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The engineering contract is composed of many documents between client and contractor, such as agreement, notification of award, tender and appendix to bid, conditions for particular application, instruction to bidders, technical specifications, design drawings and bill of quantities etc. Because of the limited time and money to prepare these documents, the defect is unavoidable. The defects include omittance, equivocalness, conflict and mistake. These defects often lead to claims. 相似文献
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To investigate the influence of operation parameters of abrasive water jet on surface roughness of carbon fiber reinforced plastic(CFRP),experimental studies were conducted.The three-dimensional landscape of cutting front was reconstructed according to the measured data byμscan laser confocal microscopy.Fourier spectral analysis was also adopted to study surface structure in detail.It is found that the morphology of cutting front is similar to that of other materials.In the smooth cutting zone,the fluctuation of amplitudes of surface profile is gentler,compared with that in the rough cutting zone.The lower part of the rough cutting zone was characterized by the periodical appearance of peaks and valleys.The roughness of surface increases with the increase of depth.While in the smooth cutting zone and part of rough cutting zone,roughness increases with the increase of traverse speed.For the thickness of samples,in the smooth cutting zone,the roughness increases with the increase of depth.The dominant harmonic component in the surface profile is concentrated in a narrow range from 0 to 10 Hz,and the relatively higher density of frequency from 10 to 50 Hz is shown in the rough cutting zone,which is caused by the interaction between perpendicular abrasive water jet and reflect jet. 相似文献
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Zheng RUAN Shumei MI Yan ZHOU Zeyuan DENG Xiangfeng KONG Tiejun LI Yulong YIN 《农业科学与工程前沿(英文版)》2015,2(2):144
Food security, the need to meet nutritional requirements, and four main problems for food protein security in China are analyzed. From the perspective of residents’ nutritional requirements and balanced dietary patterns, the conclusion is that food security in China is in essence dependent on protein production and security of supply and that fat and carbohydrates supply in China can reach self-sufficiency. Considering the situation of food protein production and consumption in China, policy suggestions are made, which could ensure a balanced supply and demand for food protein and food security in China. 相似文献
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微波裂解稻壳制备生物质油的工艺研究 总被引：1，自引：1，他引：0
近年来生物质能逐渐兴起,因此生物质的热解也受到了越来越广泛的关注。为了充分利用生物质废弃物,提供制备可再生新能源的新途径,通过采用微波快速裂解的技术,以稻壳为原料,通过微波裂解技术制备生物质油,结果表明稻壳在微波裂解温度为600℃,微波功率为2 kW,微波吸收剂用量为3%,微波时间为5 min的条件下,生物质油的得率最高。由此可知稻壳可以通过微波裂解技术制备生物质油。 相似文献
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施用生物有机肥抑制香蕉镰刀菌萎蔫病的研究 总被引：2，自引：0，他引：2
ZHANG Nan HE Xin ZHANG Juan W. RAZA YANG Xing-Ming RUAN Yun-Ze SHEN Qi-Rong HUANG Qi-Wei 《土壤圈》2014,24(5):613-624
Fusarium wilt is one of the most serious diseases of banana plants caused by soil-borne pathogen Fusarium oxysporum f.sp. cubense(FOC). In this study a pot experiment was conducted to evaluate the effects of different bio-organic fertilizers(BIOs) on Fusarium wilt of banana, including the investigations of disease incidence, chitinase and β-1,3-glucanase activities of banana plants, and FOC populations as well as soil rhizosphere microbial community. Five fertilization treatments were considered, including chemical fertilizer containing the same N, P and K concentrations as the BIO(control), and matured compost mixed with antagonists Paenibacillus polymyxa SQR-21 and Trichoderma harzianum T37(BIO1), Bacillus amyloliquefaciens N6(BIO2), Bacillus subtilis N11(BIO3), and the combination of N6 and N11(BIO4). The results indicated that the application of BIOs significantly decreased the incidence rate of Fusarium wilt by up to 80% compared with the control. BIOs also significantly promoted plant growth, and increased chitinase andβ-1,3-glucanase activities by 55%–65% and 17.3%–120.1%, respectively, in the banana roots. The population of FOC in the rhizosphere soil was decreased significantly to about 104 colony forming units g-1with treatment of BIOs. Serial dilution plating and denaturing gradient gel electrophoresis analysis revealed that the application of BIOs increased the densities of bacteria and actinomycetes but decreased the number of fungi in the rhizosphere soil. In general, the application of BIOs revealed a great potential for the control of Fusarium wilt disease of banana plants. 相似文献
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叶绿素仪(SPAD)在茶树氮素营养诊断中的适用性研究 总被引：6，自引：0，他引：6
测定叶片氮素含量是诊断茶树氮素状况的一项重要方法。本文利用盆栽试验,通过不同的供氮水平,研究了利用叶绿素仪(SPAD-502)进行茶树氮素营养快速诊断的适用性。结果表明,茶树新梢产量与氮素用量、成熟叶氮素含量之间呈线性加平台的反应关系,成熟叶的SPAD值与其全氮含量呈显著线性正相关,并与茶树产量存在着比较明显的关系拐点,初步显示SPAD可以较好地表征茶树的氮素营养状况,有可能作为快速诊断方法用于指导茶树施肥,但是还需要通过大田试验进行进一步验证。本文还探讨了测定位点、叶位、天气状况、田间原位或离体测定方式、表面清洗以及样本量等因素对SPAD测试精度的影响。 相似文献
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Research on a dynamic tracking model for reservoir water flooding of separated zone water injection 
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下载免费PDF全文 Waterflood is one of the main oil reservoir development ways. Premature flooding of production wells during water flooding process will reduce oil recovery. Therefore,it is particularly important to establish a dynamic tracking model for reservoir water flooding of separated zone water injection. Based on the basic principles of heat and mass transfer,according to well temperature curve to determine the water profile,Poisson process analysis and stochastic process methods are adopted to calculate water saturation,water breakthrough time and water cut of each layer in water flooded reservoir at any one time. When oil reservoir gradually become water flooded,the calculated water cut of model considering micro-pore distribution of the reservoir tends to the measured water cut,and the calculation error is less than 5%. Case study shows that the layer of the higher injection rate,with high flow channel such as micro fracture,where there is the faster increase in water saturation,the shorter water breakthrough time and faster increase in water cut,and vice versa. Research result provides time guarantee to take measures for inhibiting or delaying water breakthrough of production wells. 相似文献
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不论是屠体还是经过了进一步的加工,禽肉在贮藏过程中品质都要降低。尤其是高温条件下,生化反应加剧,损失更大。不少研究表明,增加日粮中 V·E 含量可以防止冷冻或新鲜肉脂肪的氧化,提高贮藏品质。日粮中 V·E含量在40mg/kg 或更高时,对于胴体肉、脂的味道有稳定作用. 相似文献
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长期施肥对潮土耕层土壤和作物籽粒微量元素动态的影响 总被引：4，自引：0，他引：4
LI Ben-Yin HUANG Shao-Min WEI Ming-Bao H. L. ZHANG SHEN A-Lin XU Jian-Ming RUAN Xin-Ling 《土壤圈》2010,20(6):725-735
Micronutrient status in soils can be affected by long-term fertilization and intensive cropping.A 19-year experiment (1990-2008) was carried out to investigate the influence of different fertilization regimes on micronutrients in an Aquic Inceptisol and maize and wheat grains in Zhengzhou,China.The results showed that soil total Cu and Zn markedly declined after 19 years with application of N fertilizer alone.Soil total Fe and Mn were significantly increased mainly due to atmospheric deposition.Applications... 相似文献