全部評論(1條)
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- 爵栗 2018-06-19 00:00:00
- 可以很明確的斷定是和田玉沒有任何問題，但是這個玉牌質量不是特別好，肉質疏松，還有棉點，工藝也一般，唯獨白度挺好的，交流味aijiao0712確定和田玉。
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熱門問答
- 請問一下董雨高手這是不是和田玉？
2018-06-18 01:49:19
437
1
- 請問一下，這是什么轉接頭
- 請問一下，這是什么轉接頭我的電腦接頭是VGA，電視機的接頭是HDMI，我這個轉接頭是不是買錯了，我連接了，電視機沒有顯示桌面，電視機當顯示屏用，
2018-04-03 19:09:58
563
2
- 請問一下這是什么樹木？
2016-03-21 00:19:56
520
3
- 這是不是黃蠟石？
2018-03-10 22:54:46
503
1
- 請問一下高手，有沒有靠溫度控制的循環(huán)泵？
- 主要是用于生活水系統(tǒng)，當水溫降到一定的溫度的時候，水泵自動啟動，讓熱水循環(huán)一邊，保證每個水龍頭那里都是熱水，當溫度起來后，循環(huán)水泵停止工作。另外在電路系統(tǒng)做一套溫度控制裝... 主要是用于生活水系統(tǒng)，當水溫降到一定的溫度的時候，水泵自動啟動，讓熱水循環(huán)一邊，保證每個水龍頭那里都是熱水，當溫度起來后，循環(huán)水泵停止工作。 另外在電路系統(tǒng)做一套溫度控制裝置我知道，就是不知道目前的循環(huán)水泵有沒有可以自帶溫度控制的？不需要通過電路來控制的。因為目前的水泵有一種自動增壓泵是通過流量控制的，但是本人對水泵不是太熟悉，所以請教一下各位大俠。如果有的話是什么品牌得？ 展開
2009-12-28 19:25:21
619
4
- 請問，圖片中這是什么儀器？（不是電流表，電壓表，歐姆表）
2014-04-01 13:17:03
369
3
- 這是不是倆通減壓閥
2015-02-09 18:26:11
361
1
- 怎么鑒定這是不是隕石
2015-06-30 00:48:11
428
3
- 并聯(lián)設置的雨淋閥組，雨淋閥入口處應設置止回閥，這是為什么
2017-08-29 19:00:43
663
4
- 并聯(lián)設置的雨淋閥組，雨淋閥入口處應設置止回閥，這是為什么
2017-11-20 19:38:57
613
2
- 請問一下我的車刮雨器一轉，電壓表就滅了咋回事
2018-06-28 07:51:01
354
4
- 求高手鑒定這是什么石頭
- 如題... 如題 展開
2018-12-09 13:39:06
352
0
- 擺錘運動控制系統(tǒng)（這是賽題，我不知道如何入手，請高手指點一下）
- 一、任務：設計控制系統(tǒng)，以控制擺錘運動。一長度約為50cm的軟繩懸掛擺錘（建議重量20~50克），另一端固定在懸臂上，自然下垂。在不接觸擺錘的前提下，控制系統(tǒng)可完成起擺，并在指定振... 一、任務： 設計控制系統(tǒng)，以控制擺錘運動。 一長度約為50cm的軟繩懸掛擺錘（建議重量20~50克），另一端固定在懸臂上，自然下垂。在不接觸擺錘的前提下，控制系統(tǒng)可完成起擺，并在指定振幅θ= 40?進行擺錘運動。示意圖如右。 二、要求： 1、基本要求： （1）系統(tǒng)能夠通過鍵盤控制起擺。 （2）使擺錘達到θ范圍內進行擺錘運動，限10秒內完成穩(wěn)定運動。 （3）擺錘到達A、B點的擺幅誤差可以控制在±5?內。 （4）控制擺錘在擺錘運動穩(wěn)定時，可顯示擺動周期。 2、發(fā)揮部分： （1）在擺錘到達A或B點時，可以發(fā)出聲音提示。 （2）在人為干擾軟繩運動后，可以在8秒內恢復穩(wěn)定擺錘運動。 （3）能夠通過鍵盤改變擺動頻率，實現(xiàn)相應穩(wěn)定運動，并顯示實際周期。 （4）其他。 展開
2006-09-27 04:19:48
440
2
- 英語高手幫忙翻譯一下
- 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. 展開
2009-09-17 10:19:02
583
2
- 50分！高手幫忙翻譯一下
- 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. 畢業(yè)設計急用，望高手幫忙翻譯一下 展開
2007-06-12 15:44:11
687
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- 請問一下這是什么轉接頭，一頭是vga母頭，另一頭是什么？
2016-07-31 23:05:05
447
1
- 請高手幫我翻譯一下這一段。。。
- 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. 展開
2010-01-13 13:35:43
370
1
- 請高手幫忙翻譯一下 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. 展開
2018-11-22 17:49:22
328
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