- 哪位師傅了解PPCO塑料物性的？幫幫忙！
-
2011-07-07 21:29:54
598
1
- 哪位大俠了解表面張力儀
-
2018-12-05 15:02:33
418
0
- 求翻譯，哪位好心人，幫幫忙！萬(wàn)分感謝
- This work was supported by Science Foundation Ireland (PIYRA 07/YI2/I1052). The authors acknowledge the European Commission under framework 7 (PERG-GA-2009-249178)， IRCSET and Intel (postdoctoral fellowship to IK and post-graduate scholarsh... This work was supported by Science Foundation Ireland (PIYRA 07/YI2/I1052). The authors acknowledge the European Commission under framework 7 (PERG-GA-2009-249178)， IRCSET and Intel (postdoctoral fellowship to IK and post-graduate scholarship to EDC) for support. We thank Dr Tatiana Perova for granting access to Micro-Raman spectrometer， Dr Daniel Heller (MIT) for fruitful discussions， Dania Movia for technical support. 展開
2013-05-03 02:56:42
528
2
- 四川省內(nèi)有沒(méi)有招聘塑料擠出機(jī)師傅
- 四川省內(nèi)有沒(méi)有招聘塑料擠出機(jī)師傅
2016-03-15 15:27:50
345
2
- 哪位大俠有CATIA工程圖國(guó)標(biāo)圖框，幫幫忙！
-
2014-08-01 16:35:04
307
1
- 哪位了解手持測(cè)距儀什么牌子好
-
2017-07-12 20:18:03
492
1
- 哪位朋友了解變頻空調(diào)有多省電
-
2018-06-20 06:48:03
474
1
- 有誰(shuí)了解德國(guó)勇士砂紙，知道的請(qǐng)幫幫忙。急需！
- 有誰(shuí)了解德國(guó)勇士砂紙的真假，2500號(hào)的里面顏色不均勻是不是假貨，有時(shí)候紙張要軟一些，有時(shí)候紙張要硬一些是怎么回事??？請(qǐng)各位知道的幫個(gè)忙吧。謝謝了
2015-08-13 08:55:44
575
1
- 哪位了解gsp藥品陳列柜的溫度為多少
-
2017-11-02 14:42:45
596
1
- 哪位英語(yǔ)高手幫幫忙，翻譯英語(yǔ)文章！謝謝1
- 英語(yǔ)高手，謝謝了！ThecatalystsupportwasimpregnatedwithacetonesolutionofRuCl3.nH2Ouptorutheniumcontentof4w%，understirringfor6h.Afterconcentrationinarotaryevaporator，theobt... 英語(yǔ)高手，謝謝了！
The catalyst support was impregnated with acetone solution of RuCl3.nH2O up to ruthenium content of 4 w%， under stirring for 6 h. After concentration in a rotary evaporator， the
obtained material was dried in air at 383 K overnight and subjected to preliminary reduction with a 1N2/3H2 stream at 698 K， and then cooled in 1N2/3H2 atmosphere. The potassium promoter was introduced by incipient wet impregnation with KNO3 solution at room temperature with molar ratio of K+ /Ru = 5/1. After stirring for 6 h and infusing for 24 h， the samples were dried in a rotary evaporator at 343K and then dried in the air
at 383K for 12 h. The ammonia synthesis activities of the catalysts with about 35-60 meshes were evaluated by 1N2/3H2 flow of 2100 mL/h at 0.2 MPa from 623 K to 773 K. The
amount of effluent ammonia was determined by titration method.
As we can see from the Table 1， under the same reaction conditions， the catalyst K-Ru/Mg(Al)O exhibited the highest activity， 38.42 mL NH3?h-1?g-1 at 673K， 3 times
more active than K-Ru/MgO， 12.88 mL NH3?h-1?g-1 at 748K. This means that selection of supports takes great effects on the activity of catalysts. The ammonia synthesis activity of
different supports are K-Ru/Mg(Al)O > K-Ru/Mg-Al-Ca(1) > K-Ru/Mg-Al-Ca(2) > K-Ru/Al2O3 > K-Ru/CaO > K-Ru/MgO. The combinatorial supports showed higher activity than single
supports. However， the sequence of temperature corresponding to the highest activity is just opposite to that of the activity. The optimal temperature for K-Ru/Mg(Al)O， 673K， is
the lowest of all， on the contrary， that of K-Ru/MgO is the highest， 748K. The Mg(Al)O has a larger surface area of 140.95 m2?g-1 ， similar to γ-Al2O3， 110-180 m2?g-1 . The other
two combinational supports have little surface areas but higher activities than Al2O3. It suggested that the activity of the catalyst is influenced not only by the dispersion of Ru
crystals but also by the crystal structure of the supports.
Table 1 Ammonia synthesis activities and BET surface areas
Catalyst Optimal activity Highest activity Surface area of support
temperature(K) (NH3/mL?h-1?g-1) (m2?g-1)
K-Ru/MgO 748 12.88
K-Ru/Al2O3 698 23.79
K-Ru/CaO 723 23.22
K-Ru/Mg(Al)O 673 38.42 140.95
K-Ru/Mg-Al-Ca(1) 698 30.75 29.10
K-Ru/Mg-Al-Ca(2) 698 26.12 14.69
Acknowledgments
This work was supported by the NNSF of China (20273053， 20023001 and 29933040)， the 973
Programming (001CB108906) and the NSF of Fujian province (E0310001).
References
1. C. J. H. Jacobsen， S. Dahl， P. L. Hansen et al.， J. Mol. Catal. A， 2000， 163， 19.
2. F. Cavani， F. Trifiro， A. Vaccari， Catal. Today， 1991， 11， 173. 展開
2018-11-14 18:00:49
318
0
- 會(huì)了解光學(xué)加工零件圖指標(biāo)的請(qǐng)幫幫忙。
- 光學(xué)零件圖中有一個(gè)指標(biāo)是（面形：L/2@633nm)。面形為什么要“L/2@633nm”這樣表示啊？有L/4@633nm、L/8@633nm.為什么沒(méi)有L/5@633nm?還有波長(zhǎng)633nm能改成其它如532nm嗎？叩謝叩謝了。
（關(guān)健關(guān)：相干光，干涉，衍射，光波）
2010-07-22 00:30:02
546
2
- 請(qǐng)問(wèn)哪位有云南大理洱源衣架安裝師傅電話？
-
2018-11-27 23:15:24
336
0
- LED燈 驅(qū)動(dòng)電源哪位師傅幫我分析一下故障？
- LED燈 驅(qū)動(dòng)電源哪位師傅幫我分析一下故障？上電后led燈亮一段時(shí)間后閃爍，閃過(guò)之后燈變成微亮。檢查了led燈珠都是好的。問(wèn)題在于電源…上電后電源出現(xiàn)噪音當(dāng)led燈閃爍或微亮?xí)r電壓會(huì)下降到幾十伏。導(dǎo)致燈微亮或不亮，這個(gè)燈是功率45w 電壓135v，經(jīng)檢查發(fā)現(xiàn)這... LED燈 驅(qū)動(dòng)電源哪位師傅幫我分析一下故障？上電后led燈亮一段時(shí)間后閃爍，閃過(guò)之后燈變成微亮。檢查了led燈珠都是好的。問(wèn)題在于電源…上電后電源出現(xiàn)噪音當(dāng)led燈閃爍或微亮?xí)r電壓會(huì)下降到幾十伏。導(dǎo)致燈微亮或不亮，這個(gè)燈是功率45w 電壓135v，經(jīng)檢查發(fā)現(xiàn)這個(gè)變壓器式電感出現(xiàn)磁飽和導(dǎo)致燈發(fā)光不正常。我的問(wèn)題是要修這個(gè)驅(qū)動(dòng)，這個(gè)電感又沒(méi)燒掉，如果換新的電感有用嗎？應(yīng)該怎么修復(fù)？還是不能修了。
展開
2017-11-14 04:35:04
556
2
- 哪位電工師傅幫我看下這個(gè)水泵的電路應(yīng)該怎么接
- 有臺(tái)220v的普通潛水泵，要兩家用，但是還要各走各家的電表，還要用兩個(gè)開關(guān)去控制這臺(tái)水泵也就是一家安一個(gè)開關(guān)，如果我兩家同時(shí)開電水泵能不能燒了啊，不知道這個(gè)有辦法接嗎？謝謝大... 有臺(tái)220v的普通潛水泵，要兩家用，但是還要各走各家的電表，還要用兩個(gè)開關(guān)去控制這臺(tái)水泵也就是一家安一個(gè)開關(guān)，如果我兩家同時(shí)開電水泵能不能燒了啊，不知道這個(gè)有辦法接嗎？謝謝大家 展開
2010-11-10 12:19:07
472
4
- 威力洗衣機(jī)老是壞水位傳感器這是什么原因請(qǐng)各位師傅幫幫忙。
-
2014-04-19 08:03:56
272
2
- 哪位師傅告訴我工地車輛沖洗臺(tái)光感時(shí)間控制接線圖
-
2018-11-14 02:43:10
380
0
- Nalgene 500ml離心瓶 聚丙烯共聚物PPCO
Nalgene 500ml離心瓶 聚丙烯共聚物PPCO 可高壓滅菌 3120-0500
本生（天津）健康科技有限公司供應(yīng)：移液器吸嘴，ELISA試劑盒，動(dòng)物血清，全系熒光定量PCR耗材，產(chǎn)品包括：PCR單管、八聯(lián)管、96孔板、384孔板。
3120-0250 250ml離心瓶PPCO
機(jī)殼材料機(jī)殼材料
Polypropylene (PP)顏 色 Translucent材 料 PPCO長(zhǎng) 度(公制) 169.8 mm每箱數(shù)量 24每 包 數(shù) 量
4外徑直徑(公制) 73.8 mm最大力度 4,800 x gNominal Capacity 500 mLUnit Size Case of
24
可高溫高壓滅菌Autoclavable
蓋子材料聚丙烯
機(jī)殼類型Sealing Cap
直徑（公制）73.8 mm
GraduatedNo
最大力4800 x G
形狀Round
通過(guò)密封蓋分裝No
容量（公制）500 mL
容積（英制）16.9 oz.
顏色Translucent
材質(zhì)PPCO
長(zhǎng)度（公制）169.8 mm
每箱數(shù)量24
每架數(shù)量4
類型Centrifuge Bottle
外徑直徑（公制）73.8 mm
標(biāo)稱容量500mL
Unit SizeCase of 24
Nalgene 500ml離心瓶 聚丙烯共聚物PPCO
2021-10-19 16:06:32
374
0
- 紅外傳感器工作原理是什么，有哪位比較了解的呢
-
2017-01-24 13:19:09
342
1
- 紅外傳感器工作原理是什么，有哪位比較了解的呢？
-
2018-11-17 18:15:22
274
0
野酒2456
贊(3)
回復(fù)(0)
滬公網(wǎng)安備 31011502008050號(hào)
參與評(píng)論
登錄后參與評(píng)論