瞬时的

Later, it makes some comparison with four kinds of modulation technique, and finally, it implements the three-level PWM switching power amplifier with the PWM technique. The power of the amplifier is 2kVA, and the frequency bandwidth is 10～3kHz. In the thesis, the author designs and makes the hardwares of the switching power amplifier. The hardwares contain power inverter rank circuit, control system circuit based on DSP, drive and isolation circuit, and protective circuit. The thesis also analyses the potential safety problems and put forward some solutions for the problems. Furthermore, the thesis accomplishes the software design of the control system, and successfully debugs it. The methods of designing higher power ampilfier are also discussed in the thesis. It analyses the feasibility of the methods, outlines the way of how to design higher power switching power amplifier, and does some experiments with the method of switches-parallelling.

根据电动振动试验系统对开关功放的要求，提出了以电感电流瞬时值控制技术为基础的三电平脉宽调制开关功放的设计方案，并通过系统仿真进行了原理性论证；然后设计并制作了开关功放的硬件，包括功率转换电路，基于DSP的控制电路，驱动、隔离电路以及保护电路；针对开关功放数学模型不易得出的特点，细致分析了模糊自适应PID控制方法，在此基础上编写了控制程序；研制出一台功率为2kVA，通频带为10～3kHz的三电平脉宽调制开关功放；论文中还探讨了实现大功率开关功放的方法，分析了各种方法的可行性，给出了实现大功率开关功放的思路，并进行了并联开关管实现大功率开关功放的实验。

The results are as follows: 1 mean length and weight tend to increase while dominant length and weight groups are noted to be increasing from Oct. 2004 to Sep. 2007; 2 by using length-weight formula, calculated weight value at the same length is higher for track-data than that for background-data; 3 growth parameters of L∞, W∞ and K respectively increase from 140.5 mm, 36.5 g and 0.28 a-1 to 186.0 mm, 118.5 g and 0.36 a-1 after artificial reef deployment; 4 appreciable increases are noted in body length and weight growth rate after artificial reef deployment, and inflexion age of weight growth increases from 2.55 to 2.58 years after artificial reef deployment; 5 there is an increase in critical biomass age from 3.21 to 3.77 years after artificial reef deployment; 6 there is a decrease in total instantaneous population mortality from 1.065 to 0.75 per year after artificial reef deployment; and 7 the overall population biomass of small yellow croaker stands at 131.5 tons.

结果表明：投礁后小黄鱼的平均体长和体重均呈上升趋势，优势体长组和体重组均向高值移动；同等体长情况下由投礁后体长体重关系式估算的体重比用投礁前的体长体重关系式估算的值大；投礁后小黄鱼个体生长方程的参数 L∞、W∞、K 值分别从投礁前的140.5 mm、36.5 g和0.28 a-1增加到186.0 mm、118.5 g和0.36 a-1；投礁后体长与体重生长速度与投礁前相比有所增大，且体重生长的拐点年龄从投礁前2.55 a提高到2007年的2.58 a；小黄鱼种群生物量增长的临界年龄从投礁前的3.21 a提高到3.77 a；小黄鱼种群的总瞬时死亡率从投礁前的1.065 a-1减小到0.75 a-1；鱼礁区小黄鱼资源量约

The project proposed and established the strict unique mathematical model of instantaneous frequency aiming at the currently existed problems in Hilbert Huang Transform form the viewpoint of physical connotative meaning; proposed and established the strict mathematical model of general intrinsic mode signal based on the concept of general continuous intrinsic mode signal and the compositive principle of practical general intrinsic mode signal; researched and proposed the fitting method of envelope lines in HHT from the viewpoint of theory, conquered the blindness and random in quondam EMD envelope line fitting and boundary treatment; developed a virtual time-frequency analyzer based on general intrinsic mode signal decomposition to open out the local time-frequency characteristics of nonlinear and nonstationary signal more deeply and accurately.

本项目针对希尔伯特-黄变换现阶段存在问题，从物理内涵的角度提出并建立了瞬时频率严格的唯一的数学模型；基于连续性的一般固有模态信号的概念和实际信号的一般固有模态信号的组成原理，提出并建立了一般固有模态信号严格的数学模型；从理论角度研究并提出HHT中的包络线构造方法，克服了原EMD的包络线构造和边界处理的盲目性和随意性；研发一台基于一般固有模态信号分解的虚拟式时频分析仪，使之可以更深入、准确地揭示非线性非平稳信号的时频局部特征。

Some Thinking of Quantitative Study on Interaction between Explosive Charge and Rock: Because of the non-linear property and the variety of rock, the instantaneity of chemical action of explosive, the complexity of the dynamic process of the interaction between explosive and rock and the limitations of the observation measurements, the former research results mainly focused on the explanation and description to the apparent phenomena, and difficult to obtain the accurate and quantitative answers.

爆炸荷载与岩体相互作用定量化研究的几点思考：由于岩体自身的非均质性及各向异性和地质构造的多样性、炸药爆炸本身的化学反应的多变性和瞬时性、炸药与岩体相互作用的复杂性，加之爆破测试方法和仪器的局限性，使得以往的研究多沿用经典理论集中于表面现象的描述与解释，难以获得完整的、准确的和定量的解答，必须从一个全新的角度研究探索爆炸荷载与岩体相互作用的本质。

Laodamia when the greek ships reached the trojan land at the outbreak of the war,a prophet declared that the first greek setting foot on the enemy soil was doomed to die .protesilaus ,a greek chief ,seeing that there was a gooddeal of hesitation among his comrades ,leapt overboard and fellinstantly ,pierced through by hector''s spear .when his wife laodamia heard of this she was simply inconsolable .she offered rich sacrifice to the gods and begged zeus to restore herslaughtered lord to her.moved by her fidelity ,zeus sent hermes to escort the shade of protesilaus back to the upper air tostay with his wife for three hours.laodamia''s joy knew nobounds when she held her slain lord once more in her arms.protesilaus told her the story of his selfsacrifice ,and laodamiawas happy to become a bride for a second time.however ,shegave a sharp cry when she saw hermes coming at the fixed hourto take protesilaus back to the lower world.so sad was she at the second parting that she died of grief not long after.the pairwere reunited in hades.

拉俄达弥亚当战争爆发时，段腊般抵达特洛伊地区。一位预言家宣称，第一个踏上敌人土地的段腊人注定会死。一位名叫普洛忒西拉斯的希腊酋长看着同伴踌躇不前，就从船上跳入水中，一瞬时他就倒下了，被海克特的长矛穿透了胸膛。他的妻子拉俄达弥亚听到这个消息，悲痛之心无法得以慰藉。她献给众神丰厚的祭品，哀求宙斯把被杀的丈夫还给她。她的忠贞感动了宙斯。宙斯派海默斯护送普洛忒西拉斯的幽魂回到阳间与他的妻子共度三个小时。她再次拥抱被杀的丈夫。她的喜悦无边无际。普洛忒西拉斯给她讲述了他自我献身的故事。拉俄达弥亚很高兴再做一次新娘。然而，当海默斯预定的时间到来时，普洛忒西拉斯将被带回阴间，她痛苦地叫了一声。对于第二次分别她如此悲痛不堪，以致于不久之后就在痛苦之中死去。他们在冥府之中再次团圆。

When the greek ships reached the trojan land at the outbreak of the war,a prophet declared that the first greek setting foot on the enemy soil was doomed to die .protesilaus,a greek chief,seeing that there was a gooddeal of hesitation among his comrades,leapt overboard and fellinstantly,pierced through by hector''s spear .when his wife laodamia heard of this she was simply inconsolable .she offered rich sacrifice to the gods and begged zeus to restore herslaughtered lord to her.moved by her fidelity ,zeus sent hermes to escort the shade of protesilaus back to the upper air tostay with his wife for three hours.laodamia''s joy knew nobounds when she held her slain lord once more in her arms.protesilaus told her the story of his selfsacrifice,and laodamiawas happy to become a bride for a second time.however,shegave a sharp cry when she saw hermes coming at the fixed hourto take protesilaus back to the lower world.so sad was she at the second parting that she died of grief not long after.the pairwere reunited in hades.

当战争爆发时，段腊般抵达特洛伊地区。一位预言家宣称，第一个踏上敌人土地的段腊人注定会死。一位名叫普洛忒西拉斯的希腊酋长看着同伴踌躇不前，就从船上跳入水中，一瞬时他就倒下了，被海克特的长矛穿透了胸膛。他的妻子拉俄达弥亚听到这个消息，悲痛之心无法得以慰藉。她献给众神丰厚的祭品，哀求宙斯把被杀的丈夫还给她。她的忠贞感动了宙斯。宙斯派海默斯护送普洛忒西拉斯的幽魂回到阳间与他的妻子共度三个小时。她再次拥抱被杀的丈夫。她的喜悦无边无际。普洛忒西拉斯给她讲述了他自我献身的故事。拉俄达弥亚很高兴再做一次新娘。然而，当海默斯预定的时间到来时，普洛忒西拉斯将被带回阴间，她痛苦地叫了一声。对于第二次分别她如此悲痛不堪，以致于不久之后就在痛苦之中死去。他们在冥府之中再次团圆。

Laodamia 拉俄达弥亚 when the greek ships reached the trojan land at the outbreak of the war,a prophet declared that the first greek setting foot on the enemy soil was doomed to die .protesilaus,a greek chief,seeing that there was a gooddeal of hesitation among his comrades,leapt overboard and fellinstantly,pierced through by hector''s spear .when his wife laodamia heard of this she was simply inconsolable .she offered rich sacrifice to the gods and begged zeus to restore herslaughtered lord to her.moved by her fidelity ,zeus sent hermes to escort the shade of protesilaus back to the upper air tostay with his wife for three hours.laodamia''s joy knew nobounds when she held her slain lord once more in her arms.protesilaus told her the story of his selfsacrifice , and laodamiawas happy to become a bride for a second time.however,shegave a sharp cry when she saw hermes coming at the fixed hourto take protesilaus back to the lower world.

当战争爆发时，段腊般抵达特洛伊地区。一位预言家宣称，第一个踏上敌人土地的段腊人注定会死。一位名叫普洛忒西拉斯的希腊酋长看着同伴踌躇不前，就从船上跳入水中，一瞬时他就倒下了，被海克特的长矛穿透了胸膛。他的妻子拉俄达弥亚听到这个消息，悲痛之心无法得以慰藉。她献给众神丰厚的祭品，哀求宙斯把被杀的丈夫还给她。她的忠贞感动了宙斯。宙斯派海默斯护送普洛忒西拉斯的幽魂回到阳间与他的妻子共度三个小时。她再次拥抱被杀的丈夫。她的喜悦无边无际。普洛忒西拉斯给她讲述了他自我献身的故事。拉俄达弥亚很高兴再做一次新娘。然而，当海默斯预定的时间到来时，普洛忒西拉斯将被带回阴间，她痛苦地叫了一声。

When the greek ships reached the trojan land at the outbreak of the war,a prophet declared that the first greek setting foot on the enemy soil was doomed to die .protesilaus,a greek chief,seeing that there was a gooddeal of hesitation among his comrades,leapt overboard and fellinstantly,pierced through by hector\''\''s spear .when his wife laodamia heard of this she was simply inconsolable .she offered rich sacrifice to the gods and begged zeus to restore herslaughtered lord to her.moved by her fidelity ,zeus sent hermes to escort the shade of protesilaus back to the upper air tostay with his wife for three hours.laodamia\''\''s joy knew nobounds when she held her slain lord once more in her arms.protesilaus told her the story of his selfsacrifice,and laodamiawas happy to become a bride for a second time.however,shegave a sharp cry when she saw hermes coming at the fixed hourto take protesilaus back to the lower world.so sad was she at the second parting that she died of grief not long after.the pairwere reunited in hades.

当战争爆发时，希腊般抵达特洛伊地区。一位预言家宣称，第一个踏上敌人土地的希腊人注定会死。一位名叫普洛忒西拉斯的希腊酋长看着同伴踌躇不前，就从船上跳入水中，一瞬时他就倒下了，被海克特的长矛穿透了胸膛。他的妻子拉俄达弥亚听到这个消息，悲痛之心无法得以慰藉。她献给众神丰厚的祭品，哀求宙斯把被杀的丈夫还给她。她的忠贞感动了宙斯。宙斯派海默斯护送普洛忒西拉斯的幽魂回到阳间与他的妻子共度三个小时。她再次拥抱被杀的丈夫。她的喜悦无边无际。普洛忒西拉斯给她讲述了他自我献身的故事。拉俄达弥亚很高兴再做一次新娘。然而，当海默斯预定的时间到来时，普洛忒西拉斯将被带回阴间，她痛苦地叫了一声。对于第二次分别她如此悲痛不堪，以致于不久之后就在痛苦之中死去。他们在冥府之中再次团圆。古希腊神话故事：阿瑞塞莎

The results show that the equiaxed zone ratio of the casting billet is greatly increased,with its soidification structure is obviously improved,and the momentum values of the electromagnetic forces both parallel to and perpendicular to the direction of the traveling magnetic field pulsate periodically with time.

采用三相通入不同电流的非平衡线性电磁搅拌技术进行了铸坯的静态浇铸实验，并对电磁搅拌过程中钢液内的电磁力各分量的瞬时值进行了理论分析·结果表明，当采用将电磁搅拌器的三相通入不同电流的非平衡线性电磁搅拌时，在钢液内所产生的电磁力是脉动的，其大小呈周期性变化，尤其是垂直于磁场运动方向上的电磁力，其脉动的幅度很大·由此认为，当采用将搅拌器的三相通入不同电流的非平衡线性电磁搅拌时，所产生的垂直于磁场运动方向上的脉动电磁力是提高等轴晶比率，改善铸坯凝固组织的一个重要原

We introduce convex,and in particular semidefinite,optimization methods,duality and complexity theory to shed new light to this relation for the single stock problem, given moments of the prices of the underlying assets,we show that we can find best possible bounds on option prices with general payoff funcations efficiently,either algorithmically(solving a semidefinite optimization problem)or in closed form, conversely,given observable option prices,we provide best possible bounds on moments of the prices of the underlying assets,as well as on the prices of the other options on the same asset by sovling linear optimization problems for options that are affected by multiple stocks either directly(the payoff of the option depends on multiple stocks)or indirectly(we have information on correlations between stock prices),we find on-optimal bounds using convex optimization methods,however,we show that it is NP-hard to find best possible bounds in multiple dimensions,we extend our results to incorporate transactions costs,this paper,in theory and practice can provide a reference to researchers and designers about Chinese financial derivative products,the full text is divided into six chapters as follows: ChapterⅠ:Papers on the background and significance of the subjects on a number of option pricing models as well as their advantages and shortcomings of the model and describes the status of research and writing papers and the main contents of the basic idea.

相应地，给定期权价格，也能够出标的资产瞬时价格的最有可能的最好的界。还有通过解决一个线性最优化问题，根据同一标的资产的其他期权的价格来找到这个期权的界值，对于期权受到多种股票价格直接影响(期权的收益依赖于多种股票)或者间接影响(我们有股票之间联系的有用信息)，如果使用凸规划方法我们就会发现没有最优的界，也能够证明对于多维情形确实是很难找到最优的最有可能的界值，最后将这一结论推广到考虑交易成本的情况。本文在理论和实践上给我国金融衍生产品研究者和设计者提供一定的参考。全文共分为六章，具体安排如下：第一章：阐述论文的选题背景和意义，介绍期权定价的一些模型以及这些模型的优点与缺点，并介绍国内外研究的现状以及论文的写作基本思路与主要内容。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。