欧式木窗专用推台铣主轴动平衡方法研究

介绍了普及型欧式木窗专用推台铣床的作用及其特性，阐述了欧式木窗推台铣床主轴的平衡理论基础．指出了该机械系统的动平衡方法，并通过试验做出了分析。     

Growth performance, energy, and nitrogen balance of weanling pigs fed a cereal-based diet supplemented with Chinese rhubarb

Forty Swiss Large White piglets of 4 weeks of age were used to determine the effect of dietary Chinese rhubarb on growth performance, as well as on energy and nitrogen metabolism by means of indirect respiration calorimetry studies. A cereal-based diet, supplemented with four different dosages of Chinese rhubarb (0.0%, 0.25%, 0.5%, 1%), was offered ad libitum to the piglets. Gaseous exchange was measured, and urine, faeces, and blood samples were taken. The addition of 0.25% dietary rhubarb increased feed intake (+32%) and daily weight gain (+67%) compared to the diet containing the greatest amount of rhubarb (1%). The piglets fed diet supplemented with 0.25% rhubarb digested and metabolised more energy and nitrogen relative to the animals of treatment 1%. As a consequence, the same group (0.25%) converted more energy and nitrogen into body protein than piglets receiving diet supplemented with 1% rhubarb. However, compared to the control group, the addition of 0.25% rhubarb to the diet resulted in not significantly alter growth performance, energy, and nitrogen metabolism of the animals.Blood parameters were not affected by the rhubarb supplementation. The dose-responding effect of Chinese rhubarb was reflected by the dry matter content of faecal samples. According to the laxative effect of higher doses of rhubarb, the addition of 1% rhubarb to the diet reduced dry matter content of faeces. This effect was well visible in practice, although not relevant in statistical terms. The addition of 0.5% dietary rhubarb had no relevant effect on growth performance or on energy and nitrogen metabolism of treated animals.     

日本北海道北部寒温带森林流域林冠层凋落物及其养分归还量的景观格局(英文)

Within a forested watershed at the Uryu Experimental Forest of Hokkaido University in northern Hokkaido, overstory litterfall and related nutrient fluxes were measured at different landscape zones over two years. The wetland zone covered with Picea glehnii pure stand. The riparian zone was deciduous broad-leaved stand dominated by Alnus hirsuta and Salix spp., while the mixture of deciduous broadleaf and evergreen conifer dominated by Betula platyphylla, Quercus crispula and Abies sachalinensis distributed on the upland zone. Annual litterfall averaged 1444, 5122, and 4123 kg.hm^-2·a^-1 in the wetland, riparian and upland zones, respectively. Litterfall production peaked in September-October, and foliage litter contributed the greatest amount （73.4%-87.6 %） of the annual total litterfall. Concentrations of nutrients analyzed in foliage litter of the dominant species showed a similar seasonal variation over the year except for N in P glehnii and A. hirsuta. The nutrient fluxes for all elements analyzed were greatest on riparian zone and lowest in wetland zone. Nutrient fluxes via litterfall followed the decreasing sequence： N （11-129 kg.hm-2.aq） 〉 Ca （9-69） 〉 K （5-20） 〉 Mg （3-15） 〉 P （0.4-4.7） for all stands. Significant differences were found in litterfall production and nutrient fluxes among the different landscape components. There existed significant differences in soil chemistry between the different landscape zones. The consistently low soil C：N ratios at the riparian zone might be due to the higher-quality litter inputs （largely N-fixing alder）.     

AM真菌对NaCl胁迫下滨梅（Prunus maritima）苗生长和营养元素吸收的影响

在温室条件下分别接种摩西球囊霉Glomus mosseae、透光球囊霉G.diaphanum和幼套球囊霉G.etunicatum,来观察盐胁迫下滨梅的生长反应。结果表明接种了AM真菌的滨梅与对照相比显著增加了滨梅幼苗的生长。接种了摩西球囊霉G.mosseae和幼套球囊霉G.etunicatum的滨梅幼苗所含的干物质总量分别高出对照47%和43%,总叶面积分别高出对照36%和35%。NaCl胁迫下接种AM真菌的滨梅幼苗叶中所有养分含量除了Fe都表现出相互作用,方差分析的结果显著;摩西球囊霉G.mosseae和幼套球囊霉G.etunicatum在提高滨梅苗的抗盐能力上比透光球囊霉G.diaphanum更有效。实验结果表明接种特定的AM真菌能够缓解土壤盐胁迫对滨梅的伤害反应。     

环境因素对淡水浮丝藻生长及产生嗅味的影响

研究温度、营养盐浓度以及光照强度对淡水浮丝藻(Planktothrix sp.)及其代谢产物二-甲基异莰醇(2-MIB)的影响,为控制丝状蓝藻生长及预警水体嗅味物质污染提供实践依据。浮丝藻由中国科学院水生生物研究所淡水藻种库分离于安徽巢湖;设置的实验温度为15、20、25、30℃,BG-11营养盐溶液体积分数为20%、30%、50%、100%,光照为1 000、2 000、3 000、4 000 lx。结果表明,温度对浮丝藻生长密度、总2-MIB生成量及胞外2-MIB分泌量影响最显著,25℃是浮丝藻最适宜生长温度,最高细胞密度可达6.04×10⁵个/mL,30℃是其最适宜的产2-MIB温度,总2-MIB生成量和胞外2-MIB分泌量均最高,分别为3.64×10³ng/L和2.78×10³ng/L;其次为营养盐浓度,增大BG-11营养盐浓度,浮丝藻生长密度和总2-MIB生成量会随之增加,低浓度营养盐时胞外2-MIB分泌量所占比例较高,表明低浓度营养盐更有利于浮丝藻进行胞外2-MIB分泌;光照对浮丝藻生长及产嗅味物质影响较小,...     

施肥对甜菜产量、物质积累和养分吸收规律的影响

采用田间试验研究了施肥对甜菜产量、干物质积累和吸肥规律的影响。结果表明：氮、磷、钾肥配合施用可以提高甜菜产量,制约甜菜产量的养分因子依次为N〉P〉K。干物质日积累规律为：苗期增长缓慢,叶和块根分别在出苗后80,125d达到最大值,在60～80d时,块根的日积累量超过叶。氮的吸收速率,全株表现为慢-快-慢的规律,叶片和块根分别在出苗后100,160d达到最大值,氮的累积总量在叶中较多。磷的吸收速率,叶片表现为出苗后40～80d最快,块根在40～120d快速增加并达到最大值;磷在叶和根中的累积量分别在出苗后80,120d达到最大,80d之后根的累积量超过叶。对于钾,叶在出苗后40—120d快速吸收并达到最大值,块根在出苗60d后吸收加快,收获时达到最大;在整个生育期内块根对K的吸收量都低于叶。甜菜单株日吸收N和P量分别在出苗后100,60d达到最大值;K的日吸收量苗期较少,40～80d快速增加达到最大,收获前出现负增长。     

基于水量平衡原理的畦灌水流推进简化解析模型研究

畦灌水流推进过程计算模型对确定灌水技术要素、田间平均入渗率和糙率有十分重要的作用。该文依据水量平衡模型,分析畦灌下渗水形状系数、地表储水形状系数的变化规律,结果表明下渗水形状系数受地表水推进过程中的推进距离和时间的幂指数影响很小,可用一个稳定值代替,由此建立了基于水量平衡原理的畦灌水流推进简化解析模型。结合已有文献资料和田间试验对模型进行检验,表明该模型具有计算求解方便、精度较高的优点,可用于畦灌合理灌水技术指标的确定。     

苦竹各器官主要营养元素分布及采伐的养分输出

本文根据四川长宁苦竹(Pleioblastus amarus)各器官生物量以及其主要营养元素含量和储量,研究了苦竹采伐的养分输出问题。结果表明:苦竹各器官中N、P、K、Si、Ca、Mg等6种营养元素以代谢旺盛的竹叶和竹鞭中含量最高;6种养分元素在各器官贮存量(单位:kg.hm-2)从大至小的排序为:叶(510.8)>竹根(230.62)>杆(182.14)>枝(163.77>竹鞭(59.19)>竹蔸(41.16)。苦竹采伐的养分年输出量(单位:kg.hm-2)从大至小的排序为:Si(50.23)>K(38.77)>N(35.58)>Mg(4.55)>P(3.86)>Ca(3.31)。对比该地区的降雨输入,苦竹林地养分以Si失衡最为严重;其次为K、N。若采伐时将竹叶带出竹林,6种元素的养分输出总量将增加1.48倍。可见,竹叶归还林地对维持地力具有极其重要的作用。     

Effects of shading and NO3:NH4 ratio on the yield,quality and N metabolism in strawberry

The effect of 50% shading and NO₃:NH₄ ratio (0:100, 75:25, 50:50, and 25:75) in the nutrient solution on growth, yield, quality and N metabolism in hydroponically grown strawberry (Fragaria × ananassa var Camarosa) was evaluated. Both fresh and dry weights of leaves were significantly lower when a high concentration of either NO₃ (100%) or NH₄ (75%) was the sole N source in the nutrient solution. In unshaded plants, increasing of both NH₄ and NO₃ ratio in the nutrient solution reduced photosynthetic (Pn) rate, however in shaded plants the reduction of Pn became more pronounced at a higher ratio of NH₄ in the nutrient solution. The yield in terms of fresh and dry weight of fruit per plant was significantly increased at the 75:25 and 50:50 (NO₃:NH₄) treatments. Fruit size was significantly affected by the treatments, so that the biggest fruits in both shaded and unshaded plants were obtained under the 75:25 and 50:50 (NO₃:NH₄) treatments. Total soluble solid (TSS) in unshaded plants was increased with increasing NH₄ ratio in the nutrient solution, however in shaded plants it was reduced at high NH₄ ratio in the nutrient solution. In both shaded and unshaded plants, higher concentration of NH₄ significantly reduced the post-harvest life of the fruits. The increase of tissue N concentration was nearly proportional to the NH₄ concentration in the nutrient solution. The activity of nitrate reductase (NR) was increased by increasing NH₄ from 0 to 50% and then reduced at a higher ratio of NH₄ in the solution. Shading increased NH₄ concentration so that the shaded plant had nearly twice as high NH₄ concentration in the leaves. The increase of NH₄ concentration induced by shading could be partially the reduction of NH₄ assimilate because of the shortage of carbohydrate.     

非淹水条件不同翻压量细叶满江红腐解及养分释放特征

为明确不同翻压量细叶满江红(Azolla filiculoides)在非淹水土壤中的腐解过程差异,以玻璃纤维滤纸与尼龙网袋结合的方法开展翻压模拟试验,研究了3个翻压量(萍土质量比为5 g·kg^-1,10 g·kg^-1和15 g·kg^-1)下细叶满江红的腐解及养分释放特征。结果表明：不同翻压量细叶满江红的腐解及养分释放规律均为前期(0～10 d)快、后期(20～60 d)慢,最终(60 d后)的腐解率和养分释放率随翻压量的增加而降低,但养分释放总量随之增加,各翻压量养分释放率均为磷>钾>碳>氮。养分释放率(y)和释放速率(v)与腐解时间(x)的关系分别符合幂函数y=ax^b(P<0.001)和指数衰减模型v=v_oe^-kx(P<0.05)。回归分析表明,增加翻压量可延缓细叶满江红养分的释放,且延缓效果为氮>碳>钾>磷;随着翻压量的增加,各养分的最大释放速率均显著提升(P<0.05),但速率衰减速度也随之加快。...