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31.
重齿小蠹对人工合成聚集信息素的昼夜反应节律发生在白天7:00~21:00,反应高峰在14:00-19:00,反应模式为"单峰式—白天型";利用人工合成的聚集信息素对重齿小蠹成虫发生期监测表明,成虫扬飞的开始时间为5月20日左右,扬飞高峰期为6月下旬和7月上旬,扬飞末期为8月26日,成虫扬飞的持续期为98 d。2007-2009年大量诱杀防治的试验前、后重齿小蠹致死木平均分别为3.39株/hm2和0.76株/hm2,致死木减少了77.58%,而对照区试验前、后致死木平均分别为15.89株/hm2和18.11株/hm2,致死木增加了13.97%,3 a大量诱杀试验的防治效果显著。 相似文献
32.
为寻求根据汽车尾气参数来诊断汽车故障的方法,利用径向基函数(RBF)神经网络,对丰田雷克萨斯(LEXUS)400电控发动机进行故障诊断研究。研究结果表明,径向基函数神经网络对发动机故障的诊断是迅速、准确的。 相似文献
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Wahlund JE Boström R Gustafsson G Gurnett DA Kurth WS Pedersen A Averkamp TF Hospodarsky GB Persoon AM Canu P Neubauer FM Dougherty MK Eriksson AI Morooka MW Gill R André M Eliasson L Müller-Wodarg I 《Science (New York, N.Y.)》2005,308(5724):986-989
The Cassini Radio and Plasma Wave Science (RPWS) Langmuir probe (LP) sensor observed the cold plasma environment around Titan during the first two flybys. The data show that conditions in Saturn's magnetosphere affect the structure and dynamics deep in the ionosphere of Titan. The maximum measured ionospheric electron number density reached 3800 per cubic centimeter near closest approach, and a complex chemistry was indicated. The electron temperature profiles are consistent with electron heat conduction from the hotter Titan wake. The ionospheric escape flux was estimated to be 10(25) ions per second. 相似文献
34.
The local effects of isolated magnetic adatoms on the electronic properties of the surface of a superconductor were studied with a low-temperature scanning tunneling microscope. Tunneling spectra obtained near magnetic adsorbates reveal the presence of excitations within the superconductor's energy gap that can be detected over a few atomic diameters around the impurity at the surface. These excitations are locally asymmetric with respect to tunneling of electrons and holes. A model calculation based on the Bogoliubov-de Gennes equations can be used to understand the details of the local tunneling spectra. 相似文献
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Physical and chemical anal ysis of pottery fragments, including a crucible shard and ore samples from Tal-i-Iblis, Iran, suggests that copper smelting may have been well advantced late in the fifth millennium B.C. 相似文献
37.
【目的】用SSR和SRAP分子标记技术,分析苹果(Malus domestica Borkh.)重要栽培品种的亲缘关系,为苹果杂交育种亲本及组合的选配提供参考。【方法】用亲缘关系较近的金冠和秦冠筛选SSR和SRAP多态性引物,利用SSR和SRAP分子标记技术对37个苹果栽培品种进行遗传多样性和亲缘关系分析。【结果】筛选出了用于37个苹果主栽品种亲缘关系分析的10对SSR和10对SRAP引物,其分别产生56和64条扩增带,平均多态性比率分别为61.09%和70.8%。根据SSR+SRAP分析结果,37个苹果品种被聚为6大类。【结论】所选取的引物能够有效地揭示供试苹果品种的遗传多样性,并且苹果品种分类与传统系谱基本一致。 相似文献
38.
Meiotic Response of In vitro Matured Canine Oocytes under Different Proteins and Heterologous Hormone Supplementation 总被引:2,自引:0,他引:2
The impact of TCM‐199 supplemented with different proteins and heterologous hormones on the in vitro maturation (IVM) rate of bitch oocytes was evaluated by nuclear staining under fluorescence microscopy. Oocytes were recovered by slicing of ovaries from bitches presented at various stages of oestrous cycle to ovariohysterectomy. The basic culture medium was TCM‐199 supplemented with 25 mM Hepes/l, with 10% heat‐inactivated oestrous cow serum (ECS), 50 μg/ml gentamicin, 2.2 mg/ml sodium bicarbonate and 22‐μg/ml pyruvic acid, 1.0‐μg/ml oestradiol (E 8875; Sigma), 0.5‐μg/ml follicle‐stimulating hormone (FSH) (Folltropin‐V; Vetrepharm Inc., Ontario, Canada) and 0.03 IU/ml human gonadotropin (hCG) (Profasi HP; Serono, Aubonne, Switzerland). Oocytes were distributed randomly between basic culture medium (control) and the corresponding experimental treatment. Hormone treatments were: oocytes cultured in; (1) medium without FSH, (2) control medium supplemented with 20 μg/ml oestradiol, or (3) medium supplemented with 1 μg/ml human somatotropin (hST; Humatrope, Lilly, Saint Cloud, France). The second experiment consisted of oocytes cultured in medium supplemented with 0.4% (w/v) bovine serum albumin (BSA, fraction V; Gibco Grand Island, NY, USA) instead of ECS, or oocytes cultured in medium with 10% inactivated oestrous bitch serum (EBS) instead of ECS. Oocytes were cultured in 100 μl droplets (up to 25 oocytes per drop) under mineral oil at 37°C in a 100% humidified atmosphere containing 5% CO2 in air. After 72 h of IVM, the highest rates (p < 0.05) of meiotic resumption were achieved with the 0.4% BSA supplementation. A positive influence on the metaphase II (MII) acquisition rate was observed with hST supplement. Oocytes cultured with 10% EBS supplementation did not develop to the MII stage. The results in this study show that the protein and hormone supplements to TCM‐199 culture medium tested did not promote the final steps of IVM of bitch oocytes. 相似文献
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Steve C. Haskins DVM MS H. Orima Y. Yamamoto John D. Patz BA 《Journal of Veterinary Emergency and Critical Care》1991,1(2):55-60
The ability of the SAV 6 high-frequency jet ventilator to effectively ventilate three anesthetized, paralyzed cats (3.2–4.2 kg), two small dogs (7.2 and 10.0 kg), six medium-sized dogs (20.5–25.0 kg), and three large dogs (36.0–43.0 kg) via a 14-gauge (dogs) or a 16-gauge (cats) catheter placed percutaneously into the trachea via the cricothyroid membrane or into a preplaced endotracheal tube was evaluated. The lowest driving pressure within the range of 0.25 to 2.0 kg/cm2 (1 kg/cm2 = 14.2 psi) and the highest cycle rate within the range of 60 to 240 per minute that would generate a PaCO2 of 30 ± 3 mm Hg were determined.
All animals could be ventilated to a PaC02 of 30 ± 3 mm Hg by the endotracheal tube and transtracheal route, except the largest dogs, which couid be ventilated to an average PaC02 of 36 mm Hg by the transtracheal route. The transtracheal route consistently required higher driving pressures and lower cycle rates than did the endotracheal tube route. Cats could be ventilated with a driving pressure of 0.25 kg/cm2 ; small dogs could be ventilated with 0.5 to 1.0 kg/cm2 ; medium-sized dogs with 1.0 to 1.5 kg/cm2 ; and large dogs with 1.5 to 2.0 kg/cm2 .
The SAV 6 high-frequency jet ventilator can effectively ventilate cats and dogs (7.2–43.0 kg) via a transtracheal catheter and an endotracheal tube. 相似文献
All animals could be ventilated to a PaC0
The SAV 6 high-frequency jet ventilator can effectively ventilate cats and dogs (7.2–43.0 kg) via a transtracheal catheter and an endotracheal tube. 相似文献