Sliding friction test analysis of TiAlN/TiN coatings on 40Cr steel

TiAlN/TiN duplex coating is made on the surface of 40Cr steel by means of multi-arc ion plating technology. Carrying capacity and tribological properties of TiAlN/TiN duplex coating are investigated with a UMT-2 wear tester without lubrication. The surface morphology of wear specimens are observed by scanning electron microscope(SEM). Elements of wear scar center and their content are analyzed by EDS. Tribological properties of TiAlN/TiN coating are evaluated through comparing with 40Cr in friction coefficient and wear volume. The results show that tribological properties of TiAlN/TiN duplex coating is better than 40Cr. The TiAlN/TiN films is superior in reducing friction and wear resistance, and can successfully resist abrasive wear and adhesive wear.     

Present Status and Development of Synthesis Technologies for TiC,TiN,Ti(C, N) Powders

The preparation technologies of TiC?TiN?Ti(C, N) powders used home and abroad in recent years are reviewed, and the technical processes and characteristics are analysed. The existing problems and development trends of these technologies are also discussed. By seeking cheaper raw materials and achieving new high temperature technologies by plasma, microwave, laser, and electric arc and combining SHS and MA the low-cast and large-scale preparation of high quality TiC, TiN, Ti(C, N) powders are becoming one of the hot research topics. With the development of research and the improvement of preparation techniques, more convenient, more economic and more efficient preparation techniques will provide TiC, TiN, Ti(C,N) powder a broader prospective application.     

PHASE ANALYSIS OF TITANIUM NITRIDE IN SLAG CONTAINING VANADIUM, TITANIUM. ( DISTIILATION-COULOMB TITRATION )

TiN is separated from orther Nitride by 1:2 Hcl, and the residue of TiN is heated with concentrated H2SO4-K2SO4 until the smoke rises from it followed by adding exceeded NaoH and by heating distillation. Using NaBr as electrolysis solution, the double platinum electrode is used to conduct the electrolysis. At the constent current of 30 mA. When it reaches the end point indicated by the dead stop method, record the time so as to calculrte the conten of TiN.     

Optimizing wheat productivity in two rain-fed environments of the West Asia–North Africa region using a simulation model

The performance of a crop simulation model (agricultural production systems simulator model, APSIM-Nwheat) was tested using data obtained from several locations in the rain-fed environments of West Asia and North Africa (WANA) in Morocco and Jordan. The model was able to simulate wheat grain yields reasonably well except at one site in one season in Morocco. The model was subsequently used to analyze the effect of soil type (soil water-holding capacity), rate and timing of nitrogen (N) fertiliser, initial soil moisture storage, cultivars (early versus late), sowing dates and density and supplemental irrigation (SI) in optimizing wheat production using 20 years of historical weather records from Morocco. The simulation indicated that yields were often limited by the amount and timing of rainfall. While the effect of N fertiliser was minimal or detrimental in dry years, it improved grain yields in wet years and when crops were sown early combined with pre-sown stored plant available water in the soil. The analysis showed that early sowing is important for achieving high yields by avoiding terminal water deficit. There is little difference between grain yields when current practice of about 300 plants/m² was compared with a density of 150 plants/m². This implies that there is scope for reducing current planting density to save seeds without reducing yields. The simulation analysis highlighted that 40 mm of SI at sowing significantly improved average grain yields as a result of enabling early crop establishment, in particular with a N fertiliser application of 40 kg N/ha. The analysis indicated that wheat grain yields in the arid and semi-arid rain-fed regions of WANA can be improved compared to current yield levels by adjusting N management to soil type, pre-sowing soil water availability, sowing opportunity and the availability of SI.     

Quality and internal characteristics of Huanghua pears (Pyrus pyrifolia Nakai, cv. Huanghua) treated with different kinds of coatings during storage

We studied the quality and internal changes in Huanghua pears (Pyrus pyrifolia Nakai, cv. Huanghua) coated with shellac, Semperfresh™ (sucrose polyester base coating), and carboxymethyl chitosan (CMC) during cold storage (4 °C). The changes in respiration rate, weight loss, cell membrane permeability and texture profile analysis (TPA) such as hardness, brittleness and chewiness were recorded periodically for up to 60 days after harvest to compare the effects of the applied coatings. Magnetic resonance (MR) imaging was used to inspect the internal characteristics of pears after storage. The soluble solids contents (SSCs), titratable acidity (TA), ascorbic acid concentration, and taste scores were also measured. Our data suggest that shellac coating was more effective in reducing the respiration rate and weight loss and in maintaining the quality of pears than Semperfresh and CMC coatings.     

赤子爱胜蚓堆制处理秸秆和牛粪混合废弃物的研究

【目的】 利用蚯蚓堆制处理碳氮比为20,25,30的小麦秸与牛粪、玉米秸与牛粪的组合,研究堆制过程中蚯蚓的生长繁殖及培养基的理化性状,以期为合理的利用秸秆提供理论依据。【方法】 将牛粪和小麦秸秆、玉米秸秆按照碳氮比20,25,30搭配,按8 ind/100g风干物质种蚯蚓后,在相同的条件下饲养,分别于15 d,30 d ,45 d,60 d时破坏性取样,测定蚯蚓的生长繁殖及培养基的理化性状。【结果】 随着时间的增加,蚯蚓的均重、日增重、日繁殖倍数均降低,且不同时期、不同组合、不同碳氮比间均差异显著（P < 0.05）,蚯蚓总数先升高后降低。不同碳氮比之间的日生殖倍数间差异显著（P < 0.05）,以碳氮比25最佳,其次是 20、30,但二者之间差异不显著（P > 0.05）。有机碳含量和碳氮比随着时间的增加而降低,且不同时期、不同组合间差异显著（P < 0.05）;全氮含量随着时间的增加而增加,且不同时期和不同组合间差异显著（P < 0.05）。【结论】时期和组合对蚯蚓的生长繁殖指标和培养基的理化性状指标都有显著的影响（P < 0.05）;以碳氮比20最有利于蚯蚓的生长,碳氮比25最有利于蚯蚓的繁殖;小麦与牛粪组合的生长繁殖均优于玉米与牛粪的组合。     

Estimating the environmental footprint of barley with improved nitrogen uptake efficiency—a Swedish scenario study

Plant breeding is a powerful tool for improving nitrogen (N) uptake efficiency and thus reducing the environmental impact relating to crop production. This study evaluated the environmental impact of current barley production systems in two Swedish agricultural areas (South and East) compared with scenarios with improved N uptake efficiency at two levels, in which the fraction of mineral N available for daily crop uptake was increased by 50 and 100%. Life cycle assessment (LCA) methodology was used to quantify energy use, global warming potential (GWP) and acidification and eutrophication potentials along the production chain for spring barley with differing N uptake efficiency, but similar N application rate. The functional unit, to which all energy use and emissions were related, was 1 Mg barley grain. Energy use, GWP and acidification proved to be higher for the East production system, mainly due to lower yield, while eutrophication was higher for South. The two impacts most affected by improved N uptake efficiency were eutrophication and GWP, with GWP decreasing due to a combination of higher yield, soil carbon sequestration and lower indirect emissions of N₂O due to lower N leaching. Accounting for land savings due to increased yield, reducing the pressure to transform land elsewhere, would further lower the carbon footprint. Potential eutrophication per Mg grain was reduced by 15% in the production system with the highest N uptake efficiency in southern Sweden. Crops with improved N uptake efficiency can thus be an important complementary measure for reducing N losses to water, provided that the N application rate does not increase. However, incentives for farmers to maintain or even lower the N application rate might be required. Using simulation modelling is a promising approach for assessment of expected effects of improved crop varieties when no long-term experimental data are available. However, advanced crop models are required to better reflect the effect of plant breeding on e.g. expected yield. Future model development should involve expertise in plant breeding, plant physiology and dynamic crop and soil modelling.     

鸡粪堆肥腐熟过程中腐熟度参数的变化

选用鸡粪与小麦秸秆为堆肥原料进行高温好氧堆肥实验,研究鸡粪高温好氧堆肥过程中堆体温度、pH值、碳氮比等理化指标的变化,为农业废弃物快速资源化利用提供科学依据和技术指导。结果表明：鸡粪与小麦秸秆在C/N=30时达到的温度最高为60℃,高温持续时间为11d,堆肥过程中pH值是先上升后下降的过程。堆肥结束时C/N为16.4,NH4+-N含量比最高时降低了74.2%。HR比开始增加了58.8%,胡敏酸相对于最低点升高了107%,富里酸与堆肥前相比降低47.1%。     

配方施肥对单季籼粳杂交稻增产增效的影响

为了解宁波市当前主要配方肥在单季籼粳杂交稻上的增产增效效果,以‘甬优7850’为材料,设置3种配方肥施肥方案,以常规复合肥为对照,探索经济效益最佳的施肥方法。结果表明：与常规复合肥纯氮用量接近时,专用配方肥处理生长表现较好,群体结构协调,成穗率较高,最终产量最高,同时节本增效效果显著,具有较好的增产增效效果,适合在当地推广应用。     

Application of DMA in Realtime Image Processing

Direct memory access(DMA)is an important technology used for fast speed data transfer in data signal processor(DSP). DMA is able to move data block independent of CPU, and this capability meets real time image processing. TMS320C6201 DSP is taken as an example, and DMA controller characteristic is introduced. According to DMA application in realtime image processing, the specific control ways and realization steps are given out. The research result shows that the flexible control DMA can not only raise image data transfer efficiency but also improve DSP speed.     

杂交稻有序机抛增密减肥处理对产量及肥料偏生产力的影响

研究全程机械化条件下有序机抛技术增密减肥处理对杂交稻主要生育期地上部干物质积累、肥料偏生产力以及产量的影响。以水稻品种晶两优华占为试验材料,采用有序机抛技术,设置常规密度（D0：16万穴/hm²）、中密度（D1：19万穴/hm²）和高密度（D2：24万穴/hm²）3个移栽密度以及常规施肥处理（N0）和减量施肥处理（N1：常规施肥基础上减肥26.56%）2个施肥水平。结果表明,移栽密度和施肥量对水稻主要生育期地上部干物质积累、肥料偏生产力和产量均存在显著影响;与D0N0处理相比,D2N1处理有利于维持千粒重,协调穗、粒矛盾,且有效提高主要生育期地上部干物质量、肥料利用率（42.44%）及产量（4.47%）。相关分析表明,产量与移栽密度显著相关（r=0.53^*）,说明在减施肥料条件下,移栽密度对产量产生较大影响。在常规施肥基础上减施肥料26.56%,移栽密度24万穴/hm²,能提高水稻产量以及肥料偏生产力,为增密减肥的最佳处理。     

氮肥管理与地膜覆盖对旱地冬小麦产量和氮素利用效率的影响

降雨偏少且季节分布不均,施肥偏多且方式不合理,缺少有效的保水栽培措施是西北旱地小麦生产面临的主要问题。2010年10月至2012年6月连续2个小麦生长季,在陕西渭北旱塬进行田间试验,比较了氮肥追施和总量减少、覆膜、增加种植密度措施较传统施肥和农民习惯施肥种植模式对冬小麦籽粒产量及氮素利用效率的影响。与农户习惯施肥相比,传统施肥不能持续增加产量和氮素利用效率;而减氮追肥、减氮垄覆和减氮垄覆增密处理的增产效果明显,同时提高了氮素利用效率,但减氮垄覆或增加种植密度却使籽粒含氮量降低,主要原因是进入开花期后土壤硝态氮累积量减少,氮素供应不足所致。综合分析,减氮垄覆增产增效更明显,小麦产量、氮肥偏生产力、氮肥生理利用率在第1年分别提高38.6%、49.6%和35.1%,在第2年分别提高7.6%、16.3%和25.7%,说明控氮与覆膜结合是实现旱地冬小麦增产的重要措施,但需注意生长后期土壤氮素供应,在增产的同时保证小麦品质。     

contact stress and steady thermal analysis of herringbone gears in a gas turbine

To obtain the distribution characteristic of contact stress and the bulk temperature on the surface of herringbone gears, parameter modeling of gears was carried out by parametric design language. A numerical simulation was given to calculate the contact stress field and the steady thermal field by combining heat transfer theory, tribology theory, and mesh theory. The distribution of contact stress, the bulk temperature and heat flux also were analyzed. The analysis results show that the distribution of the load along the contact line possesses regularity. The heat flux along the tooth depth direction decreases first and then increases. The effect of thermal conduction of the tooth is stronger than that of convective heat transfer. The conclusion indicates that the finite element emulation method can be used to estimate the transmission performance of herringbone gears.     

氮肥减量后移对玉米冠层生理性状和产量的影响

为了进一步研究氮肥减量后移对玉米生理性状和产量的影响,以‘郑单958’为试材设置5个处理：不施氮(N0)、习惯施氮(N300/2)、减量施氮(N240/2)、减量后移施氮(N240/3)、减量后移施氮(N200/3),完全随机区组设计,3次重复,种植密度75000株/hm2。结果表明,氮肥减量处理(N240/2)与习惯施氮处理(N300/2)相比叶片SPAD值、PN及产量均有所降低,Dualex值则有所增加,但差异并不显著,减量施氮在生产上应切实可行的;减量后移施氮处理(N240/3)与习惯施氮处理(N300/2)和减量施氮处理(N240/2)在出苗后30天和45天的叶片SPAD值、光合速率及产量也均有所降低,Dualex值则有所增加,表现差异也并不显著,但与减量后移施氮(N200/3)差异显著。减量后移施氮(N240/3)与习惯施氮处理(N300/2)、减量施氮处理(N240/2)和减量后移施氮(N200/3)在出苗后60天和75天的叶片SPAD值、光合速率及产量均有所增加,Dualex值则有所降低,表现差异显著。氮肥减量后移(N240/3)处理的玉米植株氮素不但能满足于玉米生长的营养需求、降低投入、提高氮素利用率且产量也得到提高。     

氮磷钾平衡施用对花椰菜经济产量及品质的影响

应用311－A拟饱和最优回归设计和{3,2}单形格子饱和设计,通过氮磷钾肥配比和氮肥分期施用田间试验,拟建花椰菜施用氮磷钾肥对经济产量、施肥利润及氮肥分期施用比例的效应函数。寻优结果表明：花椰菜最高产量的氮、磷、钾优化施肥组合为N 249.28、P2O554.33和K2O 238.83kg/hm2,其最高经济产量达54.877t/hm2;最佳施肥利润的氮、磷、钾优化施肥组合为N 243.52、P2O552.22和K2O 234.09kg/hm2,其最佳施肥利润达63784.89元/hm2,经济产量也达54.853t/hm2;较佳施氮分配比例为基肥 ：前期追肥 ：后期追肥为0.3135:0.4500:0.2365,其对应的氮肥用量分别为N76.49、109.80和57.71kg/hm2,期望较高的经济产量可达55.313 t/hm2。在同等肥底下,花椰菜维生素C、还原糖和总糖含量与施氮量之间呈一定程度上的负相关,与磷、钾施用量之间呈不同程度的正相关;而硝酸盐含量则与氮施用量呈一定程度的正相关,与磷、钾施用量之间相当程度的负相关。在磷钾用量相同的情况下,氮肥越迟施用或后期施用量越大,花椰菜维生素C、还原糖和总糖含量越低,但硝酸盐含量则越高。     

北方冬麦区小麦产量潜力及增产技术研究进展

为了合理、准确地分析北方冬麦区的小麦产量潜力,找到限制因素,探寻相应的调控技术,提高小麦生产力。归纳了本地区模型模拟的冬小麦产量和高产记录,比较分析了模型模拟和高产纪录产量水平的差异,总结了限制小麦产量差缩小的主要原因与可能的调控技术。得出当前模型模拟结果低于高产记录是因为数据采集年份和数据量的影响;产量性能理论是定量化分析产量差异原因的有效方法;指出北方冬麦区限制小麦产量差缩小的主要原因和调控技术。认为小麦产量提升应从产量差确定、产量性能分析、集成技术等3个方面依次开展。     

Influence of Motorcycle Noise on Gear Transmission

The study of motorcycle's acoustic signal shows that gears noise take a great proportion on the whole acoustic of motorcycle.So how to control the noiseof gears is very helpful for reducing the whole motor's acoustic.This paper discusses the engine matching with transmission system in reason,primary transmission and gear geometry design parameter & the mend of tooth body(tooth form & tooth direction) how to influence the acoustic of motorcycle.The study shows that the gear transmission System's matching with engine in reason can notable improve the efficiency of motorcycle.In the meaning time the exactly choosing the primary transmission gear geometry design parameter and the mend of primary transmission gear's tooth body can effectively reduce the acoustic of motorcycle.This paper has engineering practice sense.     

Color change of fresh-cut apples coated with whey protein concentrate-based edible coatings

The effect of antioxidant type and content alone or in combination with edible coatings for fresh-cut apples was studied. Edible composite coatings were prepared from whey protein concentrate (WPC) and beeswax (BW). Ascorbic acid (AA) at 0.5% and 1% content, cysteine (Cys) at 0.1%, 0.3% and 0.5% content, and 4-hexylresorcinol (4-hexyl) at 0.005% and 0.02% were incorporated in the formulations as antioxidants. Apple pieces were coated with the emulsion coatings and weight loss, color (CIE L*, a*, b*, and browning index (BI)) and sensory evaluation were measured during storage. Results showed that incorporation of the antioxidant to the coating reduced browning compared to the use of the antioxidant alone. 4-Hexyl was the least effective at reducing browning, even when incorporated into the WPC-based coating. Increasing AA and Cys content decreased browning of coated samples. The most effective treatments were WPC–BW-based coatings with 1% AA or 0.5% Cys. Apple pieces treated with 0.3% and 0.1% Cys aqueous solutions showed a pinkish-red appearance, whereas this effect was not shown when similar levels of Cys were incorporated into the WPC–BW-based coating. Coating application did not reduces weight loss in fresh-cut apples, probably due to the high relative humidity of the product. A sensory panel was able to discriminate between samples coated with WPC–Cys and samples dipped in Cys aqueous solution, but not between samples coated with WPC–AA and samples dipped in AA aqueous solution.     

Linking Policy and Outcomes: A Simulation Model of Poverty Incidence

ABSTRACT Many states are striving to meet public demand for accountability by “benchmarking”—setting social goals for the state and tracking progress in meeting the goals. However, states are finding it difficult to set realistic targets and to assess the impacts of policy on achievement of the targets without a framework that models the relationships among policy targets, policy actions and social and economic forces outside the control of policymakers. This paper develops a dynamic simulation model of one “benchmark” (poverty incidence) in Oregon, linking transitions into and out of poverty to various events (increased earnings, or having a child as a teenager, for example), and linking these events to policy. The simulation results suggest that, with current policies, Oregon will come close to achieving its poverty benchmark target of 11 percent by the year 2000 if economic conditions remain favorable. The model is used to examine the impact on poverty incidence of three policy strategies: reducing high school dropout and teen pregnancy rates, increasing the effectiveness of social support programs to JOBS participants, and boosting job growth. The simulation results suggest that when assessing the state's performance or “grading” the observed trend in the poverty benchmark, policymakers should take into account the performance of the state (and national) economy. The impact of policy efforts to reduce poverty is limited because many poverty spells are caused largely by events not affected by current state policies.     

Effect of Chemical Composition on Formation Performance of 7050 Alloy Billets

The casting technology of 7050 alloy bilits is researched. that are used to produce slabs for air materials.Because the composition of 7050 alloy is very complex,the Cu and Zn elements contents are higher and Fe and Si impurity elements contents are controlled lower, at the same time ,the specification and the width-thickness ratio are large ,all of above result the tremendous crack trend when casting and bad casting formation performance . The formation performance of 7050 alloy has been improved and qualified billits are obtained by optimizing the composition of 7050 alloy, including raising Fe/Si ratio and Zn/Mg ratio ,reducing Cu content and adopting the joint refinement with block and silk shaped Al-5Ti-1B.