衰變速率 的英文怎麼說
中文拼音 [shuāibiànsùlǜ]
衰變速率
英文
decay rate-
Given the decay rate of 26al, the lower initial ratio in the chondrules implies that these objects formed between one million and two million years after the creation of the refractory inclusions ( assuming that the radioisotope was indeed homogeneously distributed in the early solar system )
以鋁26的衰變速率估計，這些球粒的初始比值較低，表示它們是在耐火包體產生后100 ~ 200萬年才形成（假設鋁26在早期太陽系中確實是均勻分佈的） 。The breakdown of radioactive isotopes goes on at constant rates.
放射性同位素的衰變在恆定的速率下進行。The actual rate of decay may be somewhat greater or less than this expected rate.
衰變的實際速率可以比這個預期速率稍大些或稍小些。And the most advantage of ofdm is that it can convert high - rate data stream into the low - rate and reduce data bandwidth so that multi - path - fading can be transformed into flat fading in wireless circumstance
這種調制技術的最大的好處就是將高速的數據流，變換成并行的低速數據流，減小了數據帶寬，從而可將無線環境中的多徑衰落（頻率選擇性率落）轉換成平坦衰落。Objective : to investigate the effects and complications of hypertonic saline in the treatment of hyponatremia in patients with obstinate heart failure and to find out prophylactic and therapeutic measures against the complications. methods : to analyze the changes of electrolytes, urea nitrogen, serum creatinine, heart rate, blood pressure, cardiac function after the treatment of hyponatremia in patients with obstinate heart failure by 3 hypertonic saline. results : after the improvement of hyponatremia, cardiac function, the levels of electrolytes, urea nitrogen, serum creatinine were improved significantly. blood pressure rised slightly. heart rate did not change. conclusion : hypertonic saline can redress hyponatremia, improve cardiac function and decrease the levels of urea nitrogen and serum creatinine rapidly and effectively. blood pressure and heart rate did not change significantly
目的探討高滲鹽水在低鈉性頑固性心力衰竭治療過程中的作用和可能出現的並發癥以及防治對策.方法分析3高滲鹽水治療低鈉性頑固性心力衰竭前後的電解質、尿素氮、肌酐、心率、血壓、心功能的變化.結果治療前後心功能、電介質、尿素氮、肌酐有明顯改善，血壓輕度升高，心率無明顯變化.結論高滲鹽水能快速有效地糾正低鈉血癥，有助於心功能的迅速改善，降低血尿素氮、肌酐.對血壓和心率影響不大The study shows that the early and late seed rains of constructive tree species in evergreen broadleaved forest at chongqing simian mountain had no activity. the bigger the seeds of the species and the earlier or later the seeds of the species matured, the higher the proportion of the seed rain damaged by animals. the quantitative variation of seed rain, active seed rain and seed bank did not take place at the same time. at early time, the number of seed banks of castanopsis fargesii, lithocarpus glabra, quercus myrsinrefolia, castanopsis plasyacantha, cinamomum subavenium. which own more active seed rain increased by geomitric series. the seed banks of castanopsis orthacantha and schima argentea were small, only survived a short time, and did not sprout next year. the quantitative dynamics of seed banks and their increasing or decreasing rates were decided by the proportion damaged by animals, dying speed of seeds and their resistance to pathogens and adverse circumstances, and the state of seed germination
對重慶四面山常綠闊葉林建群種種子雨、種子庫的研究表明，建群種早期和晚期的種子雨無活力;種子偏早或偏晚成熟及大籽粒的樹種，其種子雨被取食的比例大;種子雨、有活力種子雨、種子庫三者的數量變化不一致;有活力種子雨量較大的栲、石櫟、小葉青岡、扁刺栲、香桂等，其種子庫密度在早期以近幾何級數的方式增長，元江栲、銀木荷種子庫小，存在時間短，翌年無一年生萌發苗;種子庫數量動態、消減率動態決定於種子被取食的強度、種子衰老的速度以及種子對病菌、逆境的抗性和種子萌發的整齊性It is indicated that the hydration process of cement - based materials with slag, fly ash and silica fume is different in some degree from that of neat cement because of the difference in mineral structure and hydration mechanism. the periods of accelerating, decelerating and terminating are prolonged and hydration reaction decelerates. the second peak of rate curve of the heat evolution could be divided into two small peaks, which are contributed to the hydration of clinkers and mineral mixtures at the temperature of 30 but when temperature comes to 50, the two small peaks combine into one and the reaction accelerates
結果表明，與硅酸鹽水泥相比，由於礦物摻合料與水泥熟料在活性和水化機理上的差異，水化歷程有較大的改變：多組分體系誘導期、加速期和衰減期延長，水化反應速率明顯降低；低溫時，水化放熱速率曲線上的第二放熱峰細化成分別對應于熟料和礦物摻合料水化的兩個小峰；高溫時，反應速率加快，雙峰合併；進一步研究發現，摻合料的種類與摻量對水化歷程也有較大的影響；建立了適用於多組分水泥基材料不同水化階段的水化動力學方程。The following algorithms have been proposed and tested in the thesis : 1 frequency selective fading : combine the isomorphism between the input space and the output space and propose a new approach to blind equalization of the channel. compared with conventional methods, the new approach offers lower computational complexity, better performance, and more robust against the over - determination of the system order ; 2 time selective fading : a new approach to the equalization of time selective channel based on the zero - forced equalizer is proposed which is more simple in its structure of algorithm ; 3 time - varying channel : using the instantaneous mean value changes of the output signal to extract the information of channel variations and model it using ar model, kalman filter is then employed to track channel variations, it bears faster ability in tracking the variation of tv channels ; based on the isomorphism between the inputs and the outputs and some of the approaches using in mimo system, a new algorithm of equalization of simo time - varying channel is proposed, which also share the merits of being robust against the over - determination of the system order ; model the time - varying channel using the multi - resolution decomposition wavelets, and then a blind identification method based " on the model is proposed ; at last, a new model for equalization and identification of mimo system is proposed
主要工作在以下幾個方面： 1 、針對頻率選擇性衰落通道：結合輸入輸出空間同構關系提出一種新的頻率選擇性通道均衡方法，與傳統方法相比，該方法計算量更小，收斂速度更快，性能更優，且對系統階次的過確定表現穩健，具有實際均衡應用價值； 2 、針對時間選擇性衰落通道：提出一種基於迫零均衡的時間選擇性通道均衡方法，演算法結構簡單； 3 、針對時變色散通道：利用瞬態均值曲線提取通道時變信息，對之ar建模，利用卡爾曼濾波器跟蹤時變通道抽頭變化，可以快速跟蹤通道變化；基於輸入輸出空間之間的同構關系以及多輸入多輸出系統的處理方法，提出了新的單輸入多輸出色散時變通道均衡與識別演算法，同樣具有對通道階次過確定保持穩健的優點；結合小波多解析度分析提出一種基於小波模型的通道盲識別演算法；研究時變的多輸入多輸出系統的盲均衡與盲反卷積問題，給出一種時變系統處理模型。According to structural characteristics of multi - phased alloy steels and the properties of ultrasonic propagation, microstructures characterization with different heat treatment processes ( normalizing, quenching / annealing, quenching plus low tempering, quenching plus high tempering ) for three steels ( 40cr, 38crmoal, gcrlssimn ) was studied experimentally by using ultrasonic methods. ultrasonic velocity, relative attenuation coefficient, and power spectral analyses were researched on the same samples respectively, on the basis of theory and experiment, the sensitivity and other characterizations of the three methods used to distinguish different microstructures were compared
根據具有多種相結構合金鋼不同熱處理轉變產物的組織特點，以及超聲波在其中的傳播規律，利用超聲波速度、相對衰減系數以及功率譜分析三種方法，對三種鋼（ 40cr 、 38crmoal及gcr15simn ）不同熱處理（正火、淬火退火、淬火+低溫回火及淬火+高溫回火）轉變產物的顯微組織進行了超聲表徵研究。In this scheme, power control is primary to the rate control. when the fading channel changes slowly, the transmit data rate will be kept on an appropriate level, and only the power control works to keep up with the channel fading and balance the sir. but when the channel quality is poor, the data rate will be switched down without sacrificing the ber ; otherwise, high data rate was selected
我們提出的方案根據反饋的sir動態改變數據的速率和功率，其中功率控制優先於速率控制，當通道變化緩慢時，數據率保持在一個相對穩定的值上，調節發射功率來維持sir平衡；當功率調節無法彌補通道的衰落時，則通過調節速率來維持sir的平衡。The respiratory rate of " chunxing " strawberry decreased gradually after harvest, but it increased in the end of the fruits senescence. therefore, " chunxing " strawberry was one late - respiration peak type fruit
春星草莓果實采后呼吸速率變化呈下降趨勢，在過熟衰老時呼吸速率又上升，應屬末期上升型。The underwater acoustic channel is very complex where cochannel interference, doppler frequency offsets, narrow bandwidth and time and frequency selective deep fades obstructs the development of high speed and fidelity underwater data transmissions. thus projects of high speed and fidelity underwater signal transmissions become a hotspot in the fields of world academic circles. the conventional serial communication must use adaptive equalizer to combat the multipath in real - time
海洋水聲通道是一種極其復雜多變的時-空-頻變參通道，其通道窄，強多途干擾，信號起伏衰落嚴重，一直是水下信息可靠高速傳輸的主要障礙，因此如何在水聲通道中高速率準確地傳輸數據，就成為世界性的熱門課題。These are correlation characteristic parameter, fourier spectrum characteristic parameter, power spectrum characteristic parameter, time domain amplitude characteristic parameter, linear prediction coding coefficients, instantaneous characteristic parameter, absorb and decay coefficient, velocity characteristic parameter and wavelet packet transform characteristic parameter. the parameters contain the surface relatively wide, the prediction which is suitable for the goal of many kinds of seism needs
分別為：自相關特徵參數、付立葉譜特徵參數、功率譜特徵參數、時域振幅特徵參數、線性預測編碼系數、瞬時特徵參數、吸收衰減系數、速度類特徵參數和小波包變換特徵參數，參數涵蓋面較寬，適用於多種地質目標的預測需要。Along with increase of pressure, the parameters such as velocity, amplitude, main frequency and quality factor of seismic wave change big gradually, while change very weakly with the change of temperature. through testing research for artificial crack and pore model, we conclude that crack density, azimuth, opening and the change of pore have obvious influences on speed, amplitude, attenuation ( or quality factor ) and main frequency of seismic wave etc. but, seismic wave dynamic characteristics are more evident than its kinematical characteristics for the change of crack and pore parameters. therefore, it offers reliable experiment foundation for detecting crack and pore by seismic wave kinematical characteristics ( such as amplitude, attenuation and main frequency etc. )
通過對人工裂縫和孔洞模型的超聲波實驗研究，可以認為：裂縫密度、方位、張開度和孔洞密度的變化對縱橫波的速度、振幅、衰減（或品質因子q ）和主頻率等參數均有明顯的影響，但裂隙參數的變化對地震波動力學特徵參數（振幅、衰減、主頻率等）的影響遠遠大於對運動學特徵參數（速度等）的影響，這為利用地震波的振幅、衰減和主頻率等屬性參數進行裂縫和孔洞特徵的檢測提供了可靠的實驗基礎。Based on these advantages we analyze the performance of constant - power variable - rate m - qam schemes for spectrally efficient data transmission over nmf channels. by introducing the adaptive modulation approach, we gain two things : 1 ) the error rate is kept at a constant level. 2 ) the achievable spectral efficiency comes within 5 db of the shannon capacity limit. at the last chapter, the presentation of a single base station and a single mobile scenario proved the feasibility of adaptive schemes
然後作者的精力轉入通道的自適應方案的研究中，首先通過研究發現nakagami衰落因子的適當調整可以近似於常見的瑞利衰落和萊斯衰落，接著研究在無線通道中採用三種不同自適應方案時的通道容量，研究表明速率的調整是增加通道容量的關鍵，在此基礎上，著重研究了離散變速率qam的情況，表明這種調制方案無論在頻帶利用率還是在系統平均誤碼率比其它情況提高很多。The accurately controlled signal source generates sinusoidal elastic wave accurately controlled in frequency and stable in phase to " illustrate " underground media. time signal stacker receive signal by stacking and doing fft to measure the transfer function of media. " sompi " cepstrum method retrieve group velocity travel times and decayed factors of wave element from observational data of transfer function in a limited frequency window
精密可控震源用於產生頻率精確相位穩定的正弦彈性波以照射地層內部，信號疊加器通過對接收信號進行疊加和進行傅立葉變換的方式實現對介質傳遞函數的精密測量， 「存否」倒譜方法能夠根據一段窄帶頻域傳遞函數數據獲得時域上各個波成分的群速度傳播時間和介質衰減因子。分享友人