The Effects of Seed Quality and Pipecolic and Djenkolic Acids on Bruchid Beetle Infestation in Water Deficit-Stressed Acacia Trees

Acacia trees in the Negev desert and the Arava valley of Israel are suffering high levels of mortality due to water stress. Additionally, recruitment is negatively affected by bruchid beetles. We hypothesized that water-stressed trees would be less able to produce secondary defense compounds, such as the nonprotein amino acids, pipecolic acid and djenkolic acid, in their seeds to decrease seed herbivory. We further hypothesized that the high seed infestation reported is due to increased fitness of beetles infesting trees that are in a poor physiological state. Contrary to our prediction, pipecolic acid concentration was higher in water-stressed Acacia raddiana trees. We found that infestation rates and beetle fitness were higher in trees in a poor physiological state, despite the higher levels of pipecolic acid in these trees. There was a significant positive correlation between infestation level and the amounts of djenkolic acid in the seeds, indicating that the beetles may have found a means of utilizing djenkolic acid for their own benefit.     

黄河内蒙古段乌兰布和沙漠入黄风积沙监测研究

黄河内蒙古段途经乌兰布和沙漠,局部河段发展为＂地上悬河＂,洪灾、凌灾频繁发生。对乌兰布和沙漠沿黄河段风沙入黄的初步监测结果进行了分析与探讨,揭示沿黄段入黄风沙运移规律并精确计算出风积沙入黄沙量。国家及有关部门应对乌兰布和沙漠对黄河的危害高度重视,形成多渠道、多学科联合攻关研究的平台,使研究结果更好地为科学治理黄河泥沙问题及完善黄河沿岸综合防护体系提供科学依据。     

基于邻域聚合与深度学习的小样本荒漠草原物种分类

随着气候变化和人类活动的影响,内蒙古草原逐渐荒漠化。为了解决传统地面调查的局限性,以及高光谱数据小样本分类难的问题。本文利用无人机(unmanned aerial vehicle, UAV)高光谱遥感技术对荒漠草原物种进行数据采集,并提出一种邻域聚合算法结合深度学习的小样本分类方法。首先,通过遗传算法(genetic algorithm, GA)与最佳指数因子(optimum index factor, OIF)对高光谱数据进行波段选择;其次,构建高光谱数据邻域特征,采用邻域聚合算法对其进行邻域特征融合;最后,采用多层感知机(multilayr perceptron, MLP)对融合后的特征进行分类。结果表明,邻域聚合算法在每类地物只有10个样本的情况下总体精度可达93.41%,Kappa系数为0.912 0;并与SVM和多种深度学习模型对比,邻域聚合算法计算效率高、模型大小最小、分类精度最高。该方法的提出,满足草原物种识别要求,为草原生态系统的动态监测提供新方法。     

膜蒸馏淡化处理油田高含盐废水的实验研究

采用减压膜蒸馏技术处理油田高含盐废水，研究了真空度、废水温度、流量以及废水含盐量对膜通量与截留率的影响。实验结果表明：随着膜下游真空度增加，膜通量先缓慢增大，当真空度超过某一临界值后，膜通量急剧增加；废水温度增加，膜通量增大，且真空度越高，膜通量随温度变化的曲线越陡；提高废水流量可增大膜通量；随着废水含盐量增加，膜通量减小，当废水含盐量大于220g／L时，馏出液电导率明显增加，但各次实验的截留率仍然接近100％，表明实验用聚丙烯中空纤维膜具有很好的疏水性。     

沙漠砂填筑土料施工质量控制指标确定方法研究

本文针对沙漠砂做为填筑材料,其填筑质量控制指标如何确定问题,参阅了国内外有关研究资料,确定了试验研究方法,阐述了试验过程,分析了试验数据,提出了施工质量控制指标。     

TEST AND STUDY ON THE CONSTITUTIV ERELATIONSHIP OF DESERT SAND UNDER MOVING VEHICLE

０ＩＮＴＲＯＤＵＣＴＩＯＮＴａｋｅｌａｍａｇａｎｄｅｓｅｒｔｉｎＸｉｎｊｉａｎｇｉｓｔｈｅｓｅｃｏｎｄｄｅｓｅｒｔｉｎｔｈｅｗｏｒｌｄａｎｄｔｈｅｆｉｒｓｔｄｅｓｅｒｔｉｎＣｈｉｎａ．Ｔｈｅａｒｅａｏｆｔｈｅｄｅｓｅｒｔｉｓ３３７ｓｑｕａｒｅｋｉ...     

一种疏水缔合型阳离子聚合物酸液稠化剂的合成及性能

以甲基丙烯酰氧乙基三甲基氯化铵(DMC)、甲基丙烯酰氧乙基二甲基正十六烷基溴化铵(HDMC)为原料,采用自由基水溶液聚合制备阳离子型疏水缔合聚合物P(DMC-HDMC)。用红外光谱、核磁共振氢谱和荧光光谱分别对其分子结构和疏水微区结构进行了表征,并对其在酸液中的流变性进行了考察。结果表明,P(DMC-HDMC)含有亚甲基长链(CH2)15,在溶液中能够形成疏水微区,且其临界缔合质量分数(CAC)为～0.17%(质量分数)。在w(HCl)=20%的溶液中,当w〔P(DMC-HDMC)〕=0.16%(CAC)时,其流出时间t分别为20.47 s和40.8 s;与非疏水缔合型聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)相比,随酸质量分数的增加,PDMC的黏度明显降低,而P(DMC-HDMC)则相对稳定,整体呈略微上升趋势;w〔P(DMC-HDMC)〕=1.0%时,在w(HCl)=20%溶液中60、90℃下的热稳定性ω分别为85.5%和70.4%;w〔P(DMC-HDMC)〕=0.8%时,w(HCl)=20%溶液中30℃、170 s-1下剪切120 min后剪切稳定性ω'为88.3%。     

沙漠表层纵波品质因子测量方法和基本特征

针对目前还没有一套成熟有效的地层品质测量方法,设计了一套品质因子测量的仪器和流程,能模拟测量不同埋深和含水饱和度条件下,未成岩的粘土或沙的品质因子.通过对塔里木和准噶尔盆地多个沙样的测试,证实了仪器和测量方法的稳定性和可靠性.研究表明:沙漠地区表层沙纵波品质因子随埋深、纵波速度的增加而增大.当相对含水量小于某一值时,品质因子随含水量增加而减小,当相对含水量达到该值后,品质因子随含水量增加而增大.对油气勘探领域地震波能量损耗机理研究及地震资料处理与解释具有重要意义.     

Changing Oviposition Preferences of the Desert Locust, Schistocerca gregaria, Suggest a Strong Species Predisposition for Gregarization

Field surveys at five sites within desert locust breeding habitats around Port Sudan during three successive seasons indicated that early in the rainy season the incoming solitary females oviposited predominantly in the vicinity of Heliotropium spp. (66%) and millet (32%) seedlings. Solitary nymphs also preferred to feed on these plants. Follow-up cage experiments were conducted in the field in which solitary and gregarious female locusts were presented with choices of selected desert plants and egg pods. When presented with bulrush millet, Heliotropium spp., Zygophyllum simplex, and untreated moistened sand, solitary females oviposited adjacent to the first two plants (40% and 60%, respectively). However, when offered a choice of either or both of these plants together with egg pods derived from gregarious and/or solitary insects, solitary females showed a significantly higher preference for ovipositing near gregaria egg pods than near the plants, with solitaria egg pods eliciting the least response. In contrast with solitary females and in the absence of gregaria egg pods, gregarious females preferred to oviposit in untreated moist (control) sand (74–77%) away from the plants (6–14%) or solitaria egg pods (4%). However, when present, gregaria egg pods elicited significantly more oviposition. These and previous results indicate a hierarchy of phase-dependent oviposition preferences in the desert locust and are interpreted in terms of a strong propensity of the species to exploit opportunities under appropriate conditions to facilitate congregation and the gregarization of the progeny.