Abstract We have studied on the temperature stability of the Pb(Mg1/3Nb2/3)A (Mn1/3Nb2/3)BTicZrDO3 (so-called PMMN) quaternary systems piezoelectric ceramics for making piezoelectric ceramic transformer. We found a transition position near morphotropic phase boundary has the most temperature stability like binary and ternary systems ceramics depending on the third and fourth elements. We have obtained a PMMN-1 composition with good piezoelectric performance and stability just on this position. The temperature stability can be improved by replacing partly Pb with Sr and adding small quantity of CeO2 such as PMMN-1F and PMMN-2b composition that will be discussed.

Extruded and hot-rolled 200 degreesC similar to 500 degreesC AZ31B plates were studied their texture using ODFs analysis. The as-extruded specimen has the strongest intensity of (0001)-ND fiber and 300 degreesC and 400 degreesC hot-rolled ones have the next, but the 200 degreesC hot-rolled one has the lowest intensity. Compared with the corresponding tensile properties, this feature evidents that a pronounced (0001) basal texture will reduce ductility of AZ31B alloy. The ODFs results also indicate that (05 (5) over bar2)- and (01 (1) over bar0)-ND fibers are related to the ductility of AZ31B alloy.

After TIG and laser welding, the microstructure, shape memory effect and chemical corrosion resistance of Fe-30Mn-6Si and Fe-30Mn-6Si-5Cr shape memory alloys have been investigated. Experimental results show that the welded zones exhibit dendrite structures. The as-welded alloys still have an excellent shape memory effect. The corrosion resistance of welded zones is found to be worse than that of the base-material for both Fe-30Mn-6Si and Fe-30Mn-6Si-5Cr alloys. The degradation of corrosion resistance is more obvious for laser-welded zone than that for TIG-welded zone. After annealing treatment of 1100°C × 2h for these welded alloys, the dendrite structures in the welded zones disappear and the corrosion resistance is improved.

The stereospecific synthesis of 6 via a highly selective, noncorrosive fluorination of 4 with Et3N·3HF was discovered. The intermediate fluorosulfonate 5 was isolated, purified and its structure verified.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The synthesis of beta-dFARPP was accomplished by Mitsunobu coupling of 6-cyanopurine with 2-deoxy-2,2-difluororibose followed by purine ring-expansion under the action of methanolic ammonia. The title compound inhibited the growth of proliferating human leukemic CCRF-CEM cells at 6.1 mu g/ml but had no effect on plaque formation by a variety of DNA and RNA viruses.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A stereospecific synthesis of 2'-deoxy-2',2'-difluorocytidine (gemcitabine), a potential anticancer agent, is described. The stereoselectivity was accomplished via two diastereoselective crystallizations, i.e. the crystallization of the key intermediate, difluororibonolactone 2a, and the crystallization of the hydrochloride salt of gemcitabine 16b from the anomeric mixture. Because of the availability of 2a in large quantities, other 2'-deoxy-2',2'-difluoropyrimidine nucleosides such as 2'-deoxy-2',2'-difluorouridine (19) were synthesized for structure-activity relationship studies.

The Phase II design of the Superconducting X-ray Lithography Source (SXLS) consists of replacing the two room-temperature 180 degrees C dipole magnets of Phase I with superconducting magnets. However, even though superconducting magnets are used, the vacuum chambers within them will operate at room temperature. The chambers are constructed as weldments and are made of INCONEL-625. They are bakeable to 150 degrees C in situ and incorporate nine photon beam ports. Each has built-in distributed sputter-ion pumps, (DIP), nonevaporable getter pumps, beam position monitors, and ion clearing electrodes. R&D is underway to optimize the DIP, which must operate at 3.86 T, and to develop a low photo yield coating or treatment for the internal surface of the chambers.<>

Based on our experience with the in‐situ cleaning of optical systems by reactive r. f. glow discharges [1,2] and the conditioning and preparation of distributed ion pump (DIP) elements [3], we have sought to develop strategies for recovering from severe vacuum accidents by restoring DIP elements of storage rings such as those at the NSLS in‐situ. In this paper we will describe a series of experiments conducted in a test apparatus to condition a so called ‘egg‐crate’ DIP in‐situ, (this type element is common in older storage rings). A new untreated element, which was unable to pump below 5×10−8 Torr in its initial condition, was treated in oxygen and subsequent argon r.f. discharges, utilizing the pump element as the discharge electrode, resulting in a nitrogen pumping speed of 168 l/s at 2×10−8 Torr. A light bake at 75°C increased this to nearly 500 l/s at 5×10−8 Torr. After exposure to atmosphere the speed was reduced to nil at these pressures but subsequently recovered, without bakeout, by glow discharg...

In the new generation of advanced synchrotron light sources, the conventional concept of distributed pumping is no longer suitable for removing the gas load caused by photon stimulated desorption (PSD). A new concept using a combination of photon absorber and pumping station has been designed, constructed, and installed in the U10B beam line at the VUV ring of the National Synchrotron Light Source. The system consists of an electrically insulated water cooled copper block, a titanium sublimation pump, calibrated BA gauges, a calibrated RGA, and a known conductance. A photon beam 10 milliradian wide and 3.26 milliradian high, having critical energy of 500 eV, is directed on the absorber. PSD yield is studied as a function of total beam dose and absorber surface preparation. The results from this experiment, pump characteristics, design of an absorber pump for future light sources, and the pressure improvement factors will be presented.

n t e r s t i t i a l f r e e s t e e l and a n o t h e r peak a t 170K ('1 Hz) f o r t h e i n t e r s t i t i a l f r e e s t e e l were observed f o r heavy plgstic-deformed specimens.n o s e peaks e x h i b i t an anomalous dependence o f s t r a i n amplitude and an aging e f f e c t .

Thick deuterium films were condensed on an aluminum cryopanel and bombarded with both fast and thermal neutrons. (AIP)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLocal Particle-Liquid Mass Transfer Fluctuations in Mixed-Phase Cocurrent Downflow through a Fixed Bed in the Pulsing RegimeTai S. Chou, Frank L. Worley Jr., and Dan LussCite this: Ind. Eng. Chem. Fundamen. 1979, 18, 3, 279–283Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://pubs.acs.org/doi/10.1021/i160071a014https://doi.org/10.1021/i160071a014research-articleACS PublicationsRequest reuse permissionsArticle Views159Altmetric-Citations44LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTransition to Pulsed Flow in Mixed-Phase Cocurrent Downflow through a Fixed BedT. S. Chou, F. L. Worley, and D. LussCite this: Ind. Eng. Chem. Proc. Des. Dev. 1977, 16, 3, 424–427Publication Date (Print):July 1, 1977Publication History Published online1 May 2002Published inissue 1 July 1977https://pubs.acs.org/doi/10.1021/i260063a029https://doi.org/10.1021/i260063a029research-articleACS PublicationsRequest reuse permissionsArticle Views186Altmetric-Citations55LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Measurements were made of the Au core-electron binding-energy shifts which occur when Au metal is made the minor constituent in alloys of Pd, Pt, and Ni. These results and binding-energy shifts previously reported for alloys with Ag, Al, and Sn were combined with M\"ossbauer isomer-shift and work-function data to derive estimates for the net charging of the Au sites in these systems. Au turns out to be negative in all cases to the extent of $\ensuremath{\sim}0.1e$, except for Au-Pt where the charging is less. Although considerably greater Au $s$ density increases are demonstrated by the M\"ossbauer data, they are largely compensated by depletion of the $d$ count. The trend in host-to-Au charge behavior is qualitatively in accord with the Pauling electronegativity scale.