Tuesday, April 7, 2009
常用数据库和期刊的的验证地址&验证字符串
b. highwire http://www.iovs.org/cgi/reprint/46/3/1078.pdf %PDF
c. acs http://pubs.acs.org/cgi-bin/arti ... html/ja044834j.html Mapping
d. kargar http://content.karger.com/Produk ... mp;ProduktNr=223832 You are logged in as
e. ejs http://ejournals.ebsco.com/login.asp?bCookiesEnabled=TRUE You have been authenticated
f. liebertonline http://www.liebertonline.com/toc/scd/14/1?part= Welcome
g. IEEE http://ieeexplore.ieee.org/xpls/VadvSearch.jsp Advanced Search
h. NETLIBRARY http://legacy.netlibrary.com/titleselect/index.asp University
i. 清华SD http://elsevier.lib.tsinghua.edu.cn SDOS
j. ingenta http://www.ingentaconnect.com Signed in as
k. nature http://www.nature.com/nature/journal/v435/n7044/pdf/435855a.pdf %PDF
l. science http://www.sciencemag.org/cgi/content/full/302/5644/406 References
m. ovid http://gateway1.ovid.com/ovidweb Choose a database
n. Dekker http://www.dekker.com/index.jsp click here
o. isi http://isi/3.isiknowledge.com/portal.cgi frameset
p. Oclc http://newfirstsearch.oclc.org/h ... 743-dsjwpud7-hk5z41 FirstSearch Home
q. bmn http://www.bmn.com/ Access
下面三个为原创95年前sd验证方法,适合各种端口的验证
r. sd偏化学四面体 http://www.sciencedirect.com/science/subscriptionSummary/5289/J subscription from Volume 1
s. sd偏药剂controlledrealease http://www.sciencedirect.com/science/subscriptionSummary/4944/J subscription from Volume 1
t. sd偏医Surgical Oncology http://www.sciencedirect.com/science/subscriptionSummary/6170/J subscription from Volume 1
US University for MSE!
Gourman ranking for Materials Science
Graduate program
1.MIT
2.UC-Berkeley
3.Stanford
4.Cornell
5.Northwestern
6.Caltech
7.Wisconsin Madison
8.CMU
9.Lehigh
10.Penn State
11.Case Western Reserve
12.Rice
13.UP
14.JHU
15.UCLA
16.Columbia
17.UM
18.Rutgers
19.Beown
20.Texas
21.Purdue
22.Florida
23.Michigan State
24.UMN
25.Cincinnati
26.V.P.I.& State U
27.North Carolina State
28.Rochester
29.Duke
30.Pittsburgh
31.Utah
32.Drexel
33.SUNY Stony Brook
34.USC
35.Tennessee
36.Vanderbilt
37.Virginia
38.Delaware
Sunday, March 29, 2009
当军品材料民用化,就有了——陶瓷手表!
所谓的太空材料,主要是指美国航天飞机上面用的隔热瓦,能耐几千度的高温,那种材料也是陶瓷的,估计性质上和雷达手表上陶瓷材料是一样的。美国“哥伦比亚”号航天飞机,就是因为在起飞的时候,左翼上的隔热瓦被砸受损,在航天飞机返航的时候,不能抵御和大气层摩擦产生的高温,导致空中解体而失事的。
陶瓷也好,高技术陶瓷也罢,首先这个材料是比较现代,还有,就是其表面非常光洁、特耐磨、物理性质稳定、耐酸碱、抗腐蚀、不会变色脱色、质量很轻、而且无公害。它还不伤皮肤,而不锈钢表壳表带里面有镍金属,镍对人的皮肤不好,很多人都会过敏的。高科技陶瓷的制造工艺,是将极精细的氧化锆粉末,把粉末以高压注入模内后,在摄氏一千多度高温的烧结炉内结成不易磨损陶瓷部件,再以用钻石粉末打磨,方可制成。因此,它还算是粉末冶金。
手表的重量,也一直是个恼人的问题。如果是表壳直径比较大而且有一定厚度的手表,再配上不锈钢的实芯表带,那就差不多要有150克的重量了,带在手上确实比较坠手腕的。高技术陶瓷似乎比钛材料还要轻,别看它的表带比较厚,但是,表带内部都是用的塑料的支撑件,(精密陶瓷款的除外)就是这种表带在拆卸表带节的时候比较麻烦点。
高技术陶瓷还可以做成各种颜色的,比较常见的有黑色、银灰色、金色、蓝色、白色等颜色的。其中,以黑色的为最多,被称为“黑陶”。
至于手表上的陶瓷材料有什么缺点,我个人总结有这么几点:(1)棱角不太分明,表壳或表带形状基本上都是圆鼓隆冬的;(2)容易碎裂,比较怕摔和怕磕碰。(3)表带节之间缝隙过大,尤其是银钻系列的,它的表带和表壳连接处(第一节)缝隙特大,在佩带者手腕比较细的情况下,尤为明显。这样的话,一则不美观,二则也容易进去脏东西。
关于雷达陶瓷材料的手表的陶瓷表带节碎裂残损的情况,在售后维修上屡见不鲜。很多消费者都信誓旦旦的说,手表并没有被摔到地上,但是表带节还是碎裂或蹦瓷,更有严重的,是当换上新的表带节后,居然没过多长时间就又坏掉。从残损的手表部位上分析,发现全都是破碎在表带的穿钉轴的位置。这个说明破裂是由于穿钉轴变形造成的,穿钉轴变形和表带受力拉撑,按装表带时候手法不对都有关系。雷达精密陶瓷的手表,还比较好,陶瓷表带节很少见有坏的,因为它有个工字型的表带框架。对于整体陶瓷和银钻系列的手表,在佩带时候,尤其要格外小心,它的陶瓷部件比较多,也比较大,更容易发生损坏。
Wednesday, March 18, 2009
申请国外博士后的好网站
Tuesday, March 17, 2009
中国期刊网文献如何导入Endnote
使用中国知网-CNKI进行文献检索时,勾选要导出的文献记录,点击存盘,即显示结果输出页,其中的Referworks可以帮助你导出研究结果到参考文献管理软件,例如Endnote。请按以下步骤具体操作如何将Referworks数据导入到Endnote。
第一步
从http://www.lib.unimelb.edu.au/endnote/filterfiles/CNKI.enf下载filter,并将其复制到你电脑中Endnote安装目录的filters文件夹中。
第二步
1、打开Endnote
2、点击File菜单,选择New来新建一个参考文献库(当然也可打开现有的文献库)
3、点击import,弹出一个对话框
4、点击choose file 来选择刚下载的RefWorks.txt,在import option中选择CNKI filter。如果它不在列中,点击other filters来找
5、在text translation中选择Unicode(UTF-8)
5、点击import来完成整个导入过程,你会发现所有在CNKI搜索结果中的文献已经被导入到Endnote了
Saturday, December 29, 2007
Going to buy a used car!!!
Friday, December 28, 2007
Silicon Nanowires Upgrade Data-Storage Technology
Scientists at the National Institute of Standards and Technology (NIST), along with colleagues at George Mason University and Kwangwoon University in Korea, have fabricated a memory device that combines silicon nanowires with a more traditional type of data-storage. Their hybrid structure may be more reliable than other nanowire-based memory devices recently built and more easily integrated into commercial applications.
As reported in a recent paper,* the device is a type of “non-volatile” memory, meaning stored information is not lost when the device is without power. So-called “flash” memory (used in digital camera memory cards, USB memory sticks, etc.) is a well-known example of electronic non-volatile memory. In this new device, nanowires are integrated with a higher-end type of non-volatile memory that is similar to flash, a layered structure known as semiconductor-oxide-nitride-oxide-semiconductor (SONOS) technology. The nanowires are positioned using a hands-off self-alignment technique, which could allow the production cost—and therefore the overall cost—of large-scale viable devices to be lower than flash memory cards, which require more complicated fabrication methods.
The researchers grew the nanowires onto a layered oxide-nitride-oxide substrate. Applying a positive voltage across the wires causes electrons in the wires to tunnel down into the substrate, charging it. A negative voltage causes the electrons to tunnel back up into the wires. This process is the key to the device’s memory function: when fully charged, each nanowire device stores a single bit of information, either a “0” or a “1” depending on the position of the electrons. When no voltage is present, the stored information can be read.
The device combines the excellent electronic properties of nanowires with established technology, and thus has several characteristics that make it very promising for applications in non-volatile memory. For example, it has simple read, write, and erase capabilities. It boasts a large memory window—the voltage range over which it stores information—which indicates good memory retention and a high resistance to disturbances from outside voltages. The device also has a large on/off current ratio, a property that allows the circuit to clearly distinguish between the “0” and “1” states.
Two advantages the NIST design may hold over alternative proposals for nanowire-based memory devices, the researchers say, are better stability at higher temperatures and easier integration into existing chip fabrication technology.
* Q. Li, X. Zhu, H. Xiong, S.-M. Koo, D.E. Ioannou, J. Kopanski, J.S. Suehle and C.A. Richter. Silicon nanowire on oxide/nitride/oxide for memory application. Nanotechnology 18 (2007) 235204.
Contact: Michael E. Newman michael.newman@nist.gov 301-975-3025 National Institute of Standards and Technology (NIST)
Image Credit: COPYRIGHT STATUS: LBNL (Lawrence Berkeley National Laboratory) authored documents are sponsored by the U.S. Department of Energy under Contract DE-AC02-05CH11231. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce these documents, or allow others to do so, for U.S. Government purposes.
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