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• 2018-12-11 13:01發(fā)布了問答

  北京哪里有賣汞的?（做試驗用）

  我需要做壓汞試驗，需要買汞，不知北京哪里有賣的，要分析純。謝謝！... 我需要做壓汞試驗，需要買汞，不知北京哪里有賣的，要分析純。謝謝！ 展開

  372人看過

• 2018-11-25 19:52發(fā)布了問答

  您好，請問你們有水泥比表面積測定，游離氧化鈣測定方法的視頻嗎？

  　

  433人看過

• 2018-04-15 00:07發(fā)布了問答

  龜頭，冠狀溝和包皮里面都長白色疙瘩

  　

  459人看過

• 2017-08-27 16:55發(fā)布了問答

  多孔材料作電極，比表面積與電容量有關(guān)系嗎

  　

  355人看過

• 2015-09-27 08:44發(fā)布了問答

  為什么肺泡表面張力減小可防止肺泡坍塌

  為什么肺泡表面張力減小可防止肺泡坍塌

  484人看過

• 2015-04-30 23:26發(fā)布了問答

  為什么液體的表面張力隨溫度升高而減少

  　

  928人看過

• 2014-10-17 15:20發(fā)布了問答

  液體表面張力系數(shù)怎么算

  　

  427人看過

• 2012-03-21 14:02發(fā)布了問答

  做水泥比表面積試驗視頻

  　

  411人看過

• 2006-06-12 05:02發(fā)布了問答

  有會翻譯化學(xué)的嗎

  Transmission electron microscopy (TEM) was used to identify and characterize carbon nanotubes. Specimens for TEM observation were prepared by ultra-sonicating carbon nanotubes in alcohol， then dipping a TEM sample grid into the dispersi... Transmission electron microscopy (TEM) was used to identify and characterize carbon nanotubes. Specimens for TEM observation were prepared by ultra-sonicating carbon nanotubes in alcohol， then dipping a TEM sample grid into the dispersion. Nitrogen adsorption isotherms of nanotube samples were measured at 77.5 K by an ASAP 2010 volumetric sorption analyzer (Micromeritics) with addi- tional options for the micropore analysis. The volume of adsorbed nitrogen at 77.5 K was measured as a function of 25 the equilibrium pressure over a range from 10 Torr to the saturation vapor pressure. Prior to adsorption measure- ments， samples were outgassed under vacuum at 573 K for 3 h. The pore size distributions (PSD) of samples were obtained by analyzing the isotherm with BJH equation. To check any significant chemical modification， the raw and conpurified sample was analyzed by X-ray photoelectron spectroscopy (XPS)， respectively. Photoelectron spectra of samples were measured using a PHI5300 X-ray photoelec- tron spectrometer (PE Corp.) with Al Ka source. The spectra were recorded at room temperature under high vacuum. All binding energies (BE) were corrected for sample charging using the BE of C as an external 1s standard (284.6 eV). All data were analyzed with the aid of an Applle Series 3500. Thermo-gravimetric analysis (TGA) was used to determine the content of the Fe catalyst in the sample， and a CAHN2000 thermo-gravimetric analyzer was used to characterize weight loss during oxidation of the samples in air with heating to 11008C at a rate of 108C/min. 展開

  318人看過