Agilent Technologies

About: Agilent Technologies is a company organization based out in Santa Clara, California, United States. It is known for research contribution in the topics: Signal & Mass spectrometry. The organization has 7398 authors who have published 11518 publications receiving 262410 citations. The organization is also known as: Agilent Technologies, Inc..

[Au14(PPh3)8(NO3)4]: An Example of a New Class of Au(NO3)‐Ligated Superatom Complexes

Abstract: Ultrasmall gold nanoparticles (usNPs) have been of considerable interest because of their unique properties, which arise from size quantization effects and thus make them attractive for applications in different areas of nanoscience and nanotechnology. 4] Among usNPs of defined composition, and especially for gold clusters, an outstanding so-called “magic” stability has been observed for certain compositions. This stability has been explained through their specific geometric or electronic structure. In the full-shell cluster model, an usNP is considered as a cut-out of the bulk fcc structure. 6] Accordingly, a central metal atom is surrounded by shells of closely packed metal atoms, each shell having (10n+2) atoms, n indicating the number of shells. Clusters possessing fully occupied shells consist of 13, 55, 147, ... atoms and are supposed to show high stability for geometric reasons, such as the well-studied Schmid cluster [Au55(PPh3)12Cl6]. [7] In another model, which goes back to the counting rules introduced by Mingos, metal clusters are considered as superatom complexes formulated as [LS·ANXM] z with electron-withdrawing ligands X or weak Lewis base ligands L attached to the core with metal atoms A and an overall core charge z. 10] Accordingly, for Au the 6s electrons are counted and corrected by the number of electrons that are located at electron-withdrawing ligands and corrected by the charge of the cluster. The remaining 6s electrons are placed within the binding delocalized orbitals of the cluster, which is analogous to valence electrons of the atomic theory. Exceptional stability is associated with a total number of: n* 1⁄4 2, 6, 12, 20, 30, . . . ð1Þ

State machine for collecting information on use of a packet network

Abstract: A protocol analyzer includes an input buffer, a lookup table and a counter memory. The input buffer includes a frame header buffer and the lookup table comprises a state machine including a CAM and a RAM. A frame is stored in the frame header buffer while the CAM and RAM analyze predetermined portions of it. If a portion is eight bits or less, it is input into the RAM and the RAM outputs instructions stored at the location indicated by the data portion. If the portion is greater than eight bits, it is input into the CAM, which outputs a RAM address at which corresponding instructions are stored. The instructions can include an instruction to increment a count in a predetermined register of the counter memory; an instruction to add a new count register in the counter memory; an instruction to generate a snapshot trigger to cause a capture RAM to store a specific data segment traveling on the packet network; and an instruction to further analyze the data portion. The instruction to further analyze the data portion includes an address offset to indicate the location of the next data segment to be analyzed. The protocol analyzer does not include a processor, and is not operated by software; it can analyze all data frames on a packet network, even at gigabit transfer rates.

Systems, tools and methods of assaying biological materials using spatially-addressable arrays

Abstract: Systems, tools and methods of assaying biological material are used to perform complex sandwich hybridization assays. The tools used comprise biological solution probes that are customized for each assay. The solution probe comprises a first region for hybridizing to a probe, in a generic set of capture probes on a universal assay apparatus, and a second region for hybridizing to a target in a sample. The solution probe assembles the target to the assay apparatus by hybridizing the second region to the target and the first region to the capture probe. In array assays, one or more biological samples, having one or more targets per sample, can be multiplexed on the same universal array comprising the generic set of capture probes in an array pattern of features on the substrate. The customized solution probe addresses and assembles a predetermined target-sample combination onto the array at a corresponding capture probe address location. The systems, tools and methods have specificity and sensitivity by systematically providing a reduced likelihood of cross-hybridizations and intramolecular structures in the probes. Specificity and sensitivity of the assay are provided by the incorporation of a chemically modified monomer in the capture probe and a similarly modified monomer complement in the first region of the solution probe. The modified monomers preferentially hybridize with each other. When the probe and respective probe region are oligonucleotides, the complementary modified nucleotides have a reversed polarity relative to the polarity of the respective probe and probe region. The complementary reversed polarity nucleotides form a thermodynamically more stable hybridization to each other than a hybridization between the reversed polarity nucleotide and a complementary nucleotide whose polarity is not similarly reversed.

Method of programming a desired source resistance for a driver stage

Abstract: The output impedance in a CMOS output driver stage is programmed and compensated by complementary current mirrors that are MOS devices in series with each of the conventional pull-up and pull-down devices. The conduction of these additional complementary devices is controlled according to complementary programming signals that are compensated for variations in manufacturing process parameters as well as for changes in temperature. A P-type programming signal may be referenced to +VDD and be produced from an N-type programming signal referenced to GND by the action of a gate voltage mirror that includes symmetrical N-type and P-type FET's in series. The N-type programming signal may be produced in the first instance from the gate voltage of an N-type FET used in a feedback loop that servos an external programming voltage to track an internally generated reference voltage. That gate voltage exhibits variations that reflect differences attributable to both process variations and to temperature. Those exhibited variations are communicated by a current mirror to a gate voltage mirror that produces the complementary programming signals, and which themselves constitute negative feedback. The complementary current mirrors are of known of gain, which in conjunction with knowing the value of VDD, allows the determination in advance of a definite table of programming resistance values versus output impedances.

Pulse-Shaping With Digital, Electrical, and Optical Filters—A Comparison

Abstract: We investigate the performance of sinc-shaped QPSK signal pulses generated in the digital, electrical, and optical domains. To this end an advanced transmitter with a digital pulse-shaper is compared to analog transmitters relying on pulse-shaping with electrical and optical filters, respectively. The signal quality is assessed within a single carrier setup as well as within an ultra-densely spaced WDM arrangement comprising three channels. An advanced receiver providing additional digital filtering with an adaptive equalization algorithm to approximate an ideal brick-wall Nyquist filter has been used for all schemes. It is found that at lower symbol rates, where digital processing is still feasible, digital filters with a large number of filter coefficients provide the best performance. However, transmitters equipped with only electrical or optical pulse-shapers already outperform transmitters sending plain unshaped NRZ signals, so that for higher symbol rates analog electrical and optical techniques not only save costs, but are the only adequate solution.