Research Square (Research Square),
Journal Year:
2021,
Volume and Issue:
unknown
Published: Aug. 30, 2021
Abstract
Phosphorus
(P)
plays
an
important
role
in
eutrophication
and
algal
adaptation
to
environmental
stresses;
therefore,
a
better
understanding
of
the
impact
P
is
essential
control
cyanobacterial
bloom.
In
this
study,
Microcystis
aeruginosa
was
treated
with
5-h
ambient
irradiation
culture
medium
different
availability
dissolved
organic
(DOP)
matter
(DOM),
explore
responses.
Compared
photosynthetically
active
radiation
(PAR),
UV-A
UV-B
exerted
oxidative
stresses
had
inhibitive
effects
on
growth
photosynthesis
M.
DOP-rich
medium.
However,
strong
capability
negative
UV
were
eliminated
DOM
addition
(5
mg
L
−
1
humic
acid
[HA]).
Combining
inorganic
(DIP)
DOP
contents
medium,
waters
could
be
mainly
achieved
through
hydrolysis
metabolism
DIP,
utilization
behaviors
greatly
affected
its
capability.
without
DOM,
APase
inactivation
after
negatively
by
,
demand
for
not
fully
met.
act
as
antioxidant
decreased
radiation,
when
utilized
faster
produce
more
DIP
increase
carotenoid,
phycocyanin
production
superoxide
dismutase
(SOD)
activity
resulting
Consequently,
showed
lowest
DOP-free
Overall,
our
findings
indicated
close
relationship
typical
cyanobacteria
DIP-limited
DOP-enriched
natural
waters.
Water,
Journal Year:
2020,
Volume and Issue:
12(4), P. 953 - 953
Published: March 27, 2020
Lake
Hulun,
the
fifth
largest
lake
in
China,
is
a
typical
eutrophic
steppe
located
Hulun
Buir
Prairie.
The
dissolved
organic
matter
(DOM)
water
of
has
high
concentration.
However,
little
known
about
occurrence
characteristics
and
source
DOM
Hulun.
spatial
temporal
distribution
concentration
were
thoroughly
surveyed,
optical
characteristics,
fluorescence
components
sources
analyzed
by
excitation
emission
matrix
(EMM)
parallel
factor
analysis
(PARAFAC)
technology.
was
6.46–42.87
mg
C/L,
highest
summer
lowest
winter.
difference
winter
significant
due
to
ice
over,
showed
trend
where
near
shore
higher
than
that
center
lake.
Three
humic-like
one
component
consisting
mixture
protein-like
substances
identified,
with
former
being
prevalent.
humification
index
2.22–9.92,
indicating
degree
humification.
mainly
derived
from
terrestrial
sources,
proportion
(91.0%
±
8.1%)
found
(66.2%
7.7%)
summer.
Given
dominated
humification,
may
have
low
bioactivity.
this
just
preliminary
judgment,
it
necessary
conduct
other
experiments
such
as
biodegradation
further
study
bioavailability
Water,
Journal Year:
2020,
Volume and Issue:
12(8), P. 2278 - 2278
Published: Aug. 13, 2020
Decaying
algal
blooms
in
eutrophic
lakes
can
introduce
organic
matter
into
the
water
and
change
nutrient
concentrations
column.
The
spatial
distribution
composition
characteristics,
sources,
contribution
to
eutrophication
of
dissolved
(DOM)
overlying
Lake
Taihu,
a
typical
lake
China,
were
analyzed
by
ultraviolet–visible
spectra
three-dimensional
fluorescence
excitation–emission
matrix
combined
with
statistical
decomposition
technique,
parallel
factor
analysis.
concentration
DOM
was
represented
carbon
(DOC),
DOC
Taihu
2.86–11.83
mg/L.
colored
(CDOM)
characterized
an
absorption
coefficient
at
280
nm
(a280)
350
(a350),
which
6.63–29.87
1.84–10.41
m−1,
respectively.
These
values
showed
increasing
trend
from
southeast
northwest,
high
concentrated
northwest
northern
areas.
analysis
(PARAFAC)
identified
two
protein-like
(C1:
tyrosine-like
C2:
tryptophan-like)
one
humic-like
(C3:
humic
acid
fulvic
acid)
components
for
fluorescent
(FDOM).
most
dominant
(C1
+
C2),
whose
intensity
contributed
87.55%
±
3.39%
total
(Ft)
FDOM
(3.38
R.U.).
mean
value
index
(FI)
recent
autochthonous
(BIX)
1.77
0.92,
DOC,
a280
intensities
all
significantly
positively
correlated
chl.
a,
indicating
that
DOM,
CDOM,
mainly
derived
activities
metabolites.
average
humification
0.66,
indicated
low
degree.
DON
DOP,
might
make
great
contributions
continuous
occurrence
blooms.
Remote Sensing,
Journal Year:
2021,
Volume and Issue:
13(18), P. 3560 - 3560
Published: Sept. 7, 2021
Chromophoric
dissolved
organic
matter
(CDOM)
is
crucial
in
the
biogeochemical
cycle
and
carbon
of
aquatic
environments.
However,
inland
waters,
remotely
sensed
estimates
CDOM
remain
challenging
due
to
low
optical
signal
complex
conditions.
Therefore,
developing
efficient,
practical
robust
models
estimate
absorption
coefficient
waters
essential
for
successful
water
environment
monitoring
management.
We
examined
improved
different
machine
learning
algorithms
using
extensive
measurements
Landsat
8
images
covering
trophic
states
develop
estimation
model.
The
were
evaluated
via
111
1708
field
light
a(254)
from
2.64
34.04
m−1.
Overall,
four
achieved
more
than
70%
accuracy
estimation.
Based
on
model
training,
validation
application
OLI
images,
we
found
that
Gaussian
process
regression
(GPR)
had
higher
stability
(R2
=
0.74,
mean
relative
error
(MRE)
22.2%)
other
models.
MRE
R2
0.75
22.5%
backpropagation
(BP)
neural
network,
0.71
24.4%
random
forest
(RFR)
support
vector
(SVR).
In
contrast,
best
three
empirical
accuracies
less
0.56.
applied
Lake
Qiandaohu
(oligo-mesotrophic
state)
better
those
Taihu
(eutrophic
because
conditions
eutrophic
lakes.
have
great
potential
based
large
datasets.
Our
study
demonstrates
are
available
map
spatial-temporal
patterns
waters.
Materials Chemistry Frontiers,
Journal Year:
2021,
Volume and Issue:
5(17), P. 6575 - 6581
Published: Jan. 1, 2021
Two
2D
COFs
containing
both
electron
acceptors
and
donors
were
prepared
successfully.
The
charge-transfer
process
results
in
distinct
near-infrared
absorption
properties
which
make
them
good
NIR
photothermal
materials.
