基于分形插值的三维路面重构与分析

原始精细的路面谱是研究车辆与路面耦合的重要基础,对车辆的通过性和噪声、振动及不平顺性NVH(noise,vibration and harshness)分析有重要的应用价值。为了构建与原始路面相同或相近的路面谱,利用非接触式激光路面不平度仪测量沥青路面、水泥路面、比利时路面和砂石路面的三维路面不平度;基于分形理论,采用迭代函数法重构这四种路面谱;结合路面不平度的统计特性评价指标和分形维数对四种路面的原始谱和重构谱进行评价。研究结果表明:重构前、后路面谱的平均值、标准差、峰度系数以及分形维数变化范围在±5%以内,除水泥路面的偏态系数变化范围均在±9%以内,重构路面谱与原始谱具有一致性;重构路面谱保持了原始路面的结构特性,并具有路面的细微结构。     

Antioxidant effectiveness of phenolic apple juice extracts and their gut fermentation products in the human colon carcinoma cell line caco-2

Apples represent a major dietary source of antioxidative polyphenols. Their metabolic conversion by the gut microflora might generate products that protect the intestine against oxidative damage. We studied the antioxidant effectiveness of supernatants of fermented apple juice extracts (F-AEs, 6 and 24 h fermentation) and of selected phenolic degradation products, identified by HPLC-DAD-ESI-MS. Cell free antioxidant capacity of unfermented apple juice extracts (AEs) was decreased after fermentation by 30-50%. In the human colon carcinoma cell line Caco-2, F-AEs (containing <0.5% of original AE-phenolics) decreased the reactive oxygen species (ROS) level more efficiently than the F-blank (fermented without AE) but were less effective than the respective AEs. Similarly, antioxidant effectiveness of individual degradation products was lower compared to respective AE constituents. Glutathione level was slightly increased and oxidative DNA damage slightly decreased by fermented AE03, rich in quercetin glycosides. In conclusion, F-AEs/degradation products exhibit antioxidant activity in colon cells but to a lesser extent than the respective unfermented AEs/constituents.     

耕作土壤表面不平度分析

利用激光式不平度测试仪测定犁耕耕地地面、圆盘耙耙地地面和驱动耙耙地地面的不平度，测定地面不平度沿着3个方向进行，即平行、倾斜和垂直于耕作方向。对每一种地面不平度的RMS高度、自相关长度和自相关函数进行了分析，结果表明：对于短的地块，可用单一尺度来表征地表不平度的特征，地表不平度特征属于指数相关函数，RMS高度和自相关长度具有明显的相关性；对于长的地块，平整的农业地表不平度具有分形性或多尺度性，其自相关函数是一种分形过程。     

The combined effects of temperature and GnRHa treatment on the final stages of sexual maturation in Atlantic salmon (Salmo salar L.) females

Atlantic salmon (Salmo salar L.) females (2 SW), maturing for the first time, were reared under one of three temperature regimes (high: 14.3 ± 0.5°C; natural: 10.6 ± 1.0°C; and cold: 6.9 ± 1.0°C) in combination with one of two experimental treatments; an injection of GnRH analogue (GnRHa) contained in biodegradable microspheres, or a sham injection (microspheres only). The six experimental groups were then reared under simulated natural photoperiod for 4 weeks. Blood samples were drawn for analysis of plasma steroid levels and the fish were inspected for ovulation weekly. Batches of stripped eggs were incubated in triplicate incubators in raceways until the eyed stage. Treatment with GnRHa resulted in a substantial advancement and synchronization of ovulation at all temperatures, while exposure to cold water also appeared to advance ovulation slightly. While 75% (warm and cold) to 90% (natural) of GnRHa fish ovulated during the 4-week trial, only 30% of sham-treated females exposed to cold water, and none of the sham-treated fish held at higher temperatures, ovulated during this period. Survival rates of embryos to the eyed-stage were significantly higher for broodstock exposed to cold water. Plasma levels of testosterone (T), 17β-oestradiol (E₂), and 17α,20β-dihydroxy-4-pregnen-3-one (17,20βP) were all significantly affected by treatment with GnRHa and, to a lesser extent, temperature. The efficiency of GnRHa in counteracting the negative effects of high temperature on ovulation and the associated changes in circulating sex steroids suggest that temperature inhibition operates at least in part at the brain or pituitary.     

多糖和寡糖的体外发酵特性及其对鸡盲肠微生物菌群的影响

本研究采用体外累积发酵产气法和16SrDNA指纹图谱鉴定技术研究了来自香菇、银耳和黄芪的天然免疫活性多糖(LenE,TreE和AstE)及酵母胞壁甘露寡糖(MOS)对鸡肠道微生物菌群及其发酵特性的影响。结果表明,三种多糖提取物的总糖含量均占干物质的60%以上,而MOS总糖含量在90%以上。多糖和寡糖具有不同的发酵模式;MOS、AstE和LenE三种糖的发酵模式相似,呈一阶段发酵模式;TreE呈两阶段的发酵模式。三种糖中,MOS和AstE发酵速度较TreE快。MOS和AstE在发酵后总VFA产量最高,pH最低;黄芪多糖发酵后产生较多的直链脂肪酸和较低的氨。这些多糖和寡糖提取物影响肠道微生物的活性和组成成分,体现在发酵模式和发酵终产物的显著改变上。以上研究结果表明,来自香菇、银耳和黄芪的天然免疫活性多糖(LenE,TreE和AstE)及酵母胞壁甘露寡糖(MOS)在体外发酵后,均具有显著改变鸡盲肠微生物发酵终产物的含量和盲肠微生物活性的作用。     

基于代码生成的电控空气悬架系统电子控制单元

为提高某型SUV车辆的行驶平顺性、通过性等,对其进行空气悬架改装,并设计了由最小系统、车速信号调理模块、电动气泵控制模块、组合电磁阀控制模块、车身高度检测模块、CAN总线模块、车身加速度测量模块等组成的以Freescale XDP512为核心芯片的电控空气悬架系统电子控制单元,利用Real-Time Workshop(RTW)代码生成技术将所制定电控空气悬架系统控制策略转化为ANSI C代码并下载至电子控制单元,然后对安装电控空气悬架系统的试验车辆进行了车身高度与车速耦合试验、转向试验、急加速试验、急减速试验、平顺性试验,结果表明所设计的电控空气悬架系统控制单元能够实现车速信号调理、车身高度与车速耦合、电动气泵控制及组合阀控制等功能。     

Analysis of free and esterified ergosterol in tomato products

A new extraction and chromatographic procedure to quantify free and esterified ergosterol in tomato products was devised. The extraction solution was composed of a dichloromethane/methanol mixture in a 2:1 (v/v) ratio. This extraction solvent allowed for higher ergosterol recovery from tomato products (an average of 25% more) compared to hexane, which is frequently employed for ergosterol extraction. Both free and esterified ergosterol were determined by HPLC reverse-phase chromatography employing a Nova-Pak C-18 column (300 x 3.9 mm), filled with 4 mm average particle size and a guard column of the same material. The elution was performed at a flow rate of 1 mL. min(-1) with a linear gradient of solvent A (methanol/water, 80:20, v/v) and solvent B (dichloromethane). The gradient, starting at sample injection, was from 0 to 50% B for 20 min for the free ergosterol analysis and additional 15 min at 50% B to analyze the ergosterol esters. This technique has proven to be more sensitive for ergosterol determination than other reported chromatographic procedures. Moreover, ergosterol esters, extracted from various fungal sources, separated well and were easily quantified.     

Ellagic acid, vitamin C, and total phenolic contents and radical scavenging capacity affected by freezing and frozen storage in raspberry fruit

The ellagic acid, total phenolic, and vitamin C contents in four raspberry cultivars (Heritage, Autumn Bliss, Rubi, and Zeva) grown in Spain were detected and quantified by HPLC in fresh, just frozen, and stored fruits at -20 degrees C for a one year period. Ellagic acid [207-244 mg kg(-)(1) of fresh weight (fw)], total phenolic (137-1776 mg kg(-)(1) of fw), and vitamin C (221-312 mg kg(-)(1) of fw) contents in raw material were higher in the late cultivars Zeva and Rubi than in the early cultivars Autumn Bliss and Heritage. The freezing process slightly affected the values of extracted ellagic acid, total phenolic, and vitamin C content. At the end of long-term frozen storage (12 months), no significant change of total phenolic content extracted was observed, but significant decreases of 14-21% in ellagic acid and of 33-55% in vitamin C were quantified. Free radical scavenging capacity measured as antiradical efficiency (AE) depends on the seasonal period of harvest. Late cultivars, Rubi (6.1 x 10(-)(4)) and Zeva (10.17 x 10(-)(4)), showed higher AE than early cultivars, Heritage (4.02 x 10(-)(4)) and Autumn Bliss (4.36 x 10(-)(4)). The freezing process produced a decrease of AE values in the four cultivars ranging between 4 and 26%. During the frozen storage, the AE values reached after the freezing process remained unchanged.