T/GVEAIA 031.3-2026 Rare Earth Intervention in Agricultural Product Production Regulation Part 3: Vapor Phase Deposition Process

Scope

This document specifies the principles and classification of gas phase deposition technology in the regulation of rare earth intervention in agricultural product production, equipment and system requirements, process parameters and flow, precursors and carrier gases, quality control and detection, safety, hygiene, and environmental protection requirements. This document applies to rare earth intervention operations implemented using gas phase metallurgy-electrical gas phase deposition (VPM-EVD) and gas-liquid interface confined electrical gas phase deposition (GLI-EVD) technologies in facility agriculture (greenhouses, sheds, and plant factories). This document provides specific operational guidelines for the "gas phase deposition" intervention method specified in T/GVEAIA 031.2 (Technical Requirements) and serves as the core process basis for precise rare earth regulation of related product categories (such as solanaceous fruits and leafy vegetables) in the T/GVEAIA 038 series of standards. 4. Process Principles and Classification 4.1 Basic Principles of Gas Phase Deposition 4.1.1 VPM-EVD Mechanism Rare earth halides are heated and volatilized (VPM stage: 400-600°C) to form gaseous REn+ions. Under the action of an electric field, these ions accelerate across the gas phase boundary layer and reach the crop surface: Physical adsorption: rare earth ions form van der Waals bonds with the leaf cuticle and wax layer; Chemical adsorption: they form coordination bonds with the carboxyl (-COOH) and hydroxyl (-OH) groups on the epidermal cell wall; Penetration and transport: they enter the mesophyll tissue via the exocytosis pathway or stomata and participate in physiological metabolism. 4.1.2 GLI-EVD Confined Effect Using the nano-scale water membrane (10-100 nm thick) formed by crop transpiration under the stomatal cavity as a "microreactor," rare earth ions undergo the following reactions at the gas-liquid interface: Hydration: RE3++nH2O[RE(H2O)?]3

Development Information

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