模拟降雨对工程建设区裸露坡地产流产沙及氮素流失的影响

为揭示不同降雨强度下工程建设区裸露坡地土壤侵蚀过程和氮素流失特征,采用人工模拟降雨的方法,研究不同降雨强度(1,1.5,2mm/min)和处理(裸地、坡面覆盖纱网)对工程裸露坡地产流产沙及氮素流失的影响。结果表明:(1)径流强度、径流含沙量、土壤剥蚀率都与降雨强度呈正相关关系,土壤入渗率与降雨强度呈现负相关关系。(2)累积泥沙量与累积径流量在裸地处理中呈现线性函数关系,在纱网处理中呈现幂函数关系。(3)地表径流中氮素流失浓度随降雨历时呈现"下降—稳定"趋势,氮素流失量随降雨强度的增加而增大,其中NO_3~-—N流失量占总氮比重高于NH_4~+—N。(4)土壤坡面覆盖纱网后能有效控制水土流失量和氮素流失量,其中径流量和NO_3~-—N流失量在小雨强处降低效果显著,分别降低了60.21%和56.74%;TN流失量和NH_4~+—N流失量在小、中雨强处降低效果较好,均达到59.26%以上;侵蚀泥沙量在小、中、大雨强处均降低了79%以上。说明土壤坡面覆盖纱网这一措施对降低工程建设区裸露坡地土壤侵蚀量和氮素流失量具有效果显著,可以作为工程建设区水土流失防止措施。     

苎麻纤维／棉变弹竹节纱的生产实践及工艺研究

结合对FA502型细纱机进行改造，采用瞬时改变中后罗拉速度的装置，通过生产实践和工艺试验，分析了纤维性能、纺纱工艺等因素对苎麻纤维／棉变弹竹节纱质量的影响，探讨了生产变弹竹节纱的工艺措施。     

混合学习模式在中职《计算机网络课程》的应用

以中职学校计算机网络课程为例,提出当前计算机网络课程的局限性,将混合学习模式引入计算机网络课程中,采取多种先进的教学手段和方法相混合的策略,从而达到更好的教学效果。     

花式线生产工艺研究

主要阐述了花式线的形成原理和加工工艺,运用ＦＢ７６２型（毛型）花式捻线机试制结子线,圈圈线的工艺要点,并列举了工艺实例,总结了直接影响花式线效果的９个因素。     

Effects of twisting parameters on characteristics of rotor-spun composite yarns with spandex

Spandex fibers have superior stretch and elastic recovery ability. Composite yarns containing spandex are frequently used to manufacture elastic textile products and accessories. We have developed a composite yarn spinning system that produces different kinds of composite yarns containing spandex on a modified open-end rotor spinning frame. By changing the twisting parameter of composite yarns, we studied the structure and properties of rotor-spun composite yarns with spandex. The results indicate that the twisting parameter has great influence on the structure and properties of rotor-spun composite yarns with spandex. The linear density of spandex filament has influence on the properties of composite yarns too. In comparison with normal rotor-spun yarn, the appearance of composite yarns is clearer, the structure is much tighter, and the properties are improved.     

Theoretic analysis on the manufacture of blended yarn by one spinneret

The possibility of producing blended yarn by using one spinneret is analyzed theoretically, especially the formation of differences in linear density and shrinkage between the monofils. Under the same spinning pressure, the die-spinning nozzles with different diameters are used to produce the differences in the flow of the melt. According to the hagen-poseuille equation for streamline flow in cylinder pipe, the volumetric flow rate and the mean melt speed of die-spinning nozzles increase with the increase of diameters. Under the conditions that the winding speeds are the same, so that the effective draw ratios decrease with the increase of the die-spinning nozzles diameters. Then, the filament formed through the die-spinning nozzle with large diameter is coarse and have a low birefringence. On the contrary, the filament formed through the die-spinning nozzle with small diameter is fine and have a high birefringence. The differences between the filament in structure and property could be acquired by one spinneret.     

A theoretical investigation on the generation of strength in staple yarns

In this article, an attempt has been made to explain the failure mechanism of spun yarns. The mechanism includes the aspects of generation and distribution of forces on a fibre under the tensile loading of a yarn, the free body diagram of forces, the conditions for gripping and slipping of a fibre, and the initiation, propagation, and ultimate yarn rupture in its weakest link. A simple mathematical model for the tenacity of spun yarns has been proposed. The model is based on the translation of fibre bundle tenacity into the yarn tenacity.     

基于混合式学习模式的《Photoshop图形图像处理》教学设计

混合式学习整合了传统课堂学习和网络学习的优势,能有效提高教育教学质量。本文针对《Photoshop图形图像处理》课程教学中存在的问题,对课程进行了混合式学习设计。     

传感器课程的混合式教学模式新探

随着教学信息化技术的迅猛发展,混合式教学已成为教育领域的必然发展趋势。将混合式教学理念引入到传感器课程教学中,设计了基于线上和线下学习的混合式教学模式。从教学内容、教学形式、在线学习资源及教学评价四个方面进行设计,将现代信息技术深度融合到传感器课程教学中去。教学效果表明,该模式能够一改传统课程教学的弊端,通过理论知识和实践项目的整合,培养了学生自主学习、自主探究能力,极大地提高课程教学效果及学生学习兴趣。     

文学文本的读者推导模型初探

从语言学角度来说,文学文本也属于“话语”,但在解读文学文木的过程中,主要是“受话人”(读者)根据文本进行推理,因此是典型的单向语境推导。本文拟根据文学文木的认知语境,构建文学文木的读者推导模型,讨论进行该推导的理据及其优势所在。