桥梁的转体半径和转体跨度在轨道交通转体桥梁的设计和施工领域均为国内首创。比选桥梁方案,从针对桥梁上部结构的非对称主体结构设计、下部结构预偏心设置、施工合拢段位置的选择、施工时对既有铁路线的防护等多方面进行论述和详细介绍。结果表明,通过上部结构非对称设计和转体结构预设偏心,有效地保证了小曲线半径大跨度桥梁转体施工时的平衡和稳定性,大大降低了施工风险。 相似文献
99.
Passenger Transport: Planning for Radical Change. Edited by J. D. Carr. (Gower: Aldershot.) [Pp. 224.] £27.50. ISBN 0 566 05183 4. Geografia Transportu Polski. Transport Geography of Poland (in Polish). Second edition. By T. Lijewski. (Panstwowe Wydawnictwo Ekonomiczne, 1986.) [Pp. 286.] Z1.240. ISBN 83 208 0474 4. Future Transport Policy. By K. J. Button and D. Gillingwater. (London: Croom Helm, 1986.) [Pp. 224.] £27.50. ISBN 0 7099 3225 1. 相似文献
100.
This two‐part paper contains most of a report prepared by TRRL for the European Conference of Ministers of Transport, and presented by one of the authors to the Council of Ministers in November 1984. Part 1, which was published in the January‐March 1986 issue of Transport Reviews, looked at the way cities have been changing over the years and the influence of growing car ownership on trip patterns. This part examines the changes in public transport use in more detail, considers the interactions between the various underlying trends, speculates on future travel patterns by both public and private means and considers the likely impact of land use and transport policies. 相似文献