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151.
152.
《环境科学学报(英文版)》2023,35(4):58-69
Co-exposure to heavy metal and antibiotic pollution might result in complexation and synergistic interactions, affecting rice growth and further exacerbating pollutant enrichment. Therefore, our study sought to clarify the influence of different Tetracycline (TC) and Cadmium(Cd) concentration ratios (both alone and combined) on rice growth, pollutant accumulation, and transportation during the tillering stage in hydroponic system. Surprisingly, our findings indicated that the interaction between TC and Cd could alleviate the toxic effects of TC/Cd on aerial rice structures and decrease pollutant burdens during root elongation. In contrast, TC and Cd synergistically promoted the accumulation of TC/Cd in rice roots. However, their interaction increased the accumulation of TC in roots while decreasing the accumulation of Cd when the toxicant doses increased. The strong affinity of rice to Cd promoted its upward transport from the roots, whereas the toxic effects of TC reduced TC transport. Therefore, the combined toxicity of the two pollutants inhibited their upward transport. Additionally, a low concentration of TC promoted the accumulation of Cd in rice mainly in the root tip. Furthermore, a certain dose of TC promoted the upward migration of Cd from the root tip. Laser ablation-inductively coupled plasma mass spectrometry demonstrated that Cd mainly accumulated in the epidermis and stele of the root, whereas Fe mainly accumulated in the epidermis, which inhibited the absorption and accumulation of Cd by the rice roots through the generation of a Fe plaque. Our findings thus provide insights into the effects of TC and Cd co-exposure on rice growth. 相似文献
153.
俞丽婷 《湖南环境生物职业技术学院学报》2006,12(1):114-116
家用综合防盗系统从实际防护入手,根据门、窗(阳台)所处位置特点,独立防护,防护系统与控制系统用无线联系,便于隐蔽、安装灵活,根据防护实际需要可随意增、减独立防护装置;采用交直流电源转换电路,增强了抗破坏能力,是工薪族家庭防非法侵入的理想防护装置.本系统由雷达扫描、护窗口(阳台)无线电发射电路、微振动护门无线电发射电路、无线电接收中央控制、功放报警电路等五部分组成. 相似文献
154.
探讨准确测量烟气含湿量的方法,采用干湿球法、重量法、阻容法、激光法同步比对测量典型温湿度污染源烟气的含湿量,通过监测结果分析,提出了不同测量方法在实际烟气测量中的准确性和适用性,为准确、规范测定烟气含湿量提供技术依据。 相似文献
155.
Twin–twin transfusion syndrome (TTTS) is a severe complication occurring in about 10% of monochorionic twin pregnancies. The chronic unbalanced transfusion of blood across placental vascular communications from the donor to the recipient twin may lead to impairment of various organ systems in the affected twins. In Hamburg, Germany, since 1995 patients with TTTS were treated with fetoscopic laser coagulation as the first causal therapeutic strategy. All survivors after laser surgery were followed up in the University Children's Hospital in Bonn, Germany. In this article, we summarize long-term follow-up studies from our German study population and compare our results with data from the literature. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
156.
多波段激光防护塑料的研制 总被引:2,自引:0,他引:2
本文以PMMA为基质制备了多波段激光防护塑料样品,对其性能进行了测试,该样品对YAG激光有很好的防护作用,达到实用要求。 相似文献
157.
某尾矿库初期坝采用分段施工,可能产生不均匀沉降,影响坝体的稳定性。采用孔径雷达干涉技术对尾矿库初期坝进行了短期变形速率观测,得出坝体右侧的后期填筑区域整体上与主体仍能够基本保持同步沉降。建立了三维流固耦合模型,分析了尾矿库初期坝的静力稳定性和渗流稳定性,结果表明:初期坝体的水平位移和竖向位移都在安全范围之内,考虑水和尾砂的共同作用,后期堆积坝堆积至1765m高程时,坝体顶部和后期回填区域,存在小量位移变形,静态稳定性安全系数达到2.25,初期坝能够保持稳定。 相似文献
158.
159.
基于视频技术的地点车速测定新方法 总被引:2,自引:0,他引:2
基于MPEG视频压缩技术的基本原理,提出了一种地点车速测定的新方法。该方法克服了雷达测速对测速角度要求苛刻、干扰正常行车而导致测量误差大的问题。借助普通的VTR录像机拍摄行车录像,应用视频处理软件VirtualDub,人工判读获取车辆接触两固定检测线的时间间隔,即可近似计算获得地点车速。实际应用中可通过调整两检测线的间距,来满足测速精度的要求。笔者还通过现场行车实验采集车速数据,进行了视频测速法与雷达测速法测速精度对比分析。 相似文献
160.
《Journal of Manufacturing Processes》2014,16(2):264-275
The evolution of mechanical components into smaller size generating a need for microwelding of these components using laser which offers better control as compared to arc and plasma processing. The present article describes the numerical simulation of laser micro-spot welding using finite element method. A two dimensional Gaussian distributed surface heat flux as a function of time is used to perform a sequentially coupled thermal and mechanical analysis. The model is used for simulating laser micro-spot welding of stainless steel sheet under different power conditions and configurations of mechanical constraints. The temperature dependent physical properties of SS304 have been considered for the simulation and an isotropic strain hardening model has been used. The simulated weld bead dimensions have been compared with experimental results and temperature profiles have been calculated. The maximum deformation of 0.02 mm is obtained with maximum laser power of 75 W. The thermal stress is more inducing factor to temperature induced residual stresses and plastic strain as compared to mechanical constraints. The plastic strain changes significantly by displacement constraints as compared to residual stress. 相似文献