玉米杂交种毕单4号的选育研究

毕单4号系毕节地区农业科学研究所针对黔西北山区自然生态特点和玉米生产实际,于1982年以墨白玉米种质自选系405为母本,以330天然杂株自选系411为父本组配而成的高产、优质、多抗、广适杂交玉米组合。该组合于1992年6月通过贵州省农作物品种审定委员会审定,已在大面积生产上推广应用。     

考摩(Cormo)型细毛羊性状遗传力估测及性状间相关分析

本文通过对考摩型细毛羊一些数量性状遗传力估测及性状间相关分析,初步揭示性状的遗传规律,对今后制定选种方法、修正性状的选择指数、预测选育进展,加快育种速度,都有一定的现实意义.     

水库景观设计研究

总结了水库的风景资源及其景观特征，并提出在水库景观设计中应该因水设景，因地制宜。     

Very-Long-Baseline Radio Interferometry: The Mark III System for Geodesy, Astrometry, and Aperture Synthesis

The Mark III very-long-baseline interferometry (VLBI) system allows recording and later processing of up to 112 megabits per second from each radio telescope of an interferometer array. For astrometric and geodetic measurements, signals from two radio-frequency bands (2.2 to 2.3 and 8.2 to 8.6 gigahertz) are sampled and recorded simultaneously at all antenna sites. From these dual-band recordings the relative group delays of signals arriving at each pair of sites can be corrected for the contributions due to the ionosphere. For many radio sources for which the signals are sufficiently intense, these group delays can be determined with uncertainties under 50 picoseconds. Relative positions of widely separated antennas and celestial coordinates of radio sources have been determined from such measurements with 1 standard deviation uncertainties of about 5 centimeters and 3 milliseconds of arc, respectively. Sample results are given for the lengths of baselines between three antennas in the United States and three in Europe as well as for the arc lengths between the positions of six extragalactic radio sources. There is no significant evidence of change in any of these quantities. For mapping the brightness distribution of such compact radio sources, signals of a given polarization, or of pairs of orthogonal polarizations, can be recorded in up to 28 contiguous bands each nearly 2 megahertz wide. The ability to record large bandwidths and to link together many large radio telescopes allows detection and study of compact sources with flux densities under 1 millijansky.     

高产精养池塘中生态因素对鲢、鳙生长速度影响作用的研究

采用多元回归分析方法,将静水高产精养食用鱼池塘中各种规格鲢鳙日增重率与水温、贮存量、浮游动物及易消化浮游植物生物量等多种因素的关系,经微机运算分析,建立了最优回归方程(以下简称回归方程),确认贮存量和水温是影响日增重率的两个重要因素。并确定鲢、鳙的最适贮存量。为定量分析高产精养池塘中诸生态因素对鱼类生长速度的影响作用和确定其作用程度(主次关系)建立了有效的现代分析方法,对研究提高池塘鱼产量及拟定科学放养和生产模式具有重要实际意义。     

Phase-coherent optical pulse synthesis from separate femtosecond lasers

We generated a coherently synthesized optical pulse from two independent mode-locked femtosecond lasers, providing a route to extend the coherent bandwidth available for ultrafast science. The two separate lasers (one centered at 760 nanometers wavelength, the other at 810 nanometers) are tightly synchronized and phase-locked. Coherence between the two lasers is demonstrated via spectral interferometry and second-order field cross-correlation. Measurements reveal a coherently synthesized pulse that has a temporally narrower second-order autocorrelation width and that exhibits a larger amplitude than the individual laser outputs. This work represents a new and flexible approach to the synthesis of coherent light.     

化学调控对稻米品质的影响研究现状及展望

就稻米品质形成的生理生化基础及化学调控在水稻生产中的应用现状进行了综述,重点剖析了化学调控剂对碳氮代谢及其相关酶活性、光合作用、干物质运转、籽粒灌浆的调节作用,在分析了目前稻米品质化学调控研究中存在的问题同时,提出了应用系统的观点,从光合生产、籽粒灌浆及相关酶系统特性、物质运转等水稻生产的“源库流”三方面入手,开展化学调控剂对米质作用机理研究,将有可能从根本上揭示米质品质形成规律。同时指出在研究实践中,抓住品质主要制约因素,利用激素间的协同与拮抗作用,开展化学调控剂的复配,将有望改善稻米品质的多个性状指标。     

黑龙江西部羊寄生虫的调查及控制技术的建立

黑龙江西部地区是该省主要牧业基地，羊的饲养主要集中在那里。为了摸清西部地区羊寄生虫的种类、感染率、感染强度和地理分布情况，对该地的124只羊进行了剖检，共检出寄生虫26种，隶属于4门6纲19科23属，其中吸虫3种，绦虫（蚴）5种。线虫9种、原虫1种、蜘蛛昆虫8种。蛇形毛圆线虫、鹿前后盘吸虫、哥伦比亚食道口线虫、捻转血矛线虫、土耳其斯坦东毕吸虫、艾美尔球虫、肝片吸虫等7种虫体为黑龙江西部地区羊寄生虫的优势虫种。在此基础上，建立了黑龙江西部地区羊寄生虫病的综合控制技术。     

培养条件对银耳孢子产交配信息素的影响

研究了培养条件对银耳孢子产交配信息素的影响。结果表明银耳孢子产交配信息素的较佳培养基为 :蔗糖 2 0 g/L ,(NH4) 2 SO41.5 84 g/L(含N 2 4mmol/L) ,MgSO4·7H2 O 0 .2 5 g/L ,KH2 PO4·3H 2 O 0 .5 g/L ,VB10 .2mg/L ,ZnSO4·7H2 O 2mg/L ,CaCl2 ·2H2 O 0 .5 g/L ,钼酸铵 0 .0 2mg/L。最佳发酵条件为培养基 pH 6 .5 ,2 3℃ ,14 0r/min摇瓶培养 4d。     

大兴安岭水湿地改造对土壤和植被的影响

采用定位观测和抽样调查方法，对大兴安岭不湿地改造前后的土壤理化性质、植物群落特征进行了系统调查。通过分析发现，经一的水湿地土壤主要理化性质及肥力的变化均利于落叶松生长；植物群落种数呈现增加、减少、再增加的变化规律。造林１０ａ后，草本植物大量减少，乔、灌木少量增加，植物群落向以落叶松为诉 森林群落发展。这种变化对当本地区经济发展有积极的一面。但地区域揿样性及生态环境产生不利影响。因此，对大兴安岭水湿