用于转化劣质渣油的LC-FiningSM沸腾床渣油加氢工艺

LC-FiningSM沸腾床渣油加氢工艺是一种高效而且可靠的劣质渣油加氢工艺。该工艺既可以在低转化率下生产低硫优质燃料油或合成原油,也可以在高转化率下将劣质渣油转化为馏分油为下游装置提供优质原料或者在流程内增加固定床加氢精制反应器的模式下直接生产清洁燃油。

Structural properties of residual carbon in coal gasification fine slag and their influence on flotation separation and resource utilization:A review

Coal gasification fine slag(FS)is a typical solid waste generated in coal gasification.Its current disposal methods of stockpil-ing and landfilling have caused serious soil and ecological hazards.Separation recovery and the high-value utilization of residual carbon(RC)in FS are the keys to realizing the win-win situation of the coal chemical industry in terms of economic and environmental benefits.The structural properties,such as pore,surface functional group,and microcrystalline structures,of RC in FS(FS-RC)not only affect the flotation recovery efficiency of FS-RC but also form the basis for the high-value utilization of FS-RC.In this paper,the characteristics of FS-RC in terms of pore structure,surface functional groups,and microcrystalline structure are sorted out in accordance with gasification type and FS particle size.The reasons for the formation of the special structural properties of FS-RC are analyzed,and their influence on the flotation separation and high-value utilization of FS-RC is summarized.Separation methods based on the pore structural characterist-ics of FS-RC,such as ultrasonic pretreatment-pore-blocking flotation and pore breaking-flocculation flotation,are proposed to be the key development technologies for improving FS-RC recovery in the future.The design of low-cost,low-dose collectors containing polar bonds based on the surface and microcrystalline structures of FS-RC is proposed to be an important breakthrough point for strengthening the flotation efficiency of FS-RC in the future.The high-value utilization of FS should be based on the physicochemical structural proper-ties of FS-RC and should focus on the environmental impact of hazardous elements and the recyclability of chemical waste liquid to es-tablish an environmentally friendly utilization method.This review is of great theoretical importance for the comprehensive understand-ing of the unique structural properties of FS-RC,the breakthrough of the technological bottleneck in the efficient flotation separation of FS,and the expansion of the field of the high value-added utilization of FS-RC.

Contrast-enhanced guided endoscopic ultrasound procedures

Contrast-enhanced endoscopic ultrasound(CH-EUS)can overcome the limi-tations of endoscopic ultrasound-guided acquisition by identifying microvessels inside inhomogeneous tumours and improving the characterization of these tumours.Despite the initial enthusiasm that oriented needle sampling under CH-EUS guidance could provide better diagnostic yield in pancreatic solid lesions,further studies did not confirm the supplementary values in cases of tissue acquisition guided by CH-EUS.This review details the knowledge based on the available data on contrast-guided procedures.The indications for CH-EUS tissue acquisition include isoechoic EUS lesions with poor visible delineation where CH-EUS can differentiate the lesion vascularisation from the surrounding parenchyma and also the mural nodules within biliopancreatic cystic lesions,which occur in select cases.Additionally,the roles of CH-EUS-guided therapy in patients whose pancreatic fluid collections or bile ducts that have an echogenic content have indications for drainage,and patients who have nonvisualized vessels that need to be highlighted via Doppler EUS are presented.Another indication is represented if there is a need for an immediate assessment of the post-radiofrequency ablation of pancreatic neuroendocrine tumours,in which case CH-EUS can be used to reveal the incomplete tumour destruction.

Mechanical Behavior Based on Aggregates Microstructure of Ultra-high Performance Concrete

We developed ultra-high performance concrete(UHPC)incorporating mullite sand and brown corundum sand(BCS),and the quartz sand UHPC was utilized to prepare for comparison.The properties of compressive strength,elastic modulus,ultrasonic pulse velocity,flexural strength,and toughness were investigated.Scanning electron microscopy and nanoindentation were also conducted to reveal the underlying mechanisms affecting macroscopic performance.Due to the superior interface bonding properties between mullite sand and matrix,the compressive strength and flexural toughness of UHPC have been significantly improved.Mullite sand and BCS aggregates have higher stiffness than quartz sand,contributing to the excellent elastic modulus exhibited by UHPC.The stiffness and volume of aggregates have a more significant impact on the elastic modulus of UHPC than interface performance,and the latter contributes more to the strength of UHPC.This study will provide a reference for developing UHPC with superior elastic modulus for structural engineering.

Fine mapping and cloning of the sterility gene Bra2Ms in nonheading Chinese cabbage(Brassica rapa ssp.chinensis)

The application of a male-sterile line is an ideal approach for hybrid seed production in non-heading Chinese cabbage(Brassica rapa ssp.chinensis).However,the molecular mechanisms underlying male sterility in B.rapa are still largely unclear.We previously obtained the natural male sterile line WS24-3 of non-heading Chinese cabbage and located the male sterile locus,Bra2Ms,on the A2 chromosome.Cytological observations revealed that the male sterility of WS24-3 resulted from disruption of the meiosis process during pollen formation.Fine mapping of Bra2Ms delimited the locus within a physical distance of about 129 kb on the A2 chromosome of B.rapa.The Bra039753 gene encodes a plant homeodomain(PHD)-finger protein and is considered a potential candidate gene for Bra2Ms.Bra039753 was significantly downregulated in sterile line WS24-3 compared to the fertile line at the meiotic anther stage.Sequence analysis of Bra039753 identified a 369 bp fragment insertion in the first exon in male sterile plants,which led to an amino acid insertion in the Bra039753 protein.In addition,the 369 bp fragment insertion was found to cosegregate with the male sterility trait.This study identified a novel locus related to male sterility in non-heading Chinese cabbage,and the molecular marker obtained in this study will be beneficial for the marker-assisted selection of excellent sterile lines in non-heading Chinese cabbage and other Brassica crops.

Quick-scanning X-ray absorption fine structure beamline at SSRF

The layout and characteristics of the hard X-ray spectroscopy beamline(BL11B)at the Shanghai synchrotron radiation facility are described herein.BL11B is a bending-magnet beamline dedicated to conventional and millisecond-scale quick-scanning X-ray absorption fine structures.It is equipped with a cylindrical collimating mirror,a double-crystal monochromator comprising Si(111)and Si(311),a channel-cut quick-scanning Si(111)monochromator,a toroidal focusing mirror,and a high harmonics rejection mirror.It can provide 5-30 keV of X-rays with a photon flux of~5×10^(11)photons/s and an energy resolution of~1.31×10^(-4)at 10 keV.The performance of the beamline can satisfy the demands of users in the fields of catalysis,materials,and environmental science.This paper presents an overview of the beamline design and a detailed description of its performance and capabilities.

Influence of Recycled Concrete Fine Powder on Durability of Cement Mortar

In this paper,the durability of cement mortar prepared with a recycled-concrete fine powder(RFP)was examined;including the analysis of a variety of aspects,such as the carbonization,sulfate attack and chloride ion erosion resistance.The results indicate that the influence of RFP on these three aspects is different.The carbonization depth after 30 days and the chloride diffusion coefficient of mortar containing 10%RFP decreased by 13.3%and 28.19%.With a further increase in the RFP content,interconnected pores formed between the RFP particles,leading to an acceleration of the penetration rate of CO_(2)and Cl^(−).When the RFP content was less than 50%,the corrosion resistance coefficient of the compressive strength of the mortar was 0.84-1.05 after 90 days of sulfate attack.But the expansion and cracking of the mortar was effectively alleviated due to decrease of the gypsum production.Scanning electron microscope(SEM)analysis has confirmed that 10%RFP contributes to the formation of a dense microstructure in the cement mortar.

Cortical activity in patients with high-functioning ischemic stroke during the Purdue Pegboard Test:insights into bimanual coordinated fine motor skills with functional near-infrared spectroscopy

After stroke,even high-functioning individuals may experience compromised bimanual coordination and fine motor dexterity,leading to reduced functional independence.Bilateral arm training has been proposed as a promising intervention to address these deficits.However,the neural basis of the impairment of functional fine motor skills and their relationship to bimanual coordination performance in stroke patients remains unclear,limiting the development of more targeted interventions.To address this gap,our study employed functional near-infrared spectroscopy to investigate cortical responses in patients after stroke as they perform functional tasks that engage fine motor control and coordination.Twenty-four high-functioning patients with ischemic stroke(7 women,17 men;mean age 64.75±10.84 years)participated in this cross-sectional observational study and completed four subtasks from the Purdue Pegboard Test,which measures unimanual and bimanual finger and hand dexterity.We found significant bilateral activation of the sensorimotor cortices during all Purdue Pegboard Test subtasks,with bimanual tasks inducing higher cortical activation than the assembly subtask.Importantly,patients with better bimanual coordination exhibited lower cortical activation during the other three Purdue Pegboard Test subtasks.Notably,the observed neural response patterns varied depending on the specific subtask.In the unaffected hand task,the differences were primarily observed in the ipsilesional hemisphere.In contrast,the bilateral sensorimotor cortices and the contralesional hemisphere played a more prominent role in the bimanual task and assembly task,respectively.While significant correlations were found between cortical activation and unimanual tasks,no significant correlations were observed with bimanual tasks.This study provides insights into the neural basis of bimanual coordination and fine motor skills in high-functioning patients after stroke,highlighting task-dependent neural responses.The findings also suggest that patients who exhibit better bimanual performance demonstrate more efficient cortical activation.Therefore,incorporating bilateral arm training in post-stroke rehabilitation is important for better outcomes.The combination of functional near-infrared spectroscopy with functional motor paradigms is valuable for assessing skills and developing targeted interventions in stroke rehabilitation.

Diagnostic and therapeutic role of endoscopic ultrasound in liver diseases:A systematic review and meta-analysis

BACKGROUND In hepatology,the clinical use of endoscopic ultrasound(EUS)has experienced a notable increase in recent times.These applications range from the diagnosis to the treatment of various liver diseases.Therefore,this systematic review summarizes the evidence for the diagnostic and therapeutic roles of EUS in liver diseases.AIM To examine and summarize the current available evidence of the possible roles of the EUS in making a suitable diagnosis in liver diseases as well as the therapeutic accuracy and efficacy.METHODS PubMed,Medline,Cochrane Library,Web of Science,and Google Scholar databases were extensively searched until October 2023.The methodological quality of the eligible articles was assessed using the Newcastle-Ottawa scale or Cochrane Risk of Bias tool.In addition,statistical analyses were performed using the Comprehensive Meta-Analysis software.RESULTS Overall,45 articles on EUS were included(28 on diagnostic role and 17 on therapeutic role).Pooled analysis demonstrated that EUS diagnostic tests had an accuracy of 92.4%for focal liver lesions(FLL)and 96.6%for parenchymal liver diseases.EUS-guided liver biopsies with either fine needle aspiration or fine needle biopsy had low complication rates when sampling FLL and parenchymal liver diseases(3.1%and 8.7%,respectively).Analysis of data from four studies showed that EUS-guided liver abscess had high clinical(90.7%)and technical success(90.7%)without significant complications.Similarly,EUS-guided interventions for the treatment of gastric varices(GV)have high technical success(98%)and GV obliteration rate(84%)with few complications(15%)and rebleeding events(17%).CONCLUSION EUS in liver diseases is a promising technique with the potential to be considered a first-line therapeutic and diagnostic option in selected cases.

Is endoscopic ultrasound a promising technique in the diagnosis and treatment of liver diseases?

Percutaneous ultrasound has been a longstanding method in the diagnostics and interventional procedures of liver diseases.In some countries,its use is restricted to radiologists,limiting access for other clinicians,such as gastroenterologists.Endoscopic ultrasound,as a novel technique,plays a crucial role in diagnosis and treatment of digestive diseases.However,its use is sometimes recommended for conditions where no clear advantage over percutaneous ultrasound exists,leaving the impression that clinicians sometimes resort to an endoscopic approach due to the unavailability of percutaneous options.

Theoretical characterization of the adsorption configuration of pyrrole on Si(100)surface by x-ray spectroscopy

The possible configurations of pyrrole absorbed on a Si(100)surface have been investigated by x-ray photoelectron spectroscopy(XPS)and near-edge x-ray absorption fine structure(NEXAFS)spectra.The C-1s XPS and NEXAFS spectra of these adsorption configurations have been calculated by using the density functional theory(DFT)method and fullcore hole(FCH)approximation to investigate the relationship between the adsorption configurations and the spectra.The result shows that the XPS and NEXAFS spectra are structurally dependent on the configurations of pyrrole absorbed on the Si(100)surface.Compared with the XPS,the NEXAFS spectra are relatively sensitive to the adsorption configurations and can accurately identify them.The NEXAFS decomposition spectra produced by non-equivalent carbon atoms have also been calculated and show that the spectral features vary with the diverse types of carbon atoms and their structural environments.

Repair of Second-Generation Recycled Fine Aggregate of Waste Concrete from Freeze-Thaw Environment by Carbonation Treatment

The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled fine aggregate(SRFA)obtained from recycled fine aggregate concrete(RFAC)subjected to freeze-thaw(FT)cycles.Before and after carbonation,the properties of SRFA were evaluated.Carbonated second-generation recycled fine aggregate(CSRFA)at five substitution rates(0%,25%,50%,75%,100%)to replace SRFA was used to prepare carbonated second-generation recycled fine aggregate concrete(CSRFAC).The water absorption,porosity and mechanical properties of CSRFAC were tested,and its frost-resisting durability was evaluated.The results showed after carbonation treatment,the physical properties of SRFA was improved and met the requirements of II aggregate.The micro-hardness of the interfacial transition zone and attached mortar in CSRFA was 50.5%and 31.2%higher than that in SRFA,respectively.With the increase of CSRFA replacement rate,the water absorption and porosity of CSRFAC gradually decreased,and the mechanical properties and frost resistance of CSRFAC were gradually improved.Carbonation treatment effectively repairs the damage of SRFA caused by FT cycles and improves its application potential.

Micro-Locational Fine Dust Prediction Utilizing Machine Learning and Deep Learning Models

Given the increasing number of countries reporting degraded air quality,effective air quality monitoring has become a critical issue in today’s world.However,the current air quality observatory systems are often prohibitively expensive,resulting in a lack of observatories in many regions within a country.Consequently,a significant problem arises where not every region receives the same level of air quality information.This disparity occurs because some locations have to rely on information from observatories located far away from their regions,even if they may be the closest available options.To address this challenge,a novel approach that leverages machine learning and deep learning techniques to forecast fine dust concentrations was proposed.Specifically,continuous location features in the form of latitude and longitude values were incorporated into our models.By utilizing a comprehensive dataset comprising weather conditions,air quality measurements,and location properties,various machine learning models,including Random Forest Regression,XGBoost Regression,AdaBoost Regression,and a deep learning model known as Long Short-Term Memory(LSTM)were trained.Our experimental results demonstrated that the LSTM model outperforms the other models,achieving the best score with a root mean squared error of 23.48 in predicting fine dust(PM10)concentrations on an hourly basis.Furthermore,the fact that incorporating location properties,such as longitude and latitude values,enhances the overall quality of the regression models was discovered.Additionally,the implications and contributions of our research were discussed.By implementing our approach,the cost associated with relying solely on existing observatories can be substantially reduced.This reduction in costs can pave the way for economically efficient fine dust observation systems,ensuring more widespread and accurate air quality monitoring across different regions.

Influence of topography on the fine structures of stratospheric gravity waves:An analysis using COSMIC-2 temperature data

We derive the potential energy of gravity waves(GWs)in the upper troposphere and stratosphere at 45°S-45°N from December 2019 to November 2022 by using temperature profiles retrieved from the Constellation Observing System for Meteorology,Ionosphere,and Climate-2(COSMIC-2)satellite.Owing to the dense sampling of COSMIC-2,in addition to the strong peaks of gravity wave potential energy(GWPE)above the Andes and Tibetan Plateau,we found weak peaks above the Rocky,Atlas,Caucasus,and Tianshan Mountains.The land-sea contrast is responsible for the longitudinal variations of the GWPE in the lower and upper stratosphere.At 40°N/S,the peaks were mainly above the topographic regions during the winter.At 20°N/S,the peaks were a slight distance away from the topographic regions and might be the combined effect of nontopographic GWs and mountain waves.Near the Equator,the peaks were mainly above the regions with the lowest sea level altitude and may have resulted from convection.Our results indicate that even above the local regions with lower sea level altitudes compared with the Andes and Tibetan Plateau,the GWPE also exhibits fine structures in geographic distributions.We found that dissipation layers above the tropopause jet provide the body force to generate secondary waves in the upper stratosphere,especially during the winter months of each hemisphere and at latitudes of greater than 20°N/S.

Young patient with a giant gastric bronchogenic cyst:A case report and review of literature

BACKGROUND Gastric bronchogenic cysts(BCs)are extremely rare cystic masses caused by abnormal development of the respiratory system during the embryonic period.Gastric bronchial cysts are rare lesions that were first reported in 1956;as of 2023,only 33 cases are available in the PubMed online database.BCs usually have no clinical symptoms in the early stage,and imaging findings also lack specificity.Therefore,they are difficult to diagnose before histopathological examination.CASE SUMMARY A 34-year-old woman with respiratory distress presented at our hospital.Endoscopic ultrasound revealed an anechoic mass between the spleen,left kidney and gastric fundus,with hyperechogenic and soft elastography textures and with a size of approximately 6.5 cm×4.0 cm.Furthermore,a computed tomography scan demonstrated high density between the posterior stomach and the spleen and the left kidney,with uniform internal density and a small amount of calcification.The maximum cross section was approximately 10.1 cm×6.1 cm,and the possibility of a cyst was high.Because the imaging findings did not suggest a malignancy and because the patient required complete resection,she underwent laparotomy surgery.Intraoperatively,this cystic lesion was found to be located in the posterior wall of the large curvature of the fundus and was approximately 8 cm×6 cm in size.Finally,the pathologists verified that the cyst in the fundus was a gastric BC.The patient recovered well,her symptoms of chest tightness disappeared,and the abdominal drain was removed on postoperative day 6,after which she was discharged on day 7 for 6 months of follow-up.She had no tumor recurrence or postoperative complications during the follow-up.CONCLUSION This is a valuable report as it describes an extremely rare case of gastric BC.Moreover,this was a very young patient with a large BC in the stomach.

Effect of Zircon Addition on Properties of Corundum Porous Materials

This paper aims to improve the corrosion resistance of dispersive purging plugs.White fused corundum particles and fine powder,α-Al_(2)O_(3) micropowder,Cr_(2)O_(3) micropowder,Guangxi clay and zircon powder were used as the main raw materials.The mass ratio of white fused corundum particles and fine powder was fixed at 85:15,and 0,1%,2%,or 3%(by mass)of zircon fine powder was added to replace the same amount of white fused corundum fine powder.The corundum porous material was prepared by the particle stacking pore-forming method at 1650℃for 3 h.The effect of the zircon addition on the properties and microstructure of porous materials was investigated.The results show that:after adding zircon,the permeability of the porous material increases,the cold and hot strengths increase obviously,and the expansion rate after firing decreases.When the addition of zircon is 2%,the comprehensive performance of the specimen is optimal with the smallest linear change rate and the highest permeability.

When Design Defines a City

Both Spain and China’s practices in urban design show how urban governance,local social development,and people’s needs shape a city’s landscape.IN the 20th century,China and Spain faced the common challenge of urban transition.In China,it began with the urbanization and revitalization process with the inception of the reform and opening-up in 1978,and in Spain.

非零方阵的一类加法分解

基于矩阵的相关性质,证明了数域上任意非零方阵均可分解为一个幂零阵与一个可逆阵之和,推进了已知相关结论.作为所得结果的应用,给出线性空间上线性变换的加法分解.

Crystallization and Microstructure of Li_2O-Al_2O_3-SiO_2 Glass-ceramics Produced with Environmentally Acceptable Fining Agents

Lithium aluminosilicate(LAS) glass-ceramics with a few gas bubbles were prepared when SnO2, V2O5 and CeO2 were used as fining agents. The effect of the complex fining agent on the crystallization, phase compositions and microstructure of LAS glass–ceramics was investigated by differential thermal analysis, X-ray diffraction and scanning electron microscopy, respectively. The results show that the introduction of fining agents promotes the crystallization at a lower temperature and has little effect on the compositions of main crystalline phase and microstructure when the crystalline phase remains β-quartz. The special colors of LAS glass-ceramics can be obtained by controlling the crystallization temperature and the amounts of V2O5 and CeO2. The complex fining agent is an environmentally friendly alternative to toxic As2O3 and can be also used as a colorant for colored LAS glass-ceramics.

Research Progress in Mechanochemistry of Inorganic Materials

With the progress of science and technology,China has gradually attached importance to research and exploration in chemistry,and the achievements in exploring mechanochemistry are also quite significant.Therefore,it is necessary to study and explore mechanochemistry.This article mainly discusses the application of mechanochemistry in powder and some silicate materials,as well as in special ceramics,and provides a brief introduction to provide reference for relevant researchers.