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[Objective] The Objectives of this study are to estimate the effects of throughfall exclusion (drought) on the sap flow in a Populus deltoides plantations and to enhance our understanding of the response of poplar plantations to changes in global precipitation patterns. [Methods] The study was conducted from September 2018 to November 2020 in a 10-year old poplar plantation in Dongtai Forest Farm. There were three treatments in this study, including CK (control), D1 (30% throughfall exclusion）, and D2 (50% throughfall exclusion）. The sap flow density and environmental factors were continuously measured by thermal diffusion probe technology and the Micro Weather Monitoring System to evaluatethe response of the poplar plantation to environmental factors. [Results] (1) In three treatments, the annual variation of sap flow in poplar plantations showed a single peak, similar to the interannual variation of vapor pressure deficit and photosynthetic active radiation. The sap flow rate reached its peak in summer, and then gradually decreased over time. In the dormant period, the sap flow density approached zero. (2) In the drought treatment, the sap flow decreased with the increasing throughfall exclusion. The average sap flow density in the growth seasons of D1 and D2 were 39.61 and 31.85 g/ (m² s）, respectively, which were significantly reduced by 24% to 39% compared to the control (p＜0.05）. (3) The mixed effect model showed that the vapor pressure deficit and soil temperature were extremely significantly correlated with sap flow (p＜0.01）, while air temperature, rainfall, and soil temperature were significantly correlated with sap flow (p＜0.05）. [Conclusion] In D1 treatment, the power of explanation of environmental factors to sap flow increased, and the sensitivity sap flow to environmental changes could be increased in drought treatments. Among them, soil temperature was significantly correlated with sap flow. Further exploration of the response of tree traits to the environment is needed in the future. [ABSTRACT FROM AUTHOR]

Aromaticity is one of the most important concepts in chemistry. However, there is still no unified chemical insight for various systems with conjugated sp2 carbon. Herein, we proposed a superatomic-molecule theory to build a generalized electron rule for polycyclic conjugated hydrocarbons, fullerenes and 2D periodic materials. Taking benzenoid units as 2D superatoms, polycyclic conjugated hydrocarbons and C60 can be seen as superatomic molecules consisting of bonded superatoms, resulting in local aromaticity. In superatomic molecules, π electrons are not totally delocalized, but localized in a single superatom forming superatomic lone pairs or shared by two atoms forming a superatomic bond, mimicking rules in classical valence bond theory. Moreover, two 2D superatomic crystals (C18H6 and C54H18) are predicted to have fairly large band gaps (∼1.8 eV), although the π electrons are conjugated and delocalized. The proposed superatomic-molecule theory provides generalized chemical insights into the nature of local aromaticity, which can be qualitatively evaluated by the chemical intuition given by superatomic Lewis structures. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy of well trajectory calculation in measurement while drilling, a segmented well trajectory calculation method based on magnetic inertia measurement is proposed in this study. When the drill bit is stopped, the tool face angle model recognition method is used to identify the borehole trajectory model of the test section, and the sub-measurement points of the test section under the constraints of the model are generated according to the depth change in the real-time measurement data. Then, the magnetic inertia measurement data is used to correct the measured points, and the corrected points are identified by piecewise trajectory model. Finally, the corresponding models are calculated by piecewise model. The experimental results show that the absolute error of the coordinate increment is reduced from 0.840 m of the single model algorithm to 0.146 m after adopting the new method, which shows that compared with the single model of the well trajectory calculation method, the error of the segmented well trajectory calculation method is smaller and the wellbore trajectory calculation method can improve the accuracy of the borehole trajectory calculation. [ABSTRACT FROM AUTHOR]

In view of the problem that the wellbore trajectory fitting deviates from the true drilling trajectory caused by the changeable wellbore trajectory shape and the single inclination mode, this study proposes a method of wellbore trajectory segmentation and pattern recognition based on characteristic parameters. On the basis of sufficient theory, the cubic b-spline function of well inclination and azimuth with well depth is established, and the curve characteristic parameters which can determine the adjacent shape of a certain point of the well trajectory are obtained. According to the characteristic parameters, and combined with the characteristic parameters of various models, the wellbore pattern recognition evaluation index and segmentation index are constructed, and the wellbore trajectory model that best matches the actual drilling is selected. In order to verify the effectiveness of this method, a prototype is designed to simulate the actual drilling experiment. The results show that the wellbore trajectory pattern recognition and segmenting method based on characteristic parameters can significantly improve the accuracy of wellbore trajectory fitting. [ABSTRACT FROM AUTHOR]

In view of the problem of serious distortion of gravitational acceleration information caused by bottom-hole vibration and noise during measurement while drilling, a method that combines generalized regression neural network and improved recursive least squares is proposed to remove noise. Using the principle of mutual cancellation of adaptive noise, the accelerometer measurement signal and drilling tool vibration signal are used as the main noise model, and the drilling tool vibration signal processed by the generalized regression neural network is used as the auxiliary noise model. Recursive least squares filter processing is used to improve the accuracy of drilling tool accelerometer measurement and calculate real-time drilling attitude information. The simulation results show that the proposed algorithm can effectively remove the vibration and noise of the drilling tool accelerometer and improve the attitude measurement accuracy. After denoising, the calculated deviation angle error is within 1.45°, and the tool face angle error is within 1.65°. [ABSTRACT FROM AUTHOR]

In view of the data drift problem of MEMS gyroscope caused by vibration while drilling, a spiking neural network algorithm is proposed in this study. First, according to the time characteristics of the drift error of the gyroscope, the pulse time of the spiking neural network is used to encode the information intensity of the gyroscope. Then, the synaptic plasticity of the Izhikevich neuron model is used to adjust the excitatory synaptic conductance and inhibitory synaptic conductance to enhance the robustness of the network, thereby improving the anti-interference ability of the gyroscope signal against noise. Finally, under different vibration frequencies, the correlation between the firing rate of the Gaussian white noise output neuron and the membrane potential is analyzed. Experimental results show that under strong vibrations of different frequencies, noise has little effect on the firing rate of output neurons and the relative change of firing rate of output layer neurons, and has little effect on the membrane potential of output layer neurons, but has a greater impact on the correlation between membrane potentials. These results indicate that the proposed method improves the anti-interference ability of the gyroscope under vibration and noise, and can provide a new idea for the processing of gyroscope drift. [ABSTRACT FROM AUTHOR]

Field tests were carried out to study the vibrations problem induced by moving train traffic under complex topography conditions on the viaduct section of Chongqing Light Rail Line 6 passing through typical slopes. Attenuation of train induced soil vibration under inclined topography conditions were analyzed. The results showed that the main frequencies of ground vibration caused by trains were distributed 30-95Hz under the semi-concave field, and the ground vibration presented wave attenuation. Two vibration amplification zones appeared in the direction of 45, and 90 degrees from the track center line. Affected by the topography of the site, the vibration was mainly concentrated in the concave field, and the attenuation of vibration in the two directions was not obvious in the concave field, but the attenuations showed significantly different variations. The vibration with a low-frequency was obvious near the pier, and the train operation had obvious periodical loading phenomenon. The ground vibration was mainly concentrated in the high-frequency part, but the attenuation of the high-frequency part was not obvious, while the vibration of the low-frequency part attenuated to some extent. What's more, the frequency vibration caused by the up train was greater than that of the down train. [ABSTRACT FROM AUTHOR]

In order to solve the problem of the serious distortion of the attitude parameters about drilling tool caused by the strong vibration of the bottom drilling tool in the process of rotary steering drilling,a magnetic/inertial-based method is proposed to extract the gravity information of the drilling tool.Firstly,a federal extraction framework for the gravity information of drilling tool is designed with gyro data-based gravity recursive model selected as the main filter,and also the accelerometer data-based and magnetometer data-based gravity observation model are used as sub filter respectively.Secondly the robust estimation and fusion of the state and observation model about sub filters are carried out respectively,and the fusion weight between state and observation model is adaptively adjusted by the adaptive factor and the equivalent weight matrix,then the local robust estimation of gravity information is obtained.Thirdly the comprehensive estimation of gravity information about drilling tool is further improved by means of federal filter.Coal mine drilling experiments indicate that the proposed method could effectively extract the dynamic gravity information of drilling tools,with the corresponding average error of inclination within 2.5 degrees. [ABSTRACT FROM AUTHOR]

Due to the fluctuation of PV power, it is difficult to keep the active power of the PV grid-connected inverter constant. To address the above problems, this paper proposed a new three-level integrated photovoltaic storage machine consisting of a T-type three-level DC/AC converter, a three-level Boost converter and a three-level bi-directional DC/DC converter and related control strategies. The three-level structure allowed for lower switching losses resulting in higher system efficiency and wider voltage range adaptability. In terms of control, frequency differentiation and deviation control were introduced in the control of the energy storage DC/DC converter to achieve frequency regulation of the transient/static support of the active power of the parallel network. The simulation and experiment show that when the frequency fluctuation range is 50.02～49.97 Hz（meeting the national standard）, the new optical storage all-in-one machine proposed in this paper can operate stably and be easily realized. [ABSTRACT FROM AUTHOR]

Objective To analyze the differences in health emergency capacity of primary healthcare workers in regions with different economic development levels in China, explore the influencing factors of these capacities, and provide a basis for promoting the construction of the health emergency system. Methods A total of 1 333 primary healthcare workers were surveyed by convenience sampling with a self-designed public health emergency response capacity questionnaire in Beijing (as a developed region) and City Q of Heilongjiang Province (as a developing region). Results A total of 1 281 valid questionnaires were collected, with an effective recovery rate of 96.10%. Among them, 589 were from Beijing and 692 from City Q. The proportions of personnel with formal establishments, professional qualification certificates, and high education in Beijing were higher than in City Q. The proportions of personnel participating in health emergency training, drills, and practical work on emergency response were also higher in Beijing than in City Q (P < 0.05). The total score of health emergency capacity of 1 281 primary healthcare workers was (114.65 ± 17.77) points, and the average score was (3.82 ± 0.59) points. The rankings from high to low based on average scores were: psychological quality (4.13 ± 0.58) points, professional skills (3.86 ± 0.69) points, and theoretical knowledge (3.63 ± 0.72) points. Multivariate linear regression analysis showed that, compared with City Q, the health emergency capacity score of primary healthcare workers in Beijing increased by 2.068 points. Compared with primary healthcare workers who had not participated in health emergency training, drills, and practice work on emergency response, the scores of those who had participated increased by 4.648, 10.935, and 3.466 points, respectively (P < 0.05). Conclusions The health emergency capacity of primary healthcare workers represents the comprehensive strength of local health and healthcare. The health emergency capacity in developing regions is still not strong enough, and efforts should be made to actively strengthen the construction of health emergency capacity and systems in order to comprehensively improve the capacity and level of health emergency response. [ABSTRACT FROM AUTHOR]

Organophosphorus pesticides (OPs), as one of the most toxic pesticides, have the characteristics of wide use, large usage and great harm to human health. With people's longing and continuous pursuit of a healthy life, it is particularly urgent and important to build accurate, sensitive, convenient and fast OPs residual analysis and detection sensor. Because of the unique optical, electrochemical and biological properties of nanomaterials, OPs detection sensors based on nanomaterials have the advantages of sensitivity, high efficiency and economy. In this paper, the domestic and foreign sensors for detecting OPs residues based on rare earth doped up conversion nanomaterials, metal nanomaterials, metal oxide nanomaterials, carbon nanomaterials and quantum dot nanomaterials from 2015 to 2023 are reviewed, providing ideas and basis for the subsequent development of nanomaterial-based OPs multi residue detection sensors. [ABSTRACT FROM AUTHOR]

Variation, variance, and correlation analyses and estimations of genetic parameters of traits related to chestnut blight resistance and growth in half-sibs of Castanea henryi were performed to screen for excellent families, individuals with good growth, and strong resistance to chestnut blight. The results showed that the average coefficient of variation (CV) of traits in 12 half-sib families was 20.19%, with the CV of the lesion area being the largest (39.76%) and that of the leaf shape index being the smallest (11.14%). Among the families, there were significant differences in lesion width, leaf area, leaf perimeter, leaf length, and vein number (P<0.05) and highly significant differences in infection rate, infection index, and leaf width(P<0.01). The seedling height showed a significant negative correlation with the infection rate (P<0.05) and a highly significant negative correlation with the infection index (P<0.01). The leaf length exhibited a highly significant negative correlation with the infection rate and index (P<0.01). Three excellent families were selected; namely, JO14 ('Bailuzi'), JO8 ('Youtongzi'), and JO2 (Dabaozhen'). Nine individuals (JO2-25, JO13-29, JO14-32, JO2-12, JO8-17, JO3-4, JO5-26, JO2-19, and JO12-20) with strong resistance and four individuals (JO2-5, JO7-16, JO8-17, and JO14-3) with good growth were selected, among which JO8-17 showed strong resistance and excellent growth. [ABSTRACT FROM AUTHOR]

Objective·To explore the association between high myopia and life quality among children. Methods·Cross-sectional study method was adopted in this study. Highly myopic children aged 4‒10 from 16 districts in Shanghai were enrolled through Shanghai Child and Adolescent Large-scale Eye Study-High Myopia Registration Study. Baseline data for spherical equivalent after cycloplegia and questionnaire data in 2020 were collected. Emmetropic children aged 4‒10 from 16 kindergartens and elementary schools in Jing'an District and Pudong New Area were enrolled. The uncorrected visual acuity, corrected visual acuity and spherical equivalent without cycloplegia were measured through myopia screening in schools, and the questionnaire on quality of life was filled out. Quality of life was measured by the Strengths and Difficulties Questionnaire (SDQ) and EuroQol Five Dimensions Questionnaire Visual Analogue Scale (EQ-VAS). After describing and testing the differences in variable distributions between the highly myopic children group and the emmetropic children group, the differences in life quality between the two groups, and the association between spherical equivalent and life quality scores of the highly myopic children were examined by a linear regression model. Results·A total of 193 children with high myopia and 209 children with emmetropia were enrolled. There were statistically significant differences in age [(9.58±0.94) years vs (7.63±1.50) years, P<0.001] and gender distribution (46.6% males vs 62.7% males, P=0.001) between the highly myopic children and emmetropic children. After adjusting for age and gender, it was found that there was no statistically significant difference in SDQ score between the highly myopic children and emmetropic children (β = 0.313, 95%CI -0.723‒1.349, P=0.553), but the EQ-VAS score in the highly myopic children was lower than that in the emmetropic children (β=-3.805, 95%CI -6.593‒ -1.017, P=0.008). There was no significant relationship between spherical equivalent and SDQ score (β=0.297, 95%CI -0.035‒0.628, P=0.079) and EQ-VAS score (β=0.579, 95%CI -0.330‒1.489, P=0.211) in the highly myopic children. Conclusion·In children with high myopia, self-evaluated overall health status reflected by EQ-VAS score is poorer compared with that in children with emmetropia. However, the EQ-VAS score is not associated with the degree of high myopia. [ABSTRACT FROM AUTHOR]

Calcineurin B-like calcium sensor(CBL)is a Ca2+-binding protein that mediates the Ca2+ signal transduction process by interacting with Calcineurin B-like calcium sensor interacting protein kinase(CIPK). CBL-CIPK signaling system is involved in the response of plants to a variety of stress conditions. For insight into the chilling mechanism of CBL and CIPK in Jatropha curcas, the CBL and CIPK gene families were identified from J. curcas based on the BLAST method, and then the phylogenetic relationship, gene structure, expression profile, and functional interaction were analyzed. The results were as follows: (1) A total of 8 CBL and 18 CIPK genes were identified from J.curcas genome. The protein length of CBLs and CIPKs ranged from 211 to 257 aa and 422 to 484 aa, respectively, and the putative isoelectric point ranged from 4.65 to 5.08 and 6.20 to 9.26, respectively. (2) Furthermore, all the CBL genes family contained 8-10 exons, while the CIPK genes family were divided into significant 1-2 exons(11 genes)and 12-15 exons(7 genes). (3) Sequence alignment revealed that CBL proteins identified 1 atypical EF-hand motif consisting of 14 amino acid residues and three typical EF-hand motifs with different substitutions, while CIPK proteins contained kinase domains in N-terminal and self-inhibiting FISL/NAF domains in C-terminal. (4) Chromosome mapping analysis indicated that 26 J. curcas CBL and CIPK genes were distributed with different densities on nine chromosomes. (5) Transcriptome data analysis showed that most of the CBL and CIPK genes were highly expressed in J. curcas leaves, roots and seeds. Among them, the up-regulated expression of JcCIPK14 and JcCIPK18 reached significant levels under cold stress, which was involved in the cold resistance of J. curcas. All the results of this study might lay a significant foundation for further studies on the gene function and chilling signaling transduction mechanism of CBL and CIPK gene families in J. curcas. [ABSTRACT FROM AUTHOR]

The high-efficient utilization of mineral resources is the leading research aspect of global mining development. Traditional optical and scanning electron microscopy have limitations in identifying the occurrence of elements in many low-grade ores and usually cannot provide quantitative mineralogy information, hindering the improvement of mineral processing of these ores. In recent years, automated mineral quantitative analysis systems based on scanning electron microscope and X-ray energy spectrometer have been increasingly applied to study complex ore formation and process mineralogy. OBJECTIVES: To enrich and expand the application of an automated quantitative mineral analysis system in process mineralogy. METHODS: The low-grade copper slag from a copper mine in China is analyzed using the TESCAN Integrated Mineral Analyzier (TIMA). RESULTS: The results show that the content of the copper element (0.08%) in the copper slag is very low, and it is mainly distributed in chalcopyrite, which accounts for 0.21%. Gangue minerals include quartz (47.6%), muscovite (10.10%), and calcite (9.88%). Chalcopyrite usually occurs in irregular granular form and shows complex associations with the above gangue minerals. The particle size is small and variable, and the particles of 10-76μm occupy a large proportion. The mass of chalcopyrite with a liberation degree below 30% accounts for 85% of the total mass, and the overall liberation degree is low, so further grinding is needed to improve chalcopyrite recovery. CONCLUSIONS: Research shows that for the ore samples with low content of useful minerals, small particle size, and complex mineralogical associations, the automated mineral analysis system, including TIMA, can provide rapid, quantitative, comprehensive, and accurate process mineralogy parameter information, which is conducive to optimizing the ore extraction and smelting process, and has an extensive application prospect in improving the comprehensive utilization of mineral resources. [ABSTRACT FROM AUTHOR]

BACKGROUND: Inductively coupled plasma-optical emission spectrometry (ICP-OES) and combustion-infrared absorption spectrometry are the most widely used methods to measure sulfur content in geological samples. The ICP-OES method has high sensitivity and good stability, but it is greatly affected by sample pretreatment and matrix interference. Combustion-infrared absorption spectrometry is convenient and efficient, but due to the interference of crystal water infrared absorption, the analysis of samples with low sulfur content has poor stability. OBJECTIVES: To study the application scope of the two methods in geological sample analysis. METHODS: The sulfur content of samples was determined by ICP-OES and combustion-infrared absorption spectrometry. The detection limit, detection range, precision, accuracy and analysis efficiency of the two methods was compared in order to study and understand the performance of the two methods in sulfur measurement of geological samples. RESULTS: The best test condition of combustion-infrared absorption spectrometry was determined thus: optimal sample weight of 0.0500 g, combustion time of 25 s, analysis time of 40 s and oxygen analysis flow rate of 4.0 L/min. The detection limit of combustion-infrared absorption spectrometry was 10×10-6 and the detection range was 10×10-6-470000×10-6. The accuracy relative standard deviation (RSD) of the method was less than 6% (n=12) and the absolute value of relative error was less than 8%.CONCLUSIONS: For the analysis of low-sulfur samples, ICP-OES method can be used to analyze or compare, and multi-element simultaneous measurement can be determined. Batch samples or samples with a complex matrix can be analyzed by combustion-infrared absorption spectrometry, which is more convenient and efficient. [ABSTRACT FROM AUTHOR]

Quanzhou Bay, the main port on the southeast coast of China, is the origin of the Maritime Silk Road. The landform is a semi-closed shelf bay. Two rivers, the Jinjiang and Luoyang, carry sediments to the bay and are connected to the Taiwan Strait. Sediment is also introduced to the bay from the open sea. Human activities have a strong influence on the bay, as does the occasional typhoon. Quanzhou Bay is characterized as a complex hydrodynamic environment with multi-source deposits. Grain size is an important indicator of the sedimentological characteristics of loose sediments, and it can reflect mixed sedimentary dynamics, sedimentary environment, and provenance. The End-Member Analysis method has the advantage of separating the mixed sedimentary dynamic components and has been widely used in sedimentology research. Many researchers have studied the sedimentological characteristics of Quanzhou Bay. However, further work on the identification of the dynamic components using End-Member Analysis methods is necessary to supplement previous work. In view of this, the present study adopts the particle size End-Member Analysis method, combined with sediment grain size parameters, water depth, and hydrodynamic forces, to analyze the sedimentation dynamics of 65 surface sediment samples collected in Quanzhou Bay of Fujian Province. Based on this analysis, we concluded that: (1) Owing to the continuous progress of sedimentary dynamics, separation, and sedimentation, provenance cannot be determined from grain size analyses, and only sedimentary kinetic characteristics can be defined; (2) Quanzhou Bay sediments are superimposed with at least four different dynamic end-member components. The distribution of the fine-grained End-Member components represented by EM 1 on the Quanzhou Bay area plane is generally corresponds to the weaker tidal hydrodynamics area. Therefore, we infer that this may represent a stagnant sedimentary environment with weak hydrodynamics. The EM 2 components, are somewhat high in the southern part of the bay mouth, and are relatively stable and with uniform distribution elsewhere in the bay. Considering the effect of tidal currents and the attenuation of tidal action in some areas, EM 2 components may represent the sedimentary dynamic environment of reworking under the action of typhoon storms. EM 3 and EM 1 components show an anti-correlation trend, which often occurs in areas with strong hydrodynamic forces. Therefore, EM 3 may be associated with a strong sedimentary dynamic environment under the action of tidal currents. The EM 4 component is generally higher in the northern part of the bay and in the estuary, but lower around the islands. This spatial distribution is likely to be caused by comprehensive human activities. There are many artificial sand-piling areas near Xiutu, and many cross-sea projects in the sea area north of Shihu, such as the wharf on the north bank east of Xiutu and the Cross-sea Bridge of Quanzhou Bay. The area affected by these projects coincides with high values of EM 4. The research in this paper is of progressive significance for a quantitative understanding of the complex sedimentary dynamics of Quanzhou Bay. Concurrently, by analyzing the dynamics and processes of sediment accumulation in the bay, a reference can be provided for channel dredging, utilization, and management for coastal zone development. [ABSTRACT FROM AUTHOR]

The green wall has been widely applied in the city as a new form of vertical planting in the city for its great importance in the landscape and ecology. But some problems often appeared such as lack of species diversity and inadaptation to the environment. This paper reported the diversity of plants in the rural wall and the city green wall, and the aim is to enrich the plant species diversity in the city green wall. This paper reported the study on plant diversity in different kinds of vertical walls by the means of field investigation in six ancient villages in Hangzhou, Ningbo and Jinhua in the east of Zhejiang Province from July 19th to August 6th. The results showed that there were 154 species on the wall, belonging to 122 genera in 69 families, in which the ferns consisted of 20 species belonging to 15 genera in 11 families and the angiosperm consisted of 134 species belonging to 107 genera in 59 families. Most of the wall plants were herbs and it mainly concentrated on Compositae, Polygonaceae, Gramineae, Crassulaceae, Rosaceae, Vitaceae, Euphorbiaceae and Urticaceae, with strong adaptability. Based on the growth types of plants, the main plant species included 107 species of herbs, 25 species of liana, 24 species of shrubs, 18 species of arbors. In addition, the statistics and results obtained from intensive analyses at different levels revealed that there were 45 kinds of plants which only growed in exposed halves and 6 7 kinds only in shaded halves respectively. On the other hand, there were 43 kinds with strong drought-enduring plants and 26 kinds of hygrophilous plants. And the analysis of the ornamental values of wall plants indicated that there were 14 kinds of foliage plants, 19 kinds of flowering plants, 5 kinds of ornamental fruit plants. At last, some suggestions about how to use the wall plants in vertical greening wall were put for-ward in the end. [ABSTRACT FROM AUTHOR]