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Le Yu
Le Yu (于乐) is a Chinese materials chemist and professor at Beijing University of Chemical Technology, known for designing hollow nanostructured electrode materials for batteries, supercapacitors, and electrocatalysis.
LEACH protocol
LEACH (Low-Energy Adaptive Clustering Hierarchy) is a clustering-based routing protocol for wireless sensor networks, reported in 2000, that rotates cluster heads to balance energy use.
Leachate
Leachate is the contaminated liquid that has passed through or emerged from solid waste, generated in landfills when water infiltrates waste and picks up pollutants.
Lead azide
Lead azide, Pb(N₃)₂, is a toxic primary explosive, the lead salt of hydrazoic acid, that detonates from weak stimuli and initiates secondary explosives in detonators, blasting caps, and fuzes.
Lead contamination in Washington, D.C., drinking water
Lead contamination in Washington, D.C., drinking water was a crisis from 2001 to 2004, when a switch to chloramine disinfection corroded lead service lines and raised lead levels fivefold.
Lead halide perovskite nanocrystals
Lead halide perovskite nanocrystals are nanometre-sized semiconductor crystals of formula APbX₃, first synthesized as colloids in 2015, used in displays, solar cells, lasers, and photodetectors despite lead toxicity and instability.
Lead magnesium niobate
Lead magnesium niobate (PMN) is a lead-based perovskite ceramic and crystal that is the prototypical relaxor ferroelectric, first found in 1958; its PMN-PT crystals hold records for piezoelectric response.
Lead rubber bearing
A lead rubber bearing (LRB) is a seismic isolation device with a lead core, developed in New Zealand in the early 1970s by W. H. Robinson.
Lead screw
A lead screw, also called a power screw or translation screw, is a threaded shaft that converts rotary motion into linear motion, moving a nut or load along the shaft.
Lead styphnate
Lead styphnate, lead 2,4,6-trinitroresorcinate, is a toxic orange-yellow primary explosive used in most modern firearm percussion primers and detonators, though it is a poor initiator of detonation.
Lead telluride
Lead telluride (PbTe) is a narrow-gap IV-VI semiconductor with the cubic rocksalt structure, one of the principal thermoelectric materials for power generation in the 500 to 800 K range.
Lead telluride thermoelectrics
Lead telluride thermoelectrics are materials based on PbTe, a narrow-bandgap semiconductor that converts heat to electricity, used in spacecraft generators since the early space program.
Lead time
Lead time is the total time a customer must wait to receive a product after placing an order, a measure used in manufacturing and supply chain management.
Lead titanate
Lead titanate (PbTiO₃) is a ferroelectric perovskite oxide ceramic with a Curie temperature of about 490 °C and the largest tetragonality among perovskite titanates, best known as the titanium-rich end member of the PZT piezoelectric system.
Lead-carbon battery
A lead-carbon battery (LCB) is a lead-acid battery with carbon materials added to the negative electrode, retarding sulfation and extending cycle life in hybrid vehicles and renewable energy storage.
Lead-cooled fast reactor
A lead-cooled fast reactor is a nuclear fission reactor cooled by molten lead or lead-bismuth eutectic in a fast neutron spectrum, one of six Generation IV systems.
Lead-free perovskite solar cell
A lead-free perovskite solar cell is a photovoltaic device using tin, germanium, bismuth, or antimony instead of toxic lead, with tin cells reaching about 18% efficiency.
Lead-free solder
Lead-free solder is a solder alloy with no more than 0.1% lead by weight, per the EU's RoHS Directive, used in electronics assembly since 2006.
Lead-free tin halide perovskite solar cells
Lead-free tin halide perovskite solar cells replace lead with tin in the perovskite absorber, reaching efficiencies approaching 18% since the first cell was demonstrated in 2014.
Lead-tin halide perovskite
A lead-tin halide perovskite is a mixed-cation perovskite semiconductor with a narrow bandgap around 1.2 to 1.3 eV, used as the bottom absorber in all-perovskite tandem solar cells.
Lead–acid battery
A lead–acid battery is a rechargeable battery invented by Gaston Planté in 1860, storing energy through lead and lead dioxide plates in sulfuric acid, and used chiefly in vehicles.
Leaded petrol
Leaded petrol is gasoline containing tetraethyl lead to boost octane and suppress knock. Used from 1923, it became a major lead exposure source and was banned worldwide by 2021.
Leader-follower formation
Leader-follower formation is a formation control strategy for multi-agent systems in which a leader follows a reference trajectory and followers regulate their relative positions, valued for simplicity, scalability, and use on UAVs, UGVs, and USVs.
Leadframe
A leadframe is a thin metal structure inside a semiconductor package that carries the chip die, conducts its signals outward, and forms the package pins after molding.
Leading
Leading, also called line spacing, is the vertical space between lines of text in typography, measured baseline to baseline and usually in points; it comes from lead strips used in metal typesetting.
Leading lights
Leading lights, called range lights in North America, are two or more lights a navigator keeps vertically aligned to hold a vessel on a channel's axis.
Leadwell CNC Machines
Leadwell CNC Machines (台湾丽伟电脑机械) is a Taiwanese manufacturer of CNC machining centers and lathes, founded in 1980 in Taichung and part of the Fair Friend Group.
Leaf spring
A leaf spring, also called a semi-elliptical or cart spring, is a spring of curved steel strips bound together that suspends a vehicle's axle from its frame.
Leah Buechley
Leah Buechley is a computer scientist, designer, and educator who invented the LilyPad Arduino, a sewable electronics kit, and founded the High-Low Tech group at the MIT Media Lab.
Leak testing
Leak testing, or leak test, is a family of engineering methods that detect and measure unintended gas or liquid leakage from sealed components, mainly in manufacturing quality control.