碎石桩复合地基加固效果的瑞利波法评价研究

对瑞利波测试技术在碎石桩复合地基加固效果评价方面的应用进行了研究,结合大量工程资料,给出了碎石桩复合地基液化的工程判别方法,并建立了利用瑞利波法评价碎石桩体质量、承载力、变形模量的工程检验方法。结合现场静载和动测的试验数据对比分析,瑞利波评价法可靠、快捷,能快速有效地检验碎石桩复合地基加固效果,有较好的工程应用前景。     

毛乌素沙地石油天然气矿山地质环境保护与土地复垦适宜性评价及工程设计研究

为探讨半干旱区的土地复垦适宜性评价方法与工程设计,通过毛乌素沙漠周边3个油气项目土地复垦工程的适宜性评价与工程实施对比分析,研究得出毛乌素沙地地区石油天然气项目的适宜性评价过程应针对不同现状问题提出相关的重点地类,针对重点地类进行单独评价,其他复垦单元采取简化评价。工程设计应减少土壤扰动、不设计表土剥覆工程,有风蚀沙埋灾害的地区应对土地复垦与矿山地质灾害工程采取统一的治理措施。     

四足机器人砂砾地面对角行走控制方法

为解决四足机器人在砂砾地面上对角行走容易失稳的问题,提高机器人对松软和凹凸不平地面的适应性,在位置控制的基础上提出了一种机身姿态角的调整策略,并在机器人对角行走的过程中采取了一种变阻抗参数的阻抗控制方法。最后在实际的砂砾地面进行了四足机器人对角行走实验,实验结果证明这种控制方法和调整策略对于四足机器人对角行走在砂砾地面上具有较好的控制效果。     

Cadmium concentration in vegetable crops grown in a sandy soil as affected by Cd levels in fertilizer and soil pH

Field trials were conducted over a three-year period with chinese cabbage (Brassica pekinensis Rupr.) and carrots (Daucus carota L.) grown in a sandy soil with pH adjusted to 5.5 and 6.5. The NPK fertilizers containing 1, 30, 90, and 400 mg Cd kg^–1 P were applied at the rate of 0.07, 2.1, 6.3 and 28 g Cd ha^–1 yr^–1. The amounts of Cd added through phosphate rock also ranged between 0.1 and 28 g ha^–1 yr^–1. The increased Cd application rates through NPK fertilizers increased the Cd concentration in both vegetables but the differences among treatments were not found to be significant. The Cd uptake by both crops was significantly (p<0.01) higher at pH 5.5 than at pH 6.5. Chinese cabbage exhibited lower Cd concentration than carrots. Carrot leaves contained higher Cd than its roots. Cadmium removals by chinese cabbage and carrot were about 0.7 and 1.3 g ha^–1 yr^–1, respectively. At pH 5.5, Cd concentrations in the two crops, based on a three-year average, were 23 and 46% higher than at pH 6.5. Cadmium uptake by chinese cabbage from different sources of phosphate rock was affected to a very limited extent. Cadmium concentration generally increased over the years. Cadmium extracted by ammonium nitrate after harvest of the crops was closely related with soil pH and Cd concentration in the plants.     

Fertilizer nitrogen balance study on sandy loam with winter wheat

The uptake of labelled nitrate was studied under field conditions using a sandy loam soil and winter wheat as the crop. Thirty per cent of the added labelled nitrate was found in the grain, 13% in the straw plus chaff and only 2% in the harvested roots. The labelled nitrogen in the plant comprised about 6% of labelled fertilizer origin, and about 94% from the soil. By analysing the soil after harvest, it was shown that 16% of the fertilizer nitrogen was in the 0–6 cm layer, 19% in the 6–12 cm layer, 6% in the 12–25 cm layer and 5% in the 25–50 cm layer. This means a total residual fertilizer nitrogen of 46%. A study was made of the border effect by analysing the plants of the first and second row around the fertilized plot. The results show that the plants of the first row took up 1.4% of the added fertilizer and those of the second row only 0.4%. The total recovery of the added fertilizer in soil and plant was 93.1%, indicating that 6.9% was lost under conventional cultivation practice.     

塑胶跑道二灰碎石基层施工质量控制

塑胶跑道基层尚无施工技术规范,具体实践中只能参考公路工程的相关标准执行。结合具体工程实践,对塑胶跑道二灰碎石基层施工质量控制进行了初步探讨,总结了质量控制的经验,为今后同类工程的施工提供一定的参考和借鉴。     

连续施用不同量污泥堆肥对土壤氮组分及δ15N的影响

为探明连续施用无害化污泥堆肥（以下简称堆肥）对土壤全氮(TN)、不同活性氮组分含量及土壤δ¹⁵N的影响,为堆肥改良和培肥沙质潮土提供理论依据。本研究以河南省小麦-玉米轮作区沙质潮土为研究对象,通过2013-2016年田间连续定位试验,基于不同土壤活性氮组分分组技术和氮稳定性同位素技术,分析土壤活性氮组分和土壤δ¹⁵N对堆肥施入量的响应特征。结果表明,1） 连续施用堆肥显著增加了土壤碳氮含量,随施入量增加而显著增加,其中施堆肥量达45 t•hm^-2时效果最为显著,较单施化肥（CK）处理分别增加了265.83%和284.31%（P<0.05）。施用堆肥可以提高活性有机氮组分含量,其中颗粒态有机氮（PON）增加了104.57%~280.91%;处理间各活性氮组分含量呈现：颗粒态有机氮（PON）>轻组有机氮（LFON）>水溶性有机氮（DON）>微生物量氮（SMBN）。增加堆肥施入量提高了PON/TN和SMBN/TN分配比例,显著降低了LFON/TN和DON/TN分配比例（P<0.05）,从而降低土壤活性氮组分在全氮中的分配比例,说明高堆肥施用量促进土壤氮素以稳定态有机氮形式储存,有利于土壤氮素的累积。2） 施用堆肥显著降低了土壤δ¹⁵N,通径分析和主成分分析表明,土壤δ¹⁵N与土壤氮含量受堆肥施入量影响显著;相关性分析表明,δ¹⁵N与土壤TN、PON和LFON含量呈显著相关性,表明土壤δ¹⁵N变化特征可指示土壤氮组分受堆肥处理作用的响应。3） 冗余分析表明,土壤pH、土壤水分及土壤肥力水平（IFI）均会对土壤氮组分含量、活性氮组分分配比例及δ¹⁵N产生影响,其中对土壤IFI和土壤pH作用显著（P<0.05）,解释率分别达48.2%和17.5%。综上可知,施用堆肥提高了土壤有机物含量,施用量达45 t•hm^-2时,显著提高了土壤氮储量和活性氮组分含量,对沙质潮土的培肥效果明显,同时,土壤稳定性同位素δ¹⁵N变化特征可作为堆肥对沙质土壤质量提升效果的指示指标。     

新疆冲洪积卵砾石地层岩土工程勘察钻探技术发展回顾

冲洪积卵砾石层是新疆岩土工程勘察的主要地层,通过对近30年来冲洪积卵砾石层工程钻探的技术总结,对孔底局部反循环取心钻进、取心钻具回转钻进、牙轮钻具全面钻进、潜孔锤全面钻进等几种主要的钻探工艺技术要点进行了总结归纳,并评述了各钻进工艺的优缺点,尤其对市场竞争环境下卵砾石层钻进工艺做出了对比分析,提出了钻探技术发展的方向。     

高压砾石一次充填防砂工艺技术

北汉庄油田出砂严重,制约了油田的正常生产。通过对出砂原因分析,决定研制高压砾石一次充填防砂工艺技术,并于2005年在3口井得到应用,工艺成功率100％,至2005年底,累计增油1 145．54 t。实践表明,对于出砂严重的疏松砂岩油藏,该项技术投入低,成功率高,增油效果显著,具有推广价值。     

砂砾石地基上水闸底板弯矩预测的多元非线性回归模型

为了简捷地确定初步设计阶段水闸结构设计参数,加快设计进度,综合考虑砂砾石地基的弹性模量、闸墩荷载、闸孔宽度、底板厚度、闸墩高度、地基厚度等影响底板应力的主要因素,通过大量的有限元计算,分析了水闸参数对底板弯矩的影响规律,建立了基于多元非线性回归的底板中心弯矩预测模型.结果表明:底板中心弯矩与底板厚度、闸孔宽度、砂砾石地...