I am not surprised Paddoboy, that our technically erudite Mod did not make any comment on the paper.
You have more than one moderator, but no right to demand a response from either.
On the first paper my comment was:
The paper is trash. It's based on a mistaken explanation of GR by Vankov in the same "journal". Where it makes mathematical claims, there is no math. Where it makes factual claims, there is no traceability. It compares the apples of GR's perihelion shift with the oranges of JPL's estimate of Mercury's actual orbit which changes shape and perihelion due to all causes, including perturbation by other planets not part of the GR discussion.
The references are antique, same-author-same-journal or Vankov who in turn relies on this author for translations.
So if you want to learn GR, learn the mathematical prerequisites, open some textbooks and do the math.
I refuse to believe that he does not understand such a simple integration,
What integration? If you are referring to the integration in
http://einsteinpapers.press.princeton.edu/vol6-trans/128?ajax I follow it.
If you are referring to the integration in the paper you attached in post #16, it's irrelevant, because it's only part of the calculation.
Einstein alleges that (after a typo corrected):
$$\int \limits_{1/r'_{+}}^{1/r'_{-}} \frac{ du }{\sqrt{ (u - 1/r_{+})(1/r_{-} - u ) + r_s u^3 }} \approx \left( 1 + \frac{ r_s}{2} \left( 1/r_{-} + 1/r_{+} \right) \right) \int \limits_{1/r_{+}}^{1/r_{-}} \frac{ \left( 1 + \frac{r_s}{2} u \right) du }{\sqrt{ (u - 1/r_{+})(1/r_{-} - u ) }} \approx \pi + \frac{ 3 \pi r_s}{4} \left( 1/r_{-} + 1/r_{+} \right) $$
Hua Di alleges $$\int \limits_{1/r_{+}}^{1/r_{-}} \frac{ \left( 1 + \frac{r_s}{2} u \right) du }{\sqrt{ (u - 1/r_{+})(1/r_{-} - u ) }} \approx \pi + \frac{ \pi r_s}{4} \left( 1/r_{-} + 1/r_{+} \right) $$ which is the
same claim because the prefactor was ignored.
He also ignores the intermediate typo which the was noted as footnote 16 inserted by the collectors of the papers.
Further, high precision numerical calculation shows the approximations are appropriate in this situation.
Assuming $$r_{-} = 46,001,200 \, \textrm{km}, \; r_{+} = 69,816,900 \, \textrm{km}, \; r_s = 2.95 \, \textrm{km}$$ we have
$$r'_{-} \approx 46,001,191.351930914033165192263953438 \, \textrm{km} \\ r'_{+} \approx 69,816,905.698068772139457806401588149 \, \textrm{km}
\\ \int \limits_{1/r'_{+}}^{1/r'_{-}} \frac{ du }{\sqrt{ (u - 1/r_{+})(1/r_{-} - u ) + r_s u^3 }} \approx \pi + 0.7500001506 \, \pi r_s \left( \frac{1}{r_{+}} + \frac{1}{r_{-}} \right)
\\ \int \limits_{1/r_{+}}^{1/r_{-}} \frac{ \left( 1 + \frac{r_s}{2} u \right) du }{\sqrt{ (u - 1/r_{+})(1/r_{-} - u ) }} = \pi + \frac{r_s}{2} \int \limits_{1/r_{+}}^{1/r_{-}} \frac{ u du }{\sqrt{ (u - 1/r_{+})(1/r_{-} - u ) }} = \pi + \frac{\pi r_s}{4} \left( \frac{1}{r_{+}} + \frac{1}{r_{-}} \right)
\\ \left( 1 + \frac{ r_s}{2} \left( 1/r_{-} + 1/r_{+} \right) \right) \left( \pi + \frac{\pi r_s}{4} \left( \frac{1}{r_{+}} + \frac{1}{r_{-}} \right) \right) \approx \pi + \frac{3 \pi r_s}{4} \left( \frac{1}{r_{+}} + \frac{1}{r_{-}} \right)
$$
