高效全自动清淤系统在酸性水库的应用

针对 pH ≤ 3 的酸性水库周边地形复杂无法进入大型机械设备、淤泥沉积深夹带有大量织物、库底覆有土工膜易破损等特点,将前置浮船可升降的水面泥浆输送系统与地面泥浆输送系统串联可实现高浓度远距离管道输送,通过全自动监测,采用智能变频控制,保证系统在泥浆浓度可变、液面高度可变的大范围区间内连续且稳定运行。系统在调试运行期间,抽送高浓度泥浆为 19220.88m3,极大提高了酸性水库的清淤效率,降低了清淤成本。     

关于贝氏体形核和台阶机制的讨论--与徐祖耀院士等商榷

一些合金固溶化(或淬水)后在预贝氏体(孕育)期内等温淬火(或时效)，既保持高温时形成的晶体缺陷，又产生新的晶体缺陷。母相中由于溶质原子扩散而在缺陷处发生偏聚，则形成贫／富溶质微区，即类拐点(spinoclal—like)分解。当贫溶质微区成分作为Ms，其温度等于或高于等温淬火(或时效)温度时，贝氏体将以马氏体样切变形核，故贝氏体是在溶质原子扩散控制下切变形核。在TEM温台试验中未发现台阶生长机制，界面上巨型台阶是贝氏体增宽(厚)速度差异所致。     

作保灵对长残效除草剂的解毒效应

利用田间试验方法研究保护剂长残效除草剂解毒效应。不同保护剂对豆磺隆解毒效应有差异，作保灵解毒效应最明显，但在除草剂高残留量时解毒作用下降。作保灵对三种长残效除草剂都具有明显的解毒作用，作物的出苗率可恢复80％～100％。解毒效应顺序为油莱＞白菜＞甜菜。     

长大隧洞工程建设中地下水处理的实践及思考

以引汉济渭工程秦岭输水隧洞(越岭段81.779 km)为例,围绕该隧洞建设过程中的地下水问题,介绍其总体富水情况以及地下水预测方法。通过对秦岭各支洞抽排水措施的综合研究,给出了抽排水方案的设计步骤,结合不同涌水的处理提出了突涌水的处理思路,并介绍了目前国内先进的突涌水预测手段及应用效果。根据秦岭隧洞抽排设备的配置思路以及洞外环保处理情况,指出了目前地下水处理过程中存在的问题并提出相应的解决方法。通过引汉济渭工程建设过程中地下水处理情况的介绍、探讨和分析,对长大隧洞处理类似地下水问题提供一定的借鉴。     

醋酸装置催化剂循环使用周期短的原因及对策

根据乙醛氧化反应催化剂的循环使用机理对湘维醋酸装置催化剂循环使用周期短的原因进行了分析，找出了反应温度偏高、氧醛比偏大、醋酸锰循环使用流程不合理、用工业水溶解醋酸锰等四项原因，并提出了改进措施，实施后使湘维醋酸装置催化剂循环使用周期达到了国内先进水平。     

Texaco煤气化装置长周期运行影响因素分析

介绍了Texaco煤气化工艺流程,从原料煤种、水煤浆浓度、操作工艺、关键设备等几个方面讨论了影响装置长周期运行的因素,提出了延长气化装置运行周期的措施。     

Increasing urea-N efficiency for transplanted lowland rice by pneumatic injection: Yield and economics at the farm level

To increase the fertilizer-N efficiency in lowland rice (Oryza sativa L.) cultivation, new management practices are needed. Main cause of the present low efficiency is the low N recovery by plants, as a considerable part of the N applied is lost; deep placement techniques improve the recovery. A pneumatic injector, with which urea prills can be point-placed at a depth of 5–10 cm in paddy soils, was tested in 38 on-farm trials in 1989/90, mostly during the wet season. The experiments, located in Africa and Asia, focussed on differences in grain yield between conventional methods of broadcasting urea and injection by the pneumatic injector, at recommended N-rates. The study shows that the pneumatic injector is effective as a tool to improve the N fertilizer efficiency. The average yield increases per region, resulting from the use of the injector, ranged from about 250 to 1300 kg grain ha^–1. The value of the yield increase would allow most farmers to recover the costs of the injector within one season, even if labour was hired to carry out the injections. The average labour requirement of the injector was 40 hours ha^–1. In Indonesia, injection of prilled urea gave yields similar to those obtained with urea briquettes.     

ASYMPTOTIC PROPERTIES OF SOME PRELIMINARY ESTIMATORS FOR AUTOREGRESSIVE MOVING AVERAGE TIME SERIES MODELS

Abstract. Some simple preliminary estimators for the coefficients of mixed autoregressive moving average time series models are considered. As the first step the estimators require the fitting of a long autoregression to the data. The first two methods of the paper are non-iterative and generally inefficient. The estimators are Yule-Walker type modifications of the least squares estimators of the coefficients in auxiliary linear regression models derived, respectively, for the coefficients of the long autoregression and for the coefficients of the corresponding long moving average approximation of the model. Both of these estimators are shown to be strongly consistent and their asymptotic distributions are derived. The asymptotic distributions are used in studying the loss in efficiency and in constructing the third estimator of the paper which is an asymptotically efficient two-step estimator. A numerical illustration of the third estimator with real data is given.     

一类考虑病毒发生变异的SIS疾病传播模型

为了研究变异行为对病毒传播的影响,提出了一个病毒发生变异的疾病传播模型,在模型中考虑了两种病毒相互转换的过程,计算机模拟结果表明,两种病毒的稳态感染比例与它们之间的相互转换概率γ1和γ2有关,当γ1＞0且γ2=0时,I1型感染者将消失,当γ1与γ2都大于0时,I1/I2与γ1/γ2成反比,且与α1/β1和α2/β2的取值无关.研究还发现病毒变异时由于缺乏对应的治疗药物和措施而出现一段真空期,这导致变异病毒的感染比例快速增加,但真空期的出现只能增加感染者的瞬时感染比例,而对稳态感染比例没有影响.该研究对人们深入理解病毒传播机理具有启发作用.