秦绣简介(A Brief Introduction of Qin Embroidery )
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陕西古称秦,是中华文明的发祥地之一,也是中国刺绣的发源地之一。
古代秦绣是以西安、咸阳为中心的陕西地区的绣品总称,相传已有几千年的历史。
当代秦绣又名穿罗绣,是陕西地区几代艺人经过艰难探索,在继承传统刺绣和民间刺绣的基础上创作出来的一种独特的刺绣形式。绣品采用真丝丝网,真丝线、手 工刺绣,以针法变化见长。秦绣做工精细,整体格调文雅,近看花中有花,具有强烈的装饰趣味和独特的地方色彩,是中华刺绣艺术的重要组成部分。
Shaan xi Province, Known as Qin in ancient times,is one of the birthplaces of China’s civilization and Chinese embroidery.
Qin embroidery in ancient times refers to embroidery products in Shaan xi Province, with Xi’an and Xian yang as the center, and has a history of several thousand years.
Qin embroidery at present, also known as Chuan luo embroidery, is a unique craft created by craftsmen of several generations on the basis of both the traditional embroidery skill and the folk embroidery skill though their hard exploration. The products are hand-embroidery with pure silk threads and silk net in varied stitching methods. They are delicate, clear in threads, rich in stitching, thus creating a magnificent three-dimentional effect with varied brilliant veins. They are elegant in style, viewed as flower at a close range, thus having strong decorative taste and peculiar local color; therefore, they are the important in the Chinese embroidery art.
作品1 作品2 作品3 作品4
古代秦绣是以西安、咸阳为中心的陕西地区的绣品总称,相传已有几千年的历史。
当代秦绣又名穿罗绣,是陕西地区几代艺人经过艰难探索,在继承传统刺绣和民间刺绣的基础上创作出来的一种独特的刺绣形式。绣品采用真丝丝网,真丝线、手 工刺绣,以针法变化见长。秦绣做工精细,整体格调文雅,近看花中有花,具有强烈的装饰趣味和独特的地方色彩,是中华刺绣艺术的重要组成部分。
Shaan xi Province, Known as Qin in ancient times,is one of the birthplaces of China’s civilization and Chinese embroidery.
Qin embroidery in ancient times refers to embroidery products in Shaan xi Province, with Xi’an and Xian yang as the center, and has a history of several thousand years.
Qin embroidery at present, also known as Chuan luo embroidery, is a unique craft created by craftsmen of several generations on the basis of both the traditional embroidery skill and the folk embroidery skill though their hard exploration. The products are hand-embroidery with pure silk threads and silk net in varied stitching methods. They are delicate, clear in threads, rich in stitching, thus creating a magnificent three-dimentional effect with varied brilliant veins. They are elegant in style, viewed as flower at a close range, thus having strong decorative taste and peculiar local color; therefore, they are the important in the Chinese embroidery art.
作品1 作品2 作品3 作品4
工频UPS与高频UPS的性能比较,它们的价格如何
1、高频机与工频机定义
从以上的比对中可以清晰的看出工频机在很多的方面优于高频机。对于可靠性要求较高的一些重要、关键部位的电源保护方案还应以工频机为首选。
价格嘛 应该工频机高点,多个变压器 铜现在很贵 哈哈
http://zhidao.baidu.com/question/16981592.html
- 高频机:利用高频开关技术,以高频开关元件替代整流器和逆变器中的工频变压器的UPS,俗称高频机,高频机体积小、效率高。
- 工频机:采用工频变压器作为整流器与逆变器部件的UPS俗称工频机,主要特点是主功率部件稳定可靠、过负荷能力和抗冲击能力强。
- 高频机不带隔离变压器,其输出零线存在高频电流,主要来自市电电网的谐波干扰、UPS整流器和高频逆变器脉动电流、负载的谐波干扰等,其干扰电压不仅数值高而且难以消除。而工频机的输出零地电压更低,而且不存在高频分量,对于计算机网络的通信安全来讲,更加重要。
- 高频机输出没有变压器隔离,如果逆变功率器件发生短路,则直流母线(DC BUS)上的高直流电压直接加到负载上,这是安全隐患,而工频机则不存在此问题。
- 工频机的抗负载冲击能力较强
| 序号 | 比较的指标、性能 | 高频UPS | 工频UPS |
| 1 | 过载能力 | 一般 | 较强 |
| 2 | 抗输入浪涌能力 | 一般 | 较强 |
| 3 | 输出抗冲击、短路能力 | 一般 | 较强 |
| 4 | 输入PF值 | 0.99 | 0.7 |
| 5 | 整机效率 | 85~90% | 75~85% |
| 6 | 功率密度 | 高 | 小 |
| 7 | 零地电压 | 相对较差, | 有高频分量 相对较好 |
| 8 | 输出级元器件 | 多 | 少 |
| 9 | 功率器件容量 | 小 | 大 |
| 10 | 故障时器件损坏程度 | 高 | 低 |
| 11 | 可靠性 | 一般 | 好 |
| 12 | 可维护性 | 较复杂 | 简易 |
| 13 | 重量 | 轻 | 重 |
| 14 | 体积 | 小 | 大 |
| 15 | 与发电机适应力 | 较差 | 好 |
从以上的比对中可以清晰的看出工频机在很多的方面优于高频机。对于可靠性要求较高的一些重要、关键部位的电源保护方案还应以工频机为首选。
价格嘛 应该工频机高点,多个变压器 铜现在很贵 哈哈
http://zhidao.baidu.com/question/16981592.html