三价铬在荷斯坦牛乳中沉积量及对泌乳量影响的研究

将 30头胎次、泌乳期、泌乳量相近的荷斯坦牛分成 6组 ,每组 5头 ,在其日粮中分别投饲 2、3及 4mg铬量的三氯化铬 (Crcl3 ·6H2 O)和吡啶甲酸铬 (CrPIF) ,以同舍非试验牛群为对照 ,饲养 36天。结果表明 :①试验组 16、36天的泌乳量 ,两种铬源均随铬水平的递增呈下降趋势 ,2mg无机铬和有机铬对泌乳量有积极影响。②三水平无机铬组乳中铬含量低于对照组 (P >0 0 5 ) ,三水平有机铬随铬浓度的递增 ,乳中铬含量亦呈下降趋势 ,均高于无机铬组 ,其中 2mgCrPIF组比对照组乳中铬含量高 43 7%(P >0 0 5 ) ,且显著高于三水平无机铬组 (P <0 0 5 )。     

ANALYSIS OF TRANSFER FUNCTION FOR COMPLEX NETWORK WITH INTEGRATION OPERATION AMPLIFIER

This paper introduces nullor,an ideal electronic part applied to I.O.A.and discusses the preordained condition with which nullor substitutes for I.O.A.equivalently.Then a criterion which can determine the work state of theoperation amplifier is offered.And a method using node admittance matrixto analyse transfer functions of networks with nullor is also introduced.     

棉花抗氧化系统对黄萎病的反应

本文阐述了棉花抗气化系统及光合、呼吸作用对黄萎病的反应。研究表明，ＣＡＴ和ＰＯＤ对黄萎病反应最早，酶活性变化最大。由于病株ＣＡＴ活性下降导致Ｈ２Ｏ２积累，并引起叶绿体中占主要地位的Ｃｕ／Ｚｎ－ＳＯＤ失活，线粒体中占主要地位的Ｍｎ－ＳＯＤ活性保持相对稳定，与之对应的光合速率下降显著超过呼吸速率。我们认为，ＣＡＴ、ＳＯＤ活性下降既造成了对宿主细胞的伤害，同时也是宿主的防御反应，在宿主－病原菌相互作用过程中，ＣＡＴ活性下降引起的Ｈ２Ｏ２积累是诱导因素。     

CaO-B2O3-SiO2-TiO2系保护渣配位结构的计算模拟

针对新型无氟保护渣CaO-B2O3-SiO2-TiO2四元渣系,采用分子动力学模拟的方法,对该保护渣系的微观结构进行了模拟计算,分析了CaO-B2O3-SiO2-TiO2渣系的配位结构,并考察了TiO2含量对保护渣配位结构的影响规律。研究表明：该渣系中硼的配位结构只存在三配位的三角体和四配位的四面体,而Ti与O之间主要以六配位的八面体结构形式存在;随着TiO2含量的增加,保护渣微观结构中Si、B、Ti的配位形式将发生明显变化,分别向四配位结构、三配位结构及五配位结构转化。     

H2O2促进大豆种子萌发的研究

研究了H2O2浸种对大豆种子萌发的影响。0.1%过氧化氢处理的种子,其发芽率、发芽指数、发芽率高峰值以及活力指数均最高。0.1%处理种子的过氧化物酶和超氧化物岐化酶的活性最高;0.01%处理的种子,其多酚氧化酶活性最高;0.01%处理明显提高种子的电解质外渗率。     

枯萎菌诱导对棉花细胞壁氨基酸含量的影响

用不同致病力的棉花枯萎菌（Ｆｔｔｓａｒｉｕｍｏｘｙｓｐｏｒｕｍｆ．ｓｐｖａｓｉｎｆｅｃｔｕｍ）７号和３号小种接种棉花，对抗、感品种根部细胞壁氨基酸含量进行分析。结果表明，感病品种在接种７号小种后，根内细胞壁氨基酸含量增加了３２．３％，抗病品种增加了４，４％；接种３号小种后抗病品种氨基酸含量下降了１４％，感病品种上升了１９．８％。感病品种受枯萎菌诱导后细胞壁氨基酸的积累明显高于抗病品种，为枯萎菌的生长提供了较多的氮源，易与枯萎菌建立寄生关系，认为细胞壁氨基酸含量与棉花对枯萎病的抗性具有一定相关性。     

Growth and yield responses of spring wheat to increasing carbon dioxide, ozone and physiological stresses: a statistical analysis of ‘ESPACE-wheat’ results

One of the major goals of the European Stress Physiology and Climate Experiment (ESPACE-wheat) was to investigate the sensitivity of wheat growth and productivity to the combined effects of changes in CO₂ concentration, ozone and other physiological stresses. Experiments were performed at different sites throughout Europe, over three consecutive growing-seasons using open-top chambers. This paper summarizes the main experimental findings of the effects of CO₂ enrichment and other factors i.e. ozone (O₃), drought stress or nitrogen supply on the biomass and yield of spring wheat (Triticum aestivum cv. Minaret). Final harvest data from different sites and seasons were statistically analysed: (1) to identify main effects and interactions between experimentally controlled factors; and (2) to evaluate quantitative relationships between environmental variables and biological responses. Generally, ‘Minaret’ wheat did not respond significantly to O₃, suggesting that this cultivar is relatively tolerant to the O₃ levels applied. The main effect of CO₂ was a significant enhancement of grain yield and above-ground biomass in almost all experiments. Significant interactions between CO₂ and other factors were not common, although modifications in different N- and water supplies also led to significant effects on grain yield and biomass. In addition, climatic factors (in particular: mean air temperature and global radiation) were identified as important co-variables affecting grain yield or biomass, repectively. On average, the yield increase as a result of a doubling of [CO₂] was 35% compared with that observed at ambient CO₂ concentrations. However, linear regressions of grain yield or above-ground biomass for individual experiments revealed a large variability in the quantitative responses of ‘Minaret’ wheat to CO₂ enrichment (yield increase ranging from 11 to 121%). Hence, CO₂ responsiveness was shown to differ considerably when the same cultivar of wheat was grown at different European locations. Multiple regression analyses perfomed to evaluate the relative importance of the measured environmental parameters on grain yield indicated that although yield was significantly related to five independent variables (24 h mean CO₂ concentration, 12 h mean O₃ concentration, temperature, radiation, and drought stress), a large proportion of the observed variability remained unexplained.     

稻属种间杂交转移药用野生稻抗褐飞虱基因研究

以高产优质的栽培稻（O．Sativa）中86—44为母本，高抗褐飞虱的广西药用野生稻（O．officinalis）为父本，远缘杂交结合胚拯救，获得高抗褐飞虱的杂种植株F1。通过和栽培稻中86—44回交，获得高抗褐飞虱的回交一代（BC1F1）及回交二代（BC2F1），经自效获得BC2F2，部分株系农艺性状优良，结实正常，高抗褐飞虱。研究表明，远缘杂交结合胚拯救，通过两次回交并结合胚拯救转移药用野生稻的抗褐飞虱基因是一条行之有效的途径。     

Development of Static Characteristic Automatic Testing System About Brake Valves of Automobile

This paper describes a PC controlled brake valve automatic testing system which uses industrial control(computer) and Advantech powerful date acquition card PCI-1710L,and chooses Advantech PCI-1730 as the I/O card,(uses) FUJI servo systrm as the transmission mechanism.The system monitor the brake valve's quality based on analyseing the static characteristics of the brake valve.The authors also introduce the principle and structure of the system,hardware and software design process.The system works well in practice.     

Chlorophyll concentration of potatoes grown under elevated carbon dioxide and/or ozone concentrations

Potato cv. Bintje was grown in open-top-chambers and free-air-CO₂-enrichment systems at 7 sites across Europe for 2 years (1998–99). The effect of different treatments (CO₂ enrichment and O₃ fumigation) on the chlorophyll content of fully expanded upper and lower canopy leaves was investigated collecting Minolta SPAD-502 meter readings. In both CO₂ treated and O₃ fumigated plants, leaves had lower chlorophyll content than those in ambient air controls; season-long chlorophyll averages were 9.3% lower in the ‘CO₂’ treatments, 9.1% lower in ‘O₃’ treatments and 12.3% lower in ‘CO₂+O₃’ treatments. The analysis of chlorophyll content in three different growth phases (Emergence–Tuber Initiation; Tuber Initiation–Maximum Leaf Area; Maximum Leaf Area–Harvest) showed that in the early growth period, i.e. before tuber initiation there was a slight indication for an higher chlorophyll content at elevated CO₂ (+3.8%) or O₃ (+1.7%). However, from tuber initiation onwards the leaves of plants grown under elevated CO₂ or O₃ showed a progressively lower chlorophyll content (−4.8% for CO₂ treatments and −2.6% for O₃ treatments) indicating a faster senescence of leaves that increased during the late growth period (−12.8% for CO₂ treatments and −12.7% for O₃ treatments) and that was enhanced by CO₂–O₃ interaction (−17.8%).