不同播期对紫花苜蓿生长发育及产量的影响

试验研究结果表明,在进入多雨季节的哈尔滨地区,分期种植对紫花苜蓿各茬次的生长发育特性和干草产量都会产生影响,表现为早期播种好于晚期。2004~2006年3a干草平均产量7月5日播种比7月25日播种增产286kg/hm2,7月25日播种比8月15日播种增产1 639kg/hm2,7月15日播种比8月15日播种增产1 925kg/hm2。     

论自然创造价值——兼论劳动生产率与价值量的关系

文章从马克思的剩余价值生产（或劳动）理论进行分析，推导出自然物具有价值，进而说明劳动生产率与商品价值量并不一定成反比例。使价值与商品的范畴既符合逻辑又符合市场实际。     

基于神经网络的矿井井型确定方法

研究了基于神经网络的矿井井型确定方法，为矿井设计提供了一种崭新的工具，应用表明，该方法是切实可行的。图２，表２，参４。     

Study on the Development of Northwestern China's Economy

ＳｔｕｄｙｏｎｔｈｅＤｅｖｅｌｏｐｍｅｎｔｏｆＮｏｒｔｈｗｅｓｔｅｒｎＣｈｉｎａ＇ｓＥｃｏｎｏｍｙ￥ＧｕｏＪｕ－ｅ（ＳｈａｎｘｉＩｎｓｔｉｔｕｔｅｏｆＦｉｎａｎｃｅａｎｄＥｃｏｎｏｍｉｃｓ，Ｘｉａｎ，７１００６１，Ｃｈｉｎａ）Ａｂｓｔｒａｃｔ：Ｔｈｒ...     

信息技术投资的绩效问题研究

目前信息技术已经渗透到经济领域,但关于信息技术对提高经济绩效的作用却引起众多的争论。阐述了信息技术投资与经济绩效的关系,并对信息技术悖论形成的原因进行了分析。     

生产率管理系统模型及实践意义

提高生产率是工业工程追求的永无止境的目标。任何生产组织，要保证较好地实现这一目标，必须实用有效的生产率管理，建立促进生产率提高的能动的运行机制。本文着重讨论生产率管理概念、管理系统模型及运行过程，分析我国推行生产率管理的实践意义。     

论科技地理学

以马克思“科技生产力”学说为基础,分析现代科技的历史作用,初步建立科技地理学的理论;根据国民经济建设客观需要,给出科技地理学学科轮廓。     

Variety distribution pattern and climatic potential productivity of spring maize in Northeast China under climate change

This study was based on the daily meteorological data of 101 meteorological stations from 1971 to 2000 and the 0.25°×0.25° grid data from 1951 to 2100 simulated by RegCM3 under the future A1B climatic scenario published by National Climate Center,in combination with the demand of climatic condition for maize growth in Northeast China.The trajectory of agricultural climatic resources and the effects of climate change on variety distribution and climatic potential productivity of spring maize in Northeast China under future climate change were analyzed.The main agro-climatic resource factors include:the initial date daily average temperature stably passing 10℃(≥10℃),the first frost date,the days of growing period,the ≥10℃ accumulated temperature,and the total radiation and precipitation in the growing period.The results showed that:(1) in the coming 100 years,the first date of ≥10℃ would be significantly advanced,and the first frost date would be delayed.The days of growing period would be extended,the ≥10℃ accumulated temperature and the total radiation would be significantly increased.However,no significant change was found in precipitation.(2) Due to the climate change,the early-maturing varieties will be gradually replaced by late-maturing varieties in Northeast China,and the planting boundaries of several maize varieties would be extended northward and eastward.(3) There would be a significant change in the climatic potential productivity of maize in Northeast China with the high-value gradually moving towards northeast.(4) It was an effective way to increase the climatic potential productivity of maize by appropriate adjustment of sowing date.     

基于PSO-GACA的采煤机螺旋滚筒参数优化设计

为了改善滚筒采煤机的装煤性能、增加采煤机的块煤率、提高其产煤经济效益,以叶片外缘直径、内、外螺旋升角、滚筒转速和采煤机牵引速度为设计变量,选择装煤生产率最大和吨煤售价最高作为目标函数,建立了各种几何约束及性能约束,采用粒子群算法和蚁群算法的混合算法(PSO-GACA算法)对螺旋滚筒的参数进行优化设计。结果表明,在保证滚筒不发生堵塞、抛煤距离合理等条件下,优化后的采煤机装煤生产率提高14.5%,块煤率增加13.2%,吨煤售价可提高0.75%。