基于无线传感网络隧道亮度信号采集系统的研究

亮度信号是高速公路隧道节能照明控制系统必须检测的物理量。本文基于zigbee的技术特点，设计了一款基于无线传感网络的隧道亮度信号采集系统。系统的传感器节点负责亮度信号的采集，经CC2530处理发送，通过逐级跳转的方式把数据传输到协调器。协调器通过RS232串口与灯具控制器通信，以此实现对亮度信号的实时采集和可靠性传输。通过实验表明，该系统达到了设计的目的，并适用于高速公路隧道节能照明控制系统。     

半干旱区农田杂草的生活史对策研究

2008-2009年通过利用当地常见的10种杂草种植于不同处理的农田,研究半干早区农田杂草群落结构以及10种杂草群落组分种对环境因子的响应,结果表明,1)同一物种在不同的气候环境下,可以表现出不同的生活史策略.蝇虫实、田旋花和金荞麦2008年生活史策略分别具有竟争型(C)对策属性、胁迫忍耐型(S)对策属性和中间型(C-...     

基于EXCEL的作物灌水率图自动绘制与修正

在灌区的规划设计中,传统作物灌水率图的绘制一般都是手工方法,不仅效率低且修正起来很不方便,而且现有的灌水率图绘制软件一般存在着灌水率计算和灌水率图绘制相互独立、无法实时动态修正等不足.基此,综合利用EXCEL软件强大的数据处理、分析功能以及图形自动绘制功能,将灌水率计算与灌水率图绘制有机结合,从而实现灌水率图的快速绘制和动态调整.这种方法操作方便、简单,值得在工程设计部门推广使用.     

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.     

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%.     

斑茅纤维降解生产燃料酒精的发酵工艺研究

以能源植物斑茅纤维为原料,探讨纤维素糖化液生产燃料酒精的发酵工艺研究,分析了时间、温度、pH、氮源种类、酵母膏用量与酵母用量等因素对斑茅纤维素酒精发酵的影响。结果表明:反应时间72~96h,温度35℃,pH4.8~5.2,酵母膏氮源用量0.8%~1.0%,酵母用量10%~15%时斑茅纤维糖化液的酒精发酵效果最好。通过正交试验确定了最佳发酵条件:时间84h、温度35℃、酵母膏用量1.2%、酵母用量20%,发酵验证酒精值达4.6%(V/V),酒精得率32.62%。     

酸奶营养品质提升的加工工艺研究

牛奶中含有丰富的活性营养物质,包括乳铁蛋白、免疫球蛋白、乳过氧化物酶、α-乳白蛋白、β-乳球蛋白等。传统工艺生产的酸奶经过高温杀菌,活性营养物质几乎完全损失。为了避免这一情况,本文推出一种新的酸奶生产工艺,生产出的酸奶可保留大部分活性营养物质。首先将牛奶的乳脂进行分离,乳脂部分进行125 ℃、5 s杀菌,脱脂牛奶部分进行75 ℃、15 s杀菌,将两部分料液混合后加入菌种发酵至酸度75~85°T,破乳后冷却后熟8 h以上。经测定,新工艺酸奶中α-乳白蛋白、β-乳球蛋白、乳铁蛋白、免疫球蛋白、乳过氧化物酶含量分别为966 mg/L、1 963 mg/L、23.4 mg/L、102 mg/L、1 025 U/L,远高于传统工艺酸奶的68 mg/L、200 mg/L、0.7 mg/L、14 mg/L、0 U/L。通过对比新工艺与传统工艺酸奶保质期内的活菌数、黏度、酸度和口感,并无显著差异。     

一种汽车车内一氧化碳监控系统

汽车车内由于CO导致的意外安全事故常常被忽略。汽车发动机和空调在运行过程中产生的CO进入车内,极易被忽视而诱发中毒的事故。利用单片机传感器技术设计一种汽车车内CO浓度监控系统,当车内CO浓度达到200 ppm时系统发出第一次报警,当车内CO浓度达到300 ppm,系统发出第二次报警提示,并开启天窗通风,保证车内人员安全。     

温度传感器在大功率采煤机摇臂故障诊断技术中的应用

为了减少大功率采煤机的故障率,在典型部件摇臂上安装了温度传感器,及时准确的获取摇臂温度信息,首先通过故障预警使采煤机故障达到防患于未然,然后通过故障信号简便的判断故障产生原因,大大的减少故障率和故障排查与维修时间。此方法结构简单,使用方便,对以后的推广奠定了一定的基础。     

Quantitative trait loci for fruit size and flowering time-related traits under domestication and diversifying selection in cucumber (Cucumis sativus)

In cucumber, the genetic basis of traits under domestication and/or diversifying selection is not well understood. Here, we reported QTL mapping for flowering time and fruit size-related traits with segregating populations derived from a cultivated × wild cross. Phenotypic data of flowering time (FT), fruit size (FS), fruit number (FN) and fruit weight per plant (FW) were collected in multiple environments. QTL analysis identified 19 QTL for these traits. We found that the major-effect QTL FT1.1 played an important role in regulating flowering time in cultivated cucumber, whereas the minor-effect QTL FT6.3 contributed to photoperiod sensitive flowering time during domestication. Two novel consensus FS QTL, FS1.4 and FS2.3, seem to be the targets of selection during breeding for the US processing cucumber. All other FS QTL were co-localized with previously detected QTL using populations derived from cultivated cucumbers, suggesting that they were under selection during both initial domestication and subsequent improvement. Results from this study also suggested that the wild cucumber is a useful resource for capturing positive transgressive segregation and novel alleles that could be explored in cucumber breeding.