Depending on the character of Lamb wave propagation , thedamage scat tering signals were time reversed and reemit ted to the damage , and then they will arrive at the damage synchronously so that the damage scat tering signal caught again will be amplified. Details about the time reversal amplifying process were analyzed and given. Based on the focalization ability of time reversal theory to the wave origin , the wave propagation was rebuilt by an image method which displays the damage as the focusing point .

根據(jù)信號傳播自身的特性国产精品第5页狼友视频，研究采用時間反轉(zhuǎn)聚焦方法使損傷散射信號能量疊加放大Aa黄色网址，從而提高信號的信噪比91在线精品啪高清免费观看，分析給出了具體的損傷信號時間反轉(zhuǎn)聚焦增強過程欧美直播a片；利用時間反轉(zhuǎn)法對波源的自適應(yīng)聚焦能力jizzjizz20，重建信號傳播波動圖国产精品iGAO视频免费，通過信號聚焦顯示損傷位置和區(qū)域。

To associate aseismic design idea that"no damage under light earthquake, reparable under medium degree earthquake and no collapse under intense earthquake"with design method based on damage property, the thesis adopted different damage limit values to control structural damages at different levels so that the designed structure can embody the substantial need of aseismic design based on damage property.

把"小震不壞99日视频这里只有精品、中震可修东南亚高清无码视频、大震不倒"的抗震設(shè)計原則與基于損傷性能的方法統(tǒng)一起來，采用不同的損傷容限值來限定各水準下的結(jié)構(gòu)損傷二级A片视频在线，從而使所設(shè)計的結(jié)構(gòu)充分體現(xiàn)基于損傷性能抗震設(shè)計的實質(zhì)要求资源站先锋。

This damage criterion reflects the character of RCC, and shows that stress degree of RCC damage decreasing with heat current density vector and temperature gradient augmenting. If this process of RCC damage is in constant temperature, the damage completely depends on stress degree, which accords with the result of experiment.

結(jié)果 碾壓混凝土熱耗散和損傷耗散累積到一定程度時18在线观看黄片，損傷破壞就會發(fā)生，且隨著熱流密度矢量和溫度梯度增大人人操人人插人人摸人人人人玩，碾壓混凝土發(fā)生損傷破壞的應(yīng)力水平將降低亚洲毛片无码一区二区，如碾壓混凝土是一個等溫變化過程，則損傷完全取決于應(yīng)力水平亚洲免费每日在线观看一级性生活片。

So in this paper a new damage variable was defined, then, Based on damage theory and Weibull distribution damage evolution rule, a simplified ameristic damage constitutive equation was established for concrete under uniaxial compression.

為了用簡單的方程將上升段和下降段連接起來国产欧美日韩免费影片在线观看，本文以峰值割線模量為基準，定義了一種新的損傷變量国产高清在线看AV网站免费；并以經(jīng)典損傷理論模型為基礎(chǔ)特黄一区黄片，根據(jù)混凝土損傷演化規(guī)律的概率密度服從Weibull分布，提出了一個統(tǒng)一的方程來描述混凝土單軸壓縮時應(yīng)力應(yīng)變關(guān)系的全過程日韩性色加勒比在线观看。

What\'s more, different intervals of UV have their own characters in influencing DNA: the damage to some bases by UVA may be more serious than that by UVB, and UVB did more severe damage to some deoxyribose than UVA; however, as far as the pyrimidine bases are concerned, the damage by UVB is by far more serious than that by UVA. These results may indicate that there are preferential damaging sites on DNA molecules caused by UVA and UVB irradiation. Moreover, with UVA or UVB irradiation for a long time, the photoreactivation of DNA occurred. The serious damage to deoxyribose and bases by UVB and UVC may confirm the conformation of cyclobutane pyrimidine dimers and (6-4) photoproducts.

而不同波段紫外輻射對DNA的損傷各具特點并且差異明顯日韩午夜一级毛片，UVA對一些堿基的損傷比UVB要嚴重，而UVB在對脫氧核糖和磷酸鹽的損傷上又比UVA要嚴厲男女猛烈无遮挡免费视频在线观看，但就嘧啶堿基來說干少妇33P图，UVB對它的損傷遠大于UVA，這似乎表明了不同的紫外波段對生物大分子DNA的損傷是有選擇性的国产高清久久久久久久。

In order to describe the fatigue damage characteristic under multiaxial proportional and nonproportional loading, a new nonlinear multiaxial fatigue damage cumulative model was presented on the basis of combining multiaxial fatigue damage characteristic. The recurrence formula of multiaxial fatigue damage model was derived under multilevel loading.

為了描述多軸比例與非比例加載下的疲勞損傷特性美女视频网址，結(jié)合多軸疲勞損傷的特點，建立了一種新的非線性多軸疲勞損傷累積模型丁香花色色网，并推導(dǎo)給出了該疲勞損傷累積模型在多級加載條件下的遞推公式色一鲁中文字幕。

With the frequency and mode shape being regarded as functions of damage parameters, the overdetermined algebraic equations with damage parameters as unknowns can then be constructed by differentiating frequency and mode function on the basis of structure mode finite element formula, the damage parameters of which are obtained via Taylor expansion. The whole damage parameters can be found via solving the algebraic equations.

本方法從結(jié)構(gòu)模態(tài)有限元算式出發(fā)，把頻率和振型看作損傷參數(shù)的函數(shù)真人av在线免费看，經(jīng)過泰勒展開獲得頻率中国无毛黄色视频、振型對損傷參數(shù)的一階偏導(dǎo)數(shù)，然后構(gòu)造以損傷參數(shù)為未知量的超定線代方程組妓女在线网，求解得到全部損傷參數(shù)值在线你懂得。

Among these three types of water locking damage, the water locking under underpressure condition has the minimal damage, the damage under overpressure condition is relatively maximal, and the damage under normal pressure is relatively medial pressure is relatively medial.

研究表明，低滲透砂巖氣藏的水鎖傷害具有普遍性和嚴重性色、操国产，其中欠壓作用下的水鎖傷害最小人人玩人人添人人澡欧美，超壓作用下的水鎖傷害最大，常壓作用下的水鎖傷害居中欧美一级免费播放。

Based on statistical damage theory, the instantaneous damage constitutive relationship of gypsum breccias is studied. In consideration of the impact of damage threshold, a statistical damage constitutional equation is established.

在以上試驗的基礎(chǔ)上羞羞自拍无码视频在线观看中文字幕，基于統(tǒng)計損傷理論研究了石膏角礫巖瞬時損傷應(yīng)力應(yīng)變本構(gòu)關(guān)系，提出統(tǒng)計損傷應(yīng)考慮損傷門檻的影響日韩午夜第一页在线播放观看，建立了考慮損傷門檻的統(tǒng)計損傷本構(gòu)方程黄免费观线看，理論計算結(jié)果與常規(guī)試驗結(jié)果比較接近。

ABSTRACT Based on the existing damage model of rock blasting and the theory of rock damage and fracture, a new damage model for rock blasting, a gas-driven fracture propagation and damage localization at the crack tip model during explosion products are proposed.

在分析研究現(xiàn)有巖石爆破損傷模型和巖石損傷斷裂理論的基礎(chǔ)上人人妻人人干人人操黄色影网站，建立了一個新的巖石爆破損傷模型和巖石在爆生氣體作用下的裂紋擴展及裂紋尖端損傷局精品中文字幕一区二区三区四区。。黄片在线免费看A片。