Further results of recursive evaluation for compound distribution with the severity distribution of mixed type

Yang et al. [J.P. Yang, S.H. Cheng, Q. Wu, Recursive equations for compound distribution with the severity distribution of the mixed type, Science in China Series A 48 (2005) 594-609] investigated a recursive procedure for a kind of compound distributions with the number of claims belonging to (a,b)-family and the severity distribution of the mixed type. In this paper, we extend their results by assuming that the claim number belongs to a larger class. As applications, the excess-of-loss reinsurance treaty is discussed and concrete examples are considered in some detail.     

液态肥扭力靶式流量计的研制及试验研究

为了实时检测液态肥变量施肥系统中排肥口的流量,研制了一种液态肥扭力靶式流量计.采用力-扭力管-应变电压的转换方式设计了流量计结构,建立了流量与应变电压的数学模型;采用FLUENT软件分析了不同靶片形状和不同直径比对扭力靶式流量计性能的影响;制作样机并对扭力靶式流量计的性能进行了校验实验.实验结果表明,该扭力靶式流量计测量结果稳定可靠,可测流量范围为0.2m3/h~3.9m3/h,误差小于2.0%FS.满足液态肥变量施肥系统中流量测量的要求.     

How causal knowledge simplifies decision-making

Making decisions can be hard, but it can also be facilitated. Simple heuristics are fast and frugal but nevertheless fairly accurate decision rules that people can use to compensate for their limitations in computational capacity, time, and knowledge when they make decisions [Gigerenzer, G., Todd, P. M., & the ABC Research Group (1999). Simple Heuristics That Make Us Smart. New York: Oxford University Press.]. These heuristics are effective to the extent that they can exploit the structure of information in the environment in which they operate. Specifically, they require knowledge about the predictive value of probabilistic cues. However, it is often difficult to keep track of all the available cues in the environment and how they relate to any relevant criterion. This problem becomes even more critical if compound cues are considered. We submit that knowledge about the causal structure of the environment helps decision makers focus on a manageable subset of cues, thus effectively reducing the potential computational complexity inherent in even relatively simple decision-making tasks. We review experimental evidence that tested this hypothesis and report the results of a simulation study. We conclude that causal knowledge can act as a meta-cue for identifying highly valid cues, either individual or compound, and helps in the estimation of their validities.     

粉煤灰磁化肥对杂交水稻效应研究

粉煤灰磁化肥在水稻土上对水稻作物试验结果表明：粉煤灰磁化肥在水稻土上一般用量为９２６ｋｇ／ｈｍ２左右．粉煤灰磁化肥比对照增产２７．７％,增产１９７７．８ｋｇ／ｈｍ２;比当地农民习惯施肥增产１０．６％,增产８７０ｋｇ／ｈｍ２;　比未磁化粉煤灰复混肥增产５．９％,增产５０７　ｋｇ／ｈｍ２．最高产量施用粉煤灰磁化肥为１１６９　ｋｇ／ｈｍ２,水稻产量为９２５３　ｋｇ／ｈｍ２;最佳产量施用粉煤灰磁化肥为９２６　ｋｇ／ｈｍ２,水稻产量为９１３１　ｋｇ／ｈｍ２．粉煤灰磁化复混肥在改善水稻生物学及经济性状,提高叶绿素含量和光合速率方面有显著的效应．     

Residual phosphate fertilizer compounds in soils

A variety of P compounds can accumulate in soils as residues of fertilizer and may influence soil test versus plant yield relationships. This work evaluates specific chemical extractants for their capacity to identify such Al, Fe and Ca phosphates in soils as a basis for increasing the precision of yield prediction. Aluminium phosphate, iron phosphate, calcium phosphate (apatite) and P sorbed onto gibbsite, goethite and calcite were added to four Western Australian lateritic soils. These soils were then subjected to sequential selective extraction using a modified Chang and Jackson procedure in order to evaluate the selectivity of these extractants for the different forms of P with the sequence of extraction: 1 M NH₄Cl, 0.5 M NH₄F, 0.1 M NaOH + 1 M NaCl, citrate-dithionite-bicarbonate (CDB), 1 M NaOH and 1 M HCl. The results show that the procedure is not sufficiently specific and thus might be of little value for estimating the forms and amounts of residues of phosphate rock fertilizers in soils.     

关于化肥生产合成气的技术路线探讨

本文分析了我国化肥生产的现状，提出了氮肥生产中技术革新、节约能源的必要性，介绍了灰熔聚流化床粉煤气化及粉煤循环流化床燃烧技术，并从技术经济的角度对利用这一新技术来解决我国生产氮肥用合成气的可行性进行了探讨。     

Using geometric Poisson exponentially weighted moving average control schemes in a compound Poisson production environment

In this study, the variable to be controlled over time is the number of defects. Meanwhile, the underlying distribution of defects is the geometric Poisson distribution, a Poisson distribution compounded by a geometric distribution. For production process control, the exponentially weighted moving average (EWMA) control scheme based on the geometric Poisson process is addressed. Performance of the EWMA control scheme is assessed not only by both in-control and out-of-control average run lengths (ARL’s), but also by higher moments of the run length (RL) distribution. The run length distribution properties can be obtained from the probability transition matrix and implemented using the computer programs developed in this study. With proper ARL and variance of RL selected, any small shift in mean can be detected via the geometric Poisson EWMA control scheme.     

复合肥副产盐酸杂质含量高的原因分析及对策

介绍硫基复合肥副产盐酸杂质含量高的原因及技改情况。技改后,用脱盐水代替自来水,减少了停车清堵时间及维修费用,产品盐酸浓度,杂质SO42、Fe的含量均达到优等品标准,年增加利润108万元。     

氮磷钾高浓度烤烟专用肥

介绍硝酸铵－磷酸－铵－硫酸钾系高浓度烤烟专用复合肥的开发应用，三年的试验推广的实践证明，其肥效可与进口肥相媲美，配方合理，但价格比进口肥每吨低４００元左右。     

Flow resistance in a compound gravel-bed bend

In this paper, the effect of a gravel-bed in a compound bend (similar to sinusoidal top view) of a natural river (Zayandehrud River flowing through Isfahan, Iran) has been investigated for flow resistance analysis, measuring the velocity with a micro current meter. The data were analysed and the following observations were made. In a compound bend, the law of the wall can be valid for up to 66% of the flow depth from the bed. The parabolic law is the most effective method for the determination of shear velocity. Based on the existing criteria for verifying the equilibrium boundary layer, the flow cannot be in equilibrium. The shear stress distribution and the sediment transport parameters have considerable influence on resistance to flow. Froude number and the flow depth relative to the representative gravel size have little effect on the flow resistance estimation.