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51.
文章在阐述城市空间发展理论的基础上,分析了城市空间不平衡发展的规律,对我国西部大开发战略进行了反思,提出了发展我国不发达地区的思路。 相似文献
52.
张甬泉 《地下空间与工程学报》1992,(1)
在某地下建筑房间内进行一次试验以了解地下空间中负离子对人员的影响。试验中采用脑电、主观感觉调查和脉膊、血压以及智力测试方法。从试验结果统计分析后得到,由于负离子缺乏,人员脑电显示出α波减低,δ、θ波升高,且人员的精神感觉也有一些不良影响,可见这就是长期在地下工作人员感到压抑、烦恼、胸闷、疲乏的原因之一。用人工负离子可以改善这一状态,其离子浓度大约控制在2400~10000个/cm~3范围内。 相似文献
53.
根据电量输出传感器测量物理量的范围,平分二段,分别建立拟合回归方程,并用电路实现之.这种线性处理方法具有通用性.以K型热电偶传感器为实验例子,未经线性处理前,理论线性度为3.2%,线性处理后,理论线性度为0.015%.测量数据标准差为0.00138.结果表明,该方法测量效果良好. 相似文献
54.
Cationic microgel emulsion with a high solid content by a multistep addition method in inverse microemulsion polymerization 下载免费PDF全文
The multistep addition of a monomer and initiator was developed to successfully synthesize cationic polyacrylamide microgels with solid contents (SCs) greater than 35% and cationic monomer concentrations of 0–40 mol % by inverse microemulsion polymerization. Two feed methods, three‐step nonuniform addition and five‐step uniform addition, were implemented to obtain microgel emulsions with 37% SC. The former addition method was designed according to the solubilization limit of the microemulsion before step polymerization, and that of the latter was a constant based on the remaining surfactant weight in the reactor. The product properties in the intermediate processes of these two methods were compared by dynamic light scattering and viscosity measurement. The results show that the products here were translucent microemulsions instead of milky ones when they were synthesized by a semicontinuous polymerization. Also, the particle sizes of these two methods were almost the same; this indicated that the oscillation phenomenon in continuous polymerization at a high SC was avoided. With the former feed method, the risk and operation cost in the synthesis process could be cut down greatly. Moreover, the viscosity of the cationic microgel emulsion conformed to the Krieger–Dougherty equation with a greater value of intrinsic viscosity than that of a hard‐sphere system because of an electroviscous effect. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40585. 相似文献
55.
常用预应力锚索的结构和特点 总被引:3,自引:0,他引:3
3.2施工中要注意的问题 3.2.1锚固段钢绞线的清洗拉力型锚索的拉力是依赖钢绞线与注浆体的粘结力经由注浆体传递给孔周的岩体,因此,锚固段钢绞上的油脂必须清洗干净。钢绞线上的防锈脂已渗入7根钢丝的内部空间,不能只清洗表面,必须把钢绞线散开,7根钢丝分别洗干净后再复原。这样做很麻烦,仅适用于锚索量小的工程。对于大型边坡工程,宜采用在封闭容器内用90℃以上高温水喷射清洗,这种方法不用散开钢绞线而且洗得干净; 相似文献
56.
Francisco Rey-García María T. Flores-Arias Luis C. Estepa Wilfried Assenmacher Werner Mader German F. de la Fuente 《International Journal of Applied Glass Science》2017,8(3):329-336
This study presents a Laser Zone Melting method with potential for producing planar waveguides at large scale, based on the surface coupling of two chemically compatible glass layers which exhibit distinct indices of refraction. The method is based on a recent patent, particularly applicable to process glass and ceramics with low thermal shock resistance. Glass coatings containing 76.24% by weight PbO are thus here reported, as obtained by this method on commercial soda-lime planar glass substrates. Their higher indices of refraction (1.58 vs 1.52 for commercial soda-lime glass) result in attractive waveguiding potential, as demonstrated with measurements using focused light from a He-Ne laser beam. Scanning and transmission electron microscopy studies reveal excellent integration and compatibility between the observed coatings and substrates, where diffusion in the proximity of the interface was studied by EDS analysis. Crystalline phases have not been found within the coating, or within the substrate, as concluded from the absence of Bragg-peaks in XRD experiments. 相似文献
57.
《Food Control》2017
The aim of this study was to investigate the effects of high pressure processing (HPP) and slightly acidic electrolysed water (SAEW) on the structure of B. cereus spores in order to understand the inactivation mechanism. The physiological response of spores was studied by scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), dipicolinic acid (DPA) release, super-resolution multiphoton confocal microscope (SMCM), and flow cytometry (FCM). The morphology of B. cereus spores treated with HPP-SAEW exhibited a large fraction damage, and also an incomplete exosporium. Furthermore, spores treated with HPP-SAEW had an irregular surface bumps, and even a critical distortion. Approximately 90% of DPA was released in the groups of treated by HPP-SAEW, and 80% of DPA was released in single HPP treatment groups. The SMCM and FCM results indicated that HPP-SAEW methods was not mainly depended on germination, but directly killed. The mechanism of HPP-SAEW possibly was that one of the proteins was particularly susceptible to SAEW under HPP conditions. 相似文献
58.
本文在对建筑内部分隔防火设计进行探讨研究时,着重从分隔设计的原理和必要性出发,探讨分析了分隔设计在建筑内部防火设计中的应用,并总结了分隔设计在防火中的优缺点。 相似文献
59.
本文通过对陕南镇安县西凤村部分农宅调研的信息和测量数据进行的分析和总结,对当地农建设提出了科学合理的指导性意见。 相似文献
60.
问津书院是湖北省现存最完整的书院之一。本文以问津书院为研究对象,力图通过对其遗存的建筑群落进行详细剖析,以明了华夏传统的建筑文化的具体体现,为今后的建筑创作工作提供一些有益的借鉴。 相似文献