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171.
《马关条约》签订后,西方列强在华侵略的主要手段由最初倾销商品、掠夺原料转为开矿设厂自主经营。它使清末中国之多数矿藏被列强霸占,导致经济利益受损。而此时的英国,通过一系列事件逐步剥夺了山西开采矿山的权利,该阶段前后持续数年,其影响大、范围广,对近代山西历史的发展走向造成了不可估量的影响。 相似文献
172.
对党务信息管理系统进行需求分析,提出了系统开发的三层体系结构,并对该系统的功能模块进行详细设计.高校党务工作要引进先进的信息化科学技术和现代化管理方法,开发党务信息管理系统至关重要. 相似文献
173.
He XL Yin HL Wu J Zhang K Liu Y Yuan T Rao HL Li L Yang G Zhang XM 《Journal of Zhejiang University. Science. B》2011,12(1):32-39
Radiation therapy has been widely applied in cancer treatment. However, it often causes thrombocytopenia (deficiency of white
blood cells) as an adverse effect. Recombinant human interleukin-6 (rhIL-6) has been found to be a very effective way against
this thrombocytopenia, but IL-6 has low stability in blood, which reduces its efficacy. To increases the stability and half-life
of rhIL-6, it was modified by polyethylene glycol (PEG). The pharmacokinetics and the tissue distribution of PEG-rhIL-6 labeled
with 125I were examined after subcutaneous injection in rats. The pharmacokinetic pattern of PEG-rhIL-6 was defined with linear-kinetics,
and we fitted a one-compartment model with half-lives of 10.44–11.37 h (absorption, t
1/2K
a) and 19.77–21.53 h (elimination, t
1/2Ke), and peak concentrations at 20.51–21.96 h (t
peak) in rats. Half-lives and t
peak of PEG-rhIL-6 were longer than those of rhIL-6 previously reported. In the present study, for deposition of PEG-rhIL-6 in
rats, the tissue distribution examination showed that blood was the major organ involved, rather than liver. However, as to
the elimination of PEG-rhIL-6, the major organ was the kidney. The excretion fraction of the injection dose recovered from
urine was 23.32% at 192 h after subcutaneous administration. Less than 6% of PEG-rhIL-6 was eliminated via the feces at 192
h. These results indicate that PEG-rhIL-6 is a good candidate drug formulation for patients with cancer. 相似文献
174.
Gas-liquid coupling oscillation is a novel approach to reducing the resonant frequency and to elevating the pressure amplitude
of a thermoacoustic engine. If a thermoacoustic engine is used to drive low-frequency pulse tube refrigerators, the frequency
matching between the thermoacoustic engine and the refrigerator plays an important role. Based on an acoustic-electric analogy,
a lumped parameter model is proposed to estimate the resonant frequency of a standing-wave thermoacoustic engine with gas-liquid
coupling oscillation. Furthermore, a simplified lumped parameter model is also developed to reduce the computation complexity.
The resonant frequency dependence on the mean pressure, the gas space volume, and the water column length is computed and
analyzed. The impact of different working gases on the resonant frequency is also discussed. The effectiveness of the models
is validated by comparing the computed results with the experimental data of the gas-liquid coupling oscillation system. An
increase in the mean working pressure can lead to a rise in the resonant frequency, and a lower resonant frequency can be
achieved by elongating the liquid column. In comparison with nitrogen and argon, carbon dioxide can realize a lower frequency
due to a smaller specific heat ratio. 相似文献
175.
How to obtain an accurate support for large components by ball joint is a key process in aircraft digital assembly. A novel
principle and device is developed to solve the problem. Firstly, the working principle of the device is introduced. When three
or four displacement sensors installed in the localizer are touched by the ball-head, the spatial relation is calculated between
the large aircraft component’s ball-head and the localizer’s ball-socket. The localizer is driven to achieve a new position
by compensation. Relatively, a support revising algorithm is proposed. The localizer’s ball-socket approaches the ball-head
based on the displacement sensors. According to the points selected from its spherical surface, the coordinates of ball-head
spherical center are computed by geometry. Finally, as a typical application, the device is used to conduct a test-fuselage’s
ball-head into a localizer’s ball-socket. Positional deviations of the spherical centers between the ball-head and the ball-socket
in the x, y, and z directions are all controlled within ±0.05 mm under various working conditions. The results of the experiments show that
the device has the characteristics of high precision, excellent stability, strong operability, and great potential to be applied
widely in the modern aircraft industry. 相似文献
176.
177.
文章针对管路的低频线谱和三向振动传递的特点,设计了一种新型悬臂梁式动力吸振器结构。基于梁的波动理论和结构阻抗分析法,推导了吸振器插入损失计算公式。通过参数分析获得了吸振器质量、弹簧片尺寸与其减振效果之间的定量关系。试验结果表明,该文提出的吸振器设计方法和吸振器结构能够达到预期的减振效果。 相似文献
178.
普通高校开展国防教育已有近30年的历史。近30年来,国防教育在高校人才培养方面虽取得了显著成绩,但新形势下仍面临着严峻的生存与发展困境。唯有坚持以"总体国家安全观"为指导,重新定位高等院校国防教育的目标和发展导向,增设"非传统安全"和"内部安全"的教学内容,开展研究性教学模式,实施"军事院校与地方高校相配合、技能训练与思想浸润相结合、传统科目与特色项目相融合"的军训模式,高校国防教育方能走出困境、破解难题,迎来崭新的明天。 相似文献
179.
自1985年开展学生军训试点以来,我国高校国防教育已走过30年的历程.经过初步探索期、全面发展期两个阶段,高校国防教育工作取得了一定成绩,积累了宝贵的经验.对其发展历程、主要成就、历史经验、当前困境等问题进行总结与分析,有助于进一步推进高校国防教育工作的科学发展. 相似文献
180.
沈克 《湖州师范学院学报》2015,(2):95-99
通过研究绿色旅游的概念,分析河南省绿色旅游的发展现状,提出河南省发展绿色旅游的对策,从而为河南省实施旅游业转型升级,实现美丽河南提供智力支持. 相似文献