The axial force balancing capacity of a balance drum is a key factor affecting the life of multi-stage centrifugal pumps. In this paper, a double shell segmental multistage pump is taken as the ...research object. The hydraulic performance and axial force performance are set as the optimization objectives, and the performance data are obtained by numerical simulation with FLUENT software. The BP neural network is used to establish the prediction model of structural parameters of the balance system, hydraulic performance and residual axial force performance, and it is used as the adaptive value evaluation model of genetic algorithm to solve the optimal value in the sample space. The results show that the radial clearance of the balance drum and the balance tube orifice flowmeter, the axial width of the balance cavity are the significant factors affecting the hydraulic performance and axial force performance of the multistage pump. When the radial clearance of the balance drum is 0.1mm, the clearance of the orifice flowmeter is 1.95mm, and the axial width of the balance cavity is 55mm, the multi-stage pump has the best hydraulic performance and the smallest residual axial force. The vortex band in the balance cavity can increase the amount of the fluid spin and enhance the axial force balancing capacity of the balance drum. The greater the area occupied by the negative high-rotation fluid in the balance cavity, the stronger the ability of the balance drum to balance the axial force. The test results show that compared with the prototype multistage pump, at nominal flow rate, the head and efficiency of the optimized model are increased by 0.71% and 1.63% respectively, and the bearing temperature and vibration speed of the multi-stage pump are significantly reduced. KCI Citation Count: 0
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•CoMFA models were built to explore the pungency of capsaicin-like dietary components.•Pharmacophore models were established to improve the pungent understanding.•The (un)favorable ...steric and electrostatic interactions were visualized and explained.•The predicted pungency of 21 capsaicin analogs were compared with experimental data.
The mechanistic insights into the oral pungency of capsaicin-related dietary components have been elucidated from the spatial structural perspectives by establishing statistically significant and highly predictive three-dimensional quantitative structure–property relationship models. Our results visualized the possible favorable and unfavorable steric and electrostatic interactions with the pungent receptors with the assistance of pharmacophore models, and revealed the suitable electronegative/positive or bulky substitutions in the vanillyl group, amide moiety, linear alkyl chain and their adjacent structural area of capsaicin required for the desired pungency, which was not only complementary to the viewpoints proposed in our previous structure-pungency correlations, but also was applied to clearly clarify the pungent differences in compounds, and well predict the pungency of 21 capsaicin analogs though with ambiguous experimental data on pungency. Hopefully, this work would benefit the overall understanding of the pungent mechanism and facile discovery/design of analogs with desired pungency to expand their applications in foods.
The purpose of this study was to investigate the antifibrotic effect and anticoagulant ability of salvianolic acid B (SAB) inhalation solution on bleomycin (BLM)-induced idiopathic pulmonary fibrosis ...(IPF) in rats. We investigated how the osmotic pressure and concentration of SAB in an aerosol exerted effects. We also determined the aerodynamic particle size distribution and the uniformity of the delivery dose; these parameters were found to be suitable for inhalation. Compared with BLM group, the levels of hydroxyproline (HYP), collagen-1 (Col-1), tissue factor (TF) / coagulation factor VII (TF-VIIa), activated coagulation factor X (FXa), thrombin-antithrombin complex (TAT), fibrinogen degradation product (FDP) and plasminogen activator inhibitor-1 (PAI-1) decreased in SAB group. The increased expression of coagulation factor Ⅱ (FⅡ), coagulation factor X (FX), tissue type plasminogen activator (t-PA) and urokinase type plasminogen activator (u-PA) proved that SAB has obvious antifibrotic and anticoagulant effects. Western blotting and immunofluorescence further showed that compared with the BLM group, the SAB group of rats exhibited significant reductions in the expression levels of protease-activated receptors-1 (PAR-1) and phospho-protein kinase C (p-PKC) and increased expression levels of protein kinase C (PKC) in lung tissue. Furthermore, SAB reduced the infiltration of lymphocytes and neutrophils, protected the basic structure of the lung from destruction, inhibited the proliferation of fibrous tissue. Collectively, our data revealed that SAB may exert its antifibrotic and anticoagulant effects by preventing the expression of PAR-1 and phosphorylation of PKC.
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•Atomization inhalation improves the effect.•PAR-1 leads to phosphorylation of PKC.•Thrombin is to contribute to the IPF.
E-waste recycling is well known for releasing halogenated organic compounds (HOCs) and heavy metals. This study investigated the occurrence and distribution of traditional and novel classes of ...contaminants, including chlorinated, brominated, and mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and polyhalogenated carbazoles (PHCZs), in soil from an e-waste disposal site in Hangzhou. PBDEs were the most abundant, at 343–69306 ng kg−1, followed by PHCZs (896–41,362 ng kg−1), PCDD/Fs (349–19,396 ng kg−1), PCBs (51.3–1834 ng kg−1), PBDD/Fs (2.99–524 ng kg−1) and PXDD/Fs (0.104–21.2 ng kg−1). The detected target compound concentrations were generally lower than those reported in the literature for informal e-waste sites. Nevertheless, they can serve as a basis of information for evaluation and subsequent control. The toxic equivalent (TEQ) contributions from these contaminants (except PBDEs) decreased as follows: PCDD/Fs > PXDD/Fs > PHCZs > PCBs > PBDD/Fs. ΣDioxins (PCDD/Fs + PBDD/Fs + PXDD/Fs) accounted for 47.7%–97.2% of the total TEQs in the soil. OCDD, 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from combustion and transport because of their low saturated vapor pressure. PXDFs were more abundant than PXDDs, and homologue profiles suggested a similar formation mechanism for PXDFs and PBDFs involving successive Br-to-Cl exchange. PHCZs were reported in soil from an e-waste disposal area for the first time, and their concentrations were several orders of magnitude higher than those of the other contaminants. Although the risk of human exposure in this study was estimated to be lower than the values recommended by the WHO (1–4 pg TEQ/kg bw/day), health implications still exist, and further investigations are necessary.
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•PHCZs were reported in soil from e-waste recycling site (EWRS) for the first time.•The maximum concentrations of the target HOCs were 0.1–1.5 km away from the source.•The TEQ contribution decreased in the order of PCDD/Fs > PXDD/Fs > PHCZs > PCBs > PBDD/Fs.•A TDI assessment revealed minor impacts of EWRS on the surrounding residents.
Dissipative pure-quartic soliton (DPQS) that arises from the balance of positive fourth-order dispersion (FOD), nonlinearity, gain and loss has been proposed to generate high-energy pulse. Herein, we ...numerically investigate the generation of dissipative pure-quartic soliton resonance (DPQSR) in an Er-doped mode-locked fiber laser with all positive FOD. Our findings indicate that the formation of DPQSR depends on the reverse saturable absorption (RSA) effect of real saturable absorber. Then, the impacts of pump power, RSA coefficient and positive FOD in generating DPQSR pulse are investigated. With the increase of pulse energy, the asymmetrical temporal profile of DPQS transforms into a rectangular one. This work can be utilized to comprehend the dissipative pure-quartic soliton resonance as well as the development of an all positive FOD Er-doped fiber laser. In addition, it lays the way for the development of highly stable, high-energy pulsed lasers.
•The dissipative pure-quartic soliton resonance in Er-doped mode-locked fiber laser is obtained by simulation.•The results demonstrate the formation of DPQSR depends on the reverse saturable absorption effect.•The impacts of pump power, RSA and positive FOD coefficient in generating DPQSR pulse are investigated.
The occurrence of pulsating behavior is a prevalent phenomenon that has been observed in various nonlinear dissipative systems, hence showcasing an extensive variety of intriguing nonlinear dynamics. ...Herein, we undertake a numerical analysis to investigate the evolution dynamics of dichromatic soliton molecule (DSM) which consist of two dissipative solitons with varying frequencies. The simulation model is built upon two cubic-quintic Ginzburg-Landau equations that are coupled with a cross phase modulation (XPM) term. The results reveal a transition from a stationary DSM to various forms of pulsating DSMs. In addition, the influence of the coupling parameters has also been discussed. These findings show the existence of out-of-phase temporal vibrations trajectories due to the presence of unbalanced nonlinear gain, resembling the behavior observed in coupled harmonic mechanical oscillators. Our investigation is expected to enhance the comprehension of the fundamental physical mechanisms involved, hence promoting subsequent experimental inquiries into the complex dynamics of soliton molecules in dissipative systems.
•Internal dynamics of dichromatic soliton molecule (DSM) is numerically simulated.•Numerical simulations reveal a transition from a stationary DSM to various forms of pulsating DSMs.•Out-of-phase temporal vibrations trajectories can be observed in the pulsating dynamics between two solitons.
A high-sensitivity curvature sensor with dual-parameter measurement ability based on angularly cascaded long-period fiber grating (AC-LPFG) is proposed and experimentally demonstrated, which consists ...of two titled LPFGs (TLPFGs) with different tilt angles and the same grating period. AC-LPFG was fabricated by using a deep ultraviolet laser and an amplitude-mask in our laboratory. The experimental results show that simultaneous measurement of curvature and temperature can be achieved by monitoring the wavelengths of two resonant peaks for different TLPFGs. The two peaks show opposite shifts with increasing curvature and has a maximum curvature sensitivity of 16.392 nm/m
. With the advantages of low cost, high sensitivity, and dual-parameter measurements, our sensor has more potential for engineering applications.
In the paper, a novel reflective all-fiber integrated sensor for simultaneous gas pressure and temperature sensing has been proposed and demonstrated in experiment. The proposed sensor is fabricated ...by combining seven core fibers (SCFs), a twin-hole and dual-core fiber (THDCF), a single-mode fiber (SMF) extrinsic Fabry-Perot interferometer (FPI) and a fiber Bragg grating (FBG). The FPI section and FBG section act as a pressure and temperature sensing unit. Especially, the MZI has the effect of filtering the FPI spectrum and is more conducive to the demodulation of the FPI reflected signal. In FPI section, the two SMFs connects with a hollow core capillary (HCC) by the ultraviolet (UV) curing glue. The sensor exhibits a high pressure and temperature sensitivity of 13.10 nm/MPa and 0.20 nm/°C in the range of 0.1-1.2 MPa and 30-90 °C, respectively. The FBG works as a temperature sensor without pressure responding, is fabricated by using the UV laser-based phase mask technology in our lab. By utilizing the dual-wavelength matrix method, both gas pressure and temperature can be measured simultaneously. In sum, with the advantage of compact size, easy fabricated, low cost, high sensitivity, reflection-type and the ability of multi-parameter measurement, our sensor is more competitive in harsh environments.
•Multimode interference all-fiber filter based on cascaded seven-core fiber (SCF)-twin-hole twin-core fiber (THDCF)-SCF hybrid structure is experimentally fabricated.•Wavelength-tunable mode-locked ...fiber lasers using a bending-based mechanism is achieved.•Continuous wavelength tuning range of 25 nm from 1558 nm to 1583 nm with a tuning efficiency of −3.38 nm/m−1 is obtained.
Wavelength-tunable mode-locked fiber lasers are highly versatile and find applications in pump–probe measurement, optical communications, optical parametric oscillation, among others. Herein, we introduce a novel approach for tuning carbon nanotube-based passively mode-locked fiber laser using a bending-based mechanism. Our method involves a bending strain controlled multimode interference all-fiber filter. This filter consists of a hybrid structure built from a cascaded seven-core fiber (SCF)-twin-hole twin-core fiber (THDCF)-SCF. It achieves a continuous wavelength tuning range of 25 nm from 1558 nm to 1583 nm with a tuning efficiency of −3.38 nm/m−1. By increasing the pump power, the dual-wavelength locked modes are also achieved at specific curvature. Owing to advantages of simple structure, low cost, and high bending sensitivity, our tunable filter shows promise for efficient wavelength tuning in ultrafast fiber laser.
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