Family selection in plant breeding

Summary Plant breeding programmes rarely take explicit practical account of the two sources of genetic variance, namely between and within full-sib families, even though existence of these two sources of variation has long been recognised. This paper refers to inbred and clonal crops, not to outbred, seed-propagated species. Theory suggests that the two variances should be of similar size, sometimes very similar. Good comparisons have never been made because variance within families is laborious to estimate. It is proposed that sets of families be assayed as to means in formal trials and only the best few, judged against standards as having potential for superior segregates, should be exploited thoroughly. The calculation as to approximate equality of genetic variances between and within families is important. The vast majority of families should probably be discarded without further ado, and at considerable economy. Sensible decision-making requires an economic component in order to exploit the trade-off between the cost of the initial trial and families discarded without further cost. The object of this paper is a critical review of practical principles, not a general review of a large and diffuse literature.     

矿区废弃地生态恢复和可持续发展研究

简述了中国矿区废弃地生态恢复的现状并对其进展缓慢的原因进行了系统的分析,通过对山东省菏泽市巨野县矿区废弃地生态恢复的研究,提出矿区废弃地的生态恢复应以可持续发展战略为指导,以改善生态环境和景观重建并控制水土流失为根本,根据各地区的发展规划,运用景观生态规划原理和恢复生态学原理,运用各种技术手段,结合矿区废弃地的具体情况,在生态恢复和尊重现实,尊重当地人民群众和政府经济利益的基础上发展诸如旅游业等产业,以求获得更大的生态效益、社会效益和经济效益。     

Flatfish selection by herring gulls Larus argentatus and lesser black-backed gulls Larus fuscus scavenging at commercial beamtrawlers in the southern North Sea

Flatfish selection by scavenging herring gulls and lesser black-backed gulls was studied onboard a commercial beamtrawler in the southern North Sea, June2 -August 1993. Dab (median total length 18 cm), plaice (23 cm), sole (22 cm) and solenette (10 cm) dominated the flatfish discard fraction of the catch. The overall consumption amounted to 30.5% of the discarded flatfish. Flatfish were selected on the basis of fish width rather than length or species, with very low consumption rates (percentage consumed of number offered) of flatfish >8 cm width. All discarded solenette, 98% of all sole and 92% of all dab were of suitable size for these gulls, whereas only 12% of all discarded plaice were small enough to be consumed. Consumption rates of discarded flatfish of ‘suitable size’ for herring gulls and lesser black-backed gulls (<8 cm width) ranged from 25.9% (plaice) to 40.5% (dab). Success indices and selected size classes of flatfish in scavenging herring gulls and lesser black-backed gulls feeding on flatfish were similar, but the first were more efficient than the latter and lost fewer flatfish as a consequence of kleptoparasitism. In contrast to earlier suggestions (based on dietary studies in colonies), there was no evidence that herring gulls were outcompeted by lesser black-backed gulls when feeding on discarded fish.     

啤酒废酵母吸附Cu~(2+)的特性研究

将啤酒废酵母制成一种新型的生物吸附剂,用于吸附重金属离子铜。研究了不同温度、时间、pH值,以及铜离子浓度和酵母浓度条件下,啤酒废酵母对Cu2+的吸附能力。初步确定了啤酒废酵母对Cu2+吸附的最佳组合,即吸附温度为35℃,吸附时间为55 min,起始pH值为5,酵母的质量浓度为1 g/L,Cu2+质量浓度为22 mg/L,在此条件下啤酒废酵母对Cu2+吸附率可达到90.00%左右。通过L16(45)正交实验表明,Cu2+质量浓度和pH值是影响啤酒废酵母吸附铜离子能力的显著因素。对吸附了铜离子的啤酒酵母进行解吸实验,表明在浓度为1 mol/L的HCl中,其解吸率为55.00%,与1 mol/L的NaOH和去离子水相比,有较高的解吸率。     

废弃苹果皮革的制备工艺研究

利用废弃苹果提取果胶来制作苹果皮革,增加废弃苹果的附加产值,以腐烂废弃的苹果为基本材料,从废弃苹果中提取果胶,分别探究料液比、pH值、黄原胶和氯化铜等条件对苹果皮革的硬度、拉伸强度、黏附性和感官弹性等性质的影响。结果表明,制备皮革的最佳工艺为料液比1∶1,pH值5,黄原胶15%,氯化铜2.5%。该试验为废弃苹果制备水果皮革提供了一个新的思路。     

Calculation of Maintenance Cost Based on the Proportional Life Setback Model

Maintenance cost is one of the most difficult parts to calculate in variant-cost, for it s decided by the reliability of components. As an important factor of reliability, life is largely affected by maintenance. The proportional life prolonged model based on maintenance is presented firsdy. Based on this model, the function of Mainenance--Life--Cost is deduced. Which provides a new method for power plant to calculate maintenance cost more accurately.     

水稻铁生物强化育种中稻米加工与铁浓度的快速测定方法

铁对人体的健康十分重要,缺铁已对人类健康和世界经济造成巨大影响。针对我国水稻生物强化育种工作中存在的样品加工过程铁污染严重,以及缺少适合育种群体大规模简便、快速的铁浓度检测手段,本研究发展了一种振荡研磨加工方法和基于邻二氮菲染色的比色测定方法。在研磨程度相同的情况下,经铁制精米机械加工的18个样品中有一半样品的铁浓度显著高于振荡研磨加工的,表明铁制精米加工机械对水稻精米加工存在明显的铁污染。本研究发明的精米振荡研磨加工方法,可以消除加工机械对样品加工过程中的铁污染。尽管对59个铁生物强化后代的测定平均铁浓度邻二氮菲比色法要比ICP-MS高出2.98mgkg-1,但两者的相关系数高达0.87,表明该测定方法适用于大批量育种群体精米铁浓度的初步筛选。与ICP-MS相比,邻二氮菲比色法具有简便、快速和低成本的特点。以铁浓度高的水稻种质为供体,导入广西本地高产品种背景,对分离后代采用上述加工和检测方法进行筛选,育成新品系精米的铁浓度比原品种提高了3倍。     

生鲜农产品冷链物流车辆配送路径优化研究

针对生鲜农产品易变质、易腐蚀的特性,探索冷链物流配送路径的优化方法。首先通过对固定成本、运输成本、货损成本、惩罚成本和能耗成本的研究,建立了以总成本最小为目标函数的农产品冷链物流车辆配送路径优化模型,然后采用改进的蚁群算法对模型进行设计,最后通过实例分析,运用MATLAB软件编写算法程序,求解结果验证了设计的模型的合理性和可行性。     

木醋液在农业上的应用研究进展

摘要：木醋液是由木质材料获得的纯绿色产品。在农业上应用,具有生产工艺简单、使用安全、无污染、无残留等优点。对于废弃植物资源的充分利用,发展有机生态农牧业和走可持续发展之路具有重要而现实意义。本文除介绍木醋液的概念、应用领域及发展历史外,重点阐述了木醋液在蔬菜、大田作物、食用菌和畜禽上的应用现状,旨在推动木醋液在农业生产上的推广应用和研究。     

5-氨基乙酰丙酸在动物铁代谢调控中的应用进展

随着动物饲养环境的变化和生产水平的提高,铁元素营养的重要性逐渐提高,铁代谢调控成为近年来关注点之一。本研究对动物生产中的铁营养现状、5-氨基乙酰丙酸(5-aminolevulinic acid,ALA)对铁代谢调控的机理及在动物饲料中的应用进展进行了综述。ALA的合成是动物体内生成血红素的限速反应。日粮补充ALA能增加血红素合成量,提高机体对铁元素的利用效率。这为动物铁代谢调控提供了一个新途径。     

乳制品冷链物流的库存-生产策略优化研究

在日益激烈的企业生存竞争中,针对乳制品生产企业如何选取合适的生产批量和库存水平的问题,提出了成本-时间-客户满意度的三目标优化模型。首先,考虑乳制品的库存费用、周转时间和客户满意度,分别建立库存生产成本、库存周转时间和客户满意度优化模型;其次,以生产批量和库存水平为决策变量,应用多目标遗传算法,集成库存生产成本模型、库存周转时间模型和客户满意度模型,求出所有非劣解;最后,应用伪权向量法,通过保质期不同的产品验证提出的模型。结果表明,对于不同保质期的产品,均可得出最优库存生产批量大小和最优库存水平。     

Rice Yield Gap due to Iron Toxicity in West Africa

Iron toxicity is a widespread nutrient disorder in lowland rice, notably in West Africa. It occurs in irrigated or rain-fed rice crops when the soil contains excessive amounts of iron. Associated with leaf discoloration symptoms (bronzing), this excessive iron uptake causes poor growth and tillering and leads to severe yield reductions. Field experiments were carried out in West Africa from 1994 to 1998 at two sites with high iron toxicity and one non-toxic site to assess the effects of iron toxicity on rice cropping and evaluate the tolerance of promising rice cultivars available in West Africa. To estimate yield losses caused by iron toxicity, the yield potential was simulated using the ORYZA-S rice growth and yield model. Based on the potential yield, the yield loss in an iron-toxic site is the combination of the yield gap caused by unknown site factors and the yield gap caused by iron toxicity. Compared to the referential yield obtained in a non-iron-toxic site, iron toxicity reduced rice yields by 16–78 % (mean 43 %). The extent of the yield loss depended on rice cultivar, iron toxicity intensity and crop management strategy (water control and mineral fertilisation). A strong correlation obtained between yield and the iron toxicity score, based on visual symptoms indicated an approx. 400 kg ha⁻¹ yield loss for each visual score point increase. The high genetic variability in iron toxicity tolerance and close correlation between leaf symptom score and grain yield between rice genotypes provide a good basis for breeding varieties that can produce higher yields under iron-toxic conditions.     

核桃外果皮的开发利用研究（Ⅱ） ——晒干、晾干、沤干的核桃外果皮中棕褐色色素的提取率与 稳定性比较

将同一采样点的样品分别晒干、晾干、沤干后，以水为萃取剂，提取棕褐色色素，并对其稳定性进行了测试与比较。结果表明：由于干燥方式不同，导致提取率有差别。色素溶液的吸光度随波长增加而减小的趋势相同，色素的水溶性，耐氧化一还原性，耐光性，盐、蔗糖、金属离子对色素的色泽的影响基本相似。     

Amelioration of the Logit Model and the solution of the Traffic Assignment Problem

Resolving traffic assignment problems with a logit model will result in some error because of the correlation of the trip cost and the flux, whereas the application of the random equilibrium assignment model is confined for its complex arithmetic. An amelioration of the logit model and a step by step arithmetic are implemented. The improved model is simple, rational and easily resoluted and the relationship of the trip cost and flux is also considered, therefore, it is applicable for the congested assignment problem and possesses widely applying prosperity.     

Analysis of Risk Factors of Project Cost Base on the Monte-Carlo Simulation

This paper combined the method of probability,mathematical statistics,and technology of computer with theory of Project cost risk management,based on the theory of initiative control and took the Crystal Ball as an assistant tool to analyze the risk of cost management in a certain project,verify the actual effect of the model when it is used to the practice,give some suggestions to evade risk in a certain degree and mend the existent decision model to improve the efficiency and precision of analysis of cost management risk.     

Integrating Mechanism of Standard Costing Activity-Based Costing and Inner Transfer Pricing

According to the mutual relations of standard costing,activity-based costing and inner transfer pricing, this paper explores systematically the approaches of the integrations of the above three in the large or medium enterprises that carry out decentralized management. Further, we raise three models as external report model, internal decision model and social contribution model, based on the financial accounting, managerial accounting and incremental accounting respectively. Finally, we investigate the principle of stratified application of the integration of standard costing, activity-based costing and inner transfer pricing, in the perspective of practice. The formula is presented that decomposes the inner transfer pricing, budgets the comprehensive cost and converses the variable cost & materiel cost into the manufacturing cost.     

STUDY OF DIGITAL SIMULATION MODEL FOR THE MAGNETIZING CHARACTERISTIC OF REACTANCE TRANSFORMER

Based on the experiment, magnetizing characteristic and its mathematical model of iron for the reactance transformer DKB has been studied in this paper. Its simulating calculation model has been achieved and implemented by program. The result of the simulation is satisfactory compared with that of the experiment.     

芦根表面铁氧化物对水体中五价砷吸附性能的研究

芦苇是多年生湿地植被,其根系具有向根际环境释放氧气和氧化性物质,并在根表和根际形成铁氧化物膜状包被的特性。笔者针对芦苇根表生物成因的铁氧化物具有两性胶体的性质,以直接和高温炭化得到的芦根表面的铁氧化物为吸附材料,采用等温平衡法研究了该吸附材料对外部溶液中五价砷吸附效果。结果表明:在酸性条件下芦根根表获取的铁氧化物对五价砷的吸附能力明显强于中性及碱性条件;两种方式获取的铁氧化物材料对砷的吸附性能如下:随着外部介质溶液中砷添加浓度的增加,铁氧化物材料对砷的吸附量逐渐增加,当外加砷浓度为200 mg/L时,砷吸附量最高分别达(17.00±3.25)mg/g和(12.82±1.01)mg/g。两种处理方式下,铁氧化物对砷的吸附均可以较好的拟合Langmuir和Freundlich等温吸附模型,通过Langmuir等温吸附方程拟合得到砷最大吸附量分别为(17.72±1.09)mg/g和(21.94±6.74)mg/g。由此可见,生物成因的铁氧化物材料对五价砷有很强的吸附能力。综合考虑芦根根表铁氧化物对砷的吸附能力及其对处理砷污染水体的可行性,该生物材料的高温炭化处理方式优于直接获取的处理方式。     

Separation and Analysis of the Ferroferric Compounds from Different Valence States in Lubricating Oil

The separation and analysis methods of ferroferric compounds in lubricating oil during mechanical transmission friction process are discussed in this paper.Owing to the iron and iron ion entered in lubricating oil yielding the wear and erosion of iron base alloy material.The separation of small wearing particles in lubricating oil and the measurement of iron are studied especially.The reliability of these methods are also verified and judged.     

Prediction Model of Soil Erosion Amount in Highway Engineering during Construction Period in Mountainous Area

The highway project in mountainous area will lead to serious soil erosion,due to its long road line and large volume of the work.While the program of water and soil conservation is drawn up,the prediction of the amount of soil erosion is needed. The whole amount of soil erosion comprises primary and new soil erosion amount. The primary soil erosion amount may be predicted by the method of average erosion modulus or universal soil loss equation.The new soil erosion amount is made up of erosion amount due to disturbed earth surface and discarded soil.Finally, the prediction model of soil erosion amount about a specific highway project during its construction period in mountainous area is analyzed.