Defensive spray of the bombardier beetle: a biological pulse jet

The defensive spray of the bombardier beetle Stenaptinus insignis is ejected in quick pulses (at about 500 pulses per second) rather than as a continuous stream. The pulsation may be a consequence of intermittency in the explosive chemical process that generates the spray. The ejection system of the beetle shows basic similarity to the pulse jet propulsion mechanism of the German V-1 "buzz" bomb of World War II.     

Equatorial jet in the Indian ocean: theory

A nonlinear numerical model and a simple analytical theory explain the basic features of the equatorial surface jet in the Indian Ocean recently reported by Wyrtki. The observed width of this transient current, 500 kilometers, is given theoretically by twice the baroclinic equatorial radius of deformation. The numerical model reproduces all Wyrtki's observations of this natural phenomenon.     

New method for the detection of light deflection by solar gravity

The prediction of Einstein's theory of general relativity that light will be deflected by the sun may be tested by sending radio waves from the earth to Venus or Mercury when either passes behind the sun and detecting the echoes with a radar interferometer.     

"Sex-ratio" condition: unusual mechanisms in bark beetles

Although males and females occur in similar frequency in the broods of most scolytid beetles, certain individuals of several species produce offspring highly aberrant in the ratio of sexes-all or mostly female. In some instances this condition reflects gynogenesis (parthenogenesis stimulated by mating); in others, a maternally transmitted factor.     

Sex pheromones: abolition of specificity in hybrid bark beetles

Specificity of sex pheromones maintains breeding isolation among three closely related species of spruce-infesting Ips. Hybrids produced in the laboratory were intermediate to the parent species in both attractiveness and response. Pheromones and pheromone receptor types in the hybrids are probably mixtures of those of the parent species.     

基于比例-积分-微分控制的喷雾干燥系统的仿真研究

对奶粉生产过程中喷雾干燥系统进行了比例-积分-微分（PID）控制研究,并利用MATLAB的仿真工具对该系统进行了仿真,仿真结果表明,系统具有较好的控制效果,适合工程应用。     

基坑复合支护结构变形机理分析

本文从水泥土的抗剪强度出发,通过有限单元法,结合实际工程,对基坑复合支护结构的变形机理进行分析,给出复合支护结构的设计建议。     

喷雾方式对农药雾滴在水稻群体内沉积分布的影响

【目的】分析喷雾方式对农药雾滴在水稻群体内沉积分布的影响,研究提出稻田合理的喷雾方式,提高稻田农药利用率。【方法】在水稻分蘖期、孕穗期和扬花期,用配有空心圆锥雾喷头的手动喷雾器叶面喷洒和配有气力式弥雾喷头的弥雾机下倾45°角喷洒指示剂丽春红-G溶液,收集并测定沉积在植株上层、中层和下层不同点位载玻片上的雾滴指示剂丽春红-G沉积量。【结果】以不同喷雾方式施药,水稻叶片正面、背面及垂直方向不同点位的丽春红-G沉积量有显著差异。在水稻分蘖期、孕穗期、扬花期用手动喷雾器叶面喷雾和弥雾机45°角下倾喷雾,丽春红-G的沉积量在水稻群体空间内的分布趋势均表现为上层＞中层＞下层。在水稻分蘖期用手动喷雾器叶面喷雾,13.3%玻片上丽春红-G的沉积量接近于平均数;52.9%玻片上丽春红-G沉积量低于平均数;33.75%玻片上丽春红-G的沉积量高于平均数。在水稻分蘖期用弥雾机45°角下倾喷雾,20.4%玻片上丽春红-G的沉积量接近于平均数;45.4%玻片上丽春红-G沉积量低于平均数;34.2%玻片上丽春红-G沉积量高于平均数。在水稻孕穗期和扬花期用手动喷雾器叶面喷雾,分别有33.3%和28.1%的玻片上没有丽春红-G的沉积;而用弥雾机45°角下倾喷雾,没有丽春红-G沉积的玻片比例分别为13.9%和5.0%。在水稻孕穗期用手动喷雾器和弥雾机喷雾,分别只有6.4%和11.7%玻片上的沉积量接近于平均值,而在扬花期时该比例分别为7.2%和17.2%。在水稻分蘖期、孕穗期和扬花期用手动喷雾器叶面喷雾,喷雾雾滴主要沉积在表示叶片正面的载玻片上,其沉积量占总沉积量的66.3%、85.1%和84.9%,其中在植株上层表示叶片正面载玻片上的沉积量占总沉积量的38.7%、42.2%和45.6%,在表示叶片背面和垂直面玻片上的沉积量很少。弥雾机下倾45°角喷雾,在表示叶片背面和垂直面玻片上的沉积量多于手动喷雾器叶面喷雾,但在表示叶片正面玻片上的沉积量仍占总沉积量的50.5%、50.6%和53.1%,其中植株上层表示叶片正面玻片上的沉积量占总沉积量的32.9%、27.9%和31.5%。【结论】如果以单位面积载玻片上的平均沉积量作为防治病虫害的有效剂量,那么在水稻群体内同时存在剂量浪费与剂量不足的现象。手动喷雾器压顶喷雾,喷雾雾滴主要沉积在植株上层叶片正面,沉积量占到总沉积量的1/3以上,而在叶片背面和茎秆上的沉积量很少,尤其是在植株基部叶片和茎秆上,沉积量趋向于零。采用弥雾机下倾45°角喷雾,喷雾雾滴在植株上层叶片正面的沉积量仍超过总沉积量的1/4,但在施药量低于手动喷雾器压顶喷雾条件下,各层叶片背面和茎秆上的沉积量都显著高于手动喷雾器叶面喷雾,说明弥雾机下倾45°喷洒,农药雾滴能够进入植株中下层,在叶片背面及茎秆上沉积。     

An equatorial jet in the Indian ocean

At the surface of the Indian Ocean along the equator a narrow, jet-like current flows eastward at high speed during both transition periods between the two monsoons. The formation of the jet is accompanied by thermocline uplifting at the western origin of the jet and by sinking at its eastern terminus. This demonstrates that a time-variable current can have profound effects in changing the mass structure in the ocean.     

Fog catchment sand trenches constructed by tenebrionid beetles, lepidochora, from the namib desert

Three species of coastal Namib Desert tenebrionid beetles (Lepidochora) build trenches on desert sand dunes. Trenches are constructed perpendicular to fog winds and concentrate moisture during fogs. The beetles return along the ridges of the trenches extracting water from them. The water content of a population of these beetles increased by 13.9 percent during one fog.     

氟化氢溶液诱导枣黑顶病的试验研究

为探明氟污染与枣黑顶病的关系,进行了氟化氢溶液喷雾诱导枣黑顶病的试验。结果表明:经氟化氢溶液喷雾处理过的枣果其果皮颜色转红速度、果实生长速度等都极显著地低于对照。氟化氢溶液喷雾诱导出的枣黑顶病发病症状、发病规律及症状变化规律都与自然条件下发生的枣黑顶病相符,从而进一步证实氟污染是引发枣黑顶病的主要原因。     

雾森在湿地公园中的应用分析

以杭州西溪国家湿地公园、山东滕州国家湿地公园、北京元大都湿地公园为例,对雾森在湿地公园中的应用作了分析。     

噻虫啉对杨树天牛成虫的毒力测定及林间防治

噻虫啉(天润)对粒肩天牛和橙斑白条天牛成虫均具有较强的毒力,稀释浓度在3 000倍液以下,对粒肩天牛成虫的校正死亡率达91.00％以上,对橙斑白条天牛成虫的校正死亡率达76.67％以上.应用噻虫啉(天润)林间喷雾防治时,以2000-3000倍液的防治效果较好;应用2％噻虫啉(天保)粉剂林间防治橙斑白条天牛成虫,以2 2...     

Timing the radiations of leaf beetles: hispines on gingers from latest cretaceous to recent

Stereotyped feeding damage attributable solely to rolled-leaf hispine beetles is documented on latest Cretaceous and early Eocene ginger leaves from North Dakota and Wyoming. Hispine beetles (6000 extant species) therefore evolved at least 20 million years earlier than suggested by insect body fossils, and their specialized associations with gingers and ginger relatives are ancient and phylogenetically conservative. The latest Cretaceous presence of these relatively derived members of the hyperdiverse leaf-beetle clade (Chrysomelidae, more than 38,000 species) implies that many of the adaptive radiations that account for the present diversity of leaf beetles occurred during the Late Cretaceous, contemporaneously with the ongoing rapid evolution of their angiosperm hosts.     

宁夏罗山步甲昆虫群落多样性研究

【目的】调查宁夏罗山国家级自然保护区垂直植被带不同生境步甲昆虫群落组成和多样性,探讨该地区步甲分布和物种多样性与生境的关系,为该地区生物多样性的长期监测和保护提供依据。【方法】根据宁夏罗山国家级自然保护区的生境类型和海拔高度,设置亚高山草甸A(SMA)、亚高山草甸B(SMB)、针叶林A(CFA)、针叶林B(CFB)、针阔混交林(MBCF)、阔叶林缘(BLFE)、灌丛(DS)和荒漠半荒漠草地(DSDG)8个不同样地,于2015年5-8月利用巴氏罐诱法对8个不同样地的步甲科昆虫多样性进行调查。【结果】共采集到步甲昆虫3 749只,隶属于12属24种,种类组成体现了荒漠半荒漠区系特点。个体数量最多的是直角通缘步甲和弗氏步甲,分别占总数量的39.11%和20.42%,为该区域的优势类群。直角通缘步甲在沿海拔梯度的各生境均有分布,弗氏步甲仅在油松林生境无分布。不同植被带步甲种类组成和优势类群差异较大,其中亚高山草甸和灌丛生境步甲物种数最多,各有17种,亚高山草甸步甲个体数量也最多;针叶林生境步甲物种数最少,仅有6种,个体数量也最少。步甲活动的高峰期为7-8月。各物种在各生境内的季节变化趋势与不同生境植被生长季节相关。灌丛生境的步甲Shannon-Wiener多样性指数和丰富度均最高,优势度最低;针叶林生境均匀度最高,Shannon-Wiener多样性指数和丰富度较低。主成分分析显示,生境相近的样地步甲昆虫群落结构也相似,步甲群落分为三大类群,样地DS、BLFE和MBCF的步甲群落聚为一类,样地CFA和CFB的步甲昆虫群落聚为一类,样地SMA、SMB和DSDG的步甲群落聚为一类。【结论】垂直植被带生境差异性与步甲昆虫群落的物种多样性和相似性密切相关,维持生境异质性是保护步甲多样性的关键。     

不同药械在稻田喷洒分布量的研究

为提高湖南省作物病虫防治的药械整体水平,对国内外手动喷雾器和国产机动风送背负机两类药械的5种机型,9种喷射部件和4种喷洒方式,在水稻生长前、中、后期分别进行喷洒分布量试验研究。采用纸卡法及染色法测定法对不同药械洒液进行定性和定量测试,结果表明,两类药械喷洒后的沉积量、药液分布均匀性和农药利用率随水稻生育期增长而提高,机动风送喷洒优于手动药械喷哂。在机动药械试验中,在泰山3WF－2．6型非旋转喷头,水平沉积法喷洒效果最好,手动药械以西班牙产“没得比”喷洒效果最佳。     

pH对胰岛素口腔喷剂中胰岛素稳定性的影响

胰岛素在胰岛素口腔喷剂中处于比较复杂的体系,对pH敏感程度如何与其稳定性有密切关系。本文在pH 8、9、10、11、12 5个梯度50 ℃下同时碱解,用RP-HPLC方法,检测出胰岛素在口腔喷剂中的碱性降解点为pH 11左右。HPLC条件：流动相,V(乙腈)∶ V(磷酸盐缓冲液,pH 3.0)=27∶ 73;流速,1 mL/min;进样量,20 μL。