频率

To undergo a process of gradual development or change over a long period, often referring to complex systems or biological species.

The loss or reduction of something (like energy, materials, or value) due to use, friction, or natural processes.

To spread out or scatter over a wide area; often used for ideas, diseases, gases, or information.

To identify and distinguish the qualities or authenticity of something. It is often used for evaluating art, products, or scientific samples.

To determine, measure, or test a value, quantity, or chemical property through scientific methods.

The state or fact of continuing to live or exist, typically in spite of an accident, ordeal, or difficult circumstances.

To combine different parts or substances into a single whole; specifically in science, to produce a substance by chemical reaction or artificial means.

To test or detect the presence, quality, or condition of something using scientific methods or equipment. Often used in medicine, environmental science, and technology.

Vertical or longitudinal; in research, it refers to studies conducted over a period of time to observe changes.

Horizontal or cross-sectional; in research, it refers to comparing different groups or variables at a single point in time.