The Performance of Niobium-Microalloying Ultra-High-Strength Bridge Cable Steel during Hot Rolling.

This study focuses on exploring the effects of niobium (Nb)-microalloying on the properties of steel for ultra-high-strength bridge cables during hot-rolling processes. We employed a combination of dual-pass compression tests, stress-strain curve analysis, and Electron Backscatter Diffraction (EBSD) techniques to investigate the influence of Nb-microalloying on the static recrystallization behavior and grain size of the steel. The key findings reveal that Nb-microalloying effectively inhibits static recrystallization, particularly at higher temperatures, significantly reducing the volume fraction of recrystallized grains, resulting in a finer grain size and enhanced deformation resistance. Secondly, at a deformation temperature of 975 °C, Nb-containing steel exhibited finer grain sizes compared to Nb-free steel when held for 10 to 50 s; however, the grain size growth accelerated when the hold time exceeded 50 s, likely linked to the increased deformation resistance induced by Nb. Lastly, this research proposes optimal hot-rolling process parameters for new bridge cable steel, recommending specific finishing rolling temperatures and inter-pass times for both Nb-containing and Nb-free steels during the roughing and finishing stages. This study suggests optimal hot-rolling parameters for both Nb-containing and Nb-free steels, providing essential insights for improving hot-rolling and microalloying processes in high-carbon steels for bridge cables.

Study of real-time parameter measurement of ring rolling pieces based on machine vision.

Real time parameter measurement cannot be carried out to dynamic ring parts during automation ring rolling processes so that rolling process parameters cannot be adjusted in time. Considering effects of shaping of ring rolling parts, a visual measurement platform was set up and a machine vision-based non-contact real -time measurement method was put forward. This article improves the subpixel level edge extraction algorithm to extract edge data information of circular rolling pieces. Based on the characteristics of circular rolling pieces, an RG-Hough transform method is proposed to fit the detected edge data information. The conversion relationship between pixel and actual sizes were determined in combination with the camera calibration to gain parameters of ring rolling parts. Measurements of ring parts (OD: 462.12mm; and ID: 315.53mm) were applied to verify the effectiveness of our method. Our measurement error is ±0.25mm and our average speed can be up to 104ms/frame. Our study can provide powerful technical supports for intelligent control of ring rolling pieces.

A trajectory tracking control system for paddle boat in intelligent aquaculture.

Trajectory tracking plays a notable role in unmanned surface vehicles (USV), especially for the emerging intelligent aquaculture, as the level of integration, high-efficiency, and low-labor-intensity of such USV is determined by trajectory tracking. Here, we report a generic trajectory tracking control system for a paddle boat by establishing a three-degree-of-freedom kinematics model, which could precisely characterize the relationship between velocities, forces and moments of the paddle boat. A Pixhawk 4 as the core controller of the hardware system could be integrated with the other hardware submodules and could complete the wireless data transmission, monitoring and remote control functions. Meanwhile, we establish a fuzzy rule table, consider the advantages of line-of-sight (LOS) guidance and fuzzy adaptive proportional-integral-differential (PID) algorithm, combine the two parts and apply them as the key algorithm in the trajectory tracking of the paddle boat. Demonstrations include trajectory tracking effect at different velocities, turning effect at left-turn moment, and trajectory tracking effect at different turning angles. The results show that the paddle boat is able to travel under the trajectory formed by following the planned waypoints within the error allowed, which is called effective trajectory tracking. And can offer an alternative pathway toward achieving effective trajectory tracking control in advanced intelligent aquaculture USV for smartly and wirelessly operated pond drug spraying.

Ambient Volatile Organic Compound Characterization, Source Apportionment, and Risk Assessment in Three Megacities of China in 2019.

In order to illustrate pollution characterization, source apportionment, and risk assessment of VOCs in Beijing, Baoding, and Shanghai, field observations of CO, NO, NO2, O3, and volatile organic compounds (VOCs) were conducted in 2019. Concentrations of VOCs were the highest in Beijing (105.4 ± 52.1 ppb), followed by Baoding (97.1 ± 47.5 ppb) and Shanghai (91.1 ± 41.3 ppb). Concentrations of VOCs were the highest in winter (120.3 ± 61.5 ppb) among the three seasons tested, followed by summer (98.1 + 50.8 ppb) and autumn (75.5 + 33.4 ppb). Alkenes were the most reactive VOC species in all cities, accounting for 56.0%, 53.7%, and 39.4% of ozone formation potential in Beijing, Baoding, and Shanghai, respectively. Alkenes and aromatics were the reactive species, particularly ethene, propene, 1,3,5-trimethylbenzene, and m/p-xylene. Vehicular exhaust was the principal source in all three cities, accounting for 27.0%, 30.4%, and 23.3% of VOCs in Beijing, Baoding, and Shanghai, respectively. Industrial manufacturing was the second largest source in Baoding (23.6%) and Shanghai (21.3%), and solvent utilization was the second largest source in Beijing (25.1%). The empirical kinetic modeling approach showed that O3 formation was limited by both VOCs and nitric oxides at Fangshan (the suburban site) and by VOCs at Xuhui (the urban site). Acrolein was the only substance with an average hazard quotient greater than 1, indicating significant non-carcinogenic risk. In Beijing, 1,2-dibromoethane had an R-value of 1.1 × 10-4 and posed a definite carcinogenic risk.

Impact of transgenic insect-resistant maize HGK60 with Cry1Ah gene on community components and biodiversity of arthropods in the fields.

In recent years, transgenic technology has developed rapidly, but the risk of the environmental release of transgenic organisms is still a key issue. Research on the impact on biodiversity is an effective way to objectively evaluate the risk. By taking transgenic maize HGK60 with insect-resistant gene Cry1Ah and common maize Zheng 58 as control, a 2-year experiment of arthropod community biodiversity in fields of them were studied using three methods.in 2019 and 2020. The results showed that a total of 124 species and 38537 individuals were observed from the experiment, belonging to 11 orders and 40 families. There was no significant difference in the individual number and species number of herbivorous, predatory and parasitic groups in the two kinds of maize in two years. Only the individual number of HGK60 was significantly higher than that of common maize Zheng 58 at heading stage in 2019. And the percentages of individual number and species number in different groups were basically the same in the two kinds of maize at each stage in two years. Analyses of Richness index, Shannon-Wiener diversity index, Dominance index and Evenness index showed no significant difference between the two kinds of maize in two years. The similarity coefficient of the arthropod community suggested that the arthropod community composition of HGK60 was similar to that of common maize Zheng 58. Furthermore, HGK60 had no significant effect on the relative stability of the arthropod community. These results indicated that despite the presence of a relatively minor difference in arthropod community between the two kinds of maize, the planting of HGK60 had little effect on arthropod community biodiversity. The results provided some data and support for the further studies of environmental risk of transgenic crops.

The effects of intestinal air cavity on dose distribution of volume modulated arc therapy for cervical cancer.

BACKGROUND: This study explored the effects of air cavity on the dose distribution of radiotherapy in patients after extensive hysterectomy. In patients who have an air cavity in the intestines near the planning target volume (PTV), the photon beams may interact with the air cavity to cause electron disequilibrium (ED), resulting in a reduction in the absorbed dose by the surrounding tissues. In this paper, the electron density assignment (EDA) of the air cavity was used to simulate the disappearance of the intestinal gas, and the effects of the intestinal air cavity on the volume modulated arc therapy (VMAT) results were examined. METHODS: A total of 21 patients who underwent VMAT after extensive hysterectomy were enrolled in this retrospective analysis. The dose parameters from the selected treatment plan were used the experimental reference. The treatment plan of the reference group was copied, and the intestinal air cavity structure was identified using the computed tomography (CT) simulation image. The electron density value of the intestine near the cavity was measured and averaged according to the intestinal electron density value recommended by International Commission Radiological Units (ICRU) report No. 46. The averaged value was assigned to the air cavity structure. Subsequently, the treatment plan was re-calculated without changing other parameters, and the resulting treatment plan was defined as the experimental group. The dose parameters of the PTV and organs at risk (OAR) in the 2 groups were assessed, and the influence of the intestinal air cavity on the VMAT dose distribution in cervical cancer patients was analyzed. RESULTS: The minimum dose (D98) and the maximum dose (D2) of the PTV was significantly different between the experimental group and the control group (P<0.05), however, mean dose of the PTV was comparable between the 2 groups. The dose parameters of OARs were not significantly different between the two groups except the bone structural organs. CONCLUSIONS: When the intestinal air cavity is large and related to the target area, the intestinal air cavity should be intervened, and the patient should be treated with radiotherapy after the intestinal gas decreases.

Application of PET/CT in Preoperative Evaluation and Diagnosis of Gastric Cancer.

The aim study to study the significance of pet clinical examination image technology for early gastric mucosal adenocarcinoma, improve the accuracy and accuracy of image examination results of gastric cancer, and provide important reference significance and value for early treatment. Study methods, we used the experimental method of clinical medicine to obtain some reference data through the intervention of different image examinations on experimental patients of different groups and stages, These data show that the use of PET-CT imaging can improve the one-year survival rate of patients and reduce the one-year recurrence rate. Lymphatic metastasis rate and hematogenous metastasis rate, so as to highlight the advantages of PET-CT imaging.

Comparison of genetically modified insect-resistant maize and non-transgenic maize revealed changes in soil metabolomes but not in rhizosphere bacterial community.

The deliberate introduction of the beneficial gene in crop plants through transgenic technology can provide enormous agricultural and economic benefits. However, the impact of commercialization of these crops on the ecosystem particularly on belowground soil biodiversity is still uncertain. Here, we examined and compared the effects of a non-transgenic maize cultivar and an insect-resistant transgenic maize cultivar genetically engineered with cry1Ah gene from Bacillus thuringiensis, on the rhizosphere bacterial community using 16S rDNA amplicon sequencing and soil metabolome profile using UPLC/MS analysis at six different growth stages. We found no significant differences in bacterial community composition and diversity at all growth stages between the two cultivars. The analysis of bacterial beta-diversity showed an evident difference in community structure attributed to plant different growth stages but not to the plant type. In contrast, the soil metabolic profile of transgenic maize differed from that of the non-transgenic plant at some growth stages, and most of the altered metabolites were usually related to the metabolism but not to the plant-microbe interaction related pathways. These results suggest that genetic modification with the cry1Ah gene-altered maize soil metabolism but had no obvious effect on the rhizosphere bacterial community.

Study on the correlation between energy spectrum computed tomography imaging and the pathological characteristics and prognosis of cervical cancer.

BACKGROUND: The purpose of this study is to investigate the correlation between energy spectrum computed tomography (CT) imaging and the pathological characteristics and prognosis of cervical cancer. METHODS: All participants underwent energy spectrum CT plain scan and enhanced scan of the cervix, uterine body, and common iliac vein. The correlation between the slope of energy spectrum attenuation curve and pathological characteristics and curative effect was analyzed, and the receiver operating characteristic (ROC) curve of the slope of energy spectrum attenuation curve to distinguish some pathological characteristics and curative effect was constructed. RESULTS: The energy spectrum curves of cervix, uterine body, and common iliac vein all showed a downward trend. The slope of cervix energy spectrum curve showed a significant difference in different differentiation degree (P<0.05), and the slope of energy spectrum curve showed an upward trend. The slope of energy spectrum curve of common iliac vein was significantly different between high and low cell proliferation antigen marker (Ki67) (P<0.05), and the slope of Ki67 high expression was higher than that of Ki67 low expression. Treatment was effective in 17 participants and ineffective in 11. After treatment, the energy spectrum curve slope of cervix and energy spectrum curve slope of common iliac vein in the effective group were significantly increased compared with before treatment (P<0.05), and the energy spectrum curve slope of cervix in the ineffective group was increased compared with before treatment, but the difference was not significant (P>0.05). The area under the curve (AUC) of distinguishing Ki67 expression of energy spectrum curve slope of common iliac vein was 0.7008, sensitivity was 66.67%, and specificity was 62.34%. The AUC of distinguishing the curative effect of cervical energy spectrum curve slope was 0.6131, sensitivity was 56.25%, and specificity was 59.09%. The AUC of distinguishing the curative effect of energy spectrum curve slope of common iliac vein was 0.6563, sensitivity was 60.42%, and specificity was 58.33%. CONCLUSIONS: The energy spectrum curve slope has potential value in the prediction of certain specific pathological types of cervical cancer and the evaluation of curative effect.

Potentially Toxic Element Pollution Levels and Risk Assessment of Soils and Sediments in the Upstream River, Miyun Reservoir, China.

This study focused on the Chao River and Baimaguan River located upstream of the Miyun Reservoir in Miyun District (Beijing, China). Soil and sediment samples were collected from the river and drainage basin. Total nitrogen, total phosphorus, and six potentially toxic elements including cadmium, zinc, lead, chromium, arsenic, and copper, were analyzed in terms of concentration, potential ecological risk, and human health risk. The average concentrations of the six potentially toxic elements were all below the soil environmental quality standards for China. Cadmium was the most serious pollutant in both soils and sediments, at 2.58 and 3.40 times its background values. The contents of Cd and Pb were very closely related (p < 0.01) to total nitrogen concentrations in both soil and sediment samples. The potential ecological risks posed by Cd in the Chao and Baimaguan River soils were considerable and moderate, respectively. The historical iron ore mining and agricultural activity were identified as the primary sources of potentially toxic element pollution of soil and sediment in the Chao-Bai River in Miyun District. Human health risk assessment indicated that non-carcinogenic risks all fell below threshold values. The total carcinogenic risks due to Cr and As were within the acceptable range for both adults and children. This conclusion provides a scientific basis for the control of potentially toxic element pollution and environmental protection of the Miyun Reservoir in Beijing.

Estimation of the daily soil/dust (SD) ingestion rate of children from Gansu Province, China via hand-to-mouth contact using tracer elements.

A total of 60 children (31 males and 29 females) between the ages of 3 and 12 years were randomly selected from Lanzhou City in Gansu Province, northwest China. Hand (soil/dust) SD samples from these children were collected using hand wipes. We determined the approximate amounts of hand SD and the concentrations of three tracer soil elements (Ce, Y, and V) in these samples. The approximate amounts of hand SD ranged from 42.28 to 173.76 mg, with a median value of 85.42 mg. In addition, the mean amounts of hand SD estimated using the concentrations of Ce, Y, and V in the samples were 4.63, 3.43, and 3.42 mg, respectively. The amount of hand SD varied greatly among the age groups: primary school children had more hand SD than kindergarten children, males had more hand SD than females, and children from rural areas had more hand SD than those from urban areas. The rates of daily ingestion of hand SD for kindergarten and primary school children were estimated to be 7.73 and 6.61 mg/day, respectively.

A review of heavy metal pollution levels and health risk assessment of urban soils in Chinese cities.

This study assessed literature-based data for the period 2006-2016 regarding heavy metal (As, Cd, Cr, Cu, Pb, Ni, Zn, and Hg) concentrations in soils from 32 Chinese cities and the associated human health risks. The mean concentrations of the eight metals were lower than the soil environmental quality standards in China, but were much higher than the background values for most cities. The enrichment factor (EF) and geoaccumulation index (I geo) values showed moderate pollution levels, possibly influenced by anthropogenic activity for Cd, Hg, Pb, and Zn. The pollution levels in eastern cities were much higher than those in western cities, and heavy metals concentrations in different types of cities followed the order: industrial based cities > more developed cities > metropoles > underdeveloped cities. The human health risk assessment for heavy metals in most cities indicated that non-carcinogenic risks were within threshold values (HI < 1). The total carcinogenic risk due to As, Cr, and Ni in most urban areas was in excess of 1 × 10-5, but was lower than 1 × 10-4. However, in some cities (e.g., Baoji City, Tiyuan City, and Xuzhou City), Ni and Cr have potential cancer risks for both adults and children. Compared to adults, children could be more seriously threatened by heavy metal contamination in soils. In general, we recommend that Cd, Hg, and Pb are selected as priority heavy metals pollutants that require control in Chinese cities.

DDT, DDD, and DDE in soil of Xiangfen County, China: Residues, sources, spatial distribution, and health risks.

We collected and analyzed 128 surface soil samples from Xiangfen County for dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE). Total DDT concentrations (DDTs; sum of p,p'-DDD, p,p'-DDE, and p,p'-DDT) ranged from ND to 427.81 ng g(-1) (dry weight, dw), with a mean of 40.26 ng g(-1) (dw). Among the three compounds, p,p'-DDD was the most dominant. The DDTs in Xiangfen County soils mainly originated from historical DDT use, but there were also new inputs likely related to dicofol use. The DDTs in Xiangfen County soils were mainly degraded under anaerobic conditions, and direct degradation to DDD was the main degradation route. Regions with relatively high concentrations of DDTs were mainly located in North and South Xiangfen County. In these regions, many soil samples contained p,p'-DDT as the predominant pollutant, suggestive of extensive new inputs of DDT. A health risk assessment revealed that there are no serious long-term health impacts of exposure to DDTs in soil, for adults or children.

Assessments of levels, potential ecological risk, and human health risk of heavy metals in the soils from a typical county in Shanxi Province, China.

A total of 128 surface soil samples were collected, and eight heavy metals, including As, Cd, Cr, Cu, Pb, Ni, Zn, and Hg, were analyzed for their concentrations, potential ecological risks, and human health risks. The mean concentrations of these eight metals were lower than the soil environmental quality standards in China, while they were slightly higher than the background values in Shanxi Province. The enrichment factor, coefficient variation, and potential ecological risk index were used to assess the pollution and eco-risk level of heavy metals, among which, Cd and Hg showed higher pollution levels and potential risks than the others in the studied area. Moreover, multivariate geostatistical analysis suggested that Hg originated mainly from point sources such as industrial emissions, while agricultural activity is the predominant factor for Cd. The human health risk assessment indicated that non-carcinogenic values were below the threshold values. The total carcinogenic risks due to As, Cr, and Ni were within the acceptable range for adults, while for children, they were higher than the threshold value (1.0E-04), indicating that children are facing higher threat to heavy metals in soils. These results provide basic information on heavy metal pollution control and human health risk assessment management in the study regions.

Heavy metals in soils from a typical county in Shanxi Province, China: Levels, sources and spatial distribution.

The concentrations of As, Cd, Cr, Cu, Pb, Ni, Zn, and Hg in 128 surface soil samples from Xiangfen County, Shanxi Province, China were measured. The concentrations of these eight heavy metals were lower than the critical values in the national soil quality standard. However, these concentrations were found to be slightly higher than their background values in soils in Shanxi Province, indicating enrichment of these metals in soils in Xiangfen County, especially for Hg and Cd. Principal component analysis coupled with cluster analysis was used to analyze the data and identify possible sources of these heavy metals; the results showed that the eight heavy metals in soils from Xiangfen County came from three different sources. Lead, Cd, Cu and Zn mainly arose from agricultural practices and vehicle emissions. Arsenic and Ni arose mainly from parent materials. Industrial practices were the main sources of Cr and Hg. The spatial distribution of the heavy metals varied greatly, and was closely correlated to local anthropogenic activities. This study will be helpful not only for improving local soil environmental quality but will also provide a basis for effectively targeting policies to protect soils from long-term heavy metal accumulation.

Quantification of soil/dust (SD) on the hands of children from Hubei Province, China using hand wipes.

A total of 120 children (58 males and 62 females) between the ages of 2 and 17 years were randomly selected from Wuhan City and Wufeng County in Hubei Province, China. We gathered hand SD samples from these children using hand wipes. We determined approximate amounts of hand SD and concentrations of three tracer soil elements (Ce, Y, V) in these samples. The approximate amounts of hand SD ranged from 6.35 to 85.42mg with a median value of 20.62mg. In addition, mean amounts of hand SD estimated using concentrations of Ce, Y, and V in samples were 1.07, 1.00, and 0.92mg, respectively. The amounts of hand SD varied greatly among age groups: primary school children had more hand SD than kindergarten and middle school children, males had more hand SD than females, and children from rural areas had more hand SD than those from urban areas. The rates of daily ingestion of hand SD for kindergarten, primary school, and middle school children were estimated as 1.79, 2.12, and 0.49mg/d, respectively.

Gridded field observations of polycyclic aromatic hydrocarbons in soils from a typical county in Shanxi Province, China.

Polycyclic aromatic hydrocarbons (PAHs) were measured in 128 soil samples collected from Xiangfen County, Shanxi Province, China. Sixteen PAH congeners were identified at high concentrations (89-100 %), with the exceptions of Ace and Acy, and were used for statistical analysis. PAH concentrations ranged from 51.91 to 10,523.58 ng/g with a mean of 722.35 ng/g indicating severe pollution at the sample sites. Four-ring PAHs were predominant followed by 3- and 5-ring PAHs. Coal combustion was found to be the greatest contributor of PAHs to the local environment. An analysis of the spatial distribution of PAHs indicated the presence of relatively high concentrations in the northwest region of the county. A source identification analysis showed that Wulidun in Fencheng Town, Shangbeirong Village in Gucheng Town, and Yandian Village in Xincheng Town were the major sources of PAHs in Xiangfen County. Modeling results indicated that the distance among the sampling sites and these point sources had a large influence on the transfer of PAHs to the soils.

[Implementation results of emission standards of air pollutants for thermal power plants: a numerical simulation].

The emission inventory of air pollutants from the thermal power plants in the year of 2010 was set up. Based on the inventory, the air quality of the prediction scenarios by implementation of both 2003-version emission standard and the new emission standard were simulated using Models-3/CMAQ. The concentrations of NO2, SO2, and PM2.5, and the deposition of nitrogen and sulfur in the year of 2015 and 2020 were predicted to investigate the regional air quality improvement by the new emission standard. The results showed that the new emission standard could effectively improve the air quality in China. Compared with the implementation results of the 2003-version emission standard, by 2015 and 2020, the area with NO2 concentration higher than the emission standard would be reduced by 53.9% and 55.2%, the area with SO2 concentration higher than the emission standard would be reduced by 40.0%, the area with nitrogen deposition higher than 1.0 t x km(-2) would be reduced by 75.4% and 77.9%, and the area with sulfur deposition higher than 1.6 t x km(-2) would be reduced by 37.1% and 34.3%, respectively.

[Temporal and spatial distribution characteristics of ozone in Beijing].

Ozone concentrations obtained from 35 automatic air monitoring stations in Beijing were analyzed to investigate their temporal and spatial distribution characteristics. A process with high ozone concentration in summer was analyzed. The results showed that ozone maintained relatively high concentration from May to August while in other months, the ozone concentration was at a low level. Overall, the average concentrations of ozone in different stations in a descending order were comparison and regional station, suburban environment evaluation station, urban environmental assessment station and traffic pollution monitoring station. Ozone diurnal variation showed a single peak distribution, the peak of which appeared at 15:00 or 16:00. Ozone concentration showed obvious weekend effect, which meant ozone concentration in daytime of weekend was higher than that in weekday. Ozone concentration was lower in urban Beijing, higher in surrounding counties and the highest in northeast area with more vegetation. A high ozone concentration process occurred in Beijing on June 3, 2013. Under the effect of southwest wind in the afternoon, the concentration peaks of ozone in Yufa, Fengtaihuayuan, Olympic center and Huairou station occurred in order from south to north. Concentration peak of ozone in Huairou station occurred at 20:00 in the night. It could be concluded that significant ozone transmission characteristic was reflected in this process.