16 research outputs found
Smooth-Muscle BMAL1 Participates in Blood Pressure Circadian Rhythm Regulation
As the central pacemaker, the suprachiasmatic nucleus (SCN) has long been considered the primary regulator of blood pressure circadian rhythm; however, this dogma has been challenged by the discovery that each of the clock genes present in the SCN is also expressed and functions in peripheral tissues. The involvement and contribution of these peripheral clock genes in the circadian rhythm of blood pressure remains uncertain. Here, we demonstrate that selective deletion of the circadian clock transcriptional activator aryl hydrocarbon receptor nuclear translocator-like (Bmal1) from smooth muscle, but not from cardiomyocytes, compromised blood pressure circadian rhythm and decreased blood pressure without affecting SCN-controlled locomotor activity in murine models. In mesenteric arteries, BMAL1 bound to the promoter of and activated the transcription of Rho-kinase 2 (Rock2), and Bmal1 deletion abolished the time-of-day variations in response to agonist-induced vasoconstriction, myosin phosphorylation, and ROCK2 activation. Together, these data indicate that peripheral inputs contribute to the daily control of vasoconstriction and blood pressure and suggest that clock gene expression outside of the SCN should be further evaluated to elucidate pathogenic mechanisms of diseases involving blood pressure circadian rhythm disruption
Stability, microstructure and mechanical properties of (Al,Fe)<sub>2</sub>TiO<sub>5</sub> porous ceramic reinforced by in-situ mullite
Ind. Eng. Chem. Res.
Gasification of coal and biomass is in pursuit of the technologies based on dual bed combination and a high-density transport bed. Dual fluidized bed gasification (DFBG) relies on rapidly circulated particles between its combustor and gasifier to provide the endothermic heat required by the gasification. High-density transport bed gasification (HTBG) has to work with a high solid flux and a high particle density inside its gasifier so as to increase the heat reserve in the bed and to suppress tar evolution there. The idea of coupling a moving bed to the bottom section of the riser of a circulating fluidized bed (CFB) was proposed to realize the desired high solid-flux conveying flow inside the riser. Experiments in a 12-m high and 90 mm i.d. riser of the newly configured CFB demonstrated that at superficial gas velocities of about 9.6 m/s, a solid circulation rate as high as 370 kg/(m(2) s) and all average solid holdup of about 0.12 in the bottom section of the riser were readily achieved simultaneously for the silica sand particles of 378 mu m in Sauter mean diameter. Parametric investigation further clarified that the solid circulation rate and the local solid holdup at the riser bottom of the newly configured CFB were highly dependent on the moving bed aeration and the primary gas velocity of the riser, whereas changing the solid inventory in the system did not greatly affect those two variables. Adoption of a secondary air injection into the riser enabled adjustment of the solid circulation rate within a certain range, showing essentially a complementary rneans for controlling the gas-solid flow inside the riser of the newly configured CFB.Gasification of coal and biomass is in pursuit of the technologies based on dual bed combination and a high-density transport bed. Dual fluidized bed gasification (DFBG) relies on rapidly circulated particles between its combustor and gasifier to provide the endothermic heat required by the gasification. High-density transport bed gasification (HTBG) has to work with a high solid flux and a high particle density inside its gasifier so as to increase the heat reserve in the bed and to suppress tar evolution there. The idea of coupling a moving bed to the bottom section of the riser of a circulating fluidized bed (CFB) was proposed to realize the desired high solid-flux conveying flow inside the riser. Experiments in a 12-m high and 90 mm i.d. riser of the newly configured CFB demonstrated that at superficial gas velocities of about 9.6 m/s, a solid circulation rate as high as 370 kg/(m(2) s) and all average solid holdup of about 0.12 in the bottom section of the riser were readily achieved simultaneously for the silica sand particles of 378 mu m in Sauter mean diameter. Parametric investigation further clarified that the solid circulation rate and the local solid holdup at the riser bottom of the newly configured CFB were highly dependent on the moving bed aeration and the primary gas velocity of the riser, whereas changing the solid inventory in the system did not greatly affect those two variables. Adoption of a secondary air injection into the riser enabled adjustment of the solid circulation rate within a certain range, showing essentially a complementary rneans for controlling the gas-solid flow inside the riser of the newly configured CFB
A Review on Thomson Coil Actuators in Fast Mechanical Switching
With the rapid development of DC power systems and the increasing demand for DC circuit breakers, electromagnetic repulsive drives-based Thomson coil actuators (TCA) are widely investigated to provide the high-speed actuating required for ultra-fast mechanical switches, especially those used in hybrid DC circuit breakers. The actuating mechanism is required to be fast, reliable, and economic. This article summarizes the development of Thomson coil actuators in circuit breakers in recent years, further illustrating the basic principles and the actuator topology. In addition, it discusses the various structural components of TCA and describes the utilized modeling and simulation methods. The main objective was to provide a comprehensive overview of the TCA field
<span style="mso-fareast-font-family:SimHei" lang="EN-US">Influence of MoO<sub>4</sub><sup>2-</sup> <span style="mso-fareast-font-family:SimHei" lang="EN-US">on crystalline perfection and optical properties of potassium dihydrogen phosphate (KDP) crystal </span></span>
105-110A series of KDP crystals are grown by rapid
growth method by altering the concentrations of the MoO42-
in the range from 0 to 500 ppm (mol ratio). The growth habits of the KDP
crystals suggest that MoO42- possess the similar effect
with metallic cations, which can inhibit the growth of prismatic faces of KDP
crystal. Lower concentrations of MoO42- could induce
liquid inclusions in the prismatic sector. The liquid inclusions overlapped
with each other. However, higher concentrations of MoO42-
can cause detached rod-like liquid inclusions in the pyramidal sector. With a
rise of MoO42- concentration, the static extinction ratio
of KDP crystals decreased, and the full width at half maximum of the rocking
curves is broadened. MoO42- enhanced the transmittance in
the range of 200-400 nm for prismatic sector, which is attributed to that MoO42-
is prone to be absorbed onto (100) face, and consequently blocked and the
entrance probability of metallic cations into KDP crystal. The conoscopic
interference indicates the optical homogeneity of KDP crystal is spoiled by MoO42-.
Additionally, MoO42- can increase the density of light
scatters and the size of single light scatter
TBM Rapid Tunneling Roadway Support Parameters Design and Process Research
Taking the specific production geological conditions of the auxiliary transportation lane in the west area of Gaojiabao coal mine of Shaanxi Zhengtong Coal Industry as the research background, based on the anchorage support theory and the characteristics of the TBM digging process, numerical simulation, theoretical analysis, and other research methods were used to investigate the depth of the destruction of the plastic zone of the surrounding rock of the roadway to form the reasonable support parameters of a large cross-section of hard rock roadway suitable for TBM digging and to propose an intelligent digging and support process of the TBM corresponding to the on-site practice. The proposed intelligent tunneling support technology corresponds to a field practice of TBM. The study shows that: combined with the field industrial test and adjusted by the peripheral rock deformation and damage law, the anchor diameter of 20 mm, the length of 2500 mm left-hand threaded steel anchors, row spacing of 1100 mm, spacing of 1200 mm, and the anchor diameter of Φ21.8 mm, the length of 6200 mm left-handed threaded steel anchors, row spacing of 1100 mm, spacing of 1200 mm are the most reasonable solutions, which can ensure the control of the tunnel peripheral rock. The program is the most economically efficient in ensuring the control of deformation of the roadway perimeter rock and maintaining normal use