如何提高奥氏气体分析仪检测粮堆中CO_2和O_2浓度的准确度

介绍了检测粮堆中CO_2和O_2气体浓度所用奥氏气体分析仪的构造、原理、操作,提出了提高奥氏气体分析仪检测准确度的方法建议。     

非线性、分形与期锌市场价格

从非线性角度研究期锌市场，运用R/S分析法对期锌市场进行分析，发现期锌市场的Hurst指数为0.6183,其价格收益率序列是分维时间序列，具有分形结构，维数为1.6174。期锌市场的平均周期长度为176天，具有强持续性和相关性。关联系数为19.47%，远远大于国外相关市场。在风险方面，期锌市场的风险比期铜市场的要小，而比股票市场的风险要大。     

Effects of Different Substrate Composition on Growth of Gesneriaceae Plants

The cultivation experiment was carried out to investigate the effects of different proportions of peat soil, perlite, vermiculite and yellow mud on growth of Gesneriaceae species(Chirita gueilinensis, Sinningia speciosa, Lysionotus pauciflorus, Hemiboea henryi, Aeschynanthus acuminatus, Saintpaulia ionantha). The growth traits of each plant growing in 7 different matrix materials were investigated.The plant height, crown width and chlorophyll content of each plant were measured. The results showed that the best substrate ratio was peat soil∶vermiculite=2∶1for C. gueilinensis, L. pauciflorus and H. henryi; peat soil∶perlite∶vermiculite = 2∶1∶1for S. ionantha; peat soil∶vermiculite∶yellow mud=2∶1∶1 for S. speciosa; peat soil∶perlite∶vermiculite∶yellow mud=2∶1∶1∶1 for A. acuminatus.     

苹果种植区的土壤养分含量情况研究—以白水县为例

为了稳定和提高苹果产量，通过对2013 年渭南白水县500 个点农业土壤区进行分析，并对土壤pH、全氮、有机质、碱解氮、速效钾、有效磷、有效铁和有效锰、锌、铜进行有效的对比研究。利用Microsoft Excel 2010 软件进行数据整理统计。结果发现：白水县苹果生长的土壤酸碱度为中性偏碱，并且土壤中的全氮和有机质的含量丰富，速效钾较丰富；有效锌、有效磷含量适中；有效铜含量高，有效铁、碱解氮、有效锰含量低。     

初探粮食仓储的管理预案

在现代新的形势下,粮食仓储的管理工作显然是非常重要的,对于保障粮食安全是非常重要的,因为不管是从哪方面考虑,它都占据着一个至关重要的位置。所以,做好粮食工作的关键之一就是要加强对粮食仓储的管理。     

Agronomic traits of soybean cultivars released in different decades after grafting record‐yield cultivar as rootstock

Breeders have seldom considered the selection for root traits during the genetic improvement in soybean. It is hypothesized that grain yield would be increased by the root function improvement, especially for the current cultivars. The objective of this grafting experiment was to determine the effect of record‐yield cultivars L14 or Z35 as rootstocks on agronomic traits of cultivars released in different decades. A total of 11 cultivars, released in different decades, were used to graft onto L14 or Z35 rootstocks. The agronomic traits were measured in the pot‐culture experiments. Grafting cultivars released in different decades onto L14 or Z35 rootstocks resulted in higher yield, 100‐seed mass and apparent harvest index as compared with those of non‐grafted or self‐grafted plants. Grain yield gain of cultivars grafted onto record‐yield cultivar rootstocks was 0.40 g/plant/year from 1966 to 2006, which was larger than that of non‐grafts and self‐grafts (0.27 g/plant/year). The yield of current cultivars should increase more if their root functions were improved.     

Can additional N fertiliser ameliorate the elevated CO2‐induced depression in grain and tissue N concentrations of wheat on a high soil N background?

Elevated CO₂ stimulates crop yields but leads to lower tissue and grain nitrogen concentrations [N], raising concerns about grain quality in cereals. To test whether N fertiliser application above optimum growth requirements can alleviate the decline in tissue [N], wheat was grown in a Free Air CO₂ Enrichment facility in a low‐rainfall cropping system on high soil N. Crops were grown with and without addition of 50–60 kg N/ha in 12 growing environments created by supplemental irrigation and two sowing dates over 3 years. Elevated CO₂ increased yield and biomass (on average by 25%) and decreased biomass [N] (3%–9%) and grain [N] (5%). Nitrogen uptake was greater (20%) in crops grown under elevated CO₂. Additional N supply had no effect on yield and biomass, confirming high soil N. Small increases in [N] with N addition were insufficient to offset declines in grain [N] under elevated CO₂. Instead, N application increased the [N] in straw and decreased N harvest index. The results suggest that conventional addition of N does not mitigate grain [N] depression under elevated CO₂, and lend support to hypotheses that link decreases in crop [N] with biochemical limitations rather than N supply.     

粮食烘干塔换热器智能折边设备研发

结合螺旋板式换热器的应用领域及其板材折边生产现状,分析了其生产弊端。针对板材折边工艺要求,研发了粮食烘干塔换热器智能折边设备,并剖析其工作机理。根据典型产品结构参数,设计智能折边装备总体装配图并计算主要零件参数,为智能折边装备制作提供理论依据,从而实现换热器板材折边智能加工,提高换热器卷板折边质量及精度。     

A calibration method of detecting soil water content based on the information-sharing in wireless sensor network

In agricultural production, there is contradiction between the cost and accuracy of detection during the course of acquiring soil water content (θ) online. This conflict is one of the core issues of automatic water-saving irrigation technology in agriculture. At the same time, capacitive soil moisture sensor (CSMS) has received considerable attention, for it can acquire θ with low cost and high precision, and meet the application requirements of wireless sensor network (WSN). But CSMS is vulnerable to the soil temperature (T_s) and salinity (S_s) in the measurement process. Therefore, this study took EC-5 sensor for example to establish water detection calibration models of soil temperature and salinity for single sensor, using Least Squares Support Vector Machines on MatLAB (LS-SVMlab) as the tool. On this basis, we explored the spatial variability of T_s and S_s, and then a method, which could be used to calibrate the output signals of sensors in multi-point network, was proposed based on the information-sharing (T_s or S_s) technology of WSN. Through laboratory experiment, we effectively reduced the impact of soil temperature and salinity on the single sensor. In example analysis, we investigated the detection precision and costs under different information-sharing radiuses (r). And the results indicated that the method we proposed based on the information-sharing technology of WSN could successfully calibrate the influence of soil temperature and salinity on sensors in multi-point network, and it was an efficacious approach to determine the balance between the calibration accuracy of moisture sensor and the investment of agricultural production. For example, while the calibration precision of soil temperature and salinity is respectively 1%, the costs can be reduced by 30%.     

Contribution of Different Organs to Grain Filling in Durum Wheat under Mediterranean Conditions I. Contribution of Post‐Anthesis Photosynthesis and Remobilization

Under Mediterranean conditions, drought affects cereals production principally through a limitation of grain filling. In this study, the respective role of post‐anthesis photosynthesis and carbon remobilization and the contribution of flag leaf, stem, chaff and awns to grain filling were evaluated under Mediterranean conditions in durum wheat (Triticum turgidum var. durum) cultivars. For the purpose, we examined the effects of shading and excision of different parts of the plant and compared carbon isotope discrimination (Δ) in dry matter of flag leaf, stem, chaff, awns and grain at maturity and in sap of stem, flag leaf, chaff and awns, this last measurement providing information on photosynthesis during a short period preceding sampling. Source–sink manipulations and isotopic imprints of different organs on final isotope composition of the grain confirmed the high contribution of both carbons assimilated by ears and remobilized from stems to grain filling, and the relatively low contribution of leaves to grain filling. Grain Δ was highly and significantly associated with grain yield across treatments, suggesting the utilization of this trait as an indicator of source–sink manipulations effects on grain yield. Chaff and awns Δ were better correlated with grain Δ than stem and leaf Δ, indicating that chaff were more involved in grain filling than other organs. Moreover, in chaff, sap Δ was highly significantly correlated with dry matter Δ. These results suggest the use of Δ for a rapid and non‐destructive estimation of the variation in the contribution of different organs to grain filling.