Formulation of thermo-hydro-mechanical coupling behavior of unsaturated soils based on hybrid mixture theory

Thermo-Hydro-Mechanical （THM） coupling pro- cesses in unsaturated soils are very important in both theoretical researches and engineering applications. A coupled formulation based on hybrid mixture theory is derived to model the THM coupling behavior of unsaturated soils. The free-energy and dissipative functions for different phases are derived from Taylor＇s series expansions. Constitutive relations for THM coupled behaviors of unsaturated soils, which include deformation, entropy change, fluid flow, heat conduction, and dynamic compatibility conditions on the interfaces, are then established. The number of field equations is shown to be equal to the number of unknown variables; thus, a closure of this coupling problem is established. In addition to modifications of the physical conservation equations with coupling effect terms, the constitutive equations, which consider the coupling between elastoplastic deformation of the soil skeleton, fluid flow, and heat transfer, are also derived.

Evaluation of Flowering Pattern, Yield and Yield Determinants of Hybrid Tea Rose in Response to Seasonal Variations and Applied Organic Manure Rates

Seasonal variations in environmental conditions can have significant influence on flowering pattern and yield of roses. Evaluation studies were conducted to determine the flowering pattern and yield determinants of two Hybrid Tea rose cultivars in response to seasonal variations under rain-fed conditions. The 2 × 2 × 4 factorial experiment arranged in split plot design at three replications was conducted at two seasons (dry and wet) using two cultivars (cv. “Immaculate” and “P.H. Baby”, white and red flowers respectively) supplied with poultry manure (PM) application rates at 5, 10 and 20 t/ha where the unfertilized (0 t/ha) served as control. The result showed that the year two environmental conditions of both experiment I and II significantly improved plant height, number of leaves, number of buds (CNB) and opened flowers (CNF) and flower yield (FYD). “Immaculate” was significantly (p ≤ 0.05) taller with more leaves but thinner girth. Although generally lower in NF/NB, and not different in FYD, the “P.H. Baby” had more flowers (CNB and CNF) in experiment I. Except for no significant difference in FYD and lower NF/NB recorded by all manure rates compared to control in experiment II, plants treated with 5 t/ha PM recorded more flowers (CNB and CNF). Significant first and second order interaction effects (p ≤ 0.05) showed that “Immaculate” had taller height and more leaves but “P.H. Baby” had more CNB and CNF, although both were not different in FYD. In addition, plants supplied with 5 t/ha PM rates were better in plant height, number of leaves, CNB and CNF compared to other manure rates. In conclusion, year two environmental conditions supported better crop growth and yield, “Immaculate” grew better vegetatively but both were not different in floral yield, while the 5 t/ha PM was considered the optimum manure application rate under the rain-fed condition.

Effects of proline on the seed-setting rate of hybrid rice

The seed-setting rate of hybrid rice is general-ly lower than that of conventional varieties.One of the factors explained this phenomenonis the proline concentration in anthers.Fiveconcentrations(30,50,80,120,and240 mg/kg)of exogenous proline were sprayedat meiosis stage of the early hybrid rice combi-nation Shanyou R3-2.Anthers were collected

Energy Absorption of Pultruded Glass-Graphite/Epoxy Hybrid Composites under High Strain-Rate Induced Transverse Tension

This paper focuses on the dynamic tensile response of glass-graphite/epoxy composites illustrating improvement in energy absorption through hybridization. The dynamic response and energy absorption characteristics of pultruded hybrid combinations of glass and graphite fibers in an epoxy matrix subjected to induced transverse tension at high strain-rate in a modified Split Hopkinson Pressure Bar (SHPB) apparatus, are presented. Transverse tensile strength was determined by diametral compression of disc samples (Brazilian indirect tensile test method). Diametral crack initiation and strain to failure were monitored with a Shimadzu HPV-2 high-speed video camera at a recording speed of 500,000 fps and Digital Image Correlation (DIC). Adequate measures were taken to ensure that initiation of specimen failure occurred at the exact center of the disc specimen, and propagated through the diameter along the compressive loading axis, for the induced transverse tension tests to be valid. A study of the strength and specific energy absorption demonstrates the benefits of hybridization. Under induced transverse tensile loading condition, the pure glass/epoxy (GL60) exhibited higher strength than pure graphite/epoxy (GR60). Pure graphite/epoxy (GR60) has higher specific energy absorption capacity than pure glass/epoxy (GL60) in transverse tension. Among all hybrids, GR30 has the highest specific energy absorption under transverse tension. Overall, hybrid GL48, with 48% low-cost glass fibers in the inner core and 12% high-cost graphite fibers in outer shell, was found to exhibit better performance under induced transverse tension at high strain-rates, showing the benefits of hybridization.

Improvement of uniformity in cultivation environment and crop growth rate by hybrid control of air flow devices

A complete control type plant factory has high efficiency in terms of cultivation area by constructing vertical multiple layered cultivation beds.However,it has a problem of irregular crop growth due to temperature deviation at upper and lower beds and increases in energy consumption by a prolonged cultivation period.In this work,air flow rate inside a facility was improved by a hybrid control of air flow devices like air conditioning and air circulation fan with an established wireless sensor network to minimize temperature deviations between upper and lower beds and to promote crop growth.The performance of proposed system was verified with an experimental environment or Case A wherein air conditioning device was operated without a control algorithm and Case B wherein air conditioning and circulation fans were alternatively operated based on the hybrid control algorithm.After planting leafy vegetables under each experimental condition,crops were cultivated for 21 days.As a result,Case B wherein AC(air conditioning) and ACF(air-circulation fan) were alternatively operated based on the hybrid control algorithm showed that fresh mass,number of leaves,and leaf length for the crops grown were increased by 40.6%,41.1%,and 11.1%,respectively,compared to Case A.

Effects of Plant Density and Nitrogen Application Rate on Grain Yield and Nitrogen Uptake of Super Hybrid Rice

The nitrogen uptake, yield and its components for two super-high-yielding hybrid rice combinations, Guodao 6 and Eryou 7954 were investigated under different plant densities （15, 18, and 21 plants/m^2） and different nitrogen application rates （120, 150, 180, and 210 kg/hm^2）. The experiment was conducted on loam soil during 2004-2006 at the experimental farm of the China National Rice Research Institute in Hangzhou, China. In these years, the two hybrid rice cleady showed higher yield at a plant density of 15 plants/m^2 with a nitrogen application rate of 180 kg/hm^2. Guodao 6 produced an average grain yield of 10 215.6 kg/hm^2 across the three years, while the yield of Eryou 7954 was 9 633.0 kg/hm^2. With fewer plants per unit-area and larger plants in the plots, the two hybrid rice produced more panicles per plant in three years. The highest nitrogen uptake of the two hybrid rice was at a plant density of 15 plants/m^2 with a nitrogen application rate of 180 kg/hm^2. Further increasing nitrogen application rate was not advantageous for nitrogen uptake in super-high-yielding rice under the same plant density.

数模联动的多特征工件加工能耗预测方法研究

在实际切削加工过程中材料去除率是不断变化的,现有将其视为恒量的能耗建模方法难以实现能耗准确预测。为了提高切削过程能耗预测精度,提出了一种基于材料去除率的数模联动加工能耗预测方法。首先,基于切削过程刀具与工件的接触关系分析了切入、完全切入和切出阶段材料去除率变化规律,并对相应的加工能耗特性进行了分析;其次,提出了数据驱动的刀具切入,切出阶段加工能耗预测方法,以及模型驱动的完全切入阶段加工能耗预测方法,实现加工过程能耗准确预测;最后,利用实验案例验证了所提模型及方法的有效性,为今后研究能耗预测精度奠定了基础。

不同化控剂处理对杂交大豆制种催熟效果的影响

为解决杂交大豆种子商业化生产过程中,母本持绿,无法机械化收获、种子皱缩,品质较差的问题,从而推进杂交大豆产业化的进程,系统研究了不同类型化控剂及处理方法对杂交大豆制种过程中母本催熟效果的影响。结果表明:3种不同类型化控剂均可加速茎叶脱水,促进植株成熟,催熟速率排序为:乙烯利<草甘膦<敌草快,化控剂浓度越大,催熟效率越高;R6期喷施草甘膦和敌草快导致籽粒无法正常发育,若晚于R7期喷施,各化控剂催熟效果均不理想,R6+7 d为最佳喷施时期,可解决不育系茎叶持绿、籽粒皱缩、百粒重过大等问题。草甘膦为内息传导型催熟药剂,喷施草甘膦会严重降低种子芽率,无法应用于种子生产,乙烯利、敌草快无此负面作用。综合考量催熟效果、环境安全及操作便利性等方面,敌草快在R6+7 d时期处理可有效促进植株成熟,加速茎叶脱水落叶,降低百粒重,保证种子品质,符合机械化收获要求。

鲜食葡萄杂交种子萌发率与亲本及亲本组合的关系分析

【目的】常规杂交育种是葡萄新品种选育的重要方法,通过对15年的鲜食葡萄育种资料进行整理汇总,分析研究不同倍性亲本选择及不同亲本杂交组合配置与杂交种子萌芽率之间的关系,为鲜食葡萄育种实践工作提供参考和借鉴。【方法】以山西农业大学果树研究所2003—2018年间进行常规杂交的45个鲜食葡萄组合为研究对象,对其亲本选择、杂交组合配置和杂交种子萌发率等进行分析。【结果】1)不同倍性亲本选择及不同亲本组合配置,杂交种子萌发率不同。2)以‘瑰宝’作为父本时,杂交种子的萌发率高。3)45个杂交组合中,不同年份、相同父母本杂交种子萌发率不同。4)45个杂交组合中,玫瑰香和红地球是良好的母本材料;瑰宝是良好的父本材料;美人指不是理想的亲本材料。【结论】选择二倍体品种做母本与四倍体品种杂交比用四倍体品种做母本与二倍体品种杂交时更容易获得种子;以四倍体为父母本时,很难得到杂交后代。

基因型与高温环境互作对杂交水稻整精米率的影响

为了提高高温伏旱区水稻的整精米率,以3个不育系(椰香A、沪旱82S、川康606A)与5个恢复系(泸恢107、泸恢127、泸恢276、泸恢1156、泸恢6150)配制的15个杂交中籼组合为材料,分别于2021、2022年早季和晚季种植,稻谷收获后分别采用40℃和80℃干燥,研究杂交水稻基因型与环境互作对整精米率的影响。结果表明,水稻生长期温度和稻谷干燥温度对整精米率的影响大,2021年水稻灌浆期气温正常,其整精米率(平均48.92%)比2022年(平均17.39%,罕见高温年景)高181.00%,稻谷干燥温度40℃处理平均整精米率(45.94%)比80℃处理(20.37%)高125.00%;恢复系对整精米率影响次之,泸恢6150所配组合整精米率最高,平均比其他恢复系所配组合高13.85%~25.34%;不育系对整精米率影响较小,其中椰香A所配组合整精米率最高,平均比其他不育系所配组合高8.97%~9.45%;不育系与恢复系的特殊配合力对整精米率影响较大,恢复系的一般配合力显著高于不育系。种植季节对整精米率影响最小,晚季种植比早季种植整精米率仅高2.97%。通过恢复系改良选择对整精米率特殊配合力高的杂交组合,使其处于适宜灌浆期温度下,并采用适宜的温度干燥稻谷,有利于大幅度提高整精米率。

不同遗传背景亲本及其杂交种对田间出苗率的影响

为了研究细胞质不同亲本及其杂交种对田间出苗率的影响,以29个AL型不育系和25个恢复系为亲本材料配制了双列杂交组合,以“同母多父”和“同父多母”的方式,对杂交种和亲本的田间出苗率进行比较分析。结果表明,细胞质遗传背景不同的恢复系、保持系、杂交种之间田间出苗率差异不显著。杂交种与双亲的田间出苗率间呈显著正相关,田间出苗率高的亲本所配置杂交种田间出苗率表现出较高杂种优势。杂交种田间出苗率应该作为优异亲本的重要指标得到重视。

脱附速率对车辆炭罐脱附性能的影响试验研究

这项研究对比分析了混合动力汽车和汽油车在中国国六蒸发排放试验中高温行驶阶段的炭罐脱附数据,发现混合动力汽车可以通过提升中高速行驶阶段炭罐脱附速率来弥补脱附时长不足。因此在炭罐测试系统上开展5、15、25、35、45L/min五种不同脱附速率的脱附试验,进一步量化脱附速率对炭罐脱附性能的影响。实验结果表明炭罐脱附效率随炭罐负载的减少而降低,随脱附速率的提高而增大。基于国六试验标准分析,五种速率中35L/min最符合试验炭罐的脱附要求。

四腔混联压电泵结构设计与试验分析

为提高压电泵的输出性能,结合串并联结构压电泵的优点,提出一种四腔混联压电泵设计。在110 V,40~400 Hz范围的正弦交流电驱动下,对制作的试验样机进行气体介质、液体介质的输送性能试验。结果显示:压电泵输送空气时,压电振子的工作模式对输出性能的影响可忽略不计,最大输出流量可达3046 mL/min。压电泵输送液体水时,采用异步驱动,输出性能更好,驱动频率为140 Hz时输出流量达到最大,为1067 mL/min。试验结果为多腔体混联压电泵的实际应用提供一定参考。

Reliability-BasedModel for Incomplete Preventive ReplacementMaintenance of Photovoltaic Power Systems

At present,the operation and maintenance of photovoltaic power generation systems mainly comprise regular maintenance,breakdown maintenance,and condition-based maintenance,which is very likely to lead to over-or under-repair of equipment.Therefore,a preventive maintenance and replacement strategy for PV power generation systems based on reliability as a constraint is proposed.First,a hybrid failure function with a decreasing service age factor and an increasing failure rate factor is introduced to describe the deterioration of PV power generation equipment,and the equipment is replaced when its reliability drops to the replacement threshold in the last cycle.Then,based on the reliability as a constraint,the average maintenance cost and availability of the equipment are considered,and the non-periodic incomplete maintenance model of the PV power generation system is established to obtain the optimal number of repairs,each maintenance cycle and the replacement cycle of the PV power generation system components.Next,the inverter of a PV power plant is used as a research object.The model in this paper is compared and analyzed with the equal cycle maintenance model without considering reliability and the maintenance model without considering the equipment replacement threshold,Through model comparison,when the optimal maintenance strategy is(0.80,4),the average maintenance cost of this paper’s model are decreased by 20.3%and 5.54%and the availability is increased by 0.2395% and 0.0337%,respectively,compared with the equal-cycle maintenance model without considering the reliability constraint and the maintenance model without considering the equipment replacement threshold.Therefore,this maintenance model can ensure the high reliability of PV plant operation while increasing the equipment availability to improve the system economy.

挪威红牛改良荷斯坦奶牛的妊娠率分析

[目的]研究现存混养的条件下挪威红牛配种荷斯坦奶牛后的妊娠优势,以提高荷斯坦奶牛的繁殖力。[方法]以荷斯坦奶牛作为母本,进口挪威红牛冻精为父本,进行杂交改良(挪威红牛♂×荷斯坦奶牛♀),培育杂种牛,统计不同月份、不同年龄段的配种数、妊娠数、妊娠率。[结果]杂交种牛相比于荷斯坦牛,自然发情配种的妊娠率提高36.41百分点;同期处理配种,妊娠率提高30.24百分点;青年牛配种,妊娠率提高47.64百分点;群体年度配种,妊娠率提高了36.83百分点,杂交牛场配种妊娠率显著高于荷斯坦牛场。[结论]杂交牛场经过挪威红牛乳肉兼用型牛的品种改良,明显提高了牛场群体繁育率。

三角梅‘伊娃夫人’的繁育体系研究

为明确开花特性和繁育系统对三角梅‘伊娃夫人’有性繁殖的影响,促进其杂交选育与园林应用。采用田间观测法探究其开花物候,同时观测其开花动态过程及花部形态特征;用FDA染色法和液体培养基法测定其花粉活力及离体萌发率;繁育系统则采用形态观测、苯胺蓝染色法及田间杂交试验三者结合的方法共同测定。结果表明:(1)‘伊娃夫人’花被管结构特殊,呈圆筒状,中上部皱缩,两端膨大,阻碍大多数虫媒传粉。(2)‘伊娃夫人’花粉粒形态为圆形或椭圆形,具网状纹路;单药花粉量为1375粒,花粉萌发适宜温度为28℃,花粉具有群体萌发效应。(3)‘伊娃夫人’花粉量与胚珠比为11000,杂交指数为4,结合田间套袋及人工授粉试验结果判断其繁育系统主要为异交类型,需要传粉者。研究结果对三角梅‘伊娃夫人’的资源利用与种质创新具有一定意义。

攸县油茶远缘杂交亲和性的解剖学研究

【目的】为了探究攸县油茶(Camellia yuhsienensis)远缘杂交亲和性的生物学机制。【方法】研究以石果毛蕊山茶[C.mairei var.lapidea(Y.C.Wu)Sealy](SG)、海南油茶‘海油3号’(C.hainanica‘Haiyou 3’)(HN-3)和普通油茶‘德油6号’(C.oleifera‘Deyou 6’)(DY-6)为父本,采用常规授粉和混合授粉方式对攸县油茶(YX)进行自交和杂交授粉。采用流式细胞仪测定亲本倍性,通过离体萌发法测定父本花粉活力,运用显微技术观察花粉萌发及花粉管生长动态以及早期果实和胚珠发育动态,并田间调查各授粉组合的座果率和落果率。【结果】(1)YX为六倍体,SG为二倍体,HN-3为八倍体,DY-6为六倍体。(2)4种油茶花粉具有较强的活力和育性,其中花粉活力最高的是DY-6,为70.13%;花粉活力最低的是YX,为40.68%。(3)自交和杂交所有组合的花粉均能在柱头上正常萌发,且花粉管在授粉后12 h均生长到花柱基部,但自交和YX×SG的花粉管进入子房后生长受阻,无法到达胚珠;YX×HN-3和YX×DY-6的花粉管则在授粉后72h到达胚珠。(4)自交和杂交授粉后100 d内,YX×DY-6的果实横径、纵径最大,YX×SG的果实横径、纵径最小;YX×DY-6的败育胚珠数最少,平均为3.83枚/果;YX×SG的败育胚珠数最多,平均为6.00枚/果。(5)自交和杂交授粉后100 d内,YX×DY-6的座果率最高,为68.0%;YX×SG的座果率最低,为4.0%;YX×HN-3的座果率为16.0%,其落果高峰主要集中在授粉后0~30 d和40~70 d;混合授粉组合YX×SD的座果率为22.0%。【结论】自交和YX×SG的杂交障碍主要为受精前障碍,YX×HN-3的杂交障碍为受精前和受精后障碍;攸县油茶远缘杂交亲和性也与亲本倍性有关,其亲和性大小为YX(六倍体)×DY-6(六倍体)>YX×HN-3(八倍体)>YX×YX>YX×SG(二倍体);混合授粉方式能在一定程度上提高攸县油茶远缘杂交亲和性。研究结果为攸县油茶远缘杂交亲和性机理研究提供了细胞学基础,也为油茶远缘杂交育种工作提供理论参考。

基于Hybrid样本的学习过程一致收敛速度的界

学习过程收敛速度的界是统计学习理论的重要组成部分,这些界决定了学习机器的推广能力.以机会理论和Hybrid变量的概念为基础,讨论了基于Hybrid样本的学习过程一致收敛速度的界,并给出了这些界和函数容量之间的关系.

考虑维护时间差异的混联系统维护决策

为提高系统开动率,同时降低维护成本,考虑设备维护时间差异的影响,建立混联系统双目标优化维护决策模型。基于设备失效率衰退曲线,综合考虑混联系统中每个设备的小修时间、预防维护时间和系统可靠度,构建了系统开动率和维护成本模型,并以系统开动率和维护成本为目标,建立在系统可靠度阈值和设备失效率阈值下的混联系统维护决策模型。案例结果表明,与既有研究中假定系统内不同设备小修时间相同、不同设备维护时间也相同制定维护决策相比,考虑系统内不同设备小修时间和预防维护时间差异制定的维护决策更符合实际,结果更真实,效果更好。

平板热管式锂离子电池热管理系统仿真分析研究

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