斑子麻黄(Ephedra rhytidosperma)群落是贺兰山山麓特有荒漠植物群落。该研究于2019年调查了16个斑子麻黄典型群落,分析了物种组成的区系特征,运用TWINSPAN软件对16个斑子麻黄群落进行了分类。结果表明:1)斑子麻黄群落物种组成以禾本科...斑子麻黄(Ephedra rhytidosperma)群落是贺兰山山麓特有荒漠植物群落。该研究于2019年调查了16个斑子麻黄典型群落,分析了物种组成的区系特征,运用TWINSPAN软件对16个斑子麻黄群落进行了分类。结果表明:1)斑子麻黄群落物种组成以禾本科、菊科、豆科和蒺藜科植物为主,隶属13科24属27种。2)斑子麻黄荒漠群落生活型以多年生草本(44.44%)和灌木(29.63%)为主;区系以古地中海成分(44.44%)和东亚成分(33.33%)为主;水分生态类型以旱生(40.74%)和强旱生(37.04%)为主。3)根据生活型和优势度,斑子麻黄群落可分为斑子麻黄-半灌木荒漠(Ephedra rhytidosperma-Semi-Shrub Desert)和斑子麻黄-草本荒漠(Ephedra rhytidosperma-Herb Desert) 2个群丛组,进一步划分为3个群丛:斑子麻黄-刺旋花-兴安胡枝子半灌木与草本荒漠(Ephedra rhytidosperma-Convolvulus tragacanthoides-Lespedeza davurica Semi-Shrub and Herb Desert)、斑子麻黄-刺旋花-中亚细柄茅半灌木与草本荒漠(Ephedra rhytidosperma-Convolvulus tragacanthoides-Ptilagrostis pelliotii Semi-Shrub and Herb Desert)和斑子麻黄-中亚细柄茅半灌木与草本荒漠(Ephedra rhytidosperma-Ptilagrostis pelliotii Semi-Shrub and Herb Desert)。展开更多
With the increasing planting area of Lilium lancifolium, the leaf fungal dis-ease of L. lancifolium is becoming more and more serious. In June and July of 2014, the excessive rainfal leads to the serious outbreak of l...With the increasing planting area of Lilium lancifolium, the leaf fungal dis-ease of L. lancifolium is becoming more and more serious. In June and July of 2014, the excessive rainfal leads to the serious outbreak of leaf disease of L. lanci-folium. In mid-June, the wilting rate of L. lancifolium in seriously-infected field was even up to 50%-70%. In some fields, the shoots of L. lancifolium even al wilted. The pathogen was isolated from the infected leaves of L. lancifolium. Its pathogenici-ty, spore morphology, 18S rDNA sequence and biological characteristics were stud-ied. The results showed the isolated pathogen was Alternaria alternate. The lethal temperature of mycelial growth was 55 ℃. The optimum pH was 6-7. Among the tested carbon sources and nitrogen sources, the optimum carbon source was mal-tose, and the optimum nitrogen source was yeast extract.展开更多
A novel 1 55μm laser diode with spot size converter is designed and fabricated using conventional photolithography and chemical wet etching process.For the laser diode,a ridge double core structure is employed.For...A novel 1 55μm laser diode with spot size converter is designed and fabricated using conventional photolithography and chemical wet etching process.For the laser diode,a ridge double core structure is employed.For the spot size converter,a buried ridge double core structure is incorporated.The laterally tapered active core is designed and optically combined with the thin and wide passive core to control the size of mode.The laser diode threshold current is measured to be 40mA together with high slop efficiency of 0 35W/A.The beam divergence angles in the horizontal and vertical directions are as small as 14 89°×18 18°,respectively,resulting in low coupling losses with a cleaved optical fiber (3dB loss).展开更多
A 1.60μm laser diode and electroabsorption modulator monolithically integrated with a novel dual-waveguide spot-size converter output for low-loss coupling to a cleaved single-mode optical fiber are demonstrated.The ...A 1.60μm laser diode and electroabsorption modulator monolithically integrated with a novel dual-waveguide spot-size converter output for low-loss coupling to a cleaved single-mode optical fiber are demonstrated.The devices emit in a single transverse and quasi single longitudinal mode with an SMSR of 25.6dB.These devices exhibit a 3dB modulation bandwidth of 15.0GHz,and modulator DC extinction ratios of 16.2dB.The output beam divergence angles of the spot-size converter in the horizontal and vertical directions are as small as 7.3°×18.0°,respectively,resulting in a 3.0dB coupling loss with a cleaved single-mode optical fiber.展开更多
文摘斑子麻黄(Ephedra rhytidosperma)群落是贺兰山山麓特有荒漠植物群落。该研究于2019年调查了16个斑子麻黄典型群落,分析了物种组成的区系特征,运用TWINSPAN软件对16个斑子麻黄群落进行了分类。结果表明:1)斑子麻黄群落物种组成以禾本科、菊科、豆科和蒺藜科植物为主,隶属13科24属27种。2)斑子麻黄荒漠群落生活型以多年生草本(44.44%)和灌木(29.63%)为主;区系以古地中海成分(44.44%)和东亚成分(33.33%)为主;水分生态类型以旱生(40.74%)和强旱生(37.04%)为主。3)根据生活型和优势度,斑子麻黄群落可分为斑子麻黄-半灌木荒漠(Ephedra rhytidosperma-Semi-Shrub Desert)和斑子麻黄-草本荒漠(Ephedra rhytidosperma-Herb Desert) 2个群丛组,进一步划分为3个群丛:斑子麻黄-刺旋花-兴安胡枝子半灌木与草本荒漠(Ephedra rhytidosperma-Convolvulus tragacanthoides-Lespedeza davurica Semi-Shrub and Herb Desert)、斑子麻黄-刺旋花-中亚细柄茅半灌木与草本荒漠(Ephedra rhytidosperma-Convolvulus tragacanthoides-Ptilagrostis pelliotii Semi-Shrub and Herb Desert)和斑子麻黄-中亚细柄茅半灌木与草本荒漠(Ephedra rhytidosperma-Ptilagrostis pelliotii Semi-Shrub and Herb Desert)。
基金Supported by Modern Agricultural Industry Technology System Project of Ministry of Agriculture(nycytx-35-02-06)Key Program for Applied Basic Research of Agriculture of Hubei Provincial Science and Technology Plan Project(2012DBA07)~~
文摘With the increasing planting area of Lilium lancifolium, the leaf fungal dis-ease of L. lancifolium is becoming more and more serious. In June and July of 2014, the excessive rainfal leads to the serious outbreak of leaf disease of L. lanci-folium. In mid-June, the wilting rate of L. lancifolium in seriously-infected field was even up to 50%-70%. In some fields, the shoots of L. lancifolium even al wilted. The pathogen was isolated from the infected leaves of L. lancifolium. Its pathogenici-ty, spore morphology, 18S rDNA sequence and biological characteristics were stud-ied. The results showed the isolated pathogen was Alternaria alternate. The lethal temperature of mycelial growth was 55 ℃. The optimum pH was 6-7. Among the tested carbon sources and nitrogen sources, the optimum carbon source was mal-tose, and the optimum nitrogen source was yeast extract.
文摘A novel 1 55μm laser diode with spot size converter is designed and fabricated using conventional photolithography and chemical wet etching process.For the laser diode,a ridge double core structure is employed.For the spot size converter,a buried ridge double core structure is incorporated.The laterally tapered active core is designed and optically combined with the thin and wide passive core to control the size of mode.The laser diode threshold current is measured to be 40mA together with high slop efficiency of 0 35W/A.The beam divergence angles in the horizontal and vertical directions are as small as 14 89°×18 18°,respectively,resulting in low coupling losses with a cleaved optical fiber (3dB loss).
文摘A 1.60μm laser diode and electroabsorption modulator monolithically integrated with a novel dual-waveguide spot-size converter output for low-loss coupling to a cleaved single-mode optical fiber are demonstrated.The devices emit in a single transverse and quasi single longitudinal mode with an SMSR of 25.6dB.These devices exhibit a 3dB modulation bandwidth of 15.0GHz,and modulator DC extinction ratios of 16.2dB.The output beam divergence angles of the spot-size converter in the horizontal and vertical directions are as small as 7.3°×18.0°,respectively,resulting in a 3.0dB coupling loss with a cleaved single-mode optical fiber.
