喷射成形+轧制Al-Pb/Al/Steel复合板材界面

对喷射成形＋轧制Ａｌ－Ｐｂ／Ａｌ／Ｓｔｅｅｌ复合板材进行了热处理,用ＳＥＭ观察了Ａｌ－Ｐｂ／Ａｌ及 Ａｌ／Ｓｔｅｅｌ界面的变化．结果表明：复合轧制后Ａｌ－Ｐｂ／Ａｌ及Ａｌ／Ｓｔｅｅｌ界面达到了良好的界面初结合; 复合板材热处理后,Ａｌ／Ｓｔｅｅｌ界面在４８０℃／１ｈ＋３００℃／３ｈ的热处理后产生了ＦｅＡｌ金属间化合物.     

小城镇土地利用环境效益综合评价探讨——以重庆市北碚区为例

提高小城镇土地利用的环境效益是小城镇建设的一项重要任务。小城镇土地利用环境效益综合评价直接反应小城镇土地利用的环境效益。文章建构了小城镇土地利用环境效益综合评价的指标体系,并采用多因素综合评价的方法,对重庆市北碚区小城镇土地利用的环境效益进行了分析,由此对小城镇土地利用环境效益综合评价的方法进行一定的探讨。     

水肥耦合作用对土壤养分变化及春小麦生长发育的影响

水肥耦合最优饱和试验研究表明,在辽西半干旱区,低水量条件易引起N肥以氨态N挥发损失,当灌水量超过460mm时,高量施N可能会导致硝态N深层淋溶,高量施用P肥,土壤表层中OlsenP增加不明显,且灌水量变化对OlsenP在土壤各深度层次中含量影响不明显,N肥是影响春小麦生育前期叶面积指数和株高的主要因子,水分对春小麦株高的影响在生育前期不明显,至灌浆期时跃居主导地位,N、P配合施用可明显提高春小麦旗叶面积和株高。     

Electric field-induced oscillation of sessile droplets

We report a novel oscillatory behavior of a sessile droplet on a hydrophobic surface. The droplet was placed on an electrode with a hydrophobic surface and close to, but not touching, a second needle-like electrode. The change in the contact angle was observed only when the droplet oscillated. In a traditional electro-wetting experiment, however, the contact angle decreased immediately when an alternating current electric field was applied. In addition, the non-contact mode gave rise to a true sessile condition of the droplet, whose oscillation amplitude was not linearly proportional to the driving voltage but reached a maximum value.     

The foxtail millet Si69 gene is a Wali7 (wheat aluminum-induced protein 7) homologue and may function in aluminum tolerance

We isolated a clone, named Si69, from a foxtail millet immature seed cDNA library. The protein encoded by Si69 contains a conserved Wali7 (wheat aluminum induced protein 7) domain and shares high-level homology with aluminum-induced proteins from other species including rice and Arabidopsis. The Si69 gene presents as a single locus in foxtail millet genome and is globally expressed in all tissues examined. Its expression is up-regulated by aluminum. The sequence feature and expression pattern suggest that t...     

Image Reconstructions from Limit Views and Angle Coverage Data for a Stationary Multi-Pinhole SPECT System

The goal of this paper is to investigate different reconstruction methods for solving the limited angle problem in reconstructing the projection data from a stationary multi-pinhole system based on a three-head clinical single photon emission computed tomography(SPECT) camera.Three iterative reconstruction approaches were studied including maximum likelihood expectation maximization(MLEM),maximum a posteriori expectation maximization(MAPEM) with a smoothing prior,and an alternating optimization schemes from...     

Leader-following consensus protocols for formation control of multi-agent network

Two protocols are presented,which can make agents reach consensus while achieving and preserving the desired formation in fixed topology with and without communication timedelay for multi-agent network.First,the protocol without considering the communication time-delay is presented,and by using Lyapunov stability theory,the sufficient condition of stability for this multi-agent system is presented.Further,considering the communication time-delay,the effectiveness of the protocol based on Lyapunov-Krasovskii function is demonstrated.The main contribution of the proposed protocols is that,as well as the velocity consensus is considered,the formation control is concerned for multi-agent systems described as the second-order equations.Finally,numerical examples are presented to illustrate the effectiveness of the proposed protocols.     

Phase reaction of Au/Sn solder bonding for GaN-based vertical structure light emitting diodes

Au/Sn solder bonding on Si substrates was used to fabricate the GaN-based vertical structure light emitting diodes (VSLEDs). The phase reaction of Au/Sn solder under different bonding conditions was investigated by the measurement of electron back scattering diffraction (EBSD), and the characteristics of VSLED were analyzed by scanning acoustic microscope (SAM), Raman scattering, current-voltage (I-V) and light output-current (L-I) curves. After the bonding process, horizontal stripes of Au/Sn phase (δ phas...     

偏Doi-Hopf π-模范畴和函子

设π-是一个群．本文我们引入了Hopfπ-代数上的模的Doi-Hopfπ-概念．得到了偏Doi—Hopfπ-模范畴上的忘却函子可分的充要条件,其中忘却函子忘却的是π-A作用．作为应用,我们证明了偏Doi-Hopfπ-模范畴上的Maschke型定理．     

梅里雪山气候变化与旅游气候舒适度评价

利用德钦气象站1954-2014年逐日观测资料,采用线性趋势分析法分析了梅里雪山气候变化特征,选用温湿指数、风效指数、着衣指数和综合舒适度指数对该山地旅游气候舒适度进行了分析和评价.结果表明:161年来梅里雪山年极端最高气温、年平均最高气温、年平均最低气温、年平均气温呈极其显著的上升趋势,年极端最低气温、年降水量、年日照时数、年相对湿度、年平均风速呈不显著的下降或减少趋势.2梅里雪山最适宜旅游出行时间为每年5-10月,1990年以来,综合舒适度指数呈下降趋势,舒适期延长,有利于旅游业的发展.3年综合舒适度指数呈下降趋势,逐渐由不舒适型向舒适型转变,主要与年平均气温和年极端最高气温的显著上升、年日照时数和年平均风速的减少有一定的关系.