Experimental study on spectral responses of offshore oil slick

Using the seawater taken from Liaodong Bay and crude oil taken from Liaohe Oilfield, a laboratory experiment was designed to study the change of reflectance spectrum of artificial offshore oil slick with its thickness and to identify the spectrum ranges suitable for quantifying the thickness of the oil slick. During the experiment, crude oil was continuously dropped into the seawater to generate artificial oil slick with different thicknesses. After every drop of crude oil was added, reflectance spectrum of the oil slick was measured with a high resolution spectroradiometer （ASD FieldSpec Pro FR）. The influence of oil slick thickness on its reflectance spectrum was explored through statistical analysis. The results show that the reflectance of oil slick changes marginally with oil slick thickness and higher than that of seawater in infrared band from 1150 to 2500 nm. This spectrum range can be practically used to distinguish oil slick from seawater. In the spectrum range from 400 to 1150 nm, the reflectance of oil slick decreases with its thickness. The negative power function is the best-fit function expressing the relationship between the reflectance and thickness. The spectral characteristics of oil slick are very distinct at 550 and 645 nm. They are the best wavelengths for monitoring the existence of offshore oil slick and estimating its thickness.     

Construction of AFLP-based genetic linkage maps for the Chinese shrimp Fenneropaeneus chinensis

Fenneropaeneus chinensis is an important species in marine fishery resources and aquaculture in China. A genetic linkage map is essential for improving the efficiency of its breeding by marker-assisted selection and identifying commercially important genes. Linkage maps of F. chinensis were constructed with an F2 mapping population （110 progenies） using amplified fragment length polymorphic （AFLP） marker in this study. Fifty-five AFLP primer combinations produced 532 AFLP markers fitting for map strategy in mapping family. The markers with 3：1 segregating ratios were analyzed using F2 intercross model for the common linkage map, while the markers with 1：1 ratio were analyzed using the pseudo-testcross strategy. The maps of male, female and common were constructed. The female map included 103 markers that formed 28 linkage groups, covering a total length of 1090 cM. All markers were linked with the linkage groups. Segregation distortion was observed for 6 of 103 markers in the female map. The average distance between markers was 14.53 cM and ranged from 4.4 to 24.8 cM. The male map included 144 markers that formed 35 linkage groups. Ten markers remained unlinked in male map. Segregation distortion was observed for 7 of 144 markers in the male map. The total distance of male map covered 1617 cM. The average distance between markers was 16.36 cM. The male map was 32.6% longer than the female map, which may reflect sex-specific recombination rates in Chinese shrimp. The common map was composed of 216 markers, including in 44 linkage groups covering a total distance of 1772.1 cM. Two markers remained unlinked. No distorted markers of 216 markers were shown in the common map. The distance between markers was 10.42 cM. An average estimated genome size for the Chinese shrimp was 2420 cM, which was consistent with the relative size of the Penaeid genome. The distribution of AFLP markers was relatively even in chromosomes of Chinese shrimp maps. The linkage analysis presented in this work provided some insight     

两种酯季铵盐表面活性剂的合成与表征

以异烟酸、长链脂肪醇和溴乙烷为原料,通过酰化、酯化和季铵化3步反应合成了2种异烟酸酯类季铵盐表面活性剂,用定性方法、红外光谱和核磁共振氢谱鉴定了其结构,并表征了这2种表面活性剂的表面活性．结果表明：这2种表面活性剂均有一定的降低水表面张力的能力．     

重金属汞对植物生理活动的影响和钙离子的拮抗作用

汞对植物各方面的生理活动均有严重影响。植物吸收的汞大都积累在根部,这是由于汞与植物根部蛋白质相结合的结果。汞也可诱发生物的染色体突变。富集在作物体内的汞进而通过食物链危害人体。人类的轻度汞中毒可通过摄入含钙食品来缓解。探讨了汞对植物体细胞和生殖细胞的影响,并研究了钙离子对植物汞伤害的缓解作用。发现汞对植物体细胞和生殖细胞均有严重影响,钙离子对植物叶细胞和生殖细胞的汞伤害均有较高程度的拮抗作用,但对根细胞的汞伤害没有明显的缓解作用。     

GSM网络无线话务调整方法

在网络优化中,经常会遇到这样的问题:由于用户分布不平衡,实际用户发展与前期规划存在一定偏差,造成话务分布不均衡,忙小区信道资源紧张,而闲小区信道资源过剩。这就需要我们在网络优化中采用各种方法来均衡小区话务,使网络资源得到充分的利用,获得最佳经济效益。NOK IA系统提供了一套丰富的方法来均衡话务。文章将主要从硬件调整和参数调整两个方面谈谈如何调整小区话务。     

浅谈后进生转化工作

后进生是指那些思想品德和学习成绩上比较落后的学生。在大力提倡素质教育的今天,后进生的存在仍然是一种较为普遍的现象。虽然他们的程度不同,但是依然给教育教学工作带来了很大的困难。笔者以所带班级为研究对象,在深入分析后进生形成原因的基础上,提出了"家庭、社会、学校"相结合的教育网络,重点阐述了在该体系架构下,为促进了后进生转化工作的实现,班主任所需担负的职责。     

图C_m·K_n的邻强边染色

将顶点集和边集分别为V={v_(ij)┃i=1,2,…,m;j=0,1,…,n-1},E={v_(10)v_(20),v_(20)v(30),…,v_(m0)v_(10)}U(Uim-1)(ij)ik┃j≠k,j,k=0,1,…,n-1}的图简记为Cm·Kn.利用图分解和色集置换的方法,给出了图Cm·Kn的邻强边色数。     

采用阶段控制技术的DC/DC开关电源软启动电路

设计了一种采用阶段控制技术实现的软启动电路,该电路消除了软启动过程中出现的浪涌电流,同时避免了传统软启动电路在软启动结束时出现的过冲现象.该电路可以完全集成在DC/DC开关电源管理芯片中,避免额外电容而占用过多面积和增加功耗.通过Hspice电路仿真,对于输入电压为5 V,输出电压为2.5 V的Buck型开关电源系统,利用该软启动电路,输出电压近似以1.9 mV/μs速度平稳上升,同时电感电流在第一阶段控制在5 A以内,第二阶段近似以3.75 mA/μs平稳上升,符合设计指标.     

关于不定方程x3+64=21y2

利用递归数列、同余式和平方剩余几种初等方法,证明了不定方程x3 64=21y2仅有整数解(x,y)=(-4,0),(5,±3);给出了x3 64=21y2的全部整数解.     

Nd2O3对反应烧结合成镁铝尖晶石的影响

研究稀土氧化物Nd2O3对反应烧结镁铝尖晶石的影响.结果表明,添加Nd2O3能促进镁铝尖晶石结晶化,有利于促进镁铝尖晶石烧结致密化及晶粒生长发育.试样中添加3%(质量分数)的Nd2O3,经1 650 ℃烧结能制备出相对密度为92%、晶粒发育良好的镁铝尖晶石.