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In order to improve the performance of complex thin wall ZL114A aluminum alloy casting， the mechanical vibration was applied to vacuum counter-pressure casting， and the effect of amplitude and frequency on Al-Si eutectic microstructure and mechanical properties of casting were systematically studied. The results indicate that the mechanical vibration can enhance the local convection of the melt. The initial solidified dendrites are broken and the Si phase is broken to form granular and short rod tissue. Meanwhile，the mechanical vibration can promote the uniform distribution of solute in solidification front and inhibit the excessive growth of the Si phase. Therefore， the Al-Si eutectic around the primary phase is induced to transform the network. The effect of amplitude and frequency on strength and plasticity are opposite. At high frequency and low amplitude， the highest tensile strength of the sample near the source of vibration is 335.6 MPa， but the elongation decreases to 1.54%. However， the tensile strength and elongation of the sample staying away from the source of vibration only reach 327.06 MPa and 1.67% because of energy wastage during vibration energy diffused at molten alloy. In addition， the performance attenuation fitting analysis shows that increasing frequency is conducive to inhibiting the wastage of vibration energy and improving the treatment effect of molten alloy which stays away from the source of vibration.

As the construction of new power systems, DC microgrids will become an important part of the distribution network. As AC load connecting to DC microgrids, the oscillating power will enter the DC system, which affects the power distribution of energy storage system. To solve this issue, the comprehensive principle of power distribution of distributed energy storage system was given, and a wireless power sharing method was proposed. This method takes the charge state as the “information carrier”, each energy storage unit can realize state of charge (SOC) balancing and oscillating power sharing at same time. In addition, from the perspective of equivalent output impedance, this paper gived a detailed analysis and discussion on the distribution effect of different control algorithms, which showed the proposed control algorithm could meet the requirements of the comprehensive principle. Finally, the effectiveness of the proposed distributed energy storage control strategy was validated by experiments.

Stress path change has a great relationship with the effect of deformation and strength of rock. However, the underground rock body is in the engineering environment where the stress field, seepage field, and other fields are coupled to change, the law of fluid flow in the rock body is complex and variable. The change in the stress field has an important effect on the seepage characteristics of rock body; therefore, it is necessary to study the pattern of rock permeability evolution pattern by different stress paths. This study is based on the study of limestone, conducting triaxial unloading seepage mechanics experiments, the evolution of permeability properties of limestone specimens was analyzed based on the test results. The results show that in the conventional triaxial loading seepage test, the permeability of the limestone decreases before the rock stress reaches the peak intensity and increases after that. Increasing axial pressure unloading surrounding pressure compression section, permeability loss rate and effective stress are in line with the changing law of Gaussian distribution function. Under the action of constant axial pressure unloading surrounding pressure, with the increase in unloading amount, the permeability rate of change appears to increase slowly, and in the late stage of unloading section, the permeability rate of change appears to surge. Unloading section permeability change rate and cumulative unloading amount are in line with the law of change of the exponential function. Creep unloading pressure seepage test found that unloading pressure stage strain-time and permeability-time evolution characteristics are in line with the exponential rule of change. The experimental results of this study can provide an important experimental and theoretical basis for the permeability analysis of low-permeability rock body under complex stress conditions in underground engineering.

Wild rodents serve as reservoirs for Cryptosporidium and are overpopulated globally. However, genetic data regarding Cryptosporidium in these animals from China are limited. Here, we have determined the prevalence and genetic characteristics of Cryptosporidium among 370 wild rodents captured from three distinct locations in the southern region of Zhejiang Province, China. Fresh feces were collected from the rectum of each rodent, and DNA was extracted from them. The rodent species was identified by PCR amplifying the vertebrate cytochrome b gene. Cryptosporidium was detected by PCR amplification and amplicon sequencing the small subunit of ribosomal RNA gene. Positive samples of C. viatorum and C. parvum were further subtyped by analyzing the 60-kDa glycoprotein gene. A positive Cryptosporidium result was found in 7% (26/370) of samples, involving five rodent species: Apodemus agrarius (36), Niviventer niviventer (75), Rattus losea (18), R. norvegicus (155), and R. tanezumi (86). Their respective Cryptosporidium positive rates were 8.3%, 5.3%, 11.1%, 7.1%, and 7.0%. Sequence analysis confirmed the presence of three Cryptosporidium species: C. parvum (4), C. viatorum (1), and C. muris (1), and two genotypes: Cryptosporidium rat genotype IV (16) and C. mortiferum-like (4). Additionally, two subtypes of C. parvum (IIdA15G1 and IIpA19) and one subtype of C. viatorum (XVdA3) were detected. These results demonstrate that various wild rodent species in Zhejiang were concurrently infected with rodent-adapted and zoonotic species/genotypes of Cryptosporidium, indicating that these rodents can play a role in maintaining and dispersing this parasite into the environment and other hosts, including humans.

Blastocystis sp., a significant zoonotic parasite with a global distribution, was the focus of this study, which aimed to investigate its prevalence and genetic diversity among diarrheic and asymptomatic children in Wenzhou, China. We collected 1,032 fecal samples from Yuying Children’s Hospital, Wenzhou, China, comprising 684 from children with diarrhea and 348 from asymptomatic children. Genomic DNA extracted from these samples was used to detect Blastocystis spp. by PCR, targeting the small subunit ribosomal RNA gene. Subsequently, a phylogenetic tree was constructed, applying the maximum likelihood method. Blastocystis spp. were detected in 67 (6.5%) of the fecal samples. The prevalence rate of Blastocystis spp. in diarrheic children (8.8%; 60/684) was significantly higher than that in asymptomatic children (2.0%; 7/348) (χ 2 = 17.3, p

The water-lubricated bearing is mainly installed at the stern of the ship to support the rotation of the main shaft of the ship, which is an important component of the ship’s power plant. The rubber stave of the water-lubricated bearing acts as an elastic body, which can effectively suppress the rotational vibration of the rotating shaft and improve the shaft alignment effect. To monitor the operational status of the water-lubricated bearing at the stern of a ship, a design method of smart rubber stave for water-lubricated bearings is proposed in this article. According to the structure of the rubber stave, the packaging and protection form of the optical fiber, the forming process of the rubber stave, and the mechanical analysis were carried out to determine the distribution design principle of the fiber Bragg grating (FBG) in the rubber stave. Then, FBGs were packaged, protected, and implanted with an uneven distribution into the rubber stave to achieve force sensing in the bearing. With reference to the force state of the water-lubricated bearing during shipbuilding and ship operation, various types of condition monitoring tests were conducted on the smart rubber stave using an elastomer testing machine, which were to analyze the effects of load sizes, frequencies, and ambient temperatures. The tests showed that the FBGs in the rubber stave could monitor the static and dynamic loads of the bearing under the seawater environment or inland water environment below 30°C. This method can be used for the smart designing and online load condition monitoring of water-lubricated bearings.

The low-carbon transformation of power sector is significant for achieving the goal of carbon peak and carbon neutrality in China. Based on the evaluation of power carbon budget, three power transformation scenarios of deep low-carbon, zero carbon, and negative carbon were built, the key boundary conditions such as power consumption demand were studied, and a path planning optimization model was established in the paper. Using the GESP-V software package for optimized analysis, the low-carbon transformation paths were determined for power structure, power carbon emissions, and power supply costs under different scenarios. The major issues that are critical for the low-carbon transformation of the power system were discussed, including coal power development, renewable energy development and utilization, diversified supply of clean energy, and electric power balance. Several suggestions were further proposed. Specifically, the top-level design should be strengthened to steadily plan the transformation pace, major low-carbon technologies should be developed to coordinate the overall technology and industrial layout, and the market mechanism with balanced interests should be improved while establishing a green finance policy system. The high-quality low-carbon transformation of China’s power sector in the medium and long term can be promoted through the coordination of policies, technologies, and mechanisms.

In order to solve the problem that alumina based ceramic core is not easy to remove core, a certain amount of PA66 fiber was added as pore forming material to prepare porous aluminum based ceramic core by hot pressing. The influence of PA66 fiber content on the porosity, room temperature bending strength and sintering shrinkage of aluminum based ceramic core was investigated, and the mechanism of PA66 fiber content on the porosity of aluminum based ceramic core was analyzed. The results show that the porosity of alumina based ceramic core is significantly increased by adding PA66 fiber, and the sintering shrinkage of the core is effectively blocked. With the increase of PA66 fiber, the porosity of alumina based ceramic core is increased, and the bending strength and line shrinkage rate at room temperature are decreased. When the PA66 fiber content is 0.9%(mass fraction), the porosity of the aluminum based ceramic core is 41.14%, the bending strength is 15.33 MPa, and the linear shrinkage rate is 0.418%.

The vibration failure issue of the motor control unit during the vibration test was studied,and the reasons of the failure were analyzed by applying spectrum analysis method,the results showed that the coupled vibration is the main reason of the vibration failure. The optimization schemes against this problem were designed,the octave criterion was applied to design the component for avoiding coupled vibration,and the damping was increased to decrease the peak of the vibration response. The optimization schemes were verified by simulation and experiment,the results showed the vibration acceleration decreased by 23% ～ 31% using octave criterion design,and decreased by 25% ～ 34% through increasing damping. The conclusion can be drawn that two optimization ways can decrease vibration acceleration level obviously,and the fatigue durability of the product was improved.

Blastocystis sp. is an important gastrointestinal parasite with global distribution, prevalent in humans, farmed animals, and wildlife. Therefore, this study aimed to investigate the prevalence and genetic diversity of Blastocystis sp. in Asiatic brush-tailed porcupines (Atherurus macrourus), bamboo rats (Rhizomys pruinosus), and masked palm civets (Paguma larvata) in Hainan Province, China. A total of 900 fecal samples were collected from three farmed animal species including 257 porcupines, 360 rats, and 283 civets. Genomic DNA was extracted from each fecal sample and Blastocystis sp. was detected by PCR at the small subunit ribosomal RNA (SSU rRNA) gene. A phylogenetic tree was constructed using the maximum likelihood method. Blastocystis sp. was detected in 47 (5.2%) fecal samples: 12 (4.7%) Asiatic brush-tailed porcupines, 8 (2.2%) bamboo rats, and 27 (9.5%) masked palm civets. Three known Blastocystis sp. subtypes, including ST1, ST4, ST5, and one unnamed subtype (unST), were found in one, 19, 26, and one animal, respectively. Subtypes ST4 and unST were detected in porcupines, ST4 in rats, and ST1 and ST5 in civets. Our results suggest that the three farmed animal species reported in this study could serve as reservoirs for potentially zoonotic Blastocystis sp. subtypes and transmit this parasite to humans, other farmed animals, and wildlife.

Recently, deep convolutional neural networks (CNNs) have been attracting considerable attention in single image super-resolution. Some CNN-based methods, such as VDSR verified that residual learning can speed up the training and significantly improve the performance of accuracy. However, with very deep networks, convergence speed is still a critical issue in training due to the cost of requiring enormous parameters. In order to deal with this issue, we redesign the residual networks based on dilated networks. In this paper, we propose symmetrical dilated residual convolution networks (FDSR) to tackle image super-resolution problems. Our network is on the basis of the dilated convolutions supported exponential expansion of the receptive field without loss of resolution and coverage. This means that FDSR can speed up the training and improve the performance of accuracy without increasing the model's depth or complexity. Meanwhile, we attempt to combine the image pre-processing approach of VGG-net with mean squared error (MSE) to enhance the performance. The experimental results demonstrate that the training time-consuming proposed model achieves nearly a half with even superior restoration quality. Further, we present a novel network with less layers and parameters can achieve real-time performance on a generic CPU and still maintain superior performance.

BACKGROUND: Aedes albopictus is an important vector for pathogens such as dengue, Zika, and chikungunya viruses. While insecticides is the mainstay for mosquito control, their widespread and excessive use has led to the increased resistance in Ae. albopictus globally. Gut symbiotic bacteria are believed to play a potential role in insect physiology, potentially linking to mosquitoes metabolic resistance against insecticides. METHODS: We investigated the role of symbiotic bacteria in the development of resistance in Ae. albopictus by comparing gut symbiotic bacteria between deltamethrin-sensitive and deltamethrin-resistant populations. Adults were reared from field-collected larvae. Sensitive and resistant mosquitoes were screened using 0.03% and 0.09% deltamethrin, respectively, on the basis of the World Health Organization (WHO) tube bioassay. Sensitive and resistant field-collected larvae were screened using 5 × LC50 (lethal concentration at 50% mortality) and 20 × LC50 concentration of deltamethrin, respectively. Laboratory strain deltamethrin-sensitive adults and larvae were used as controls. The DNA of gut samples from these mosquitoes were extracted using the magnetic bead method. Bacterial 16S rDNA was sequenced using BGISEQ method. We isolated and cultured gut microorganisms from adult and larvae mosquitoes using four different media: Luria Bertani (LB), brain heart infusion (BHI), nutrient agar (NA), and salmonella shigella (SS). RESULTS: Sequencing revealed significantly higher gut microbial diversity in field-resistant larvae compared with field-sensitive and laboratory-sensitive larvae (P

Enterocytozoon bieneusi is a zoonotic fungal pathogen with a high degree of host diversity that can parasitize many animals, including humans. Pigs may play an important role in the epidemiology of E. bieneusi as reservoir hosts. Nevertheless, the genotypes of E. bieneusi in pigs in China remain poorly understood. The aim of this study was to determine the prevalence of E. bieneusi infection amongst pigs raised on farms from four cities of Hainan Province, using nested polymerase chain reaction (PCR) of the partial small subunit of the ribosomal RNA gene, and to identify genotypes of E. bieneusi isolates based on sequence analysis of the ribosomal internal transcribed spacer (ITS) region. Among 188 stool samples, E. bieneusi was detected in 46.8% (88/188). Eight genotypes including four known (EbpA, CS-4, MJ14, and CHG19) and four novel (HNP-I – HNP-IV) genotypes were identified. Using phylogenetic analysis, genotypes EbpA, CS4, CHG19, HNP-III, and HNP-IV were clustered into zoonotic Group 1, while the remaining three genotypes (MJ14, HNP-I, and HNP-II) clustered into Group 10. The high prevalence of zoonotic genotypes of E. bieneusi among pigs suggests that pig farming is a potential source of human infection. Additionally, this is the first identification of genotypes in Group 10 in pigs indicating unique epidemic features of E. bieneusi in pigs in Hainan Province, the southernmost part of China.

Enterocytozoon bieneusi is an intestinal pathogen that infects a wide range of species, including humans. Cattle constitute an important host for E. bieneusi; however, there is a scarcity of information on the prevalence and genotyping of E. bieneusi in cattle in the Hainan Province of China. In this study, PCR analysis of 314 fecal samples from cattle in six cities of Hainan was performed for genotype identification. The average prevalence of E. bieneusi in these animals was 9.9% (31/314), and ranged from 0.0% (0/12) to 20.5% (8/39). Five known genotypes – EbpC (n = 14), BEB4 (n = 12), J (n = 2), I (n = 1), and CHG5 (n = 1) – and a novel genotype: HNC-I (n = 1) – were identified. Genotypes EbpC and HNC-I were placed in zoonotic Group 1, and the remaining four genotypes (BEB4, J, I, and CHG5) were placed in Group 2. Since 93.5% of the genotypes found in the cattle (29/31) (EbpC, BEB4, J, and I) have previously been found in humans, these genotypes are probably involved in the transmission of microsporidiosis to humans.

Enterocytozoon bieneusi is an important pathogen commonly found in humans and animals. Farmed animals with close contact to humans are important hosts of E. bieneusi. The role of goats in the transmission of E. bieneusi, however, remains unclear. In this study, 341 fresh fecal samples of black goats were collected from five locations in Hainan Province, China. Enterocytozoon bieneusi was identified and genotyped by sequences of the internal transcribed spacer (ITS) region. Phylogenetic analysis was performed by constructing a neighbor-joining tree of the ITS gene sequences. The average prevalence of E. bieneusi in black goats was 24.0% (82/341) with rates ranging from 6.3% (4/63) to 37.2% (32/86) across the locations (χ2 = 17.252, p

BackgroundMosquitoes are vectors of many pathogens, such as malaria, dengue virus, yellow fever virus, filaria and Japanese encephalitis virus. Wolbachia are capable of inducing a wide range of reproductive abnormalities in their hosts, such as cytoplasmic incompatibility. Wolbachia has been proposed as a tool to modify mosquitoes that are resistant to pathogen infection as an alternative vector control strategy. This study aimed to determine natural Wolbachia infections in different mosquito species across Hainan Province, China.MethodsAdult mosquitoes were collected using light traps, human landing catches and aspirators in five areas in Hainan Province from May 2020 to November 2021. Species were identified based on morphological characteristics, species-specific PCR and DNA barcoding of cox1 assays. Molecular classification of species and phylogenetic analyses of Wolbachia infections were conducted based on the sequences from PCR products of cox1, wsp, 16S rRNA and FtsZ gene segments.ResultsA total of 413 female adult mosquitoes representing 15 species were identified molecularly and analyzed. Four mosquito species (Aedes albopictus, Culex quinquefasciatus, Armigeres subalbatus and Culex gelidus) were positive for Wolbachia infection. The overall Wolbachia infection rate for all mosquitoes tested in this study was 36.1% but varied among species. Wolbachia types A, B and mixed infections of A × B were detected in Ae. albopictus mosquitoes. A total of five wsp haplotypes, six FtsZ haplotypes and six 16S rRNA haplotypes were detected from Wolbachia infections. Phylogenetic tree analysis of wsp sequences classified them into three groups (type A, B and C) of Wolbachia strains compared to two groups each for FtsZ and 16S rRNA sequences. A novel type C Wolbachia strain was detected in Cx. gelidus by both single locus wsp gene and the combination of three genes.ConclusionOur study revealed the prevalence and distribution of Wolbachia in mosquitoes from Hainan Province, China. Knowledge of the prevalence and diversity of Wolbachia strains in local mosquito populations will provide part of the baseline information required for current and future Wolbachia-based vector control approaches to be conducted in Hainan Province.

By the technique of coupled solutions, the notion of viscosity solutions is extended to fully nonlinear retarded parabolic equations. Such equations involve many models arising from optimal control theory, economy and finance, biology, and so forth. The comparison principle is shown. Then the existence and uniqueness are established by the fixed point theory.