天业电石炉钢结构框架高效安装技术

文章针对该工程工期特别紧张的特点,介绍如何高速、优质的进行超高层钢结构安装以及常规安装技术在该工程的创新引用。     

砂姜黑土玉米秸秆有机碳的矿化特征

 【目的】探讨不同温度（10℃、20℃、30℃）、不同秸秆加入量（秸秆全量和过量）条件下,玉米秸秆还田对土壤有机碳矿化特征及其环境因子的响应机制。【方法】采用室内恒温控湿好气培养试验,对安徽淮北砂姜黑土在不同温度（10℃、20℃、30℃）条件下,设置50 g土样中加秸秆0.3 g（处理Ⅰ）、1.5 g（处理Ⅱ）、3.0 g（处理Ⅲ）及不加秸秆（CK）的处理,进行240 d的矿化培养。【结果】温度对有机碳矿化影响显著,在对照（CK）和秸秆加入量相同的处理中,有机碳的矿化累积量均随温度（10—30℃）升高而增加;温度较低（＜20℃）时,CK、Ⅰ、Ⅱ、Ⅲ各处理的有机碳矿化温度系数（Q10）平均值约为1.229、1.251、1.572、1.399,温度较高（＞20℃）时,CK、Ⅰ、Ⅱ、Ⅲ的Q10平均值约1.006、1.249、1.401、1.374,Q10值在温度较低时大于温度较高时,说明低温条件下,有机碳矿化速率对升温更敏感。同一温度条件下,不同处理秸秆加入量越大,有机碳矿化累积量越高,有机碳矿化的日变化量也越大。本试验中,一级动力学方程能较好地描述了不同处理土壤有机碳的矿化累积动态。土壤有机碳的潜在矿化量（C0）随温度变化不明显,在同一温度条件下,秸秆加入量越大,C0值越大。【结论】一级动力学方程能较好地描述不同处理土壤有机碳的矿化累积动态。不同温度、不同秸秆还田量及温度和秸秆还田量的交互作用,对玉米秸秆矿化过程中土壤有机碳含量的影响均达到显著水平。     

不同改良剂对铬胁迫下土壤—小白菜系统的影响

本研究以小白菜为材料,采用盆栽试验研究了石灰、活性炭及石灰+活性炭处理对铬胁迫下小白菜铬吸收量及对铬污染土壤中铬形态分布的影响,旨在阐明改良剂抑制重金属铬对小白菜的毒害作用机理。其研究结果表明:(1)在铬污染土壤中,小白菜不同部位铬含量顺序依次为根>叶>叶柄,改良剂能有效抑制小白菜对土壤中铬的吸收,不同改良剂在不同铬处理下对小白菜吸收铬的抑制效果不同。(2)形态提取分析表明,施用改良剂处理使土壤铬的水溶态、可交换态和碳酸盐结合态减少,而有机结合态和残渣态增加,从而降低小白菜对土壤中铬的吸收。     

乳中掺尿素快速检测方法影响因素的探索

[目的]部分不法奶商在原料乳中加水后同时加尿素来提高蛋白质含量及增加密度,快速检测乳中掺尿素,找出并拒收这部分掺假异常乳.[方法]对年乳掺尿素的检测方法(格里斯法)所用的试剂浓度、用量、搭配比例进行筛选,对掺不同浓度尿素的牛乳采用试管法进行检测比较.[结果]用1;亚硝酸钠溶液0.4mL的剂量,格里斯试剂用量为0.2 g,浓硫酸用量为1 mL,对掺尿素乳检测的结果比较明显,尿素最低检出量为0.04;,能方便、快速的检测出牛乳掺尿素.[结论]该法用于牛乳掺尿素的检测,操作简单,检测快速,灵敏度较高,检测成本低,适用于各奶站及牛乳检测机构的快速检验.     

石灰用量对酸性土壤pH值及有效养分含量的影响

采用室内培养法,设置不施生石灰和生石灰用量0.3、0.9、1.8、2.4、4.8 g/kg,共6个用量梯度,研究不同生石灰用量对酸性土壤pH值动态变化、有效养分含量的影响及土壤pH值与有效养分含量之间的相关性。结果表明,生石灰的施入,可以显著提高土壤pH值,改善土壤酸度。培养到第90 d,生石灰用量4.8、2.4、1.8g/kg处理较对照分别提高了2.88、1.16和0.74个pH单位。施用生石灰对土壤全氮含量影响不大,但对土壤无机氮影响显著。生石灰用量在0~2.4 g/kg范围内,土壤硝态氮含量随生石灰用量的增加而显著增加,增幅为12.4%~146.8%,当生石灰用量2.4 g/kg时,土壤硝态氮含量显著降低。土壤铵态氮的变化趋势则刚好相反,随着生石灰用量的增加而减少;土壤有效磷含量随着生石灰用量的增加先升高后降低;对于土壤速效钾来说,当生石灰用量0.9 g/kg,其含量随着石灰用量的增加而显著降低,降幅为2.9%~21.7%。施用生石灰可以显著提高土壤有效Ca含量,且随生石灰用量的增加而显著增加,增幅为32.3%~543.0%。生石灰的施用显著降低了土壤有效Fe、Mn、Cu、Zn的含量,且当生石灰用量≥2.4 g/kg时,土壤有效Mn、Zn含量均已处于极其缺乏的状况。土壤pH值与土壤全氮、铵态氮、速效钾、有效Fe、Mn、Cu、Zn呈显著线性负相关,与有效Ca呈极显著线性正相关,与土壤硝态氮、有效磷和有效Mg则符合二次函数,各相关系数均达到极显著水平。土壤养分与土壤酸度有着较好的相关性,在施用石灰改良酸性土壤时,要特别注意其施用量及土壤有效Mn、Zn等微量元素的及时补充。     

秸秆还田配施石灰对水田土壤铜、锌、铅、镉活性的影响

秸秆还田是我国培肥地力和增加农田土壤碳固定的重要措施,但进入农田的秸秆存在着活化土壤重金属的风险。为了解不同来源的秸秆对污染水平不同农田土壤重金属活性的影响,采取相应措施防止因秸秆还田对农田土壤重金属的激活,开展了盆栽和田间小区试验研究秸秆还田配施石灰对水田土壤铜、锌、镉、铅活性的影响。盆栽和田间试验在轻度和重度污染2种土壤上同时进行。盆栽试验中施用秸秆包括重污染水稻秸秆、轻污染水稻秸秆和轻污染油菜秸秆3种,石灰用量设对照(0 kg·hm-2)和石灰处理(750 kg·hm-2)2个处理;田间小区试验设对照(不施秸秆和石灰)、秸秆还田及秸秆还田+石灰3个处理。动态观察了试验过程中土壤有效态重金属、重金属形态及水稻籽粒中重金属积累情况。结果表明,试验初期(前20 d)秸秆还田显著增加了水田土壤中水溶性有机碳与水溶性重金属的含量;与对照处理比较,水溶性重金属含量以重度污染土壤增幅较为明显。试验后期(60 d后)秸秆还田对土壤重金属的活性的影响逐渐变得不明显。油菜秸秆还田土壤中水溶性重金属含量低于水稻秸秆还田,重污染水稻秸秆还田土壤中水溶性重金属含量高于低污染水稻秸秆还田。盆栽试验和田间试验的结果都表明,重污染水稻秸秆还田可轻微增加水稻籽粒中镉的积累,但轻度污染水稻秸秆还田与油菜秸秆还田对水稻籽粒镉积累的影响较小;3种秸秆还田对水稻籽粒铅、铜、锌积累的影响不明显。配施石灰可显著降低土壤中水溶性重金属的含量,降低水稻籽粒中重金属的积累。研究认为,在污染农田管理上应控制重污染水稻秸秆还田,在秸秆还田的同时适量配施石灰。     

Liming as an ameliorator of copper toxicity in black oat (Avena strigosa Schreb.)

This study aimed to assess the effect of liming as an ameliorator of copper (Cu) toxicity in black oats (Avena strigosa Schreb.) grown in soil with a sandy texture. The treatments were soil supplementation with increasing doses of lime (0.0, 0.5 and 1.0 g kg^?1) and two of Cu (0 and 50 mg kg^?1). Pre-germinated black oat seeds were sown for 30 days in the soil, subsequently, the plant height, root and shoot dry mass and concentration of total chlorophyll, chlorophylls a and b, carotenoids and total soluble carbohydrates and starch were analyzed. The dose of 50 mg kg^?1 soil Cu caused a toxic effect on black oat plant growth and development, affected the internal distribution of nutrients, decreased the leaf chlorophyll concentration and increased the leaf concentration of total soluble carbohydrates and starch. Increasing lime doses ameliorated the toxic effects of Cu.     

Effects of Farm Yard Manure and Lime on Cadmium Uptake by Rice Grown in Two Contaminated Soils of Chittagong

A pot experiment was conducted to evaluate the efficiency of farm yard manure （FYM） and lime （calcium carbonate） on reducing the uptake of Cd by rice in two Cd contaminated soils of Chittagong. The effects of farm yard manure, lime and farm yard manure mixed with lime （FYM ＋ Lime） on rice （Oryza sativa L.） growth, Cd uptake by rice and 0.1 N HC1 extractable Cd in soil were investigated. Results showed that addition of lime and farm yard manure mixed with lime significantly decreased 0.1 N HCl extractable Cd in the city sewage soil. Application of farm yard manure significantly decreased Cd concentration in rice in the city sewage soil. Lime and farm yard manure mixed with lime significantly reduced Cd concentration in rice m both the contaminated soils. Lime was more efficient than farm yard manure in reducing the uptake of Cd by rice.     

奶牛乳房炎大肠杆菌刃天青微量板快速诊断及药敏试验

为了建立奶牛乳房炎大肠杆菌快速诊断与药敏试验方法,用刃天青钠取代大肠杆菌选择培养基MQQ中的酚红指示剂,通过对刃天青的工作浓度、大肠杆菌接种量和培养时间等参数的研究,建立了奶牛乳房炎大肠杆菌刃天青微量板快速诊断方法.将不同细菌及其感染模拟奶样进行刃天青微量板快速培养结果显示,此刃天青微量板对大肠杆菌具有很强的选择培养特性,能在10 h内获得明确诊断结果,并能反映奶牛乳腺大肠杆菌感染强度.对89份临床奶样进行大肠杆菌刃天青微量板快速诊断敏感性和特异性检测,结果显示,此刃天青微量板法诊断大肠杆菌阳性奶样敏感性高达100%,诊断大肠杆菌阴性奶样特异性高达94.9%,总符合率高达95.5%.在此基础上用矫正浓度10种抗生素包被微量板,分别用10株大肠杆菌纯培养菌株及其感染模拟奶样和10份大肠杆菌阳性奶样进行快速药敏试验,所获结果与标准纸片扩散法完全一致.这些研究结果表明,本研究建立的刃天青微量板法可以取代常规方法用于奶样大肠杆菌的快速诊断及药敏试验.     

Chlorophyll fluorescence imaging: a new method for rapid detection of herbicide resistance in Alopecurus myosuroides

Due to the steadily increasing number of putative herbicide‐resistant weed populations, the demand for rapid in‐season tests is rising. In this study, we introduce a new quantitative herbicide‐resistance test system based on chlorophyll fluorescence imaging analysis of photosynthesis‐related parameters. Susceptible and herbicide‐resistant populations of Alopecurus myosuroides (black‐grass) were cultivated in multiwell tissue culture plates containing nutrient agar and different dosages of fenoxaprop‐P‐ethyl and mesosulfuron+iodosulfuron. The maximum quantum efficiency of the PSII was measured 3 h after transplanting (HAT) and then for seven days every 24 h. Data of maximum quantum efficiency of the PSII were compared with standard whole‐plant pot tests and molecular tests for target‐site mutations. It was possible to fit dose‐response curves and calculate corresponding resistance factors for ED90 for all populations tested using the chlorophyll fluorescence imaging. It was possible to distinguish between resistant and susceptible populations. The results of the chlorophyll fluorescence imaging corresponded well with the standard whole‐plant pot tests in the glasshouse. However, populations with proved target‐site mutations did not differ from other herbicide‐resistant populations in the maximum quantum efficiency values of the PSII. We conclude that the chlorophyll fluorescence imaging provides reliable data on herbicide resistance for both modes of action tested in a shorter time and using less space, compared with standard whole‐plant pot tests in the glasshouse.