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太阳能玻璃生产中要严格控制玻璃成分中着色氧化物的含量,以提高玻璃的透光率。为此,要从多方面着手,首先要选择优质的原料,包括澄清剂;其次在原料的储存、运输加工、称量、混合过程中要尽量减少铁等金属氧化物的混入,防止原料被污染;第三对生产过程中混入的铁等要采取措施尽量除去;第四要根据高透过玻璃液的特点优化熔窑结构。 相似文献
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利用传递矩阵法对干气密封试验台转子系统进行了简化,并分段建模。对其典型单元的状态进行了数学描述,针对干气密封试验台转子自身的结构数据,在Maple中进行编程求解,获得了转子的一阶固有频率。同时基于干气密封试验台测试系统的LabView平台测试和分析,得到了干气密封试验台转子的一阶固有频率与传递矩阵法的计算结果基本吻合。这表明:用传递矩阵法计算干气密封试验台转子的固有频率是可行的,而且很接近实际情况,对今后实际工况下的干气密封系统转子的动力学分析具有重要的参考价值。 相似文献
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Foliar P concentration of slash pine was significantly related to the stand growth in the first 11.5 years. The relationship between foliar P concentration and total stand growth at foliar sampling improved as the plantation aged with coefficient of determination (R2) increasing from 0.14–0.15 at age 3.3 years to 0.56–0.65 at age 9.6 years. However, only 12–18% of the variation in total stand growth was explained by foliar P concentration at age 11.5 years when additional 40 kg P ha–1 was applied to the stands at age 10 years. This suggests that caution should be exercised in interpreting the foliar P concentrations of the established stands which had received application of P fertilizer just prior to foliar sampling. Periodic stand growth was more closely related to the foliar P concentration than total stand growth. Basal area and volume periodic annual increment (PAI) was better related to the foliar P concentration than height PAI.Optimum foliar P concentration, at which the maximum stand growth was obtained, was between 0.093% and 0.110%. The optimum foliar P concentration for height PAI immediately prior to foliar sampling decreased from 0.097% at age 3.3 years to 0.070% at age 9.6 years. Critical foliar P concentration at age 9.6 years, at which 90% of the maximum basal area growth was obtained, was between 0.066% and 0.070%. Both optimum and critical foliar P concentration might decrease as the plantation aged. 相似文献
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Qiang‐Qiang Xiao Zheng‐Xiang Huang Xu‐Dong Zu Xin Jia 《Propellants, Explosives, Pyrotechnics》2016,41(1):76-83
The penetration depth of shaped charge jet into target is strongly affected by the stand‐off. The penetration process terminates even when the jet velocity is still high, and the penetration capability of jet particles degrades after jet breakup at a large stand‐off. This work presents an analytical model to describe the radial drift velocity and distance between jet particles, which leads to decreased penetration depth. The results show that jet particles with low drift velocity impact the crater wall easily. Furthermore, the jet particles cannot reach the crater bottom to increase depth because the crater diameter generated by the jet is quite small. Moreover, the distances between jet particles also play an important role in penetration depth under the influences of strain hardening of target, as well as tumbling and dispersion of jet particles. The radial drift velocity and distance between jet particles are investigated by applying the model to non‐precision charge and precision charge penetrations into target at different stand‐offs. The cutoff jet velocity and cutoff penetration velocity also are determined based on the analytical model. With increased stand‐off, the cutoff jet velocity increases, and the cutoff penetration velocity is almost constant. This result is proven by a number of experiments. The stand‐off curves of two charges are also calculated, and results are in good agreement with experiments. The stand‐off curve can be determined with only two or three experiments using the proposed method. Notably, jet particles should have a slow drift velocity and great penetration capability after breakup for suitable shaped charge. 相似文献
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通过在料层内安装支撑板,减轻下部料层荷重,改善料层尤其是燃烧带的透气性,达到提高生产率的目的.以利用系数、转鼓强度为考察对象,通过正交实验,研究了烧结混合料水分、支撑板高度、支撑面积对利用系数、烧结矿转鼓强度的影响,应用综合分析法确定了最佳支撑结构,即支撑板高度约为料层高度的1/2,支撑面积为所支撑烧结饼面积的1.0%~1.2%.最优方案与基准实验的对比表明,应用料层减荷烧结,烧结生产率最大提高28.05%,转鼓强度下降3.75%,料层收缩减小28 mm,还原性提高0.46%. 相似文献
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陶瓷材料以其优异的耐高温?高强度?耐磨损?耐腐蚀等性能和优点被广泛应用在各个领域中。文中介绍了陶瓷成型加工技术的新方式?新特点和新进展。 相似文献
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根据画法几何学研究的理论价值及服装结构设计的特点,指出了画法几何学理论与服装结构设计相结合的必要性。通过研究立领结构设计中平面与曲面之间的几何关系,采用画法几何理论分析了立领结构,得出了立领领口线和立领的结构设计方法,为服装结构设计向信息化迈进作出了有意义的探索。 相似文献
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Fertilization at plantation establishment and later age is often required to maximize stand growth of slash pine (Pinus elliottii) in subtropical Australia. A field experiment was conducted to examine stand growth response of slash pine in the first 11.5 years of plantation following (1) initial fertilization at plantation establishment with phosphorus (P) at 11, 22, 45 and 90 kg P ha–1 which were either banded or broadcast in the presence or absence of basal fertilizers containing 50 kg nitrogen (N) ha–1, 50 kg potassium (K) ha–1 and 5 kg copper (Cu) ha–1 and (2) additional application of 40 kg P ha–1 at age 10 years.The initial P fertilization significantly increased the stand growth in the first 9.6 years. The P banded application was more effective in improving the stand growth than the P broadcast application. Application of the N, K and Cu basal fertilizers did not affect the stand growth. Overall, 53–73% of the variation in basal area and volume growth in the first 9.6 years was explained by the initial P fertilization, indicating that P deficiency was the major factor limiting the stand growth under the experimental conditions. Optimum plantation age, at which the maximum periodical annual increment (PAI) of basal area was obtained, increased from age 10.9 to 12 years when the initial P rate increased from 11 to 90 kg P ha–1. Application of additional 40 kg P ha–1 at age 10 years resulted in a further improvement in the stand growth at age 11.5 years. With 66% of the variation in basal area PAI between ages 9.6 and 11.5 years, 50% was explained by the initial P fertilization and 16% by the additional P applied at age 10 years. Similarly, 51% and 12% of the variation in volume PAI were attributed to the initial P fertilization and the additional P application, respectively. This highlights the need of refertilization with P on some established stands of slash pine at later ages. 相似文献
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介绍了双金属络合物(DMC)催化合成聚醚多元醇的催化机理,通过对国内有代表性观点的讨论与分析,并结合自身科研实践经验,研究了DMC催化体系中有机配体与活性中心的关系,对全面了解DMC催化剂的催化机理具有重要意义. 相似文献