The concave-convex property of a surface is one of the important and classical issues in differential geometry.

This article present the continuity,differentiability,monotonicity,concave-convex,parity and periodicity of the function netermined by the definite integral of variable upper limit and variable lower limit,establishes the sufficient and necessary requirements of functional convex and integrability of derived function by using the definite integral of variable upper limit.

Some definitions and discriminating methods have been given on the monotonicity,extreme value,concave-convex and inflection points of the curve r=r(θ).

Remediation of attapulgite on copper contaminated soil;

Character of attapulgite adsorbent and its application in oil bleaching;

Effect of PP-g-MAH on Mechanical Properties of PP/Attapulgite Composites;

Adsorption properties of attapulgite clay and activated carbon to water-soluble dyes;

Bleaching of hemp seed oil with activated attapulgite clay;

Study on the treatment of chromium contarining wastewater with modified attapulgite clay;

Study on the Ion exchange of potassium,calcium and magnesium by alter-attapulgite;

Preparation and characterization of nano TiO_2-attapulgite composites;

Study on the simultaneous determination of Zn(Ⅱ) in food based on pre-separation/enrichment by attapulgite with FAAS;

Preparation and properties of attapulgite/bentonite/sodium polyacrylate composite superabsorbent;

Separation and purification of Gansu attapulgite clay minerals;

Advances in attapulgite/polymer composites;