2种烟草种植模式种植成本分析

分析了我国烟草生产不同发展阶段的传统烟草种植和现代烟草种植模式下烟农种植过程中的成本投入,结果表明:因烟草专业化服务组织农业机械化水平和专业化程度的提高,烟草种植的人工投入数、人工成本分别由传统烟草种植模式的15.01个/667 m2和758元/667 m2降低到现代烟草种植模式的2.41个/667 m2和120.25元/667 m2;由于人工成本的大幅度降低,烟草种植总成本由传统烟草种植模式的798元/667 m2降低到现代烟草种植模式下的307.25元/667 m2。     

弱光条件下东方百合的生长发育及光合特性研究

为了探明弱光条件下东方百合的生长发育及光合特性,为我国北方地区东方百合切花的耐弱光品种选育提供依据,以东方百合品种‘Marcopolo’、‘Tiber’、‘Constanta’和‘Acapulco’为试验材料,在整个生长季对其进行不同遮光处理(正常光照、50%遮光、75%遮光),测定不同光强下各品种光合参数及生长发育指标。结果表明:75%遮光条件下东方百合各品种的净光合速率(Pn)、光补偿点(LCP)、光饱和点(LSP)、暗呼吸速率(Rd)降低,表观量子效率(AQY)下降,叶绿素含量增高,叶绿素a与叶绿素b的比值降低,比叶质量减小,叶面积增大,切花观赏品质有所下降;不同百合品种的耐弱光性不同,弱光下‘Marcopolo’的LCP、Rd较低,比叶质量较小,AQY变化幅度小,表现出较强的耐弱光性;相反地,‘Acapulco’则对弱光较敏感。     

Thermal Structure of Jupiter's Upper Atmosphere Derived from the Galileo Probe

Temperatures in Jupiter's atmosphere derived from Galileo Probe deceleration data increase from 109 kelvin at the 175-millibar level to 900 ± 40 kelvin at 1 nanobar, consistent with Voyager remote sensing data. Wavelike oscillations are present at all levels. Vertical wavelengths are 10 to 25 kilometers in the deep isothermal layer, which extends from 12 to 0.003 millibars. Above the 0.003-millibar level, only 90- to 270- kilometer vertical wavelengths survive, suggesting dissipation of wave energy as the probable source of upper atmosphere heating.     

四种大黄属高山药用植物蒽醌类成分含量的测定

为比较掌叶大黄、喜马拉雅大黄、菱叶大黄、头序大黄4种高山药用大黄中蒽醌类成分含量的差异,采用紫外分光光度法,以大黄素为对照品,0.5%醋酸镁-甲醇溶液为显色剂,测定了样品溶液在510nm处的吸光度。结果表明,4种大黄中总蒽醌和结合蒽醌的含量为喜马拉雅大黄掌叶大黄菱叶大黄头序大黄,游离蒽醌的含量为喜马拉雅大黄掌叶大黄头序大黄菱叶大黄,与藏药用大黄的等级划分基本一致。     

Gravity Waves in Jupiter's Thermosphere

The Atmosphere Structure Instrument on the Galileo probe detected wavelike temperature fluctuations superimposed on a 700-kelvin temperature increase in Jupiter's thermosphere. These fluctuations are consistent with gravity waves that are viscously damped in the thermosphere. Moreover, heating by these waves can explain the temperature increase measured by the probe. This heating mechanism should be applicable to the thermospheres of the other giant planets and may help solve the long-standing question of the source of their high thermospheric temperatures.     

典型黑土环境下的高、低镉积累白菜品种筛选及耐性比较

为探究不同白菜(Brassica pekinensis L.)品种在典型黑土环境中的镉敏感程度和镉积累特性,筛选出具备高镉、低镉积累特征的耐镉品种。试验以东北地区20种主栽白菜品种为材料进行盆栽模拟试验,研究基于不同白菜品种镉胁迫下的剂量-效应、镉积累特征,对得到的高、低镉积累品种的浓度积累效应及氧化损伤程度进行评估。结果显示:供试品种间剂量-效应差异明显,JF和BCCRQJ为镉耐性最强两个品种,耐受阈值分别为1.204 mg·kg~(-1)和1.036 mg·kg~(-1)。高镉浓度下(≥0.6 mg·kg~(-1))JF叶镉含量最低,根向叶迁移系数(TF)、叶富集系数(BCF)均小于1;BCCRQJ净化率最高。土壤镉含量与两者根、叶积累量、过氧化氢(H_2O_2)、超氧阴离子(O_2~-)、丙二醛(MDA)、游离脯氨酸(FPRO)均呈正相关,与净化率呈负相关(P0.05),此外高浓度下BCCRQJ氧化损伤程度较JF更高。综合试验结果表明,JF是镉耐性极高的低积累品种,而BCCRQJ为镉耐受力略逊于JF的高积累品种。     

樱桃番茄盆栽技术

介绍盆栽樱桃番茄的观赏、食用功能,并详述了品种选择,育苗,肥水管理、温湿度管理,病虫害防治等技术。     

Effect of DHA Containing Oils and Powders on Baking Performance and Quality of White Pan Bread

Different sources of DHA and/or n-3 (omega-3) rich oils, oil emulsions and microencapsulated (ME) powders were tested at two different concentrations with the aim of producing fortified pan bread. Three oils (S-algae, fish and flax), two emulsified algae oils (Emulsion-P and Emulsion-L) and two ME oils (ME-S algae and ME-C algae) were compared. The DHA and n-3 oils replaced part of the shortening in order to obtain 32 g slices enriched with 25 or 50 mg DHA, 35 or 70 mg total n-3 from fish oil and 90 or 180 mg linolenic from flax oil. Addition of oils did not significantly affect water absorption but reduced mix time whereas addition of the ME oils decreased both water absorption and mix time. Breads enriched with flax or ME-C oils had lower volume and higher density than the control, ME-S algae, Emulsion-P and Emulsion-L breads. All breads lost texture throughout 14 d storage, the major changes occurred after 3 d. The ME-S algae oil bread had the best softness after 14 d storage whereas breads produced from ME-S algae or ME-C algae oils had the poorest texture. Sensory evaluations indicated that the color of the ME-S algae oil fortified bread was significantly less preferred than the other loaves. After 6 d the control bread had higher acceptability compared with the rest of the breads enriched with high levels of DHA or omega-3 oils. The high-enriched fish oil bread was well accepted during the first days of storage but had the least preferred acceptability after 13 d. The best fortified breads were those supplemented with S-algae oil, Emulsion-P and Emulsion-L oils.     

起垄方式和种植密度对浓香型有机烟叶产量和品质的影响

为探讨浓香型有机烟叶适宜的栽培方法,在河南省叶县浓香型有机烟叶种植基地,通过田间小区随机试验,以纯施化肥处理为对照（CK）,研究了起垄方式（一垄单行和一垄双行）和种植密度（16500株/hm2和20000株/hm2）对有机烟叶产量和品质的影响。结果表明,与纯化肥处理相比,有机烟叶处理产量显著降低,上等烟比例、中上等烟比例和均价显著提高;4个有机烟处理间上等烟比例、中上等烟比例、均价无显著差异,产量和产值以一垄双行＋20000株/hm2处理最高（分别为2351.45 kg/hm2和58621.65元/hm2）,显著高于其他3个处理。与纯化肥处理相比,有机烟叶外观质量、常规化学成分、感官质量显著改善;但4个有机烟处理之间外观质量、常规化学成分无显著差异,烟感官质量方面以一垄双行＋20000株/hm2处理最好,一垄单行＋20000株/hm2处理最差。综合考虑烟农经济效益和烟叶品质,在河南浓香型烟区,有机烟叶栽培以一垄双行＋种植密度20000株/hm2比较合适。     

山西省主要畜产品竞争力排序及提升对策

山西省地处黄土高原,是一个以资源型经济为主的省份,受地理、气候和水资源等因素制约,发展种植业有着诸多不利条件,而发展畜牧业具有明显优势。采用竞争力差值分析法,对山西省主要畜产品竞争力的位次进行排序,并提出调整山西省畜产品生产结构和进一步提升山西省畜产品竞争力的对策建议。