Relationship Between Hyperspectral Parameters and Physiological and Biochemical Indexes of Flue-Cured Tobacco Leaves

The experiment was set up for examining the physiological and biological indexes quickly and exactly, for obtaining information of tobacco-field fertilizing and tobacco growing. The ASD Field spec FR 2500 was used to measure spectra reflectance of flue-cured tobacco and the relationship between hyperspectral parameters and biochemical contents （total nitrogen, chlorophyll, carotenoid）, and physiological indexes （fresh weight, dry weight, moisture content） of flue-cured tobacco leaves was studied by correlation and stepwise regression statistic methods at different nitrogen and potassium levels. The results indicated that the spectra curves of different treatments had obvious rules and great diversities. There were high correlations between different types of spectra parameters and ten physiological and biochemical indexes of flue-cured tobacco leaves. Hyperspectral characteristic variables of ten physiological and biochemical indexes were found through stepwise regression, and SDr/SDb was the characteristic variable closest to seven biochemical contents. Simultaneously, the R2 and regression coefficient of equations reached 0.05 significant level and the equations had good estimating effects through the examination of other samples. Accordingly, this study suggested that the ten physiological and biochemical indexes could be estimated quickly by the estimating models, at the same time nitrogen-potassium fertilization and growth condition of flue-cured tobacco could be inspected.     

东方红-404Z拖拉机前装载设计开发

介绍了东方红-404Z轮式拖拉机加前装载的设计方法、技术参数以及整机的设计计算。     

Evaluation of supplementary stevia (Stevia rebaudiana,bertoni) leaves and stevioside in broiler diets: effects on feed intake,nutrient metabolism,blood parameters and growth performance

A perennial schrub, stevia, and its extracts are used as a natural sweetener and have been shown to possess antimicrobial properties. Stevia contains high levels of sweetening glycosides including stevioside which is thought to possess antimicrobial and antifungal properties. Little is known about the nutritional value of the schrub in livestock. This study determined the potential use of the shrub as a prebiotic animal feed supplement in light of the recent ban on the use of antibiotics in animal feed and the role of its constituent stevioside in the effects of the shrub. Male Cobb broiler chicks were fed a basal broiler diet without antibiotic but with performance enhancing enzyme mix (positive control), a basal diet without antibiotic and enzymes (negative control), or diets in which 2% of the negative control diet was replaced with either dried ground stevia leaves or 130 ppm pure stevioside during 2 week starter and 2 week grower periods. Body weight gains, feed conversion, abdominal fat deposition, plasma hormone and metabolites and caecal short chain fatty acids (SCFA) were measured in the broilers at 2 and 4 weeks of age. There was no significant effect of the treatments on feed intake during the starter period but birds fed diet supplemented with stevia leaves and stevioside consumed more feed (p < 0.05) than those fed the positive control diet during the grower period. Weight gain by birds fed the positive control and stevioside diets was higher (p < 0.05) than those fed other diets only during the starter period. Feed/gain ratio of birds fed the positive control and stevioside diets was superior (p < 0.05) to others. There was no effect of the treatments on nutrient retention and water content of the excreta. Dietary stevia leave and stevioside decreased total concentration of SCFA and changed their profile in the ceca. There was no effect of the treatments on pancreas weight. Dietary stevia reduced blood levels of glucose, triglycerides and triiodothyronine (T₃) but had no effect on non-esterified fatty acids. In contrast, stevioside only decreased T₃. Both the stevia leaves and stevioside diets significantly increased abdominal fat content. It is concluded that dietary enzyme growth promoters are beneficial to the broilers only during the starter stage and that inclusion of stevia leaves or stevioside has no beneficial effect on the performance of broilers.     

机械制造企业的网络计划分层模型

由于机械制造网络计划庞大，因素众多，网络计划技术应用存在缺陷，交血以是一个较好的方法，已有的层次分解方法大多割裂了层次之间的复杂关系，提出了的方法较的解决了这个问题，并已成功运用到机械制造的具体实践中，获得了满意的结果。     

河南轻质土壤畦灌水肥耦合技术参数试验研究

水肥耦合是当前我国农业灌溉施肥技术发展的趋势,近年来与高效节水灌溉技术结合发展迅速,然而,畦灌水肥耦合技术的研究相对落后,无法满足我国当前和近期相当长一段时期内的农业节水节肥发展需求。【目的】要探索地面灌溉水肥一体化节水节肥适宜参数。【方法】以河南轻质土壤为例,开展了畦灌水肥耦合试验研究,探索畦灌随水施肥模式下的节水节肥和灌水施肥质量控制的适宜参数。【结果】对于畦灌,50 m以内的畦长可获得较好的灌水质量,间隔灌溉方式灌水质量最好,从不冲不淤以及灌水质量综合考虑,入畦单宽流量宜小于1.98 L/(m·s),畦长小于35 m时,间隔加肥下,N和K的施肥均匀度均在80%以上,N和K的储肥率均在85%以上,连续加肥下,N和K的施肥均匀度分别在80%、45%以上,N和K的储肥率均在80%以上。【结论】从灌水施肥综合效果来看,轻质壤土畦灌的畦长不宜大于35 m,入畦单宽流量控制在1.98 L/(m·s)左右,施肥方式宜采取间隔加肥方式。     

精氨酸分解代谢及其在马健康养殖中的应用研究进展

精氨酸,又名2-氨基-5-胍基戊酸,是哺乳动物体内一氧化氮的唯一氮供体和尿素循环的关键氨基酸之一。精氨酸是20种蛋白质氨基酸中碱性最强的氨基酸,具有亲水性侧链。饲粮中添加适量的精氨酸可以调控母畜的生殖系统血流量及胎盘对营养物质的转运和代谢,进而提高繁殖性能。本文主要从精氨酸分解代谢以及饲粮中补喂精氨酸对马生殖系统血流量、血液参数和胎盘功能等方面的影响进行总结,为精氨酸在马健康养殖中的应用提供科学的理论参考。     

乳酸杆菌和囊素三肽对肉鸡生产性能、血清生化指标及免疫功能的影响

为研究乳酸杆菌和囊素三肽对肉鸡生产性能、血清生化指标及免疫功能的影响,采用日粮中添加乳酸杆菌和肌肉注射囊素三肽的方法,将156只1日龄肉鸡随机分为4个组,Ⅰ组为对照组,Ⅱ组为囊素三肽组,Ⅲ组为乳酸杆菌组,Ⅳ组为囊素三肽+乳酸杆菌组,试验期为42d。结果显示:1)21日龄,乳酸杆菌和囊素三肽显著增加了肉鸡平均日增重,降低了料重比(P0.05);2)42日龄,乳酸杆菌和囊素三肽显著降低了血清甘油三酯浓度(P0.05);3)42日龄,乳酸杆菌和囊素三肽显著促进外周血T淋巴细胞增值转化(P0.05),囊素三肽的注射显著提高了饲喂添加乳酸杆菌日粮的肉鸡血清总免疫球蛋白G含量(P0.05)。综上所述,日粮中添加乳酸杆菌和肌肉注射囊素三肽在一定程度上能改善肉鸡生产性能,显著提高免疫功能。     

沙松纸浆用材不同种源苗期生长模型的建立与拟合

通过对10个种源沙松(Abies holophylla)苗期高生长量的连续观测,并用Logistic方程对其生长动态过程进行拟合,获得苗高物候期与生长特征参数。结果表明:10个种源的沙松苗高生长节律基本一致,但各种源的速生期起止时间和持续时间存在差异,其中不同种源间线性生长始期最多相差5 d,线性生长末期最多相差7 d,线性生长期持续时间最多相差9 d。线性生长量占总生长量的55%以上,该时期为幼苗生长的关键期,应在线性生长期内做好除草、施肥、病虫害防治等管理工作,促进苗期苗高的生长。     

持续动态瘤胃模拟系统研制现状与应用展望

持续动态人工瘤胃装置是研究瘤胃微生物学、评定新饲料资源、进行动物新添加剂毒理试验等较为理想的模型。利用该模型进行反刍动物营养研究不仅简单、方便易操作，且能较大程度的体现体内瘤胃环境的真实情况。作者对持续动态人工瘤胃装置的种类、结构组成、控制参数、模拟效果、培养方法、装置应用及存在的不足等进行了综述。     

芒果品种资源叶片δ13C与若干生理指标的相关性分析

为了分析芒果品种植株叶片碳稳定性同位素(δ13C)与叶片若干生理指标的相互关系，测定64个芒果品种的δ13C值，及叶片中氮、磷、钾、水分、叶绿素和脯氨酸的含量。结果表明：芒果叶片δ13值与叶片含水量、叶绿素a、叶绿素b、总叶绿素和脯氨酸含量的相关性均不显著；芒果叶片氮、磷、钾含量均与δ13C值呈显著的正相关(P＜0.05)；多元逐步回归分析结果表明，叶片氮含量是引起品种间δ13C差异的主要因素。