ANALYTICAL SOLUTION AND FIELD TEST OF CRITICAL BEARING CAPACITY AND SETTLEMENT OF PILE TIP

In order to explore the relationship between the critical bearing capacity and settlement of closed pile tip pierced into the soil, based on the Boussinesq solution and the Kelvin solution, the analytical solution between the critical bearing capacity and the critical settlement of the closed pile tip is derived by combining the stress distribution function. The analytical solution of critical bearing capacity and settlement of pile tip is verified by field test of static pressure pile penetrating into layered soil with a full-section pressure sensor installed at pile tip. The results show that during the penetration process, the bearing capacity increase stage of the pile tip is divided into linear steepening section and nonlinear slow increasing section. The soil in the linear steep increase section behaves as an elastic state. The bearing capacity of the pile tip before the punctured soil layer is linear with the settlement, and the final value of the linear steep increase section is the elastic limit value and the critical bearing capacity of the piercing pile tip. When the residual pile tip force is not considered, the critical settlement of the pile tip is between 0.095-0.119d; when considering the residual pile tip force, the critical settlement is between 0.091-0.105d. In particular, when the Poisson's ratio is 0.5, the analytical solution of the semi-infinite space is equivalent to the analytical solution of the infinite space

Sequencing and phylogenetic analysis of mitochondrial genome of Aspergillus cristatus

Aspergillus cristatus are the dominantly present microorganisms in dark tea. The whole mitochondrial genome sequence of A. cristatus was sequenced and reported in this study. The mitochondrial genome in A. cristatushas a full length of 77,649 bp, which is reported to be the longest among the mitochondrial genomes of Aspergillus species. The basesincluding A (34.14％), T (37.64％), C (15.61％) and G (12.61％) are found in their genome. A total of 42 genes (15 protein-coding genes, lrRNA/srRNA and 25 tRNAs) are encoded by the mitochondrial genome of this fungus. Phylogenetic analysis showed a closest relationship betweenA. pseudoglaucusand the taxonomic status of A. cristatus

Analytical Solution for Estimating Bearing Capacity of a Closed Soil Plug: Verification Using An On-Site Static Pile Test

When the open-ended pile penetrates the soil layer, the resistance generated by the soil plug cannot be ignored. A pile with a full-size pressure sensor installed at pile tip can detect resistance more accurately than a microsensor when the pile penetrates into the soil. In this paper, the pile installed full-size pressure sensor was used for penetration test and the relationship between formation parameters and pile tip force is obtained. Using the solution of the Kelvin problem in infinite space and the plane stress distribution function, the analytical solution of the bearing capacity of the soil plug is derived under the condition that the displacements of the bottom of the pile and the soil plug are consistent. The results show that the ultimate stress of the soil plug is closely related to the pile diameter and pipe thickness. The bearing capacity of the soil plug is closely related to the properties of the soil layer. The analytical solution of the bearing capacity of the soil plug has a linear relationship with the formation parameters SPT and CPT. The analytical solution of the ultimate bearing capacity of the soil plug has been verified by field test data and has a good match with the geometric dimensions of the pile tip and the formation parameters

Complete mitochondrial genome and phylogenetic analysis of Penicillium citrinum in dark tea

Penicillium citrinum is a common polluting microorganism in dark tea production. Our study was performed to report the complete mitochondrial genome of P. citrinum. The mitochondrial genome of P. citrinum was a circular DNA molecule of 27,537 bp in length, encoding 42 genes as follows: 15 PCGs, two rRNAs, 24 tRNAs, and an independent ORF. A (36.14%), T (37.06%), C (11.83%), and G (14.98%) was composed of genomic bases. In addition, phylogenetic analysis showed that Penicillium sp. exhibited a closest relationship with the taxonomic status of P. citrinum

Development of Cotton Picker Fire Monitoring System Based on GA-BP Algorithm

Due to the characteristics of the cotton picker working in the field and the physical characteristics of cotton, it is easy to burn during the operation, and it is difficult to be detected, monitored, and alarmed. In this study, a fire monitoring system of cotton pickers based on GA optimized BP neural network model was designed. By integrating the monitoring data of SHT21 temperature and humidity sensors and CO concentration monitoring sensors, the fire situation was predicted, and an industrial control host computer system was developed to monitor the CO gas concentration in real time and display it on the vehicle terminal. The BP neural network was optimized by using the GA genetic algorithm as the learning algorithm, and the data collected by the gas sensor were processed by the optimized network, which effectively improved the data accuracy of CO concentration during fires. In this system, the CO concentration in the cotton box of the cotton picker was validated, and the measured value of sensor was compared with the actual value, which verified the effectiveness of the optimized BP neural network model with GA. The experimental verification showed that the system monitoring error rate was 3.44%, the accurate early warning rate was over 96.5%, and the false alarm rate and the missed alarm rate were less than 3%. In this study, the fire of cotton pickers can be monitored in real time and an early warning can be made in time, and a new method was provided for accurate monitoring of fire in the field operation of cotton pickers

Field Test of Excess Pore Water Pressure at Pile–Soil Interface Caused by PHC Pipe Pile Penetration Based on Silicon Piezoresistive Sensor

Prestressed high-strength concrete (PHC) pipe pile with the static press-in method has been widely used in recent years. The generation and dissipation of excess pore water pressure at the pile–soil interface during pile jacking have an important influence on the pile’s mechanical characteristics and bearing capacity. In addition, this can cause uncontrolled concrete damage. Monitoring the change in excess pore water pressure at the pile–soil interface during pile jacking is a plan that many researchers hope to implement. In this paper, field tests of two full-footjacked piles were carried out in a viscous soil foundation, the laws of generation and dissipation of excess pore water pressure at the pile–soil interface during pile jacking were monitored in real time, and the laws of variation in excess pore water pressure at the pile–soil interface with the burial depth and time were analyzed. As can be seen from the test results, the excess pore water pressure at the pile–soil interface increased to the peak and then began to decline, but the excess pore water pressure after the decline was still relatively large. Test pile S1 decreased from 201.4 to 86.3 kPa, while test pile S2 decreased from 374.1 to 114.3 kPa after pile jacking. The excess pore water pressure at the pile–soil interface rose first at the initial stage of consolidation and dissipated only after the hydraulic gradient between the pile–soil interface and the soil surrounding the pile disappeared. The dissipation degree of excess pore water pressure reached about 75–85%. The excess pore water pressure at the pile–soil interface increased with the increase in buried depth and finally tended to stabilize

Synthesis, Characterization of Nano- β

It is difficult to synthesize nano-β-tricalcium phosphate (nano-β-TCP) owing to special crystal habit. The aim of this work was to synthesize nano-β-TCP using ethanol-water system and characterize it by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Malvern laser particle size analyzer, and transmission electron microscope (TEM). In addition, the inhibitory effect of nano-β-TCP on human hepatocellular carcinoma (HepG2) cells was also investigated using MTT assay, lactate dehydrogenase (LDH) leakage test, and 4′-6-diamidino-2-phenylindole (DAPI) staining. The results showed that negatively charged rod-like nano-β-TCP with about 55 nm in diameter and 120 nm in length was synthesized, and the average particle size of nano-β-TCP was 72.7 nm. The cell viability revealed that nano-β-TCP caused reduced cell viability of HepG2 cells in a time- and dose-dependent manner. These findings presented here may provide valuable reference data to guide the design of nano-β-TCP-based anticancer drug carrier and therapeutic systems in the future

Data Classification and Demand Prediction Methods Based on Semi-Supervised Agricultural Machinery Spare Parts Data

Because of the continuous improvement of technology, mechanization has emerged in various fields. Due to the different suitable seasons for the growth of agricultural plants, agricultural mechanization faces problems different from other industries. That is, agricultural machinery and equipment may be used frequently for a period of time, or may be idle for a long time. This leads to the aging of equipment no longer becoming regular, the maintenance time of spare parts is not fixed, the number of spare parts stored in the spare parts warehouse cannot be too large to occupy funds, and the number cannot be too small to meet the maintenance needs, so the prediction of agricultural machinery spare parts has become particularly important. Due to the lack of information, the difficulty of labeling, and the imbalance of positive and negative sample classification, this paper used a semi-supervised learning algorithm to solve the problem of agricultural machinery spare parts data classification. In order to forecast the demand for spare parts of agricultural machinery, this paper compared the IPSO-BP neural network algorithm and BP neural network algorithm. It was found that the IPSO-BP neural network was used to forecast the demand for spare parts of agricultural machinery, and the error between the predicted value and the actual value was small and met the accuracy requirements

Chinese and global distribution of H9 subtype avian influenza viruses.

H9 subtype avian influenza viruses (AIVs) are of significance in poultry and public health, but epidemiological studies about the viruses are scarce. In this study, phylogenetic relationships of the viruses were analyzed based on 1233 previously reported sequences and 745 novel sequences of the viral hemagglutinin gene. The novel sequences were obtained through large-scale surveys conducted in 2008-2011 in China. The results revealed distinct distributions of H9 subtype AIVs in different hosts, sites and regions in China and in the world: (1) the dominant lineage of H9 subtype AIVs in China in recent years is lineage h9.4.2.5 represented by A/chicken/Guangxi/55/2005; (2) the newly emerging lineage h9.4.2.6, represented by A/chicken/Guangdong/FZH/2011, has also become prevalent in China; (3) lineages h9.3.3, h9.4.1 and h9.4.2, represented by A/duck/Hokkaido/26/99, A/quail/Hong Kong/G1/97 and A/chicken/Hong Kong/G9/97, respectively, have become globally dominant in recent years; (4) lineages h9.4.1 and h9.4.2 are likely of more risk to public health than others; (5) different lineages have different transmission features and host tropisms. This study also provided novel experimental data which indicated that the Leu-234 (H9 numbering) motif in the viral hemagglutinin gene is an important but not unique determinant in receptor-binding preference. This report provides a detailed and updated panoramic view of the epidemiological distributions of H9 subtype AIVs globally and in China, and sheds new insights for the prevention of infection in poultry and preparedness for a potential pandemic caused by the viruses