不同管理方式下吉林省农田黑土流失量

本文利用土壤流失方程式的计算机应用程序[1],模拟计算吉林省榆树和德惠两市黄土质黑土坡耕地在不同管理利用方式下的土壤流失强度。结果表明,黑土种植玉米降雨流失量在4～45 t/hm2·a之间。种植大豆流失量高出玉米一倍。流失量随耕地坡度加大和A层变薄而增加。吉林黑土A层厚度正在逐渐下降,下降幅度因土种和管理方式而异,范围在0.5～4.5mm/a。种植玉米,吉林省黑土每年会流失830×104t表土,相当于流失近20×104t有机物质。种植大豆会使土壤和有机质流失量加倍。与传统的耕作方式模拟对比,保护性耕作可以显著降低吉林黑土的流失量。     

玉米高产群体叶层结构和光分布与产量关系的研究

光分布关系到作物群体能截获多少日光能并影响产量的高低。本研究于1981～1983年在沈阳农学院试验地以丹玉6、沈单3和沈农171×330为试材,用大田切片法和数理统计概念,分析了玉米不同生育阶段的叶层结构及其光分布的关系。分析结果表明,至玉米生育中期和后期,随着叶层的增加,群体内的光强度自上而下星对数方式下降,其规律符合 Beerlambert 定律。经不同群体光分布理论分析,不同玉米群体的消光系数存在着差异,如植株高大品种大于植株矮小品种,宽行大垄小于窄行小垄,密度增大消光系数降低。因此,为了建立高产群体结构和合理利用光能,既要考虑选用耐密高产品种,又要注意确定适宜的种植方式。     

关于当前玉米育种的若干问题

配合力是玉米自交系最重要的遗传特性。传统的配合力测定方法已不适应于直接应用单交种为主的现代玉米育种。试验和实践表明,只用一个具有高配合力的自交系作为测验种,足可从早代群体中测别出一般配合力上的高配合力系。根据有关试验结果,作者也讨论了选育多抗系的重要意义和对单一病害片面追求过高抗性的有害影响,并对加强优良新自交系的选育和利用,提出了有关建议。     

直立穗型水稻品种演进状况分析

20世纪上半叶 ,国内外开始陆续出现了直立穗型水稻品种。自1974年辽宁省农作物品种审定委员会成立以来 ,共审定直立、半直立穗型水稻品种30个 ,占审定品种总数的36.6% ,其中 ,“八五”期间达到审定品种总数的32% ,“九五”期间则上升到55%。自20世纪90年代以来 ,辽宁省直立穗型水稻品种的种植面积迅速扩大 ,年种植面积从6.67×104hm2提高到26.67×104hm2 ,种植比例也迅速提高 ,从15%左右提高到50 %以上 ,1999年高达63.6%。辽宁省审定的直立穗型水稻品种中 ,有2/3的品种直立穗型基因来自意大利古老品种巴利拉 ,而且与辽粳5号亲缘关系密切。中国北方地区 (除辽宁省外 )推广种植的直立穗型水稻品种中 ,有53.3 %的品种与巴利拉有亲缘关系。以辽宁省审定的62个粘型常规水稻品种为对象进行对比分析 ,发现直立穗型品种相对于弯曲穗型品种 ,具有产量潜力较高 ,株高较矮、穗型短小而着粒密度较大等特点     

辽东地区农民采用玉米品种影响因素调查分析

以随机访问形式对辽东地区丹东市五龙背镇农民进行问卷调查.调查结果表明,农民对玉米品种的认知比较模糊,当地主栽品种为丹玉99、丹科2157、丹大5号和辽丹933,其中丹玉99、丹科2157、丹大5号适合中等以上肥力地块种植,辽丹933适合坡岗地种植;农民采用玉米品种受农民自身经济文化水平、品种性状因素及外部环境因素影响.建议落实粮食优质优价政策,促进种植业结构调整;提高农民科技素质,加大科技培训力度;种子科研部门要不断开发符合市场需求的优势品种;充分利用大众传播媒介,宣传玉米品种信息;建立以农户为中心的品种推广机制;大力发展农民合作组织,促进玉米品种推广;充分发挥农业技术推广部门在玉米品种推广中的作用.     

基于多时相Sentinel-2影像的黑河中游玉米种植面积提取研究

玉米是黑河中游种植面积最大的农作物,生长期需水量大、蒸散量高.准确获取玉米种植面积对该区域农作物种植结构调整、水资源合理规划有重要参考意义.基于2019年4月至9月Sentinel-2多时相影像,采用随机森林算法开展了黑河中游玉米种植面积提取研究.研究方法分为两类—直接提取法和两步提取法.进一步探讨了多时间信息量对玉米...     

1996年葫芦岛地区玉米叶部病害大流行特点及原因

1996年玉米叶部病害在葫芦岛市大发生,此病发展速度之快和危害损失之严重,在该市历史上尚属首次。据不完全统计,全市播种的9．28万hm2玉米中,病害发生面积6．67万hm2,占种植面积的71．840;减产9成以上近于绝收的面积0．57万hm2,占发生面积的8．5％,全市共损失粮食1．75亿kg。1玉米叶部病害发生特点玉米叶部病害主要以弯孢菌叶斑病[Currularialuata(Wokker）Boed]为主,混以发生玉米大斑病、小斑病、灰斑病等病害。弯抱菌叶斑病是继玉米大斑病、小斑病、圆斑病之后的又一种新的玉米叶部流行性病害,此病害近年在北京郊区和河北省的…     

玉米弯孢菌叶斑病菌的存活和致病力

１材料与方法１．１病原菌越冬存活与分生孢子萌发病原菌采自河北省地区玉米病株上,经分离、纯化后ＰＤＡ斜面保存;孢子萌发检测:将保存与斜面上的病原菌分别置于室内外不同场所和不同时间处理后,自培养基上洗下病原菌的分生孢子,滴于凹形载玻片上,２５℃或不同温度培养,２４ｈ后镜检孢子萌发率。１．２病原菌致病力分化病原菌采自河北省不同玉米产区玉米病株,分离纯化后经ＰＤＡ扩繁,与接种前制成浓度为１．５×１０８个·Ｌ-１的孢子悬浮液;玉米品种:黄早四,Ｍｏ１７,冀５３号。１．３试验方法和玉米资源抗病性鉴定将３个玉米自交系播种于…     

CBERS-02星CCD数据在天山西部生态

以新疆天山西部的蒙玛拉林场为研究区,通过典型地物光谱分析,建立了中巴资源卫星02星CCD数据的森林资源遥感解译标志,并以此为依据,采用人机交互的目视解译技术,结合野外调查,提取生态公益林信息.结果表明蒙玛拉林场的生态公益林总面积为2.8378×104hm2.其中,重点公益林为0.8948×104hm2,占生态公益林总面积的31.53%;山区国有公益林为1.9430×104hm2,占生态公益林总面积的68.47%.通过此次研究,证明中巴资源卫星02星CCD数据在森林资源调查等应用中,具有经济实用等特点,可用于县级、州级、省级等中大尺度区域的森林资源调查监测工作.     

从组织、管理、技术三方面解决企业信息安全问题

中国××集团依赖于高科技的力量在2002年度获得了快速的增长,核心数据网络在该过程中起到了至关重要的作用.为了更好满足中国××集团业务增长和市场发展的需求,强化主机和网络系统的安全可靠性和抗干扰能力、继续改善系统资源性能、建立亚洲一流的安全生产体系和信息安全体系,成为该集团2003年度的重点工作之一.     

Concurrency and parallelism in MC and MD simulations in physics

Certain problems lend themselves admirably to SIMD architecture computers. A number of such problems in physics will be discussed and their implementation on the ICL DAP analyzed. Monte Carlo (MC) problems such as the 3-D Ising model and quantum chromodynamics (QCD) calculations need care and attention with respect to maintaining detailed balance on a SIMD architecture, whereas molecular dynamics (MD) problems do not pose such problems. The efficient use of a DAP requires the development of parallel algorithms designed to make use of the particular architecture and size of the machine, though further software developments must be made which remove the user one stage farther from the particular details of the computer. Experience on the DAP, especially those with only 2 Mbytes of store such as the Edinburgh DAPs, has led to thought about the detailed precisions necessary for the various calculations being done—many computers operate at an accuracy which is in excess of requirement whereas the bit-serial DAP can have its program finely tuned in accuracy.The present DAPs are far from the modern state of the art in fabrication, and future engines of similar design could be made with present technology with a rating well over a Gflop, providing very cost-effective computing.     

Ecofeedback and Significance Feedback in Neural Nets and in Society

A central theme of both Cybernetics and Systems Research has been the study of complex, richly-interconnected systems, particularly those having properties of self-organization. Although social and economic systems are frequently mentioned in the literature, the systems which have been studied most have been the nervous system and artificial systems of neuron-like elements.     

摄影在艺术设计中的价值及作用

摄影的视觉语言在摄影师独特的艺术情感下,形成运动的感受,重复的形状、斑斓的色彩,丰富的情感。艺术设计的表现语言同样是设计师将形状、色彩、构成富于了情感,运用视觉语法规则传递着运动、节奏、韵律的美感。这种情感在艺术设计创作过程中是表现的重点,通过摄影的练习把握好人类对设计元素的微妙情感,可以创造出富有灵性的艺术设计品。     

Fluctuations in Economic and Activity and Stabilization Policies in the CIS

In this study, a highly flexible form of nonlinear time series models called artificial neural networks (ANNs) are employed to predict fluctuations in economic activity in selected members (Armenia, Azerbaijan, Georgia, Kazakhstan, and Kyrgyzstan) of the Commonwealth of Independent States (CIS) using macroeconomic time series [treasury bill rate (T-bill), long term bond rate (BondLT), money supply (MS), industrial production (IP), spread (10-year treasury bond rate less 3-month treasury bill rate), BRTB (bank rate less 3-month treasury bill rate), and GDP growth rate]. Forecasting recessions being very important though challenging, recessions in the selected countries are modeled recursively 1–10 quarters ahead out-of-sample using ANNs in conjunction with macroeconomic time series for all the countries. The out-of-sample forecast results show that in general no single macroeconomic variable employed appears to be useful for predicting recessions in any of the series. However, for Armenia, the treasury bill rate, industrial production, money supply, and the spread (the yield curve) are candidate variables for predicting recessions 1–10 quarters ahead. For Georgia, Kazakhstan, and Kyrgyzstan, the treasury bill rate and money supply series are candidate variables for predicting recessions 1–10 quarters ahead.     

Formaldehyde and nitrogen dioxide in the atmosphere during summer weather extremes and wildfires in European Russia in 2010 and Western Siberia in 2012

Based on the data from the Ozone Monitoring Instrument (OMI; Aura) satellite instrument, an analysis of changes in total formaldehyde (CH₂O) column and tropospheric nitrogen dioxide (NO₂) column, associated with the extreme summer weather regimes and wildfires in European Russia (ER) in 2010 and Western Siberia (WS) in 2012, was carried out. In both territories, over the clusters of intense fires, an approximately two-fold increase in CH₂O content and a 20% increase in NO₂ content were observed. Unlike NO₂, the changes in the CH₂O content over ER and WS also reveal positive correlation with the regional surface temperature.     

Heat balance and transfer in men and women exercising in hot-dry and hot-wet conditions*

Sex-related differences in heat balance and transfer were studied in nine female and ten male heat-acclimatized subjects exposed to two hot-dry (HD) conditions(49°C, 20% rh; 54°C, 10% rh) and three hot-wet (H W) conditions (32°C, 80% rh; 35°C, 90% rh; 37°C, 80%rh). Exposures lasted 120min: l0min rest, 50min walk, l0min rest, 50min walk. Walking speed was 1 34 ms^-1 (level), and for 49°C, 20% rh, in addition, 1-34ms^-l, 5% grade. No sex-related differences were found in metabolic heat production (M), nor in heat exchange by radiation and convection (R + C)or evaporation (E), when expressed per unit body weight (wt). However, E per unit body surface area (A _D) was lower in females by 9–13% (P<0 05 in all HD conditions and for the 32°C, 80% rh condition) due to their lower M/A _D, and 4-6% lower (R + C)/A _D in HD. Core-to-periphery heat conductance was similar in both sexes despite a lower core-to-skin temperature gradient for women in HD. It was suggested that women have an advantage over men in heat transfer particularly in HW because of their higher A _D/wt. The disadvantage of a high A _D/wt at high HD environmental temperatures is diminished by a higher skin temperature, thus reducing (R + C) heat gain. The net effect is to require lower evaporative cooling for women in both HW and HD environments.     

Detecting Irregularities in Images and in Video

We address the problem of detecting irregularities in visual data, e.g., detecting suspicious behaviors in video sequences, or identifying salient patterns in images. The term “irregular” depends on the context in which the “regular” or “valid” are defined. Yet, it is not realistic to expect explicit definition of all possible valid configurations for a given context. We pose the problem of determining the validity of visual data as a process of constructing a puzzle: We try to compose a new observed image region or a new video segment (“the query”) using chunks of data (“pieces of puzzle”) extracted from previous visual examples (“the database”). Regions in the observed data which can be composed using large contiguous chunks of data from the database are considered very likely, whereas regions in the observed data which cannot be composed from the database (or can be composed, but only using small fragmented pieces) are regarded as unlikely/suspicious. The problem is posed as an inference process in a probabilistic graphical model. We show applications of this approach to identifying saliency in images and video, for detecting suspicious behaviors and for automatic visual inspection for quality assurance. Patent Pending     

DIS和HLA系统中的记录与回放

记录和回放在军用仿真系统中有着重要的意义，该文具体分析了ＤＩＳ和ＨＬＡ系统中记录与回放的基本实现方法，并从两个方面比较了两种系统中实现上的不同点。     

Sensors and interfacing in robotics and manufacturing

Sensing is one of the most essential aspects of any robotic application, be it manufacturing or any automated process. Robotic sensors can be divided into two classes of “internal” and “external”. Examples of the first group are position or velocity, while the second group includes proximity, touch, or vision to name a few. The other important problem in manufacturing is interfacing with the environment within a cell. The object of this tutorial paper is to survey the two issues of “sensing” and “interfacing” in robotics and manufacturing.