Search

In the digital economy era, take-out shops relying on the online-to-offline e-commerce platform have gathered in central cities on a large scale, forming large-scale food processing spaces—"Takeaway Factories"— to serve immediate local catering needs. In addition to the impact of the platform economy, consumer demand, and space costs, riders are an important and dynamic factor that promote the final formation of a "Takeaway Factory". Based on the analysis framework of virtual and real-space interactions using the participatory survey method, the specific roles of crowdsourcing and special delivery riders in the formation of "Takeaway Factory" was elucidated. Riders, as the core intermediaries of virtual agglomeration that leads to physical agglomeration, play a role at different stages and spatial scales. In the initial stage, because dedicated takeout shops tend to prefer low-cost, high-demand urban gap spaces, they face challenges in matching with special delivery riders until they are included in the special delivery distribution station. Thus, crowdsourcing riders with free-movement attributes are their first choice. Crowdsourcing riders have a strong preference for store clusters and select food through the two tools of the regional order heat map and grab order hall, bringing about differences in distribution efficiency and promoting the phenomenon of large regional differentiation of relatively concentrated and dispersed stores within the city scale. In the middle stage, in the face of the uneven distribution efficiency of different areas in the city, the platform divides the size of the stations according to the size of the shops in different areas, and matches the special delivery riders of the corresponding scale, which eliminates the uneven distribution efficiency of different areas to a certain extent, and promotes the distribution efficiency of different sections to reach a basic balance. With the emergence of special delivery systems, the special delivery riders are distributed in the station area through the delivery system, which effectively alleviates the distribution pressure of the relatively dispersed, inferior-location stores and promotes the balance of the distribution efficiency of different sections. In the final stage, the special delivery and crowdsourcing riders in the area jointly promote the agglomeration of shops in the area, and ultimately promote the formation of a more polarized takeaway factory. Crowdsourcing riders continue to promote agglomeration from the initial stage, whereas the emergence of special delivery riders promotes both equilibrium and agglomeration. With the increasing maturity of the special delivery and crowdsourcing system, the time-space behavior of different types of riders will eventually promote the completion of the high-density and large-scale agglomeration of takeaway shops in the area (distribution site) through virtual tools, such as site order thermal maps, order dispatching systems, resident points, and order-grabbing halls.

The spot-welding defects of highly alloyed Ni-base superalloy GH4065A were investigated by using SEM and EBSD analysis methods. Effects of the welding defects on fatigue life and fracture behavior were studied by comparing thin plate samples with a central hole that were non-welded，densely welded and sparsely welded respectively. The results show that the lack-of-fusion defect，solidification crack and liquation crack are the main welding defects responsible for significant reductions in low-cycle fatigue life as well as combined low and high cycle fatigue life. These welding defects result in a transition of the fatigue crack initiation site from the inner surface of the central hole in the non-welded sample to the welding spot in the welded sample，leading to 44%-83% reductions in low-cycle fatigue life at 700 ℃/700 MPa. For the combined low and high cycle fatigue conditions（with a stress amplitude of 700 MPa for the low cycle loading part and 100 MPa for the high cycle loading part），the welding defects not only alter the site at which fatigue cracks initiate，but also make the crack propagation mode more intergranular. This results in dramatic decreases of over 85% in the fatigue life of welded samples at both 600 ℃ and 700 ℃. Due to shorter distance between the welding spot and the central hole，densely-welded samples exhibit a slightly lower level of fatigue life under low-cycle loading conditions compared to sparsely welded samples. However，the fatigue life difference between them becomes negligible when subjected to combined low and high cycle loadings.

Objective： Based on transcriptome sequencing analysis, the effect of grape seed procyanidins on HepG2 cell genes and related functions was identified. The key genes and metabolic pathways involved in the treatment of HepG2 cells with procyanidins were confirmed. Methods: Through transcriptome sequencing, screening differential genes, gene functional annotation and enrichment analysis of the KEGG pathway, transcriptome studies were conducted on grape proanthocyanidin-treated cells. Results: After treating HepG2 cells with grape anthocyanins, the main biological processes enriched are cellular processes, metabolic processes, biological regulatory processes, immune system processes, reproductive regulation, and growth regulation. Research has found that 12 key differentially expressed genes in cell apoptosis are associated with TNF, p53, MAPK, PI3K-Akt and NF-κB signaling pathway is closely related. Conclusion: Cell apoptosis is closely related to the TNF signaling pathway, p53 signaling pathway, PI3K/Akt signaling pathway, NF-κB signaling pathway and MAPK signaling pathway.

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.

C18H15BrF2N4O, monoclinic, C2/c (no. 15), a = 22.984(4) Å, b = 10.0726(16) Å, c = 16.551(3) Å, β = 107.972(2)°, V = 3644.8(10) Å3, Z = 8, Rgt(F) = 0.0412, wRref(F2) = 0.1051, T = 296(2) K.

It is critical to develop the methods and technologies of studying the species and concentration in the processing of adsorption, and diffusion of some important radionuclides in spent fuel waste processing such as Beishan granites in domestic institutions and universities for the geological disposal of high-level radioactive wastes. Enrich the models used or constructed and the calculation procedures developed in the past two decades in this field. In order to evaluate the safety of the repository, chemical speciation analysis of nuclides is the premise of research to accurately predict the migration behavior of nuclides. In view of the rapid development of China's nuclear energy industry and the need to establish the identification of nuclides in the environment, it is of great significance to carry out the study of the chemical forms of nuclides around the repository in China. Aiming at the research requirements of element speciation distribution in the environment, a set of B/S architecture element speciation distribution simulation software is developed with JAVA as the development tool, MySQL as the database, and Tomcat as the container. In order to solve the convergence problem of chemical reaction equilibrium nonlinear equations encountered in simulation calculation, the method based on chemical reaction potential energy is introduced to solve the chemical reaction nonlinear equations quickly, and the multi-phase equilibrium calculation can be expanded. SSCS was used to study the species of U in groundwater and the effects of Eh, pH, different ions and concentrations. The calculation results indicate that neptunium mainly exists as NpO2CO-3(aq) in groundwater. Under strong acidic conditions, neptunium maily exists as NpO+2(aq), while in weak acidic, neutral or weak alkaline conditions, the main species are NpO+2(aq) and NpO2OH.When the solution is in strong alkaline conditions, the species are complicated most of neptunium exists as NpO2(CO3)-3(aq), with the possible generation of NpO2(CO3)3-2 or NpO2(CO3)5-3. Np(Ⅴ) is stable in the reduction condition, while Np(Ⅳ) and Np(Ⅵ) are the possible generation. Comparing the neptunium calculation results of the software in the environment with the PHREEQC calculation results, the relative error is within 10 %. For the distribution of trace elements in the environment, a theoretical calculation solution is provided.

The urban-rural fringe is located between the central urban built-up area and the rural hinterland, which is a transition zone for land use, economic development, and population structure. It is the most dynamic area between urban and rural areas and has become the focus of academic research in terms of geography, sociology, and urban planning. Boundary definition is the most fundamental and primary task for urban research and is particularly important for the spatial definition of the urban-rural fringe. However, a literature review reveals that an unclear spatial definition hinders in-depth scientific research on the urban-rural fringe. The absence of a spatial scope also results in a lack of targeted spatial governance policies attuned to the unique characteristics of urban, non-urban, rural, and both urban and rural areas. Existing policy instruments that exclusively focus on urban or rural areas face significant challenges in fringe regions. Recently, the establishment of a national land spatial planning system has created favorable conditions for studying the spatial definition of urban-rural junction areas. The simultaneous implementation of Territorial and Spatial Planning surveys as part of the construction of this planning system also provides technical support for accurately defining these junction areas. High precision "three adjustments" data allows for an accurate representation of the current state of urban and rural land use, enabling the precise identification of the physical geographical extent of cities. In the context of this study, a reasonable and widely accepted method for spatially defining the urban-rural fringe is essential. To address these issues, this study proposes a spatial definition method based on the urban entity regions identified in three land spatial planning surveys. The approach relies on mature territorial planning technology and addresses three key questions: indicators, thresholds, and units for defining the urban-rural fringe. 1) These indicators were derived from the precise identification of physical urban areas by the Ministry of Natural Resources of the People's Republic of China. The research units were administrative villages and neighborhood committees from previous government policies. It can effectively connect with the territorial spatial planning technology system; 2) Adopt the 25% to 75% ideal value and cluster analysis method recognized based on a comprehensive review of relevant literature and practices in spatially defining the urban-rural fringe domestically and internationally. At the end of the paper, Guangzhou is taken as a typical case study to test the effectiveness of the proposed method in defining the spatial boundaries of the urban-rural fringe. It was determined that a threshold of 10%-75% is reasonable for the spatial definition of the urban-rural fringe in Guangzhou. 3) Through the literature review and practice of government on the spatial definition of urban-rural fringe, as well as the urban-rural fringe identification and examination in Guangzhou. This study proposes a definitive approach based on the physical urban areas of territorial and spatial planning. Finally, accurate measurement indicators, clear research units and highly operable definition methods has an effective integration into the process of Territorial and Spatial Planning, which could provide a solid foundation for further spatial research and the implementation of effective governance strategies.

Objective To investigate the changes of neural function and its correlation with cognitive function and emotion in patients with neuropsychiatric systemic lupus erythematosus (NPSLE). Methods A total of 46 patients with systemic lupus erythematosus (SLE) admitted to The Affiliated Taizhou People's Hospital of Nanjing Medical University from June 2020 to September 2022 were included. The patients were divided into the NPSLE group (n = 26) and the non⁃NPSLE group (n = 20) based on the presenceor absence of neuropsychiatric symptoms. The mean regional homogeneity (mReHo) and mean fractional amplitude of low⁃frequency fluctuation (mfALFF) were calculated by resting⁃state fMRI (rs⁃fMRI). The Mini⁃Mental State Examination (MMSE) was used to evaluate overall cognitive function, the Fatigue Scale for Motor and Cognitive Functions (FSMC) was used to assess both motor and cognitive fatigue, and the Hospital Anxiety and Depression Scale (HADS) was used to measure anxiety and depression mood. Pearson correlation analysis and partial correlation analysis were conducted to explore the correlation of mReHo and mfALFF values in various brain regions with neuropsychologcial tests. Results The MMSE scores in NPSLE group was lower than non⁃NPSLE group (Z = ⁃ 3.934, P = 0.000). Additionally, the FSMC⁃ Motor (t = 2.016, P = 0.050), FSMC⁃Cognition (t = 2.055, P = 0.046), HADS⁃Anxiety (Z = ⁃ 2.424, P = 0.015) and HADS⁃Depression (Z = ⁃ 2.731, P = 0.006) scores in NPSLE group were higher than those in non⁃NPSLE group. The mReHo values of the right dorsolateral superior frontal gyrus, right middle occipital gyrus, right posterior central gyrus, right inferior parietal margin angular gyrus and right inferior temporal gyrus decreased, while mfALFF values of the right middle occipital gyrus and right posterior central gyrus decreased in the NPSLE group (false discovery rate correction; voxel level P < 0.001, cluster P < 0.05). The mReHo and mfALFF in the right postcentral gyrus were both negatively correlated with HADS⁃Depression (r = ⁃ 0.483, P = 0.017; r = ⁃ 0.504, P = 0.012). The mReHo in the right inferior parietal gyrus was negatively correlated with FSMC ⁃Motor (r = ⁃ 0.475, P = 0.019) and FSMC ⁃Cognition (r = ⁃ 0.414, P = 0.044). The mReHo in the right inferior temporal gyrus was negatively correlated with FSMC⁃Cognition (r = ⁃ 0.427, P = 0.037). Conclusions NPSLE patients exhibited abnormal local activity in brain regions, and neural function is closely related to neuropsychological test.

In order to study the cause of wire falling accident caused by fracture of 500 kV composite insulator in the no-fly zone of a province， various inspections and tests were carried out on the accident insulator string according to the current standard. The results of comprehensive detection and analysis and on-site fault investigation show that due to the defects in the interface between the glass fiber and the silicone rubber sheath of the composite insulator rod， the rod of the insulator is aged after many years of operation. In addition， due to the comprehensive influence of the operating environment， the internal fibrosis and overall structural degeneration of the rod are aggravated， which eventually causes the insulator to break down and cause the wire to fall off. Finally， in order to avoid the recurrence of such accidents and ensure the safe and stable operation of the power grid， the operation and maintenance strategy of composite insulators is given for the lines under the jurisdiction of the UAV no-fly zone and weak signal zone.

Uranium content measurement is very important to nuclear material accounting and product quality control in nuclear bulk facilities. It needs high accuracy and precision. In this work, 3 different measurement steps from 2 analytical standards GB 11841—1989 and ASTM C1267-17, which were uranium content test methods by iron(Ⅱ) reduction followed by chromium(Ⅵ) titration, were discussed by simulated experiments and following uncertainty evaluation. The results show that, the total uncertainties of the 3 steps are all lower than 0.1%, which is the international target value of uranium content measurement by redox potential titration method. The step for 2.3 g sample of GB 11841—1989 is more suitable to sign value measurement in reference material production, because of its lowest uncertainty. In routine testing works, the step for 0.20-0.25 g sample of GB 11841—1989 is better in sample weighting, the step of ASTM C1267-17 is better in titration and potassium dichromate solution preparation.

Public center systems planning is of great significance in controlling and guiding the optimization of urban spatial structures, activating the efficiency of urban operations, and improving the quality of urban spaces and human living environments. However, most previous studies used a single data source and focused on identifying the physical space characteristics centered on traditional commercial and public service facilities, making it difficult to accurately measure the actual operational performance of public centers. Therefore, this study relied on multiple data sources to research Dongguan City in South China from multiple perspectives. The formation of Dongguan's central system was affected by two factors: the external force of the megacity region and the endogenous driving force of urban development. First, qualitative and quantitative calibration methods were used to identify the spatial patterns of public centers from the spatial morphological dimension in an all-round and all-temporal manner using Kernel Density Estimation (K) and the Getis-Ord Gi* statistical method. Second, the functional hierarchy and service hinterland of centers at all levels were identified using the dynamic human activity links of the recreational population. Third, the effectiveness of planning implementation was evaluated from the perspective of spatial morphology and functional connection. Finally, starting from the factors of policy system, foreign investment, industrial economy, land factors, and transportation facilities, this study explored the formation mechanism of the center in a targeted manner, trying to provide a reference for the benign development of similar manufacturing cities. The results showed that: 1) the technical method using multisource data such as POI, cell phone signaling, and Baidu building footprint and traditional land use data to identify the public center system was effective, accurate, and practical. Dongguan had initially formed a center system with dual spatial characteristics of "morphological polycentric" and "functional monocentric"; 2) the plan had a certain role in promoting the construction of the center system. However, the development in terms of morphology and function was somewhat different from the plan; 3) the center system resulted from a multiparty game between the government and the market power. Thus, the center system depended on government policy formulation, land allocation, and facility construction and was closely related to capital investment and industrial transfer. Dongguan's urban public center system was important and highly correlated with the city's degree of industrial development. Therefore, this study included modern productive service elements in the center identification elements for the first time while focusing on extending the research object to the functional network of the Pearl River Delta megacity region, using the regional dynamic spatial movement trajectory of human flow to identify the distribution of urban center systems, and comprehensively defining the elements and technical methods of urban public center system identification, in an attempt to provide a reference for similar manufacturing cities.

Based on the implementing grain security projects and instituting other relevant grain security policies, China has promoted the process of digitalization and intelligence of grain storage and built the world's largest grain Internet of Things, since the 18th National Congress of the Communist Party of China. But, the resulting large amount of grain data, mainly based on temperature, can not effectively support decision-making and management on grain storage. Based on the study of the multi-field coupling theory of grain pile ecosystem, our research team further extracted the continuity principle, periodicity principle, and coordination principle of digital supervision of grain reserves, and proposed a series of intelligent strategies such as AID, ABC, 6R, SIN, CAE, O, and U. However, the application of these strategies directly faces the original data, which has some problems such as low efficiency and large error. To apply the intelligent strategies efficiently and correctly, the basic data manual of intelligent analysis of grain condition has been developed, according to the original grain condition data of typical granaries and main grain varieties in different grain storage ecological regions in China. The development of this manual is expected to consolidate the foundation of intelligent analysis of grain situation, which could promote the digital monitoring of grain storage quantity and quality, and realize the transformation from "manual defense" to “technical defense”.

The stored grain can be regarded as a complex ecosystem, which exist a complex multi-field coupling interaction among the abiotic factors, the biotic factors, and the surrounding environment. In this system, only a few parameters such as temperature can be accurately detected, which causes the system to operate like a “black box” to the outside world. To truly and accurately detect various grain pile parameters, and further study the multi-field coupling interaction in grain piles, a graphical detection system for multi-filed interaction in grain storage based on NMR has been developed. The system consists of an NMR imaging analyzer, a test grain bin, and a data acquisition and processing system, which can accurately detect the grain pile temperature, humidity, and moisture simultaneously, and intuitively and vividly present the cloud map of the temperature field, humidity field, and moisture field in the grain pile through the cloud map drawing software. In this system, the NMR imaging technology was applied to the research field of multi-field coupling interaction in grain piles for the first time, which can provide a new technical means to find out the complex coupling relationship of stored grain ecosystem and further confirm the correctness of relevant theoretical research. The development of this system will be helpful in deepening the theory of multi-field coupling and biological field of grain piles, developed by the industry.

Thermal ionization mass spectrometry (TIMS) is a well-established instrumental technique for accurately analyzing isotopes of elements with low first ionization potential. However, the measurement accuracy is affected due to the existence of the mass fractionation effect. Generally, applying the external standard method or total evaporation method is the most common way to correct the mass fractionation effect. Total evaporation (TE） technology is the most conventional method for uranium major isotope ratio measurement (235U/238U) using TIMS. However, due to the strong peak tailing of the major isotopes and other factors, the measurement precision and accuracy of minor isotope ratios (234U/238U and 236U/238U) are relatively low. In this study, the modified total evaporation (MTE) method for highly precise measurement of uranium isotopes ratios by TIMS was developed based on the research of dynamic heating procedures, dynamic and static receiving procedures, peak tailing correction, efficiency calibration of collectors and mass discrimination calibration. The accuracy and reliability of the MTE method were verified with different reference materials. The experiment results showed that the yield of uranium oxide should be monitored and the related parameters should be precisely controlled to reduce the yield of uranium oxidation during measurement. This action could guarantee the effectiveness of the MTE measurement and improve the uranium samples utilization. The initial strength of 187Re+ played an important role in the ionization efficiency of uranium and the yield of uranium oxide. The optimal signal of 187Re+ should be set in the range of 0.17-0.22 V. When uranium samples with 2% 235U isotopic abundance were measured by the MTE method using TIMS, the measurement precisions of 235U/238U, 234U/238U and 236U/238U were 0.024%, 0.06%, and 0.19%, and the bias between the measured value and reference value were 0.025%, 0.19%, and 0.38%, respectively. Compared to the TE method, the MTE method showed the same precision for the 235U/238U ratio measurement. As for the MTE measurement of 234U/238U and 236U/238U ratios, the major uranium isotopes (235U and 238U) were used as an internal standard to overcome the mass fractionation effect. When the tailing effects were eliminated, the measurement precisions of 234U/238U and 236U/238U ratios were improved by 5 to 10 times. As for sample amount, the TE method generally requires the uranium amount of less than 1 μg, while 5 μg is required for the MTE method.

Objective: This study aimed to help with the scientific management of leek food safety in Hunan Province. Methods: 24 kinds of pesticides and 5 kinds of heavy metals in 690 leek samples from Hunan Province were detected. Results: ① Pesticide residues were detected in 23.19% of the 690 samples, and the top three pesticides were determined to be carbendazim, procymidone and cypermethrin. The exceeding rate of pesticide residues was 5.80%, and the highest exceeding rate was 2.61% of procymidone. ② The detection rate of heavy metal elements was 77.68%, and the exceeding rate was 3.62%. The highest detection rate and exceeding rate of heavy metal elements was Cd. Conclusion: High pesticide residues in leek were confirmed, and the detection rate of heavy metal elements in leeks is much higher than that of pesticide residues. Among them, pesticide procymidone and heavy metal Cd are the main over-standard items of leeks. It is suggested to strengthen the continuous monitoring of pesticide residues and heavy metal pollution in leeks.

Abstract The respiratory tract is known to harbor a microbial community including bacteria, viruses, and fungi. New techniques contribute enormously to the identification of unknown or culture‐independent species and reveal the interaction of the community with the host immune system. The existing respiratory microbiome and substantial equilibrium of the transplanted microbiome from donor lung grafts provide an extreme bloom of dynamic changes in the microenvironment in lung transplantation (LT) recipients. Dysbiosis in grafts are not only related to the modified microbial components but also involve the kinetics of the host‐graft “talk,” which signifies the destination of graft allograft injury, acute rejection, infection, and chronic allograft dysfunction development in short‐ and long‐term survival. Microbiome‐derived factors may contribute to lung xenograft survival when using genetically multimodified pig‐derived organs. Here, we review the most advanced knowledge of the dynamics and resilience of microbial communities in transplanted lungs with various pretransplant indications. Conceptual and analytical points of view have been illustrated along the time series, gaining insight into the microbiome and lung grafts. Future endeavors on precise tools, sophisticated models, and novel targeted regimens are needed to improve the long‐term survival in these patients.

Objective: This study aimed to the optimize infrared drying process of Hami-melon slices and improve quality and efficiency. Methods: Using ultrasonic treatment as a pretreatment method, the effects of drying temperature, slice thickness and ultrasonic treatment time on drying time, color difference value and vitamin C content were studied, and the drying time, quality and microstructure of the products were compared with those without ultrasonic treatment. Results: The optimal process parameters of ultrasonic pretreatment for infrared drying of Hami-melon slices were drying temperature 61 ℃, slice thickness 6 mm and ultrasonic treatment time 15 min. Under the control of these conditions, the drying time was 115 min, the color difference value was 13.79, and the vitamin C content was 112.1 mg/100 g. Compared with the untreated products, the drying time was shortened by 45.24%, the color difference was reduced by 13.38%, and the vitamin C content was increased by 16.71%. The microstructure showed that ultrasonic waves caused the expansion and contraction of the internal tissue of Hami-melon slices, and the structure was multi-channel. Conclusion: Ultrasonic treatment can be used as a pretreatment method to improve the infrared drying of Hami-melon slices, thereby improve the quality and efficiency of the drying process.

In view of the needs of applications such as human-computer interaction(HCI) systems and virtual reality(VR) systems, the study on theories and methods of 3D gesture tracking has become one of the hot issues with widespread concern at home and abroad.In recent years, the 3D gesture tracking algorithms based on computer vision develop rapidly.Among them, the more economical and ubiquitous monocular RGB camera has the most potential.It is an important tool and way for 3D gesture tracking applications to take into reality, which has been focused by researchers.In order to comprehend the development status of gesture tracking algorithms, and assist researchers in this field to conduct more deep-going explorations, firstly, in comparison with the traditional methods, this paper introduces the 3D gesture tracking algorithms based on monocular RGB image, and divides it into three categories:discriminative methods, generative methods and hybrid methods, and summarizes the corresponding advantages and disadvantages.Secondly, the influence of RGB image characteristics on 3D gesture tracking is discussed, and the methods to alleviate the depth ambiguity of the image are generalized.Thirdly, according to the classification, the representative algorithms with RGB as input data are emphatically analyzed, and the specific superiority and weaknesses of related algorithms are compared through visualized performance evaluation index.Finally, the problems faced with the current 3D gesture tracking algorithms are summarized and the future development is prospected.

At present, natural gas accounts for a low proportion in China's primary energy consumption structure and is highly dependent on foreign sources. Changqing gas province of the Ordos Basin where PetroChina Changqing Oilfield Company (referred to as Changqing Oilfield) is located is one of China's four major natural gas production bases. It bears the important responsibility for ensuring people's livelihood and promoting the healthy development of society economy. In recent years, Changqing Oilfield actively implements national instructive spirit on vigorously promoting domestic oil and gas exploration and development strength and formulates the secondary acceleration development strategies. Its annual natural gas production in 2020 reaches 448.5 × 108 m3 and oil and gas equivalent exceeds 6000 × 104 t, tamping its important position of “Western Daqing” in this industry. In order to further promote the continuous stable production and realize the goal of quality and efficiency improvement in Changqing gas province, this paper analyzes the situations and challenges of natural gas development in this gas province, prepares the development technological countermeasures and forecast the natural gas development prospect. And the following research results are obtained. First, the natural gas exploration and development in Changqing gas province is divided into four stages and the main technologies for the development of low-permeability carbonate gas reservoir, low-permeability sandstone gas reservoir and tight sandstone gas reservoir are formed. Second, the natural gas development in Changqing gas province faces six challenges, such as low reserve production degree, sharp decline of production rates and complex distribution of remaining undeveloped reserves of developed gas fields. And twenty-six development technological countermeasures are put forward correspondingly, such as well pattern thickening, extension and reserve increase, secondary production layer potential tapping and fine gas well management. Third, the development direction and goal of natural gas development in Changqing gas province is to pay equal attention to the stable production of old gas fields and the production increase of new areas and carry out conventional gas and unconventional gas research simultaneously. In conclusion, the annual natural gas production of Changqing gas province will maintain a sound momentum of steady growth and will exceed 500 × 108 m3 at the end of the 14th Five-Year Plan and maintain at a stable level for a long term, which is conducive to the optimization of domestic energy consumption structure and realization of “carbon peak and carbon neutrality”.

Objective To study the effect of lncRNA UNC5B-AS1 targeting miR-339-5p on the proliferation and apoptosis of lung cancer cells and its molecular mechanism. Methods The human lung adenocarcinoma cell line A549 was cultured in vitro, and si-NC, si-UNC5B-AS1, miR-NC, miR-339-5p mimics, si-UNC5B-AS1 and anti-miR-NC, si-UNC5B-AS1 and anti-miR-339-5p were transfected into A549 cells respectively. Real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression of UNC5B-AS1 and miR-339-5p in lung cancer tissues and in adjacent tissues; Cell counting kit (CCK-8) was used to detecte cell proliferation; The targeted regulation relationship between UNC5B-AS1 and miR-339-5p was examined by dual luciferase reporter gene experiment; Western blot was used to detect the expression of cyclin D1 (cyclin D1), p21 protein lymphoma-2(Bcl-2), and B lymphoma-2 related protein (Bax). Results Compared with adjacent tissues, the expression level of UNC5B-AS1 in lung cancer tissue was significantly increased (P＜0.05), and the expression level of miR-339-5p was significantly decreased(P＜0.05). Compared with the si-NC group, the cell viability of the si-UNC5B-AS1 group was significantly reduced (P＜0.05), the apoptosis rate was significantly higher(P＜0.05). Compared with the miR-NC group, the cell viability of the miR-339-5p group was significantly reduced (P＜0.05), and the apoptosis rate was significantly increased(P＜0.05). Compared with the (si-UNC5B-AS1+anti-miR-NC)group, the cell viability of the (si-UNC5B-AS1+anti-miR-339-5p) group was significantly increased (P＜0.05); the apoptosis rate was significantly reduced (P＜0.05). Conclusions Interference with UNC5B-AS1 promotes apoptosis and inhibits cell proliferation of human lung adenocarcinoma cancer cell line A549 by up-regulating the expression of miR-339-5p.

BACKGROUND The direct discharge of Hg(Ⅱ) is harmful to the environment. At present, activated carbon is used to remove it, but the production of activated carbon through high-temperature pyrolysis and activation is very expensive. OBJECTIVES To investigate the adsorption difference and mechanism on low-concentration Hg(Ⅱ) for durian shell, coconut shell activated carbon and activated carbon fiber under different conditions. METHODS The remaining Hg(Ⅱ) in the adsorption solution was determined by atomic fluorescence spectrometry. The adsorb kinetic parameters of different adsorbents were determined by Lagergren pseudo-second-order kinetic model. RESULTS In the Lagergren pseudo-second-order kinetic model, the maximum adsorption capacity (QM) of the three materials was as follows: activated carbon fiber (5.61μg/g)>durian shell (1.68μg/g)>coconut shell activated carbon (0.96μg/g). The adsorption test and thermodynamic equation showed that the adsorption of Hg(Ⅱ) by the three materials was spontaneous (ΔG < 0). The adsorption of Hg(Ⅱ) by coconut shell activated carbon was mainly physical adsorption (ΔH>0), while the adsorption of durian shell was an endothermic process (ΔH < 0). Due to the increase of temperature, the adsorption rate and adsorption capacity were improved. CONCLUSIONS Durian shell from a wide range of sources can be used as an effective adsorbent to treat wastewater containing Hg(Ⅱ).

[C24H38N6S2], triclinic, P1‾$P\overline{1}$ (no. 2), a = 5.9953(4) Å, b = 7.6132(5) Å, c = 15.3709(10) Å, α = 82.089(5)°, β = 88.307(6)°, γ = 75.992(6)°, V = 674.24(8) Å3, Z = 1, Rgt(F) = 0.0587, wRref(F2) = 0.1516, T = 296(2) K.

Objective To study the expression and function of miR-433 in the development of colorectal cancer. Methods RT-qPCR was used to detect the expression of miR-433 in clinical specimens and serum of patients with colorectal cancer, and compared with those from adjacent tissues or at different stages of tumore development and from normal persons. The colorectal cancer cell lines HT-29, HCT-116, SW480 and normal colon cell line NCM460 were cultured, and the expression of miR-433 was measured by real-time quantitative PCR. Subsequently, miR-433 mimic was transfected into SW480 cells,CCK-8 was used to detect cell proliferation, flow cytometry was used to detect cell cycle changes, scratch test and Transwell test were used to detect cell migration and invasion respectively. Results Compared with the adjacent tissues, the expression of miR-433 in colorectal cancer tissues was significantly decreased(P＜0.05). The serum level of miR-433 in patients with colon cancer was also significantly lower than that in normal persons(P＜0.05). In addition, from stage Ⅰ to stage Ⅳ of TNM, the expression of miR-433 in colorectal cancer tissues gradually and significantly decreased. Compared with normal human colon epithelial cell line NCM460, the expression of miR-433 was down-regulated in colorectal cancer cell lines HT-29, HCT-116 and SW480(P＜0.05). Compared with the control group, the proliferation of SW480 cells was significantly inhibited(P＜0.05) and the proportion of G2 and M phase cells increased after SW480 transfection. The invasion and migration of cells decreased significantly after up-regulation of miR-433(P＜0.05). Conclusions The expression of miR-433 is decreased in colorectal cancer. Up-regulation of its expression in SW480 cells inhibits cell proliferation, invasion and migration.

BACKGROUND The high content of potassium, sodium, zinc, and chlorine in dust ash significantly affects the stable operation of converter. To recycle the dust ash, it is necessary to accurately determine the contents of the components. Dust ash contains a broad range of potassium, sodium, zinc, and chlorine; therefore, the traditional X-ray fluorescence spectrometry (XRF) exceeds the range of the work curve. OBJECTIVES To develop a method for the determination of 14 components in the dust ash with a broad concentration range of potassium, sodium, zinc, and chlorine. METHODS Standard reagents of potassium chloride, sodium chloride, and zinc oxide were added to commercially available iron ore standards in a quantitative manner to provide a new series of calibration samples with wide ranges of potassium, sodium, zinc, and chlorine contents. The 14 components in the dust ash were determined by XRF spectrometry with a powder-pelleting-lined boric acid preparation. RESULTS The measurement ranges of potassium, sodium, zinc, and chlorine were 1.36%-12.00%, 0.43%-6.85%, 0.24%-35.00%, and 0.25%-10.00%, respectively. The results of the 14 components in the dust ash were consistent with those of the traditional method, yielding a relative standard deviation of < 5.2% (n=7). CONCLUSIONS XRF spectrometry with the powder-pelleting-lined boric acid preparation showed good accuracy and precision during the determination of 14 components in the dust ash.

Objective: Osteoarthritis (OA) is a degenerative joint disease. Excessive nitric oxide (NO) mediates the chondrocyte inflammatory response, apoptosis, and extracellular matrix (ECM) degradation during the occurrence and development of OA. NO in chondrocytes is mainly produced by inducible nitric oxide synthase (iNOS). The aim of this study was to design and synthesize an iNOS dimerization inhibitor and evaluate its effects on chondrocyte inflammation and articular cartilage injury in OA via in vitro and in vivo experiments.Design: The title compound 22o was designed, synthesized, and screened based on a previous study. The effects of different concentrations (5, 10, and 20 μM) of compound 22o on chondrocyte inflammatory response and ECM anabolism or catabolism were evaluated by Western blot and real-time quantitative reverse transcription-polymerase chain reaction using the rat chondrocyte model of IL-1β-induced OA. Furthermore, different doses (40 and 80 mg/kg) of compound 22o were administered by gavage to a rat OA model induced by anterior cruciate ligament transection (ACLT), and their protective effects on the articular cartilage were evaluated by histopathology and immunohistochemistry.Results: Compound 22o showed effective iNOS inhibitory activity by inhibiting the dimerization of iNOS. It inhibited the IL-1β-induced expression of cyclooxygenase-2 (COX-2) and matrix metalloproteinase 3 (MMP3) in the chondrocytes, decreased NO production, and significantly increased the expression levels of the ECM anabolic markers, aggrecan (ACAN), and collagen type II (COL2A1). Gavage with compound 22o was found to be effective in the rat OA model induced by ACLT, wherein it regulated the anabolism and catabolism and exerted a protective effect on the articular cartilage.Conclusions: Compound 22o inhibited the inflammatory response and catabolism of the chondrocytes and reduced articular cartilage injury in the rat OA model, indicating its potential as a disease-modifying OA drug.

Parkinson’s disease (PD) is a kind of common neurodegenerative disease in the world. Previous studies have proved that nervonic acid (NA), extracted from Xanthoceras sorbifolia Bunge, has the potentials of neuroprotection. However, the effect of NA on the PD remained unknown. This study was designed to investigate the NA’s potential function and relative mechanism on motor disorder.

A series of 1g model tests was carried out using a motor servo horizontal cyclic loading equipment to study the stiffness and cumulative displacement of the large-diameter single pile in sand under horizontal cyclic loading. The test results indicated that the residual displacement generated by one loading and unloading cycle is about 80% of the peak displacement. As the number of cycles increases, the area of the cyclic loading hysteresis curve gradually decreases, indicating that the behavior of soil around the pile changes from elastoplastic to elastic stage. The secant stiffness of the hysteretic curve increases firstly and then decreases with the increase of the number of cycles, which is caused by the trend that the soil around the pile is gradually dense, and the resistance of the soil around the pile is developing from shallow to deep. The secant stiffness of the hysteretic curve increases firstly and then decreases with the increase of the number of cycles, which is caused by the progressive compaction of the soil around the pile in the shallow layer and the tendency of the resistance of the soil around the pile to transfer from the shallow layer to the deep layer. The cumulative displacement of the pile top decreases to approximately the same extent as the pile diameter increases. However, with the increase of burial depth, the reduction of displacement also gradually decreases, revealing the existence of critical burial depth. An empirical model of cyclic cumulative displacement is proposed by linear fitting in a double logarithmic coordinate system based on the exponential model. It is found that the effect of increasing the pile diameter on the reduction of cyclic cumulative displacement is superior to that of increasing the buried depth

Lung transplantation is a potentially life-saving therapy for patients with terminal respiratory illnesses. Long-term survival is limited by the development of a variety of opportunistic infections and rejection. Optimal means of differential diagnosis of infection and rejection have not been established. With these challenges in mind, we tried to use transbronchial lung biopsy (TBLB) rapid on-site cytological evaluation (ROSE), metagenomic next-generation sequencing (mNGS), and routine histologic examination to timely distinguish infection and rejection, and accurately detect etiologic pathogens. We reviewed the medical records of all patients diagnosed with infection or rejection by these means from December 2017 to September 2018 in our center. We identified seven recipients whose clinical course was complicated by infection or rejection. Three patients were diagnosed with acute rejection, organizing pneumonia, and acute fibrinoid organizing pneumonia, respectively. Four of the seven patients were diagnosed with infections, including Pneumocystis carinii pneumonia, cytomegalovirus, Aspergillus, and bacterial pneumonia. These patients recovered after proper treatment. TBLB + ROSE + mNGS might be a good method to accurately detect etiologic pathogens, which may help us to facilitate the use of targeted and precision medicine therapy in postoperative complications and avoid unnecessary potential adverse effects of drugs.

A fatty acid value determination method in grain was developed by using automatic photometric titrator with KOH as standard titration solution in this paper, in which magnetic stirring apparatus was selected as extraction device, anhydrous ethanol was used as extraction solvent, and thymol blue was used to control directing terminal. Finally, the fatty acid value was calculated by combining the consumed volume of KOH's standard titration solution. The instrument can automatically complete the whole process of extraction, filtration,quantitative transfer, titration and calculation. The results showed that the determination method has high precision, and the repeatability, accuracy and stability can meet the requirements of the national standard method, the consistency between instruments can meet the repeatability requirement of national standard method, the measuring time of paddy and wheat flour were one-third and one-half respectively of those by potentiometric or manual titration, and the measuring time of maize was two-fifths of the potentiometric titration and one-half of the manual titration. With a wide application range, the method was easy to operateand less to be disturbed by human factors, it is very suitable for batch and rapid determination of fatty acid value in grain. In a word, this method provided a suitable method for strict quality control in the grass-roots grain storage companies when purchasing grain and detection of large quantities fatty acid value in grain inspection agency.

Precious metal nanoclusters have unique electronic structure and fluorescent properties, and can be used as fluorescent probes in a wide range of applications such as biomarkers and ion detection. This paper reviews the preparation methods of thiol-protected silver clusters, including bottom-up and top-down methods, focusing on optimizing the reduction process of the reaction, selecting excellent thiol ligands, changing the pH values of the system, and strictly controlling. The research status of the preparation of thiol-protected silver clusters was introduced in terms of etching time and reaction temperature during the reaction, and ideas and suggestions for further research were provided. At the same time, based on the excellent fluorescence properties of thiol-protected silver clusters, the research progress in the detection of small molecules such as Cu2+, Hg2+, I- and cysteine was introduced. Finally, it was pointed out that the fluorescence quantum yield and safety of metal nanoclusters are improved, and the reaction mechanism of metal nanoclusters with heavy metal ions and biomacromolecules is studied in depth, and the synthesis methods of high purity and diversity alloy clusters or transition metal nanoclusters are explored. The preparation of fluorescent sensing materials for the realization of highly efficient thiol-protected silver clusters is a hot trend in future research.

A more stable and reliable method of the fatty acid values determination in grain was studied based on the establishment of manual titration method associated with the automatic potentiometric titration.The GB/T 20569—2006 Guidelines for evaluation of paddy storage character for the sample pre-treatment was used, and the manual titration was replaced by automatic potentiometric titration to determine the free fatty acid in grain with KOH as the standard titration solution.At the same time, the change of pH values in test solution were determined during titration, following by the corresponding real time change curves of pH-titration volume which will be stopped at the set terminal PH values, and phenolphthalein indicator was used as the finish monitoring in the process of the titration.The results showed that the titration processes were not affected by man-made factors, and the accuracy has no significant difference compared with manual titration method, thus ensuring the determination results has better repeatability, reproducibility and stability,and with the wider application scope.

The layered double hydroxides become research hot spot of oxygen evolution catalyzer for its easy preparation, feasible moderation of interlayer object,low cost and good stability but due to its low transmission speed of its electric charge,higher overpotential, so the modification is needed before mass application. The constructional character of the layered twinned material was firstly introduced, the catalytic mechanism of its oxygen evolution reaction was briefly described, then different kinds of optimization modification strategies to enhance its catalytic activity were introduced. The optimization modification strategies include:combination with conductive substrate, synthesis ultrathin nanometer plate, graphene compounding process, hybrid modification. The application of the stratified dihydride oxygen evolution catalyst in electrolysis of water to hydrogen and the advantages and disadvantages of different modification methods were put forward. The better-efficient oxygen evolution catalyst can be achieved through different kinds of modification. In the end, the difficulties in this kind of catalyzer were pointed out, including low recycle rate, catalyst stability, current density not meeting the requirements of industrialization and massive production.

In this work, it is shown that surface-enhanced Raman scattering (SERS) measurements can be performed using liquid platforms to perform bioanalysis at sub-pM concentrations. Using magnetic enrichment with gold-coated magnetic nanoparticles, the high sensitivity was verified with nucleic acid and protein targets. The former was performed with a DNA fragment associated with the bacteria Staphylococcus aureus, and the latter using IgG antibody, a biomarker for COVID-19 screening. It is anticipated that this work will inspire studies on ultrasensitive SERS analyzers suitable for large-scale applications, which is particularly important for in vitro diagnostics and environmental studies.