Chinese English

Appearance

View mode
Number of cards in a row Here you can select the number of cards to be placed in a row for each of supported screen resolutions. Your current resolution is highlighted in this way.
	Large desktop
	Desktop
	Tablet
	Phone

Page size

Total record count: 6216.

Records per page

	Term	术语	Definition	定义
	underwater sound projector	水下发声换能器	A TRANSDUCER used to produce SOUND in water. The conversion from electrical energy to SOUND is achieved through the use of either the pi... more A TRANSDUCER used to produce SOUND in water. The conversion from electrical energy to SOUND is achieved through the use of either the piezoelectric or magnetostrictive effect. See MAGNETOSTRICTION and PIEZOELECTRICITY.	用于水下发声的换能器。从电能到声的转换是通过压电效应或磁致伸缩效应获得的。
	underway (or under way)	在航，航行中	(adv.). Without MOORINGS; not secured in any way to the ground or a WHARF. In motion, particularly the start of such motion after a standsti... more (adv.). Without MOORINGS; not secured in any way to the ground or a WHARF. In motion, particularly the start of such motion after a standstill.	没有停泊；没有以任何方式向陆地或码头停靠。正常航行，尤指停顿后所开始的航行。
	undulating	波浪形的，起伏的	(adj.). Having the form of WAVES or SWELLS, as undulating LAND.	有波或涌浪似的形状，如起伏的陆地。
	undulation	波动，起伏	A continuously propagated motion to and from, in any fluid or elastic medium, with no permanent translation of the particles themselves.	在流动或弹性媒体中进行连续往复的传播运动，其粒子本身没有定常运动。
	undulation of the geoid	大地水准面起伏	The distance between the mathematical REFERENCE SPHEROID and the GEOID.	理论参考椭球与大地水准面之间的距离。
	unidirectional antenna	单向天线	See ANTENNA.	在一个方向上具有最大辐射密度或最大增益的一种天线。
	unifilar magnetometer	单丝磁力仪	See MAGNETOMETER.	一种为了在海岸上使用而设计的磁力仪，用于测量地磁的水平强度；亦能用于测定磁差。
	uniform flow	均一水流	Any CURRENT in which neither CONVERGENCE nor DIVERGENCE is present.	无会聚或发散的水流。
	unit magnetic pole	单位磁极	In magnetic theory, a fictitious entity analogous to a unit electric charge in electrostatic theory.	在磁理论中，指一种与静电理论中单位电荷相似的假想体。
	United Nations (UN)	联合国	The major international organization established to maintain international peace and security, to develop friendly relations among nations... more The major international organization established to maintain international peace and security, to develop friendly relations among nations, to achieve cooperation in solving international problems.	为维护国际和平与安全、发展国家之间的友好关系、在解决国际问题方面达成合作而成立的重要国际组织�... more 为维护国际和平与安全、发展国家之间的友好关系、在解决国际问题方面达成合作而成立的重要国际组织。
	United Nations Conference on Trade and Development (UNCTAD)	联合国贸易和发展会议	Helps to restructure patterns of international trade in order to enable developing countries to play their part in world commerce.	旨在帮助调整国际贸易模式，以确保发展中国家在世界经济中发挥自己作用。
	United Nations Development Programme (UNDP)	联合国发展计划署	An UN agency which registers organizations and institutions located in developing countries which have the capacity for cooperative techni... more An UN agency which registers organizations and institutions located in developing countries which have the capacity for cooperative technical activities with organizations in other developing nations. The subject matter includes education and training courses, research and technological development activities, consulting and expert services, and scientific and technical information and used primarily by institutions and governments in developing countries.	注册发展中国家组织和机构的—个联合国机构，该机构可促成它与其他发展中国家间的科技合作活动。其�... more 注册发展中国家组织和机构的—个联合国机构，该机构可促成它与其他发展中国家间的科技合作活动。其主题涉及教育及培养方向、研究及科技发展活动、咨询及专家服务、科学及技术信息，主要面向发展中国家的政府及机构。
	United Nations Educational, Scientific, and Cultural Organization (UNESCO)	联合国教科文组织	Organized in 1945 to promote collaboration among nations in education, science, and culture; UNESCO is the parent agency for the INTERGOVERN... more Organized in 1945 to promote collaboration among nations in education, science, and culture; UNESCO is the parent agency for the INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION.	该组织成立于1945年，主要目的是促进国家之间教育、科学、文化的合作，它是政府间海洋学委员会的上级�... more 该组织成立于1945年，主要目的是促进国家之间教育、科学、文化的合作，它是政府间海洋学委员会的上级机构。
	universal drafting machine	全能绘图仪	See PROTRACTOR: PARALLEL MOTION.	以一个量角器为基础的仪器，其一个或多个臂与平行运动装置相连接，因此向任何方向移动这些臂，均是�... more 以一个量角器为基础的仪器，其一个或多个臂与平行运动装置相连接，因此向任何方向移动这些臂，均是做平行运动。该量角器可旋转并安置在任何位置上，以便在图上定向。
	universal level	圆水准器；通用水准器	See LEVEL: SPIRIT.	一种小型密封的容器（玻璃管），其内部表面上部是弯曲的，容器填充了低粘度的液体（酒精或乙醚），�... more 一种小型密封的容器（玻璃管），其内部表面上部是弯曲的，容器填充了低粘度的液体（酒精或乙醚），在容器顶部的位置上保留了足够形成气泡的自由空间，应用于测量方面有两种类型水准器，一种是球形曲面，产生圆形气泡，称为圆水准器（也称通用水准器或气泡圆水准器）。另一种是大多数情况下使用的类型，容器是一圆形管，其纵向轴也呈圆形。日常所称“水准器”即指这一类型。水准器亦称水准气泡或灵敏气泡。
	Universal Time (UT)	世界时	TIME as defined by the rotational motion of the EARTH and determined from the apparent diurnal motions which reflect this ROTATION. Because ... more TIME as defined by the rotational motion of the EARTH and determined from the apparent diurnal motions which reflect this ROTATION. Because of variations in the rate of rotation, Universal Time is not rigorously uniform. Also called Greenwich mean time.	根据地球自转运动定义的时间，它取决于反映地球自转的周日视运动。由于地球自转速率的变化，世界时�... more 根据地球自转运动定义的时间，它取决于反映地球自转的周日视运动。由于地球自转速率的变化，世界时并不完全均匀。亦称Greenwich mean time（格林威治平时）。
	Universal Time 0 (UT0)	直接测定世界时	The uncorrected TIME of the EARTH's ROTATION as measured by the TRANSIT of STARS across the observer's MERIDIAN. This ROTATION is referred... more The uncorrected TIME of the EARTH's ROTATION as measured by the TRANSIT of STARS across the observer's MERIDIAN. This ROTATION is referred to a fiducial mark on the ECLIPTIC which approximates the position of the MEAN SUN.	英文缩写UT0。指未加地球自转改正的时间，它是由星体通过当地子午圈直接测定的一种时间。地球自转以�... more 英文缩写UT0。指未加地球自转改正的时间，它是由星体通过当地子午圈直接测定的一种时间。地球自转以黄道上某一基准点为参考，该点在平太阳位置附近。
	Universal Time 1 (UT1)	极动世界时，真世界时	UT0 corrected for polar motion.	缩写UT1。指已进行极移改正的UT0。
	Universal Time 2 (UT2)	季差世界时，平世界时	UT1 corrected for seasonal variations in the EARTH's ROTATION.	英文缩写UT2。对UT1进行地球自转季节性变化改正的世界时。
	Universal Time Coordinated (UTC)	协调世界时	The time scale that is available from most broadcast time signals. It differs from INTERNATIONAL ATOMIC TIME by an integral number of second... more The time scale that is available from most broadcast time signals. It differs from INTERNATIONAL ATOMIC TIME by an integral number of seconds. UTC is maintained within 1 second of UT1 by the introduction of 1-second steps (leap seconds) when necessary, normally at the end of December. DUT1, an approximation to the difference UT1 minus UTC, is transmitted in code on broadcast time signals.	英文缩写UTC。指可从大部分广播时间信号获得的时标。它与世界原子时相差整数秒。当需要时，可通过闰�... more 英文缩写UTC。指可从大部分广播时间信号获得的时标。它与世界原子时相差整数秒。当需要时，可通过闰秒方式使其保持在真世界时（UT1）的1秒范围内，一般在12月底调整。DUT1近似表示为UT1减去UTC之差，通过在广播时间信号上编码传送。
There are no records to display