Process for the preparation of enantiomerically pure 3-phenyl-3-hydroxypropylamine
    92.
    发明授权
    Process for the preparation of enantiomerically pure 3-phenyl-3-hydroxypropylamine 失效
    制备对映体纯的3-苯基-3-羟基丙基胺的方法

    公开(公告)号:US06838581B2

    公开(公告)日:2005-01-04

    申请号:US10309010

    申请日:2002-12-04

    CPC classification number: C07C215/30 C07B2200/07 Y02P20/582

    Abstract: The present invention relates to an improved process for the synthesis of enantiomerically pure 3-phenyl-3-hydroxypropylamine of formula I; more particularly the present invention relates to the said process using styrene; the synthetic strategy features a Sharpless asymmetric dihydroxylation (SAD) route to the target compound, using styrene, a readily accessible starting material gives the optically pure dihydroxy compound (ee >97%; the selective monotosylation of primary alcohol, nucleophilic displacement by cyano and subsequent reduction to amino group furnishes the desired 3-phenyl-3-hydroxypropylamine in enatiomerically pure form, a key intermediate in the synthesis of variety of oxetine related anti-depressant drugs.

    Silicon carbide semiconductor device and manufacturing method

    公开(公告)号:US06576929B2

    公开(公告)日:2003-06-10

    申请号:US10135522

    申请日:2002-05-01

    CPC classification number: H01L29/66068 H01L29/1608 H01L29/7722 H01L29/8083

    Abstract: A channel layer 4 is formed on an n−-type epitaxial layer 2 and first gate areas 3, and field enhanced area(s) 5 and second gate areas 6 are formed on the first gate areas 3. Furthermore, n+-type source areas 7 and a third gate area 8 are formed on the second gate areas 6. These steps result in a device structure having a first J-FET with the n+-type source areas 7 and the n+-type substrate 1 as a source and drain and the first gate areas 3 at the right and left in the figure as a gate; and the second J-FET with the n+-type source areas 7 and the n+-type substrate 1 as a source and drain and the second gate areas 6 and the third gate area 8 as a gate. The first J-FET is normally-on, while the second J-FET is normally-off.

    Silicon carbide semiconductor device
    98.
    发明授权
    Silicon carbide semiconductor device 有权
    碳化硅半导体器件

    公开(公告)号:US06573534B1

    公开(公告)日:2003-06-03

    申请号:US09265582

    申请日:1999-03-10

    Abstract: A semiconductor device, comprising: a semiconductor substrate comprising silicon carbide of a first conductivity type; a silicon carbide epitaxial layer of the first conductivity type; a first semiconductor region formed on the semiconductor substrate and comprising silicon carbide of a second conductivity type; a second semiconductor region formed on the first semiconductor region, comprising silicon carbide of the first conductivity type and separated from the semiconductor substrate of the first conductivity type by the first semiconductor region; a third semiconductor region formed on the semiconductor region, connected to the semiconductor substrate and the second semiconductor region, comprising silicon carbide of the first conductivity type, and of higher resistance than the semiconductor substrate; and a gate electrode formed on the third semiconductor region via an insulating layer; wherein the third semiconductor layer is depleted when no voltage is being applied to the gate electrode so that said semiconductor device has a normally OFF characteristic.

    Abstract translation: 一种半导体器件,包括:包含第一导电类型的碳化硅的半导体衬底; 第一导电类型的碳化硅外延层; 形成在所述半导体衬底上并且包括第二导电类型的碳化硅的第一半导体区域; 形成在所述第一半导体区域上的第二半导体区域,包括所述第一导电类型的碳化硅并且通过所述第一半导体区域与所述第一导电类型的半导体衬底分离; 形成在所述半导体区域上的第三半导体区域,与所述半导体衬底和所述第二半导体区域连接,所述第二半导体区域包括所述第一导电型的碳化硅,并且具有比所述半导体衬底更高的电阻; 以及经由绝缘层形成在所述第三半导体区域上的栅电极; 其中当没有电压施加到所述栅电极时,所述第三半导体层被耗尽,使得所述半导体器件具有正常OFF特性。

    Single crystal thickness and width cuts for enhanced ultrasonic transducer
    99.
    发明授权
    Single crystal thickness and width cuts for enhanced ultrasonic transducer 有权
    增强超声波换能器的单晶厚度和宽度切割

    公开(公告)号:US06465937B1

    公开(公告)日:2002-10-15

    申请号:US09521167

    申请日:2000-03-08

    CPC classification number: H01L41/1875 H01L41/18

    Abstract: This invention is directed to a transducer comprising a lead-based single crystal wherein the crystal is diagonally oriented and has an effective coupling constant of at least 0.70. In one embodiment, the lead-based crystal has the formula Pb(B′B″)O3—PbTiO3 wherein B′ is Mg2+, Zn2+, Ni2+ or Sc3+ and B″ is Nb5+, Ta5+ or W6+. Preferably, the lead-based crystal has of the formula Pb(B′B″)O3—PbTiO3 where B′ is Mg2+, Zn2+, Sc3+ and B″ is Nb5+ or more specifically Pb(Mg1/3Nb2/3)O3—PbTiO3 (“PMN—PT”), Pb(Zn1/3Nb2/3)O3—PbTiO3 (“PZN—PT”), and Pb(Sc1/3Nb2/3)O3—PbTiO3 (“PSN—PT”). The invention also includes a transducer comprising a plurality of lead-based single crystal transducers. In one embodiment the ultrasonic probe comprising one or more piezoelectric components having surfaces that function as transmitting and/or receiving elements; and electrodes placed upon opposite surfaces of the elements, and wherein each lead based piezoelectric component as described above. In addition, the invention includes improved materials for reduced spurious modes. Furthermore, the invention includes diagonally oriented lead-based transducers.

    Abstract translation: 本发明涉及一种包含铅基单晶的换能器,其中晶体是对角线取向的,并且具有至少0.70的有效耦合常数。 在一个实施方案中,铅基晶体具有式Pb(B'B“)O3-PbTiO3,其中B'是Mg2 +,Zn2 +,Ni2 +或Sc3 +,B”是Nb5 +,Ta5 +或W6 +。 优选地,铅基晶体具有式Pb(B'B“)O3-PbTiO3,其中B'是Mg2 +,Zn2 +,Sc3 +和B”是Nb5 +或更具体的是Pb(Mg1 / 3Nb2 / 3)O3- PbTiO3(“PMN-PT”),Pb(Zn1 / 3Nb2 / 3)O3-PbTiO3(“PZN-PT”)和Pb(Sc1 / 3Nb2 / 3)O3-PbTiO3(“PSN-PT” 还包括包括多个基于铅的单晶振子的换能器。 在一个实施例中,超声波探头包括一个或多个具有用作发射和/或接收元件的表面的压电元件; 以及设置在元件的相对表面上的电极,并且其中每个基于铅的压电元件如上所述。 此外,本发明包括用于减少杂散模式的改进材料。 此外,本发明包括对角定向的基于铅的换能器。

    Spare capacity planning tool
    100.
    发明授权
    Spare capacity planning tool 失效
    备用容量规划工具

    公开(公告)号:US6137775A

    公开(公告)日:2000-10-24

    申请号:US1827

    申请日:1997-12-31

    CPC classification number: H04Q3/0079

    Abstract: A spare capacity planning tool for planning spare capacity in a transport network during a multiple-span failure following a single failure event. The spare capacity planning tool simulates restoration of a transport network regardless of the sequence of failures. The system and method utilize a permutation reducer to minimize the number of sequences to be verified during simulated or actual restoration activities. The permutation reducer reduces the number of sequences to to during simulated restoration activities to a first order function rather than a factorial function of the number of failed spans.

    Abstract translation: 一个备用容量规划工具,用于在单个故障事件发生的多级故障期间规划传输网络中的备用容量。 备用容量规划工具模拟传输网络的恢复,而不管故障顺序如何。 该系统和方法利用置换减少器来最小化在模拟或实际恢复活动期间要验证的序列的数量。 排列减少器将在模拟恢复活动期间的序列数减少到一阶函数,而不是失败跨度数量的阶乘函数。

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