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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

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

Tight gas sandstone represents a significant unconventional resource extensively discovered across numerous sedimentary basins around the world. Tight sandstone reservoirs are characterized by low porosity, low permeability, variable source material, rapid spatial and temporal changes, poor reservoir properties, and strong heterogeneity. Traditional geophysical methods struggle to meet the demands of exploration and development of these types of reservoirs. This study applies a high-precision comparative approach using well-seismic integration to establish a relative isochronous stratigraphic framework. Based on this framework, extracting seismic properties can effectively predict tight sandstone reservoirs. This paper, focusing on the Penglaizhen Formation in the Luodai Gas Field of the Western Sichuan Jurassic system. This entire process accomplished in three steps: starting with regional marker layers as the initial framework; followed by the establishment of a relative isochronous framework through precise well-seismic integration; and finally stratigraphic slicing techniques to delineate isochronous stratigraphic framework with shorter time intervals. Thereby enhancing the reliability of subsurface stratigraphic information and data accuracy. The study posits that current technological means cannot create a truly isochronous stratigraphic framework; thus, "isochronous" is considered a relative concept in this context. The framework aims to ensure temporal consistency by minimizing discrepancies through mutual constraints between well and seismic data, serving to exploration and development requirements. Furthermore, analyses such as sensitive attribute extraction, impedance inversion, and assessment of hydrocarbon potential in tight sandstone reservoirs demonstrate strong correlation with drilling results. This validation underscores the framework's efficacy in interpreting industrial gas production flows, thereby providing robust support for future oil and gas exploration. [ABSTRACT FROM AUTHOR]

For piezoelectric catalysis, the catalytic mechanism is a topic of great controversy, with debates centered around whether it belongs to the energy band theory or the screening charge effect which are similar to mechanisms of photocatalysis and electrochemical catalysis, respectively. Due to the formation of different intermediate active‐species during two‐electron oxygen reduction reaction (ORR) via electro‐ and photo‐catalysis, the key to solving this problem is precisely monitoring the active species involved in ORR during electro‐, photo‐, and piezo‐catalysis under identical condition. Here, a semiconductor material, BiOBr with abundant oxygen vacancies (BOB‐OV) was found remarkable catalytic activity in H2O2 production by all three catalytic methods. By employing in situ electron paramagnetic resonance (EPR) spectroscopy, the H2O2 evolution pathway through piezo‐catalysis over BOB‐OV was monitored, which showed a similar reaction pathway to that observed in photo‐catalytic process. This finding represents solid evidence supporting the notion that piezo‐catalytic mechanism of ORR is more inclined towards photo‐catalysis rather than electro‐catalysis. Significantly, this exploratory conclusion provides insight to deepen our understanding of piezo‐catalysis. [ABSTRACT FROM AUTHOR]