正如你在图片中看到的（红线），空格之内脚注存在。我尝试使用这两个命令：
\setlength{\footnotesep}{1pt} % space between footnotes
\setlength{\skip\footins}{1cm} % space between body text and footnoes
我使用\setstretch{1.3}命令。
我想要的是清除脚注文本内的间距，与正文不同。
A平均能量损失是：
\documentclass[a4paper, 12pt]{book}
%\usepackage[french]{babel}
\usepackage[backend=bibtex,
hyperref=true,
url=false,
isbn=false,
backref=false,
style=numeric-comp,
maxcitenames=3,
maxbibnames=100,
block=none]{biblatex}\usepackage[colorlinks=true]{hyperref}
\usepackage{manyfoot}
\ExecuteBibliographyOptions{citetracker=true,sorting=none}
% Citation footnotes: use \footnoteA
\DeclareNewFootnote{A}
% Vanilla footnotes: use \footnoteB
\DeclareNewFootnote{B}
% Number of each bibliography entry in brackets
\DeclareFieldFormat{labelnumberwidth}{\mkbibbrackets{#1}}
\makeatletter
\newtoggle{brkText}
% Citation number in brackets
\renewcommand\@makefntext[1]{%
\iftoggle{brkText}
{\normalfont[\@thefnmark]\enspace #1}
{\mkbibsuperscript{\normalfont\@thefnmark}\enspace #1}%
\global\togglefalse{brkText}}
%---------------------------------------------------------------
% Mostly verbatim from Joseph Wright
% http://www.texdev.net/2010/03/08/biblatex-numbered-citations-as-footnotes/
\DeclareCiteCommand{\bfcite}[\bracketing]%
{\usebibmacro{cite:init}%
%\let\multicitedelim=\supercitedelim
\iffieldundef{prenote}
{}
{\BibliographyWarning{Ignoring prenote argument}}%
\iffieldundef{postnote}
{}
{\BibliographyWarning{Ignoring postnote argument}}}
{\usebibmacro{citeindex}%
\usebibmacro{bfshortcite}%
\usebibmacro{cite:comp}}
{}
{\usebibmacro{cite:dump}}
\newbibmacro*{bfcite}{%
\ifciteseen
{}
{\xappto\cbx@citehook{%
\global\toggletrue{brkText}%
\noexpand\footnotetextA[\thefield{labelnumber}]{%
\fullcite{\thefield{entrykey}}\addperiod}}}}
\newbibmacro*{bfshortcite}{%
\ifciteseen%
{}%
{\iffieldequalstr{entrytype}{article}% checks if the entry type is "article",
% and if true, entry fields and punctuation are
% printed as specified below; if false, default
% biblatex citation scheme is used
{%
\xappto\cbx@citehook{%
\global\toggletrue{brkText}%
\noexpand\footnotetextA[\thefield{labelnumber}]{%
\entrydata{\thefield{entrykey}}{%
\usebibmacro{author/translator+others}\addperiod\addspace%
\usebibmacro{title}
\mkbibemph{\printfield{shortjournal}},\addspace%
\printfield{year}\addperiod}}}%
}%
{\usebibmacro{bfcite}}}}%
\newrobustcmd{\bracketing}[1]{%
\mkbibbrackets{#1}%
\cbx@citehook%
\global\let\cbx@citehook=\empty}
\let\brkText=\empty
%---------------------------------------------------------------
\makeatother
\usepackage{setspace}
\setstretch{1.3} % space between lines
\addbibresource{example_ref_list.bib}
\begin{document}
\chapter{Title}
\null\vfill\noindent
Vanilla footnote.\footnoteB{Vanilla footnote text.}
First citation\bfcite{Torquato2002}.
First citation\bfcite[e.g.][530]{Bernal1959}.
Vanilla footnote\footnoteB{Vanilla footnote text 2.}.
First ``multi'' citation\bfcite{Bernal1960,Bernal1959}.
\printbibliography
\end{document}
以及围兜条目：
@book{Torquato2002,
author = {Torquato, S.},
isbn = {978-0387951676},
publisher = {Springer},
title = {Random heterogeneous materials: microstructure and macroscopic properties},
year = {2002}
}
@article{Bernal1962,
author = {Bernal, J. D.},
doi = {10.1098/rspa.1964.0147},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical \& Engineering Sciences},
shortjournal = {Philos. Trans. R. Soc. A},
pages = {299--322},
title = {The Bakerian Lecture, 1962. The structure of liquids},
volume = {280},
year = {1964}
}
@article{Bernal1960,
author = {Bernal, J. D. and Mason, J.},
doi = {10.1038/188910a0},
journal = {Nature},
shortjournal = {Nature},
pages = {910--911},
publisher = {Nature Publishing Group},
title = {Packing of spheres: co-ordination of randomly packed spheres},
volume = {188},
year = {1960}
}
@article{Bernal1959,
author = {Bernal, J. D.},
doi = {10.1038/183141a0},
journal = {Nature},
shortjournal = {Nature},
pages = {141--147},
title = {A geometrical approach to the structure of liquids},
volume = {183},
year = {1959}
}
答案1
默认情况下，脚注与正文一样，都是单倍行距：
我猜测你的代码看起来像这样：
\documentclass{article}
\renewcommand{\baselinestretch}{1.5}
\usepackage{kantlipsum}
\begin{document}
\kant[1-2]
This is some text\footnote{Here is a footnote which goes on and on and on and on some more until it takes more than the rest of the line.}. This is some more\footnote{This is another footnote whose name is Harry. Harry is very, very pleased to meet you and ever so excited to be playing a part in this document.}
\end{document}
产生如下脚注：
这里的问题是使用
\renewcommand{\baselinestretch}{1.5}
不采取任何预防措施来避免不必要的间距错误。使用标准类（book、article、report）正确执行此操作的方法是使用setspace（或自行采取预防措施）：
\documentclass{article}
\usepackage{setspace}
\onehalfspacing
\usepackage{kantlipsum}
\begin{document}
\kant[1-2]
This is some text\footnote{Here is a footnote which goes on and on and on and on some more until it takes more than the rest of the line.}. This is some more\footnote{This is another footnote whose name is Harry. Harry is very, very pleased to meet you and ever so excited to be playing a part in this document.}
\end{document}
由于您没有提供最小工作示例（MWE），除了猜测之外，不可能做更多的事情。因此，如果这不是问题所在，请提供一份完整的、可编译的文档来说明该问题（并记住在发布未来问题时这样做）。
答案2
由于@cfr提供了一个简单的答案，但是，我的MWE涉及一些高级代码，我只是\setstretch{1.0}在里面添加了\@makefntext[1]：
\renewcommand\@makefntext[1]{%
\setstretch{1.0}
\iftoggle{brkText}
{\normalfont[\@thefnmark]\enspace #1}
{\mkbibsuperscript{\normalfont\@thefnmark}\enspace #1}%
\global\togglefalse{brkText}}