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"Huang, H. Z."
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Evolution Mechanism of Mesocrack and Macrocrack Propagation in Carbonaceous Mudstone under the Action of Dry-Wet Cycles
2022
The crack propagation evolution of carbonaceous mudstone under the action of dry-wet cycles is an important cause of the unstable failure of this type of slope. This paper attempts to reveal the evolution mechanism of mesocrack and macrocrack propagation in carbonaceous mudstone under the action of dry-wet cycles from chemical, physical, and mechanical perspectives. Firstly, the soaking solution of carbonaceous mudstone during the dry-wet cycles was extracted for an ion concentration test to analyze the chemical reactions of carbonaceous mudstone. Then, CT scans were performed on the carbonaceous mudstone samples to study the changing pattern of mesostructure of carbonaceous mudstone during the dry-wet cycles. In the end, the mechanical properties and failure characteristics of carbonaceous mudstone after dry-wet cycles were studied by triaxial compression tests. The results showed that chemical reactions such as calcite dissolution, potassium feldspar hydrolysis, and sodium feldspar hydrolysis occurred during the dry-wet cycle of carbonaceous mudstone. Affected by the dry-wet cycles, the mesostructure of the carbonaceous mudstone gradually changed from face-face contact and edge-face contact to edge-corner contact and corner-corner contact, and the interlayer flake structure was opened and was locally curled and fractured. With the increase in the number of dry-wet cycles, the failure characteristic of carbonaceous mudstone transformed from tensile failure to shear failure, the failure surface of carbonaceous mudstone was deflected from 90° to 60°, and the crack propagation path of carbonaceous mudstone became more complicated. The chemical reaction of carbonaceous mudstone minerals during the dry-wet cycle is an important reason for the initiation and development of pores. The dry-wet cycle aggregates the propagation of mesocracks and structural disorder, transforming the uniform stress state of the rock mesostructure to the concentrated stress state, which is the important reason for the macrocrack propagation evolution of carbonaceous mudstone.
Journal Article
SMURF1-Interference Effects Autophagy and Pulmonary Fibrosis through SMAD7 and the TGF-β1/SMAD Pathway
by
Ye, X.-L.
,
Xue, D.
,
Chen, L.-M.
in
Biochemistry
,
Biomedical and Life Sciences
,
Cell Molecular Biology
2024
SMAD-specific E3 ubiquitin proten ligase 1 (SMURF1) is involved in transforming growth factor (TGF)-β1/Smad pathway-mediated tissue fibrosis. However, its role in pulmonary fibrosis and the related molecular mechanisms are still unclear. This study aims to investigate whether SMURF1 inhibits autophagy and promotes pulmonary fibrosis via SMAD family member 7 (SMAD7) and TGF-β1/SMAD signal pathway. MRC-5 cells were treated with TGF-β1 followed by
MURF1-
interference. The rate of cell migration was assessed using the cell scratch test. Autophagosomes were analyzed using a transmission electron microscope. mRNA levels of SMURF1, SMAD7, TGF-β1, phosphorylated (p)-SMAD1, p-SMAD3, α-smooth muscle actin (α-SMA), matrix metallopeptidase 7 (MMP7), microtubule-associated protein light chain 3 (LC3 ) and Beclin1 were evaluated by quantitative real-time PCR (qPCR), Western blotting, and immunofluorescence. The interaction between SMURF1 and SMAD7 was investigated in a co-immunoprecipitation (Co-IP) experiment. We found that after TGF-β1 treatment, the mRNA levels of SMURF1, α-SMA, MMP7, and p-Smad1/3 were increased, and the levels of Beclin1 and LC3 were decreased. Apart from these, cell autophagy was decreased, while the migration ability was increased. After SMURF1-interference, SMURF1, α-SMA and MMP7 mRNA levels were significantly decreased, p-SMAD1 was slightly reduced, and p-Smad3 was not changed. As for Beclin1 and LC3, their transcription increased, cell autophagy increased, and migratory ability decreased. The interaction between SMURF1 and Smad7 was confirmed by Co-IP. In conclusion, SMURF1 may inhibit autophagy and promote lung fibrosis by downregulating
SMAD7
and activating the TGF-β1/SMAD pathway. These results may serve as a basis for the development of new therapeutic targets in the pulmonary fibrosis clinic.
Journal Article
Different outcomes after intracytoplasmic sperm injection without oocyte activation in two patients with different types of globozoospermia
2016
Summary Different outcomes after intracytoplasmic sperm injection (ICSI) without oocyte activation in two patients with different types of round‐headed spermatozoa (globozoospermia) are reported. After controlled ovarian hyperstimulation and oocyte pick‐up, retrieved oocytes were underwent ICSI without oocyte activation and a 33.33% (4/12) fertilisation rate was obtained in the first case, whereas an abnormal fertilisation was achieved in the second case. The transfer of two grade II embryos in the first couple resulted in clinical pregnancy with a healthy livebirth. It was concluded that the main problem of cases with globozoospermia was a low fertilisation rate or failure fertilisation, and even though ICSI and artificial oocyte activation have been employed to increase this rate, it is not necessarily needed to achieve a pregnancy.
Journal Article
Geospace magnetic field responses to interplanetary shocks
by
Liu, J. B.
,
Li, H.
,
Kan, J. R.
in
Earth sciences
,
Earth, ocean, space
,
Exact sciences and technology
2009
We perform a statistical survey of geospace magnetic field responses, including the geosynchronous magnetic field and the sudden impulses on the ground, to interplanetary shocks (IP shocks) between 1998 and 2005. The magnitude of the geosynchronous magnetic field (dBz) responses to IP shocks depends strongly on local time, which peaks near the noon meridian; however, the relative magnitude of the responses depends only weakly on local time. These results are similar to those obtained from the statical study of the responses to solar wind dynamic pressure pulses. However, negative responses (where dBz is negative) were sometimes observed in the nightside of the magnetosphere even though the IP shocks always caused increases in the solar wind dynamic pressure, a new phenomenon not widely reported in the literature. Our analysis shows that ∼75% of negative responses in the midnight sector are associated with southward interplanetary magnetic field. For a moderately compressed magnetosphere, the amplitude of the geosynchronous response dBz could be determined by the average value of the background local magnetic field. As the magnitude of the upstream solar wind dynamic pressure increases, the rate of response increases correspondingly. The dBz at the geosynchronous orbit near local noon and the amplitude of sudden impulses (dSYM‐H) on the ground are highly correlated.
Journal Article
The CUPID-Mo experiment for neutrinoless double-beta decay: performance and prospects
2020
CUPID-Mo is a bolometric experiment to search for neutrinoless double-beta decay (
0
ν
β
β
) of
100
Mo
. In this article, we detail the CUPID-Mo detector concept, assembly and installation in the Modane underground laboratory, providing results from the first datasets. The CUPID-Mo detector consists of an array of 20
100
Mo
-enriched 0.2 kg
Li
2
MoO
4
crystals operated as scintillating bolometers at
∼
20
mK
. The
Li
2
MoO
4
crystals are complemented by 20 thin Ge optical bolometers to reject
α
events by the simultaneous detection of heat and scintillation light. We observe a good detector uniformity and an excellent energy resolution of 5.3 keV (6.5 keV) FWHM at 2615 keV, in calibration (physics) data. Light collection ensures the rejection of
α
particles at a level much higher than 99.9% – with equally high acceptance for
γ
/
β
events – in the region of interest for
100
Mo
0
ν
β
β
. We present limits on the crystals’ radiopurity:
≤
3
μ
Bq/kg
of
226
Ra
and
≤
2
μ
Bq/kg
of
232
Th
. We discuss the science reach of CUPID-Mo, which can set the most stringent half-life limit on the
100
Mo
0
ν
β
β
decay in half-a-year’s livetime. The achieved results show that CUPID-Mo is a successful demonstrator of the technology developed by the LUMINEU project and subsequently selected for the CUPID experiment, a proposed follow-up of CUORE, the currently running first tonne-scale bolometric
0
ν
β
β
experiment.
Journal Article
Cosmogenic background study for a 100Mo-based bolometric demonstration experiment at China JinPing underground Laboratory
2022
We perform simulation study for a 10-kg 100Mo-based bolometeric demonstration experiment for neutrinoless double-beta decay (0νββ) search at China JinPing underground Laboratory (CJPL). Cosmogenic production of radionuclides in 100Mo-enriched lithium molybdate crystals and copper components of the detector system are studied using Geant4 toolkit based on the simulated cosmic ray data from the CRY library. Background energy spectra of the cosmogenic radionuclides including 56Co, 82Rb and 88Y which are harmful for the 100Mo-based 0νββ experiment are investigated. We then evaluate the total cosmogenic background level in the 100Mo 0νββ search energy region of interest (ROI) for the demonstration experiment. After one year of cooling down underground, the residual background contribution is found to be 1.8 × 10-6 cts/kg/keV/yr and 3.3×10-4 cts/kg/keV/yr from crystals and copper components, respectively. Furthermore, underground cosmogenic activation of copper and lithium molybdate crystal is calculated based on the simulation spectra of neutron and proton in CJPL. The underground cosmogenic background is found to be negligible in the ROI.
Journal Article
The projected background for the CUORE experiment
by
Lim, K. E.
,
Hickerson, K. P.
,
Benato, G.
in
Astronomy
,
Astrophysics and Cosmology
,
Beta decay
2017
The Cryogenic Underground Observatory for Rare Events (CUORE) is designed to search for neutrinoless double beta decay of
130
Te with an array of 988 TeO
2
bolometers operating at temperatures around 10 mK. The experiment is currently being commissioned in Hall A of Laboratori Nazionali del Gran Sasso, Italy. The goal of CUORE is to reach a 90% C.L. exclusion sensitivity on the
130
Te decay half-life of 9
×
10
25
years after 5 years of data taking. The main issue to be addressed to accomplish this aim is the rate of background events in the region of interest, which must not be higher than 10
-
2
counts/keV/kg/year. We developed a detailed Monte Carlo simulation, based on results from a campaign of material screening, radioassays, and bolometric measurements, to evaluate the expected background. This was used over the years to guide the construction strategies of the experiment and we use it here to project a background model for CUORE. In this paper we report the results of our study and our expectations for the background rate in the energy region where the peak signature of neutrinoless double beta decay of
130
Te is expected.
Journal Article
A new class of penalized NCP-functions and its properties
2011
In this paper, we consider a class of penalized NCP-functions, which includes several existing well-known NCP-functions as special cases. The merit function induced by this class of NCP-functions is shown to have bounded level sets and provide error bounds under mild conditions. A derivative free algorithm is also proposed, its global convergence is proved and numerical performance compared with those based on some existing NCP-functions is reported.
Journal Article
Predictor-corrector smoothing Newton method, based on a new smoothing function, for solving the nonlinear complementarity problem with a P0 function
2003
By smoothing a perturbed minimum function, we propose in this paper a new smoothing function. The existence and continuity of a smooth path for solving the nonlinear complementarity problem (NCP) with a P0 function are discussed. We investigate the boundedness of the iteration sequence generated by noninterior continuation/smoothing methods under the assumption that the solution set of the NCP is nonempty and bounded. Based on the new smoothing function, we present a predictor-corrector smoothing Newton algorithm for solving the NCP with a P0 function, which is shown to be globally linearly and locally superlinearly convergent under suitable assumptions. Some preliminary computational results are reported.
Journal Article
Effects of the addition of ethanol and cetane number improver on the combustion and emission characteristics of a compression ignition engine
2008
Abstract
Combustion and emission characteristics of a direct-injection diesel engine fuelled with diesel—ethanol blends were investigated. The results show that the ignition delay and the premixed combustion duration increase, while the diffusive combustion duration and the total combustion duration decrease with increase in the oxygen mass fraction in the blends. The addition of 0.2 per cent volume fraction of cetane number improver (isoamyl nitrite) could mean that the ignition delay and the premixed combustion duration of the fuel blends with 10vol% ethanol fraction recover to those of diesel fuel. Meanwhile, with the increase in the ethanol fraction in the fuel blends, the centre of the heat release curve moves closer to the top dead centre. The brake specific fuel consumption increases, while the diesel equivalent brake specific fuel consumption decreases with increase in the ethanol fraction. The exhaust smoke concentration increases and exhaust nitrogen oxide (NO
x
) concentration decreases on prolonging the fuel delivery advance angle for both diesel fuel and the blended fuels. For a specific fuel injection advance angle, the exhaust smoke concentration shows a large decrease and the exhaust NO
x
concentration a small decrease on ethanol addition.
Journal Article