All articles A–Z

Diffuse optical imaging

Diffuse optical imaging (DOI) is a biomedical imaging technique using near-infrared light to reconstruct maps of hemoglobin, oxygenation, and blood flow in tissue several centimeters deep.

Diffuse optical spectroscopy (DOS) is a noninvasive technique that uses near-infrared light to measure hemoglobin, water, and lipid in thick tissue, applied to breast cancer monitoring and cerebral hemodynamics.

Diffuse optical tomography

Diffuse optical tomography (DOT) is a medical imaging method that reconstructs 3-D maps of near-infrared light absorption in thick tissue, applied to breast tumors and brain function.

Oct 21, 2026

Diffuse orbital inflammation

Diffuse orbital inflammation (ICD-11 9A22.1), also called diffuse idiopathic orbital inflammation or orbital pseudotumor, is a noninfectious, non-neoplastic inflammatory condition diffusely involving orbital fat, diagnosed by exclusion and treated first with corticosteroids.

Oct 20, 2026

Diffuse panbronchiolitis

Diffuse panbronchiolitis (DPB, 弥漫性泛细支气管炎) is a rare idiopathic inflammatory lung disease of respiratory bronchioles, mainly affecting East Asians, marked by chronic sinusitis, cough, sputum, tree-in-bud HRCT nodules, and treatable with low-dose macrolides.

Diffuse reflectance infrared Fourier transform spectroscopy

Diffuse reflectance infrared Fourier transform spectroscopy, also known as diffuse reflectance infrared spectroscopy or DRIFTS, is an infrared technique for analyzing powders without pellet pressing, widely used in catalyst research.

Diffuse reflectance spectroscopy

Diffuse reflectance spectroscopy (DRS) is an optical technique measuring light scattered back from turbid materials, powders, and biological tissue to recover absorption and scattering properties, used in medicine and industry.

Diffuse reflection

Diffuse reflection scatters light or electromagnetic radiation into many directions rather than a single mirror direction, occurring when a surface is rough on the scale of its wavelength.

Diffuse scattering

Diffuse scattering is the component of a diffraction pattern spread continuously through reciprocal space rather than concentrated in sharp Bragg peaks, arising from thermal motion and disorder.

Diffuse sky radiation

Diffuse sky radiation, also called diffuse horizontal irradiance (DHI), is the sunlight scattered by molecules, aerosols, and clouds that reaches the ground from the whole sky rather than directly from the sun.

Diffuse supernova neutrino background

The diffuse supernova neutrino background (DSNB), also called the supernova relic neutrino background, is the accumulated neutrino flux from all past core-collapse supernovae, first indicated by Super-Kamiokande in 2026.

Oct 20, 2026

Diffuse unilateral subacute neuroretinitis

Diffuse unilateral subacute neuroretinitis (DUSN), or unilateral wipe-out syndrome, is a unilateral chorioretinitis caused by a mobile subretinal nematode such as Toxocara canis or Baylisascaris procyonis, treated by laser photocoagulation or albendazole.

Diffuser (compressor)

A diffuser in a compressor is a stationary passage downstream of the impeller that slows the working fluid, converting kinetic energy into static pressure, especially in centrifugal compressors.

Diffusing-wave spectroscopy

Diffusing-wave spectroscopy (DWS) is an optical technique measuring particle motion in opaque materials like colloids, gels, and tissue, introduced by Pine, Weitz, Chaikin, and Herbolzheimer in 1988.

Diffusion

Diffusion is the net movement of a substance from regions of higher to lower concentration, driven by random particle motion without external energy, described by Fick's laws.

Diffusion bonding

Diffusion bonding, also called diffusion welding, is a solid-state joining process in which heat and pressure unite clean surfaces by atomic diffusion without melting, used mainly in aerospace.

Diffusion brazing

Diffusion brazing, also known as transient liquid phase (TLP) bonding, is a joining process where a liquid filler diffuses into the base metal until the joint matches its strength.

Diffusion chronometry

Diffusion chronometry is a geochemical method that converts chemical zoning profiles in minerals into durations of thermal events, most commonly the interval between magma recharge and eruption.

Diffusion combustion

Diffusion combustion, also called non-premixed combustion, is combustion in which fuel and oxidizer start separate and burn where they mix, as in diesel engines and open fires.

Diffusion encoding (NMR spectroscopy)

Diffusion encoding is an NMR technique that applies magnetic field gradients to measure molecular self-diffusion coefficients; its DOSY variant separates mixture spectra without physical separation.

Diffusion equation

The diffusion equation is a partial differential equation describing how heat or concentration spreads through a medium over time, first derived by Joseph Fourier in 1822 and identical to the heat equation.

Diffusion kurtosis imaging

Diffusion kurtosis imaging (DKI) is an MRI technique that quantifies non-Gaussian water diffusion in tissue, extending diffusion tensor imaging; it was introduced by Jens Jensen and colleagues in 2005.

Diffusion map

Diffusion map is a nonlinear dimensionality reduction method introduced by Ronald Coifman and Stéphane Lafon in 2006 that embeds high-dimensional data by running a random walk on a similarity graph.

Diffusion maps

Diffusion maps are a nonlinear manifold learning method introduced by Ronald Coifman and Stéphane Lafon in 2006, in which a random walk on the data yields eigenfunction coordinates describing its geometry.

Diffusion model

A diffusion model, also called a diffusion probabilistic model, is a generative neural network that produces data by learning to reverse a gradual noising process step by step.

Diffusion Monte Carlo

Diffusion Monte Carlo (DMC), also known as diffusion quantum Monte Carlo, is a stochastic quantum Monte Carlo method that projects a trial wave function onto the exact ground state.

Diffusion MRI

Diffusion MRI (dMRI), also known as diffusion-weighted MRI, is an MRI technique that measures water diffusion to reveal tissue microstructure, used for stroke diagnosis and white matter tractography.

Diffusion of innovations

Diffusion of innovations is a theory, formulated by Everett Rogers in 1962, explaining how new ideas, practices, and products spread through a social system, with adopters grouped into five categories.

Diffusion of responsibility

Diffusion of responsibility is the reduced sense of personal responsibility people feel when acting in a group rather than alone; established by Darley and Latané's 1968 bystander experiments, it underlies the bystander effect and extends to advice-taking, online helping, and agency.