Efecto de la fertilización nitrogenada y la densidad de siembra sobre la producción de biomasa y composición química del Marango (Moringa Oleífera) en suelo arcilloso de Juigalpa, Chontales, 2010

El presente trabajo tuvo como objetivo evaluar el efecto de la fertilización nitrogenada y la densidad de siembra sobre la producción de biomasa y la composición química del Marango (Moringa oleífera) en 1 corte a 90 días en periodo de establecimiento, en suelo arcilloso de Juigalpa, Chontales. El ensayo se llevó a cabo en la hacienda «San Esteban", localizada geográficamente a 12°07'26.80" latitud Norte y 85°27'13.93" longitud Oeste, municipio de Juigalpa, Chontales, de agosto a diciembre 201O. El diseño experimental usado fue un bifactorial con 3 niveles de fertilización nitrogenada (TI-O kg N ha'1,T2-100 kg N ha'1 y T3-150 kg N ha'1),como factor principal y 2 densidades de siembra (Dl-200,000 plantas ha·1 y D2-250,000 plantas ha'1), como factor secundario en bloques completos al azar con arreglo de parcelas divididas usando los niveles de fertilización nitrogenada como parcela principal y las densidades de siembra como sub parcela. Se realizó análisis de varianza y comparación de media con la prueba de Tukey, utilizando el Software Statical Analisys System versión 8, 2001. La fertilización nitrogenada mostró efectos significativos (p<0.05) sobre: altura de planta, diámetro de copa, emergencia de plántula, rendimiento de biomasa fresca y seca: total, fracción fina y fracción gruesa de Moringa oleífera, siendo menor en T1 y superior en T3, que no mostró diferencias estadísticas con T2; la densidad de siembra no mostró efectos significativos (p<0.05) en dichas variables, aunque numéricamente los valores superiores los mostró DI. En las variables de composición química, mostraron efectos significativos tanto fertilización nitrogenada como densidad de siembra, el contenido de materia seca mostró valores similares tanto en fertilización nitrogenada como en densidad de siembra; los contenidos de cenizas y proteína cruda mostraron menores valores en dosis de fertilización nitrogenada de l00 y 150 kg N ha·1 con respecto al tratamiento de O kg N ha·1 y en la densidad menor correspondiente a 200,000 plantas ha'1; los contenidos de fibra detergente neutro y fibra detergente ácida mostraron superior valor en dosis mayores de nitrógeno y en la densidad menor.

测量万瓦级CO_2激光连续输出的鼠笼式能量计

<正> CO_2激光器连续输出功率可达数万瓦以上,运转时间短的仅几秒,一般的功率计很难兼顾承受高功率密度和响应时间快这两个要求。

力学和它的发展

<正> 为什么十七世纪以前没有真正的“科学”? 公元前三世纪,希腊文化曾经有过高度的发展。阿基米德(287—212,B.C.)的静力学,欧几里得(300,B.C.)的几何学,都是杰出的科学先驱例子。但是最有影响的亚里士多德(384—322,B.C.)的动力学,却是一些荒谬的唯心臆测。可是由于亚里士多德在学术界的权威性,他的思想整整统治了西方经院学派达两千年之久,其中经过随着希腊文化的衰

关于弹塑性混合体的变分原理及其应用

<正> 关于彈性及塑性体力学的变分原理已有不少学者研究过(参看文献[1])。胡海昌在他的論文[1]中曾賦与了这些变分原理以相当廣泛的形式。但是研究彈塑性混合体的变分原理并把它们应用于具体問題的工作,就作者所知,还为数不多。由于在彈塑性混合体的力学問题中,彈塑性区域的分界事先是不知道的,因而用嚴格的方法求解这类問题遭遇到了巨大的数学困难。考虑到变分原理在彈性力学中应用时所获得的巨大成

航空技术的展望

<正> 一引言虽然人们对航空的兴趣是很古老的,它在神话和传说中已经出现了,但是真正的航空时代还只有五十多年,比起许多其它工程技术部门,航空是很年轻的。然而航空技术的发展是非常迅速的,在短短的五十多年内,我们已经看到多大的变化:早年的木架蒙布结构的双翼式飞机很快地就被钢架包干层板的结构所代替,速度也从60公里/时加高到250公里/时。但在1980年后,全金属铝合金的单翼飞机出现了,航空技术又有了很大的进步,民用航空随着发展,航线上的速度达到800公里/时以上。军用飞机的速

On laser-induced reverse plugging effect

A new kind of failure induced by long pulsed laser, named as reverse plugging effect (RPE), was experimentally observed in thin foil of brass. The whole failure process can be divided into three stages, namely thermal reverse bulging, shear deformation localization and reverse perforation. In this paper, a description of experimental and theoretical study on this newly discovered phenomenon is presented in detail.

电解沉积纳米镍退火析出相的EBSD分析

电解沉积方法制备的纳米晶镍经650℃退火处理后,晶粒发生了长大,在晶内沿特定晶面析出了第二相颗粒,样品的拉伸断口为沿晶断口。利用EDS和EBSD对这种第二相析出物进行的成份分析和结构/取向分析表明:这种第二相颗粒是NiS2颗粒,其晶格取向与基体镍保持一致。NiS2颗粒沿基体镍的(001)面析出导致了晶界生长为台阶状并使晶界弱化。

反分析确定金属薄膜与陶瓷间界面的力学性能参数

该文基于薄膜撕裂实验测量和反分析来确定铝膜与陶瓷基体之间界面的力学参数(指界面粘结功和分离强度),薄膜是通过一层环氧树脂胶粘结到基体的。薄膜厚度20μm―250μm,撕裂实验中撕裂角度取90°、135°和180°三种。嵌入粘聚力单元(cohesive zone elements)的有限元模型用于模拟撕裂过程,反分析中有限元计算结果作为一个神经网络的训练数据。将撕裂实验结果输入训练后的网络,可得界面粘结功和分离强度。

Diário da Constituinte [gravação de vídeo] : [programa n. 110]

As grandes cidades brasileiras estão inchadas e a superpopulação causa grandes problemas. Ibsen Pinheiro (PMDB-RS) diz que as regiões ricas são os "primos pobres" do nosso sistema tributário e que a nova Constituição deverá disponibilizar maiores recursos aos grandes centros urbanos para resolver e melhorar a vida de millhões de brasileiros. A Comissão de Ordem Econômica sugere dispositivos para acelerar a reforma urbana, sendo o primeiro deles o que ataca a especulação imobiliária sobre terras urbanas, com a criação de um imposto progressivo nas áreas não construídas e não usadas. Joaquim Bevilacqua (PTB- SP) defende a necessidade de iniciar uma economia de produtividade, em que o capital não seja especulativo, mas que contribua para o desenvolvimento social. Outro dispositivo é o que cria o usucapião urbano, que permite ao cidadão requerer o título de propriedade de uma área de até 250 m2 que ocupar por cinco anos. Gerson Marcondes (PMDB-SP) diz que a proposta atende grande parte das grandes cidades, onde existem não só as favelas, mas também os lotes populares, os loteamentos clandestinos e irregulares. Para evitar problemas urbanos é preciso acabar com o inchaço das cidades grandes e, por isso, os constituintes sugerem o estímulo à povoação de áreas vazias. Renato Bernardi (PMDB-PR) apresenta emenda que estimula o desenvolvimento de áreas pouco povoadas. Jovens a partir de dezesseis anos poderão votar (voto facultativo). Aécio Neves (PMDB-MG) promove campanha para que os jovens de dezesseis aos dezoito anos possam votar. Tito Costa (PMDB-SP) não crê que o cidadão de dezesseis anos esteja apto a votar e a ser votado. Airton Cordeiro (PDT-PR) opina que os jovens podem votar, sobretudo em uma sociedade que impõe a este jovem a necessidade de entrar no mercado de trabalho. Bernardo Cabral (PMDB-AM) entregará relatório da Comissão de Sistematização a Ulysses Guimarães, Presidente da Assembleia Nacional Constituinte (ANC).

液池中大Pr数流体的热流体波

数值研究零重力条件下浅液池中大Pr数流体（Pr=105．6）的热流体波．液池的两侧有不同的温度，形成一定的温度差．当温度差增加并超过临界温度差时，在液池中会出现从冷端向热端传播的行波．扰动温度，扰动速度和扰动压强的相位关系表明这种行波为扰动温度所驱动，为热流体波．热流体波很弱，在热流体波出现时，在液池中几乎观测不到振荡的流场和温度分布．对热流体波的形成机理进行了分析和讨论．

中国科学院高温气体动力学重点实验室研究进展

在钱学森先生的倡导下，中国科学院力学研究所自20世纪50年代末期就开始了高温气体动力学的基础研究，相关研究进展曾经为发展我国“两弹一星”和神州飞船做出了重要贡献．在钱学森先生创立的气动研究队伍和科研积累的基础上，中国科学院于1994年组建了中国科学院高温气体动力学重点实验室．

Estudio de los rayos en el País vasco y su relación con la precipitación

245 p. : il.

Interim report on the progress of an inventory of artesian wells in Florida: leading to the enforcement of sections 370.051 - 370.54, Florida statues

One of the causes of lower artesian pressure, water waste and aquifer contamination is the misuse and insufficient care of artesian wells. In 1953, Senate Bill No. 57, entitled "An Act to Protect and Control the Artesian Waters of the State" (see Appendix) became a law. This law was passed through the efforts exerted by leading members of the Senate and the House of Representatives, who understood the need for a wise and controlled expenditure of our most valuable natural resource. The State Geologist and his authorized representatives were designated by this law to enforce this conservation measure; however, no financial provision was included for the 1953-55 biennium. The proposed program of the Florida Geological Survey for this biennium did not include the funds nor provide any full-time personnel for the enforcement of this statute. As a result, little actual work was accomplished during these two years, although much time was given to planning and discussion of the problem. Realizing that this program could provide additional basic data needed in the analysis of the water-supply problem, the State Geologist sought and was granted by the 1955 Legislature adequate funds with which to activate the first phase of the enforcement of Florida Statute No. 370.051-054. Enumerated below is a summary of the progress made on this investigation as outlined previously: 1. Data have been collected on 967 wildly flowing wells in 22 counties. 2. Chloride determinations have been run on 850 of the 967 wells. 3. Of the 967 wells, 554 have chlorides in excess of the 250 ppm, the upper limit assigned by the State Board of Health for public consumption. 4. Water escapes at the rate of 37, 762 gallons per minute from these 967 wells. This amounts to 54, 377, 280 gallons per day. The investigation is incomplete at this time; therefore, no final conclusions can be reached. However, from data already collected, the following recommendations are proposed: 1. That the present inventory of wildly flowing wells be completed for the entire State. 2. That the current inventory of wildly flowing wells be expanded at the conclusion of the present inventory to include all flowing wells. 3. That a complete statewide inventory program be established and conducted in cooperation with the Ground Water Branchof the U.S. Geological Survey. 4. That the enforcement functions as set down in Sections 370.051/.054, Florida Statutes, be separated from the program to collect water-resource data and that these functions be given to the Water Resources Department, if such is created (to be recommended by the Water Resources Study Commission in a water policy law presented to the 1957 Legislature). 5. That the research phase (well inventory) of the program remain under the direction of the Florida Geological Survey. (PDF contains 204 pages.)

A comprehensive method for the elastic calculation of the two-point wheel-rail contact

This work shows the method developed to solve the wheel-rail contact problem via a look-up table with a three-dimensional elastic model. This method enables introduction of the two contact point effect on vehicle movement using three-dimensional analysis of surfaces including the influence of the angle of attack. This work presents several dynamic simulations and studies the impact that the introduction of the two contact points on three dimensions has on wear indexes and derailment risk against traditional bidimensional analysis. Furthermore, it studies advantages and disadvantages of using a look-up table against an on-line resolution of the problem.