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Pulse Amplitude Modulation
Pulse-amplitude modulation (PAM) is a form of signal modulation in which the message information is encoded in the amplitude of a pulse train interrupting the carrier frequency. Demodulation is performed by detecting the amplitude level of the carrier at every single period. Types There are two types of pulse amplitude modulation: * In ''single polarity PAM'', a suitable fixed DC bias is added to the signal to ensure that all the pulses are positive. * In ''double polarity PAM'', the pulses are both positive and negative. Pulse-amplitude modulation is widely used in modulating signal transmission of digital data, with non-baseband applications having been largely replaced by pulse-code modulation, and, more recently, by pulse-position modulation. The number of possible pulse amplitudes in analog PAM is theoretically infinite. Digital PAM reduces the number of pulse amplitudes to some natural number. Uses Ethernet Some versions of the Ethernet communication standard are an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
100 Gigabit Ethernet
40 Gigabit Ethernet (40GbE) and 100 Gigabit Ethernet (100GbE) are groups of computer networking technologies for transmitting Ethernet frames at rates of 40 and 100 gigabits per second (Gbit/s), respectively. These technologies offer significantly higher speeds than 10 Gigabit Ethernet. The technology was first defined by the IEEE 802.3, IEEE 802.3ba-2010 standard and later by the 802.3bg-2011, 802.3bj-2014, 802.3bm-2015, and 802.3cd-2018 standards. The first succeeding Terabit Ethernet specifications were approved in 2017. The standards define numerous port types with different optical and electrical interfaces and different numbers of optical fiber strands per port. Short distances (e.g. 7 m) over twinaxial cable are supported while standards for fiber reach up to 80 km. Standards development On July 18, 2006, a call for interest for a High Speed Study Group (HSSG) to investigate new standards for high speed Ethernet was held at the IEEE 802.3 plenary meeting in Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyll Fluorescence
Chlorophyll fluorescence is light re-emitted by chlorophyll molecules during return from Excited state, excited to non-excited states. It is used as an indicator of photosynthetic energy conversion in plants, algae and bacteria. Excited chlorophyll dissipates the absorbed light energy by driving photosynthesis (photochemical energy conversion), as heat in non-photochemical quenching or by emission as fluorescence radiation. As these processes are complementary processes, the analysis of chlorophyll fluorescence is an important tool in plant research with a wide spectrum of applications. The Kautsky effect Upon illumination of a dark-adapted leaf, there is a rapid rise in fluorescence from Photosystem II (PSII), followed by a slow decline. First observed by ''Kautsky et al., 1932'', this is called the Kautsky Effect. This variable rise in chlorophyll fluorescence is due to photosystem II. Fluorescence from photosystem I is not variable, but constant. The increase in fluoresce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thylakoid
Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacterium, cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a #Membrane, thylakoid membrane surrounding a #Lumen, thylakoid lumen. Chloroplast thylakoids frequently form stacks of disks referred to as #Granum and stroma lamellae, grana (singular: ''granum''). Grana are connected by intergranal or Stroma (fluid), stromal thylakoids, which join granum stacks together as a single functional compartment. In thylakoid membranes, chlorophyll pigments are found in packets called quantasomes. Each quantasome contains 230 to 250 chlorophyll molecules. Etymology The word ''Thylakoid'' comes from the Greek language, Greek word ''thylakos'' or ''θύλακος'', meaning "sac" or "pouch". Thus, ''thylakoid'' means "sac-like" or "pouch-like". Structure Thylakoids are membrane-bound structures embedded in the chloroplast stroma (fluid), stroma. A stack of thy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescence Spectroscopy
Fluorescence spectroscopy (also known as fluorimetry or spectrofluorometry) is a type of electromagnetic spectroscopy that analyzes fluorescence from a sample. It involves using a beam of light, usually ultraviolet light, that excites the electrons in molecules of certain compounds and causes them to emit light; typically, but not necessarily, visible light. A complementary technique is absorption spectroscopy. In the special case of single molecule fluorescence spectroscopy, intensity fluctuations from the emitted light are measured from either single fluorophores, or pairs of fluorophores. Devices that measure fluorescence are called fluorometers. Theory Molecules have various states referred to as energy levels. Fluorescence spectroscopy is primarily concerned with electronic and vibrational states. Generally, the species being examined has a ground electronic state (a low energy state) of interest, and an excited electronic state of higher energy. Within each of these ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabolism. ''Photosynthesis'' usually refers to oxygenic photosynthesis, a process that produces oxygen. Photosynthetic organisms store the chemical energy so produced within intracellular organic compounds (compounds containing carbon) like sugars, glycogen, cellulose and starches. To use this stored chemical energy, an organism's cells metabolize the organic compounds through cellular respiration. Photosynthesis plays a critical role in producing and maintaining the oxygen content of the Earth's atmosphere, and it supplies most of the biological energy necessary for complex life on Earth. Some bacteria also perform anoxygenic photosynthesis, which uses bacteriochlorophyll to split hydrogen sulfide as a reductant instead of water, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCI Express 6
PCI may refer to: Business and economics * Payment card industry, businesses associated with debit, credit, and other payment cards ** Payment Card Industry Data Security Standard, a set of security requirements for credit card processors * Provincial Competitiveness Index, a governance index of Vietnamese provinces * Ceridian-UCLA Pulse of Commerce Index, a U.S. economic indicator based on trucking fuel consumption * Per capita income * Equitable PCI Bank, a Philippine bank Science and technology * Panel call indicator, telephone signalling system * Pavement condition index, used in transportation civil engineering * Picocurie (pCi), a unit of radioactivity * Peripheral Component Interconnect, a computer bus ** PCI-X (PCI eXtended), a computer bus ** PCI Express (PCIe), a computer bus * Projects of Common Interest, a category of EU projects for interconnecting energy infrastructures * Protocol-control information, in telecommunication * Pulverized coal injection method, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GDDR6
Graphics Double Data Rate 6 Synchronous Dynamic Random-Access Memory (GDDR6 SDRAM) is a type of synchronous graphics random-access memory (SGRAM) with a high bandwidth, "double data rate" interface, designed for use in graphics cards, game consoles, and high-performance computing. It is a type of GDDR SDRAM (graphics DDR SDRAM), and is the successor to GDDR5. Just like GDDR5X it uses QDR (quad data rate) in reference to the write command clock (WCK) and ODR (Octal Data Rate) in reference to the command clock (CK). Overview The finalized specification was published by JEDEC in July 2017. GDDR6 offers increased per-pin bandwidth (up to 16 Gbit/s) and lower operating voltages (1.35 V), increasing performance and decreasing power consumption relative to GDDR5X. Commercial implementation At Hot Chips 2016, Samsung announced GDDR6 as the successor of GDDR5X. Samsung later announced that the first products would be 16 Gbit/s, 1.35 V chips. In January 2018, Sam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-return-to-zero
In telecommunications, a non-return-to-zero (NRZ) line code is a binary code in which ones are represented by one significant condition, usually a positive voltage, while zeros are represented by some other significant condition, usually a negative voltage, with no other neutral or rest condition. For a given data signaling rate, i.e., bit rate, the NRZ code requires only half the baseband bandwidth required by the Manchester code (the passband bandwidth is the same). The pulses in NRZ have more energy than a return-to-zero (RZ) code, which also has an additional rest state beside the conditions for ones and zeros. When used to represent data in an asynchronous communication scheme, the absence of a neutral state requires other mechanisms for bit synchronization when a separate clock signal is not available. Since NRZ is not inherently a self-clocking signal, some additional synchronization technique must be used for avoiding bit slips; examples of such techniques are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GDDR7 SDRAM
Graphics Double Data Rate 7 Synchronous Dynamic Random-Access Memory (GDDR7 SDRAM) is a type of synchronous graphics random-access memory (SGRAM) specified by the JEDEC Semiconductor Memory Standard, with a high bandwidth, "double data rate" interface, designed for use in graphics cards, game consoles, and high-performance computing. It is a type of GDDR SDRAM (graphics DDR SDRAM), and is the successor to GDDR6. History * At Samsung Tech Day 2022, Samsung announced GDDR7 as the successor of GDDR6X, which could deliver up to 36 GT/s. Samsung announced two months later that it would use PAM-3 signaling to achieve the highest transfer rate. * On March 8, 2023, Cadence announced the verification solution tool for preliminary GDDR7 SDRAM production. * On June 30, 2023, Micron announced that it will be manufactured using 1β node (equivalent to 12–10 nm process node), slated to release in H1 2024. * On July 18, 2023, Samsung announced the first generation of GDDR7, which can re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GeForce 30 Series
The GeForce RTX 30 series is a suite of graphics processing units (GPUs) developed by Nvidia, succeeding the GeForce RTX 20 series. The GeForce RTX 30 series is based on the Ampere architecture, which features Nvidia's second-generation ray tracing (RT) cores and third-generation Tensor Cores. Part of the Nvidia RTX series, hardware-enabled real-time ray tracing is featured on GeForce RTX 30 series cards. The lineup, designed to compete with AMD's Radeon RX 6000 series of cards, consists of the entry-level and previously laptop-exclusive RTX 3050 and laptop-exclusive RTX 3050 Ti, mid-range RTX 3060, upper-midrange RTX 3060 Ti, RTX 3070 high-end RTX 3070 Ti, RTX 3080 10 GB, RTX 3080 12 GB and enthusiast RTX 3080 Ti, RTX 3090, and RTX 3090 Ti. This is the last generation from Nvidia to have official support for Windows 7 and 8.x as the latest drivers available for this generation require Windows 10. The GeForce RTX 30 series began shipping on September ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GDDR6 SDRAM
Graphics Double Data Rate 6 Synchronous Dynamic Random-Access Memory (GDDR6 SDRAM) is a type of synchronous graphics random-access memory (SGRAM) with a high bandwidth, "double data rate" interface, designed for use in graphics cards, game consoles, and high-performance computing. It is a type of GDDR SDRAM (graphics DDR SDRAM), and is the successor to GDDR5. Just like GDDR5X it uses QDR (quad data rate) in reference to the write command clock (WCK) and ODR (Octal Data Rate) in reference to the command clock (CK). Overview The finalized specification was published by JEDEC in July 2017. GDDR6 offers increased per-pin bandwidth (up to 16 Gbit/s) and lower operating voltages (1.35 V), increasing performance and decreasing power consumption relative to GDDR5X. Commercial implementation At Hot Chips 2016, Samsung announced GDDR6 as the successor of GDDR5X. Samsung later announced that the first products would be 16 Gbit/s, 1.35 V chips. In January 2018, Sam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
