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•1-1/2 story substructures can better simulate seismic responses of the prototype.•Seismic behaviors of rehabilitated frames with exterior cantilevers were evaluated.•The validity of ...various retrofit strategies was verified and compared.•The seismic characteristics of a strengthened frame was enhanced substantially.
Due to inadequate lateral stiffness and insufficient structural redundancy, many single-span reinforced concrete (RC) frames were highly damaged or collapsed in previous earthquakes. This paper presents an experimental study on seismic performance of rehabilitated single-span RC frames. Four frames were strengthened using various retrofitting strategies and one non-retrofitted frame served as the reference specimen. All these frames were fabricated and tested under cyclic loadings. The failure modes, hysteretic behavior, skeleton curve, energy dissipation, strength and stiffness degradation of each frame were evaluated. The validity of different strengthening methods for improving frames’ failure mechanisms and seismic performances was verified. Test results indicated that strength, stiffness, as well as many seismic characteristics of the strengthened frames were improved substantially.
By means of first principles calculation and experiments, a detailed mechanism is proposed to include the stages of slip, adjustment, and expansion for the HCP → FCC phase transformation with the ...prismatic relation of Formula: see text and Formula: see text in titanium. It is revealed that the formation of four FCC layers is preferable after the slip of Shockley partial dislocations of 1/6 Formula: see text on Formula: see text planes, and that the adjustment of interplanar spacing and the volume expansion are energetically favorable and could happen spontaneously without any energy barrier. It is also found that the transformed FCC lattice first follows the c/a ratio (1.583) of HCP and then becomes an ideal FCC structure (c/a = √2). The proposed mechanism could not only provide a deep understanding to the process of HCP → FCC prismatic transformation in titanium, but also clarify the controversy regarding volume expansion of HCP-FCC phase transition of titanium in the literature.
•Bond behaviour between the deteriorated concrete and corroded deformed steel bars are studied.•The specimen failure mode is mainly splitting failure, but the mark of steel bars became unclear ...gradually.•The relative thickness of protective concrete has great effect on the ultimate bond strength.•Estimation model of bond strength between deteriorated concrete and corroded deformed steel bar was established.
An experimental investigation was conducted to explore the degradation model of bond stress between concrete and deformed steel bars with four different diameters (12, 16, 20 and 25mm) to determine the coupling effects on the bond between deteriorated concrete and corroded steel bars. The results indicated that the failure mode of the specimens was primarily splitting failure; however, the marks of the steel bars at the interface between the deteriorated concrete and corroded steel bars became unclear as the corrosion ratio increased. The ultimate bond strength of the two specimens with the smaller diameters increased with deterioration before a crack appeared and then it decreased, whereas that of the two specimens with the larger diameters continuously decreased due to smaller protective concrete thickness. A simplified calculation model of the bond strength between the cracked concrete and heavily corroded deformed steel bars was established based on the bonding theory of concrete and plane steel bars suing the following factors: the corrosion ratio of the steel bars, the compressive strength of concrete, the width of the cracks in the concrete and the friction factor between the deteriorated concrete and corroded steel bars.
This study investigated the potential effect of n-6/n-3 polyunsaturated fatty acids (PUFA) on inflammation and myocardial ischemic reperfusion injury (MIRI) in rats, together with the underlying ...protective mechanisms, and screen out most effective ratio of n-6/n-3 within limits. The rats with pre-infarct treatment were distributed among 5 groups according to the n-6/n-3 ratio (36:1; 1:1, 5:1, 10:1, 50:1); for the post-infarct treatment, the rats were distributed among 6 groups, including the control group (36:1) which was subjected to a sham procedure; the model group (36:1); and 4 test groups (n-6/n-3 ratio: 1:1, 5:1, 10:1, 50:1). All of the rats were fed a purple perilla seed oil and safflower oil-based fatty emulsion. The serum levels of monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were determined using enzyme-linked immunosorbent assay. Staining with triphenyl tetrazolium chloride, hematoxylin and eosin, or Masson’s trichrome was performed for histological examination. Cardiomyocyte apoptosis was examined by TUNEL assay. Western blotting was performed to examine the expression levels of apoptosis-related proteins and signaling pathway proteins. Our data indicate that in both the pre-infarct treatment and post-infarct treatment, low ratios of n-6/n-3 PUFAs significantly inhibited the levels of serum inflammatory factors, the infarct size of MIRI rats, number of cardiomyocytes undergoing apoptosis, and the expression levels of caspase-3, Bcl-2, and Bax in the MIRI group. Thus a low ratio of n-6/n-3 PUFAs ameliorates inflammation and myocardial ischemic reperfusion injury.
Finite Groups with Some Bounded Codegrees Yang, Dong Fang; Zeng, Yu; Lv, Heng
Acta mathematica Sinica. English series,
2024/7, Letnik:
40, Številka:
7
Journal Article
Recenzirano
For a character
χ
of a finite group
G
, the number cod(
χ
)≔ ∣
G
: ker(
χ
)∣/
χ
(1) is called the codegree of
χ
. In this paper, we give a solvability criterion for a finite group
G
depending on the ...minimum of the ratio
χ
(1)
2
/cod(
χ
), when
χ
varies among the irreducible characters of
G
.
Abstract
Objectives
To outline 44 major infectious diseases in the post-SARS (severe acute respiratory syndrome) in China and describe their long-term trends and changes by age, sex, epidemic season, ...and province.
Background
After the outbreak of severe acute respiratory syndrome (SARS) in 2003, with the change of infectious disease prevention and control system and the improvement of residents’ quality of life, the incidence and mortality of infectious diseases have undergone major changes.
Methods
The data of 44 major infectious diseases in China from 2004 to 2018 were obtained from the monthly analysis report of the China Information System for Disease Control and Prevention (CISDCP) and the Public Health Science Data Center. Joinpoint r regression models were used to examine trends in incidence and mortality for 44 major and important infectious diseases from 2004 to 2018.
Results
From 2004 to 2018, 20,105, 500, 772 patients (10, 306, 546, 523 males and 9, 798, 954, 249 females) were diagnosed with 44 major infectious diseases. The overall incidence of 44 infectious diseases increased significantly from 294.6 per 100,000 people in 2004 to 479.1 per 100,000 people in 2010, with 7.9% APC (95% CI 5.2% -10.7%,
P
< 0.001), then slowed, and then increased to 561.2 per 100,000 people in 2018, with 1.5% APC (-0.1%—3.2%,
P
= 0.070). The overall mortality rose significantly, from 0.49 to 1.13 per 100,000 people between 2004 and 2011, with an APC increase of 11.6% (7.7% -15.6%,
P
< 0.001), and then remained stable until 2018. Among these, the prevalence of vaccine-preventable diseases and gastrointestinal & enteroviral diseases remained high and increased year by year. Patients with zoonotic diseases have the greatest risk of death, while patients with sexually transmitted and blood-borne diseases have the greatest number of deaths. Incidence rates vary considerably across geographic regions. Western China has a disproportionate burden of infectious diseases compared with eastern regions.
Conclusions
After the event of SARS in 2003, infectious disease preventing and controlling model has undergone major changes in China, and certain achievements have been made in this field. Although overall morbidity and case fatality rates are still rising, they have leveled off. In reducing the disproportionate disease burden in the western region, expanding vaccination programs, preventing further increases in rates of sexually transmitted diseases, renewing efforts for emerging and persistent infectious diseases, and addressing seasonal and unpredictable outbreaks (such as the COVID-19 pandemic), there are still remain many challenges.
Abstract
Barium titanate/polyvinylidene fluoride (BaTiO3/PVDF) piezoelectric membrane was successfully prepared and generated in-situ vibrations to reduce membrane fouling by applying alternating ...current (AC) signal for oily bilge water ultrafiltration. The effect of in-situ vibration on membrane fouling was investigated through changing in the excitation alternating voltage and its frequency, pH, crossflow rate. The results indicated that the piezoelectric membrane by applying AC signal remarkably alleviated the membrane fouling for bilge water ultrafiltration. The membrane fouling decreased with increasing the AC signal voltage. The final steady-state permeate flux from the piezoelectric membrane for bilge water ultrafiltration increased with the AC signal voltage, raising it by up to 63.4% at AC signal voltage of 20 V compared to that of the membrane without applying AC voltage. The high permeate flux was obtained at the resonant frequency of 220 kHz. During the 50-h ultrafiltration of bilge water with the piezoelectric membrane excited at 220 kHz and 15 V, the permeate flux from the membrane was stable. The oil concentration in outflow from the piezoelectric membrane was below 14 ppm, which met the discharged level required by IMO convention. The total organic carbon removal rate in bilge water was over 94%.
Hemorrhagic fever with renal syndrome (HFRS), caused by hantavirus, is a serious public health problem in China. Despite intensive countermeasures including Patriotic Health Campaign, rodent control ...and vaccination in affected areas, HFRS is still a potential public health threat in China, with more than 10,000 new cases per year. Previous epidemiological evidence suggested that meteorological factors could influence HFRS incidence, but the studies were mainly limited to a specific city or region in China. This study aims to evaluate the association between monthly HFRS cases and meteorological change at the country level using a multivariate distributed lag nonlinear model (DLNM) from 2004 to 2018. The results from both univariate and multivariate models showed a non-linear cumulative relative risk relationship between meteorological factors (with a lag of 0-6 months) such as mean temperature (Tmean), precipitation, relative humidity (RH), sunshine hour (SH), wind speed (WS) and HFRS incidence. The risk for HFRS cases increased steeply as the Tmean between - 23 and 14.79 °C, SH between 179.4 and 278.4 h and RH remaining above 69% with 50-95 mm precipitation and 1.70-2.00 m/s WS. In conclusion, meteorological factors such as Tmean and RH showed delayed-effects on the increased risk of HFRS in the study and the lag varies across climate factors. Temperature with a lag of 6 months (RR = 3.05) and precipitation with a lag of 0 months (RR = 2.08) had the greatest impact on the incidence of HFRS.
Exploiting a comparative advantage through resource endowment is a way to promote the transformation and upgrading of enterprises and high-quality economic development. Based on resource-based ...theory, this paper takes the listed companies of China’s manufacturing industry as a sample and classifies them into leading, potential, catching-up, and exiting enterprises according to the abundance of financial and human resources. In terms of the research perspective, this paper adopts resource abundance as the starting point to explore its impact on enterprise transformation and upgrading and incorporates technological innovation into the framework to investigate its transmission mechanism. The results indicate that the resource abundance of enterprises directly promotes the transformation and upgrading of enterprises. Notably, the mechanism identification test suggests the following. (1) From the perspective of innovation investment, innovation investment intensity is an important channel for manufacturing companies to transform and upgrade. (2) From the perspective of innovation direction, higher levels of resources allow leading enterprises to accelerate transformation and upgrading through product and process innovation. In contrast, catching-up enterprises tend to foster product innovation rather than process innovation to transform and update, while potential enterprises are likely to foster process innovation to transform and update rather than product innovation. On the other hand, the path of transformation and upgrading through product or process innovation is obstructed for the exiting enterprises. (3) From the perspective of innovation output, all but the exiting enterprises can be transformed and upgraded by increasing their innovation output. Overall, considering the impact of corporate innovation behavior, this research offers new insights into the relationship between resource abundance and transformation and upgrading, and it provides inspiration for promoting transformation and upgrading in Chinese manufacturing enterprises.
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