全部评论(1条)
-
- 爵栗 2018-06-19 00:00:00
- 可以很明确的断定是和田玉没有任何问题,但是这个玉牌质量不是特别好,肉质疏松,还有棉点,工艺也一般,唯独白度挺好的,交流味aijiao0712确定和田玉。
-
赞(15)
回复(0)
热门问答
- 请问一下董雨高手这是不是和田玉?
2018-06-18 01:49:19
415
1
- 请问一下,这是什么转接头
- 请问一下,这是什么转接头我的电脑接头是VGA,电视机的接头是HDMI,我这个转接头是不是买错了,我连接了,电视机没有显示桌面,电视机当显示屏用,
2018-04-03 19:09:58
527
2
- 请问一下这是什么树木?
2016-03-21 00:19:56
498
3
- 这是不是黄蜡石?
2018-03-10 22:54:46
470
1
- 请问一下高手,有没有靠温度控制的循环泵?
- 主要是用于生活水系统,当水温降到一定的温度的时候,水泵自动启动,让热水循环一边,保证每个水龙头那里都是热水,当温度起来后,循环水泵停止工作。另外在电路系统做一套温度控制装... 主要是用于生活水系统,当水温降到一定的温度的时候,水泵自动启动,让热水循环一边,保证每个水龙头那里都是热水,当温度起来后,循环水泵停止工作。 另外在电路系统做一套温度控制装置我知道,就是不知道目前的循环水泵有没有可以自带温度控制的?不需要通过电路来控制的。因为目前的水泵有一种自动增压泵是通过流量控制的,但是本人对水泵不是太熟悉,所以请教一下各位大侠。如果有的话是什么品牌得? 展开
2009-12-28 19:25:21
593
4
- 请问,图片中这是什么仪器?(不是电流表,电压表,欧姆表)
2014-04-01 13:17:03
344
3
- 这是不是俩通减压阀
2015-02-09 18:26:11
336
1
- 怎么鉴定这是不是陨石
2015-06-30 00:48:11
395
3
- 并联设置的雨淋阀组,雨淋阀入口处应设置止回阀,这是为什么
2017-08-29 19:00:43
628
4
- 并联设置的雨淋阀组,雨淋阀入口处应设置止回阀,这是为什么
2017-11-20 19:38:57
588
2
- 请问一下我的车刮雨器一转,电压表就灭了咋回事
2018-06-28 07:51:01
333
4
- 求高手鉴定这是什么石头
- 如题... 如题 展开
2018-12-09 13:39:06
328
0
- 摆锤运动控制系统(这是赛题,我不知道如何入手,请高手指点一下)
- 一、任务:设计控制系统,以控制摆锤运动。一长度约为50cm的软绳悬挂摆锤(建议重量20~50克),另一端固定在悬臂上,自然下垂。在不接触摆锤的前提下,控制系统可完成起摆,并在指定振... 一、任务: 设计控制系统,以控制摆锤运动。 一长度约为50cm的软绳悬挂摆锤(建议重量20~50克),另一端固定在悬臂上,自然下垂。在不接触摆锤的前提下,控制系统可完成起摆,并在指定振幅θ= 40˚进行摆锤运动。示意图如右。 二、要求: 1、基本要求: (1)系统能够通过键盘控制起摆。 (2)使摆锤达到θ范围内进行摆锤运动,限10秒内完成稳定运动。 (3)摆锤到达A、B点的摆幅误差可以控制在±5˚内。 (4)控制摆锤在摆锤运动稳定时,可显示摆动周期。 2、发挥部分: (1)在摆锤到达A或B点时,可以发出声音提示。 (2)在人为干扰软绳运动后,可以在8秒内恢复稳定摆锤运动。 (3)能够通过键盘改变摆动频率,实现相应稳定运动,并显示实际周期。 (4)其他。 展开
2006-09-27 04:19:48
420
2
- 英语高手帮忙翻译一下
- ThequalitysystemofthecompanyisinconformitywithISO9002.Makingcomprehensiveuseofbiotechnology,thecompanyspecializesinmanufacturingandsellingC-4seriesorganicacidsandchiralpr... The quality system of the company is in conformity with ISO 9002 . Making comprehensive use ofbiotechnology, the company specializes in manufacturing and selling C-4series organic acids and chiral products. These products are widely used in many fields such as food, phamaceutical and chemical industries, and are well accepted by the overseas markets. The man products are L-Malic acid , DL-Malic acid, L(+)-Tartaric acid , Fumaric acid, Maleic acid and other organic acids. Annual productivity amounts to 20,000 tones. The company has become an important manufacturer of C-4 series organic acids in the world . All the products of the company have respectively met the different international aadvanced standards such as Food chemicals Codex, U.S. Pharmacopoeia ,British Pharmacopoeia and the products have obtained Star-K Kosher certificate. Above 70% of the Companys products are exported to Japan, Europe, Australias, the United states and middle East , and they are renown and well recognized in the international markets. The company will devote itself to research and development of enzyme technology and organic electrochemistry. It will continuously introduce new food additives, chiral pharmaceutical intermediates, chiral auxiliaries and chiral drugs. Depending on superior quality, good service and high reputation, the company is willing to establish a long-term mutually beneficial business partnership with overseas customers and continue contribute to the happy life of humans. 展开
2009-09-17 10:19:02
555
2
- 50分!高手帮忙翻译一下
- LabVIEWisapowerfulandcomplexprogrammingenvironment.LabVIEWisshortforLaboratoryVirtualInstrumentEngineeringWorkbench.Itisapowerfulandflexibleinstrumentationandanalysissoft... LabVIEW is a powerful and complex programming environment. LabVIEW is short for Laboratory Virtual Instrument Engineering Workbench. It is a powerful and flexible instrumentation and analysis software development application created by the folks at National Instruments—a company that creates hardware and software products that leverage computer technology to help engineers and scientists take measurements, control processes, and analyze and storem data. National Instruments was founded over twenty-five years ago in Austin, Texas by James Truchard (known as Dr. T), Jeffrey Kodosky, and William Nowlin. At the time, all three men were working on sonar applications for the U.S. Navy at the Applied Research Laboratories at The University of Texas at Austin. Searching for a way to connect test equipment to DEC PDP-11 computers, Dr. T decided to develop an interface bus. He recruited Jeff and Bill to join him in his endeavor, and together they successfully developed LabVIEW and the notion of a “virtual instrument.” In the process they managed to infuse their new company—National Instruments—with an entrepreneurial spirit that still pervades the company today. Engineers and scientists in research, development, production, test, and service industries as diverse as automotive, semiconductor, aerospace, electronics, chemical, telecommunications, and pharmaceutical have used and continue touse LabVIEW to support their work. LabVIEW is a major player in the area of testing and measurements, industrial automation, and data analysis. For example, scientists at NASA’s Jet Propulsion Laboratory used LabVIEW to analyze and display Mars Pathfinder Sojourner rover engineering data, including the position and temperature of the rover, how much power remained in the rover’s battery, and generally to monitor Sojourner’s overall health. LabVIEW provides an extensive library of virtual instruments and functions to help you in your programming. It includes conventional program debugging tools with which you can set breakpoints, single-step through the program, and animate the execution so you can observe the flow of data. 毕业设计急用,望高手帮忙翻译一下 展开
2007-06-12 15:44:11
649
2
- 请问一下这是什么转接头,一头是vga母头,另一头是什么?
2016-07-31 23:05:05
419
1
- 请高手帮我翻译一下这一段。。。
- Carbonnanomaterialsarenovelmanufacturedmaterials,havingwidespreadpotentialapplications.Adsorptionofhydrophobicorganiccompounds(HOCs)bycarbonnanomaterialsmayenhancetheirto... Carbon nanomaterials are novel manufactured materials, having widespread potential applications. Adsorption of hydrophobic organic compounds (HOCs) by carbon nanomaterials may enhance their toxicity and affect the fate, transformation, and transport of HOCs in the environment. In this research, adsorption of naphthalene, phenanthrene, and pyrene onto six carbon nanomaterials, including fullerenes, single-walled carbon nanotubes , and multiwalled carbon nanotubes was investigated, which is the first systematic study on polycyclic aromatic hydrocarbons (PAHs) sorption by various carbon nanomaterials. All adsorption isotherms were nonlinear and were fitted well by the Polanyi-Manes model (PMM). Through both isotherm modeling and constructing “characteristic curve”, Polanyi theory was useful to describe the adsorption process of PAHs by the carbon nanomaterials. The three fitted parameters (Q0, a, and b) of PMM depended on both PAH properties and the nature of carbon nanomaterials. For different PAHs, adsorption seems to relate with their molecular size, i.e., the larger the molecular size, the lower the adsorbed volume capacity (Q0), but higher a and b values. For different carbon nanomaterials, adsorption seems to relate with their surface area, micropore volume, and the volume ratios of mesopore to micropore. Quantitative relationships between these sorbent properties and the estimated parameters of PMM were obtained. These relationships may represent a first fundamental step toward establishing empirical equations for quantitative prediction of PAH adsorption by carbon nanomaterials and possibly other forms of carbonaceous (geo-) sorbents, and for evaluating their environmental impact. In addition, high adsorption capacity of PAHs by carbon nanotubes may add to their high environmental risks once released to the environment, and result in potential alteration of PAHs fate and bioavailability in the environment. 展开
2010-01-13 13:35:43
341
1
- 请高手帮忙翻译一下 3
- 2.2.1. Physical and physicochemical characterization The particle size distribution of the Ch-zeolite was determined using a laser diffraction equipment (CILASk 1064) and standard wet sieving (Mesh Tylerk series). Scanning electron mic... 2.2.1. Physical and physicochemical characterization The particle size distribution of the Ch-zeolite was determined using a laser diffraction equipment (CILASk 1064) and standard wet sieving (Mesh Tylerk series). Scanning electron microscopy (SEM-PHILIPSk XL20) was used for photomicrographs as well as to analyse the Ch-zeolite composition (Energy Dispersion X-ray, EDX). The sample was initially placed in a vacuum chamber for coating with a thin layer (few nanometers) of gold (Au). The specific surface area of the material was measured by the methylene blue technique and by nitrogen gas adsorption methods, with the latter also providing information about particle porosity. In the methylene blue adsorption method, aqueous solutions (50 ml) of methylene blue (100 mg l 1) were agitated using an orbital shaker (Marconik) for an hour at room temperature in the presence of different quantities of the Ch-zeolite (0.05–0.3 g). The suspensions were then allowed to settle for 23 h and the resulting supernatants were centrifuged at 5000 rpm before the analysis of the residual methylene blue concentration. Results obtained correspond to averaged values of three different experiments. The specific surface area was evaluated by the Langmuir model, assuming the formation, at high concentrations, of a dye monolayer and 1.08 nm2 molecule 1, for the cross-sectional area (Van den Hul and Lyklema, 1968). The Ch-zeolite specific surface area was evaluated by the nitrogen gas adsorption method, using automated equipment (Autosorb 1-Quantachrome Instrumentsk), employing multipoint BET isotherm adsorption data fitting. Also from these data, the porosity of the material was evaluated through parameters such as volume of total pores (d < 206 nm), surface area and volume of micropores (d < 2 nm; Micropore Analysis Method). Zeta potential measurements for the natural and ammonia loaded zeolite, as a function of medium pH, were determined using a Zeta Plusk equipment (Brookhaven Instruments). Suspensions (0.01% v/v) of the Ch-zeolite, previously sieved below 37 Am (400 Mesh Tylerk), in a 10 3 mol l 1 solution of KNO3 were used and the medium pH was controlled with the addition of HNO3 (pH< 7) and KOH (pH>7), separately. For the Ch-zeolite saturated with ammonia, suspensions of the material were prepared by the same procedure, except that the sample was loaded with 100 mg NH3–N l 1 of ammonia. 展开
2018-11-22 17:49:22
284
0
12月突出贡献榜
推荐主页
最新话题
-
- #八一建军节——科技铸盾,仪器护航#
- 如何选择到合适的磷青铜绞线?磷青铜绞线的质量...如何选择到合适的磷青铜绞线?磷青铜绞线的质量解析和如何选择到合适的绞线?磷青铜绞线是一种特殊的铜合金导线,由铜、锡和磷等元素组成,具有很好的机械性能、电气性能和耐腐蚀性。磷青铜绞线基本定义与特性:磷青铜是铜与锡、磷的合金,质地坚硬,可制弹簧。典型成分为铜(90%)、锡(6-9%)及磷(0.03-0.6%)锡元素提升合金的强度和耐腐蚀性,磷则细化晶粒、增强耐磨性铸造性能。耐磨性:表面氧化层使其在特殊环境下耐腐蚀,使用寿命长导电性:保持铜很好导电性能的同时有化电子传输路径非铁磁性:不含铁元素,避免在强磁场环境中产生额外能量损耗弹性:受到外力作用时能迅速恢复原状
- 八一建军节 铁血铸军魂













参与评论
登录后参与评论