Research on Identification Method of Argillaceous Interlayer in Compound Sand

For the compound sand body, the interlayer is an important factor affecting the adjustment of oil production structure and remaining oil distribution. According to the origin of argillaceous interlayer, the interlayer is divided into three types, including barriers between two single layers, intercalations between two single sands and intercalations in a single sand. In this study, the upper limit of physical properties of interlayer was obtained by analyzing the relationship between physical parameters and production index per-meter. The discriminant index and comprehensive discriminant chart of interlayer were obtained by grey correlation method, which realize the quantitative identification of different types of interlayer. The intercalations between two single sands in the target area are distributed almost in the whole area, which is one of the most important factors influencing the mining effect of compound sand, so the planar distribution is mainly aimed at it. Firstly, through cross-well comparison, we summarize three interlayer patterns, then establish their forward modeling, so as to obtain the vertical seismic characteristics of different patterns. Secondly, according to the thickness of intercalations between two single sands, we take the top of bottom sand as the baseline, extract the average amplitude attribute from the upper and lower 3 ms, then, according to the seismic section and planar characteristics of the well, the interlayer structures represented by different seismic section and planar characteristics are summarized. Finally, starting from the real drilling interlayer of the well, the planar spread of interlay can be obtained according to their variation trend and distribution.

Research on Well Testing Interpretation of Low Permeability Deformed Dual Medium Reservoir

Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and established. The difference method was used to solve the problem, and pressure and pressure derivative double logarithmic curves were drawn to analyze the seepage law. The research results indicate that the influence of starting pressure gradient and medium deformation on the pressure characteristic curve is mainly manifested in the middle and late stages. The larger the value, the more obvious the upward warping of the pressure and pressure derivative curve;the parameter characterizing the dual medium is the crossflow coefficient. The channeling coefficient determines the time and location of the appearance of the “concave”. The smaller the value, the later the appearance of the “concave”, and the more to the right of the “concave”.

Speech Separation Algorithm Using Gated Recurrent Network Based on Microphone Array

Speech separation is an active research topic that plays an important role in numerous applications,such as speaker recognition,hearing pros-thesis,and autonomous robots.Many algorithms have been put forward to improve separation performance.However,speech separation in reverberant noisy environment is still a challenging task.To address this,a novel speech separation algorithm using gate recurrent unit(GRU)network based on microphone array has been proposed in this paper.The main aim of the proposed algorithm is to improve the separation performance and reduce the computational cost.The proposed algorithm extracts the sub-band steered response power-phase transform(SRP-PHAT)weighted by gammatone filter as the speech separation feature due to its discriminative and robust spatial position in formation.Since the GRU net work has the advantage of processing time series data with faster training speed and fewer training parameters,the GRU model is adopted to process the separation featuresof several sequential frames in the same sub-band to estimate the ideal Ratio Masking(IRM).The proposed algorithm decomposes the mixture signals into time-frequency(TF)units using gammatone filter bank in the frequency domain,and the target speech is reconstructed in the frequency domain by masking the mixture signal according to the estimated IRM.The operations of decomposing the mixture signal and reconstructing the target signal are completed in the frequency domain which can reduce the total computational cost.Experimental results demonstrate that the proposed algorithm realizes omnidirectional speech sep-aration in noisy and reverberant environments,provides good performance in terms of speech quality and intelligibility,and has the generalization capacity to reverberate.

Optimization of Injection Parameters for Profile Control and Flooding in an Oilfield during High Water Cut Period

In order to improve the effect of water control and oil stabilization during high water cut period, a mathematical model of five point method well group was established with the high water cut well group of an Oilfield as the target area, the variation law of water cut and recovery factor of different injection parameters was analyzed, and the optimization research of injection parameters of polymer enhanced foam flooding was carried out. The results show that the higher the injection rate, the lower the water content curve, and the higher the oil recovery rate. As the foam defoamed when encountering oil, when the injection time was earlier than 80% of water cut, the later the injection time was, the better the oil displacement effect would be. When the injection time was later than 80% of water cut, the later the injection time was, the worse the oil displacement effect would be. The larger the injection volume, the lower the water content curve and the higher the recovery rate. After the injection volume exceeded 0.2 PV, the amplitude of changes in water content and recovery rate slowed down. The optimal injection parameters of profile control agent for high water content well group in Oilfield A were: injection rate of 15 m3/d, injection timing of 80% water content, and injection volume of 0.2 PV.

Experimental study on anti-penetration mechanism of bolted composite protective structure with limited span under impact of low-velocity projectile

In order to study the influence of the bolt joint mode on low-velocity projectiles penetrating the composite protective structure,two bolt joint models which connect the composite target to the fixed frame were designed,the ballistic test of the bolted composite protective structure with limited span was carried out,and the bearing and failure characteristics of the bolted region,as well as the energy dissipation of each part of the structure,were analyzed.The results show that in the condition of lowvelocity impact,there are three failure modes for the bolted composite protective structure subjected to projectile penetration,including failure of the impact point of the composite target,failure of protective structure connecting components and failure of the holes in the bolted region of the composite target;the failure mode of bolt holes in the bolted region has a great influence on the protection performance,and the allowable value of the bearing capacity of the bolted region depends on the sum of the minimum failure load in the failure modes and the friction force;shear-out failure occurring in the bolt holes in the bolted region exerts the greatest effect on ballistic performance,which should be avoided;When simultaneous failure occurs in the bolted region and the free deformation region of the composite protective structure,the energy absorption per unit surface density of the composite protective structure reaches the maximum,which can give full play to its anti-penetration efficiency.

Heterotopic pancreas adenocarcinoma in the stomach: A case report and literature review

BACKGROUND Heterotopic pancreas is a common lesion found in the gastrointestinal tract and is usually considered a benign disease.Reports of malignant change of heterotopic pancreas are scarce.CASE SUMMARY A 44-year-old Chinese female underwent a gastroscopy to assess abdominal distension that had persisted for 2 months.A protruding lesion in the gastric antrum was revealed but no malignant tissue was found in the biopsy specimen.The patient's symptom persisted and progressed to repeated vomiting.Endoscopy after 4 months revealed obstruction of the gastric outlet caused by the protruding lesion.A distal gastrectomy was performed.Histopathological examination of the surgical specimen showed the malignant transformation of aberrant pancreas in the stomach.Chemotherapy consisting of folinic acid,fluorouracil,and oxaliplatin was administered for three cycles,and was changed to gemcitabine monotherapy because of adverse effects and increased serum tumor marker levels.The patient remained asymptomatic during a 12-month follow-up.CONCLUSION Pancreatic heterotopy should be considered as source of a potentially malignant lesion,and early treatment or close monitoring for aberrant pancreas is recommended.

Near-infrared lead chalcogenide quantum dots:Synthesis and applications in light emitting diodes

This paper reviews the recent progress in the synthesis of near-infrared(NIR) lead chalcogenide(PbX;PbX = PbS,PbSe, PbTe) quantum dots(QDs) and their applications in NIR QDs based light emitting diodes(NIR-QLEDs). It summarizes the strategies of how to synthesize high efficiency PbX QDs and how to realize high performance Pb X based NIR-QLEDs.

Pleural lump after paragonimiasis treated by thoracoscopy: A case report

BACKGROUND Paragonimiasis is a parasitic disease that has multiple symptoms,with pulmonary types being common.According to our clinical practices,the pleural effusion of our patients is full of fibrous contents.Drainage,praziquantel,and triclabendazole are recommended for the treatment,but when fibrous contents are contained in pleural effusion,surgical interventions are necessary.However,no related reports have been noted.Herein,we present a case of pulmonary paragonimiasis treated by thoracoscopy.CASE SUMMARY A 12-year-old girl presented to our outpatient clinic complaining of shortness of breath after exercise for several days.Enzyme-linked immunosorbent assay revealed positivity for antibodies against Paragonimus westermani,serological test showed eosinophilia,and moderate left pleural effusion and calcification were detected on computed tomography(CT).She was diagnosed with paragonimiasis,and praziquantel was prescribed.However,radiography showed an egg-sized nodule in the left pleural cavity during follow-up.She was then admitted to our hospital again.The serological results were normal except slight eosinophilia.CT scan displayed a cystic-like node in the lower left pleural cavity.The patient underwent a thoracoscopic mass resection.A mass with a size of 6 cm×4 cm×3 cm adhered to the pleura was resected.The pathological examination showed that the mass was composed of non-structured necrotic tissue,indicating a granuloma.The patient remainded asymptomatic and follow-up X-ray showed complete removal of the mass.CONCLUSION This case highlights that thoracoscopic intervention is necessary when fibrous contents are present on CT scan or chest roentgenogram to avoid later fibrous lump formation in patients with pulmonary paragonimiasis.

基于STM-32的红外语音控制系统

目的:设计一种低成本、适应性强的基于WIFI的智能家居网关的语音控制系统。方法:搭建基于STM-32单片机内核的硬件平台,通过语音指令的收集处理和识别,做出相应反馈,并通过WIFI和红外射频做媒介,达到远程控制家电的目的。结果:经实验测试表明,文章所设计的智能家居网关能够很好的满足智能家居控制系统对家居环境智能化的需求。结论:以STM-32为核心的智能家居网关系统的方案可行,为廉价智能家居的推广提供了参考依据。

Infrared light-emitting diodes based on colloidal Pb Se/Pb S core/shell nanocrystals

Colloidal Pb Se nanocrystals(NCs)have gained considerable attention due to their efficient carrier multiplication and emissions across near-infrared and short-wavelength infrared spectral ranges.However,the fast degradation of colloidal Pb Se NCs in ambient conditions hampers their widespread applications in infrared optoelectronics.It is well-known that the inorganic thick-shell over core improves the stability of NCs.Here,we present the synthesis of Pb Se/Pb S core/shell NCs showing wide spectral tunability,in which the molar ratio of lead(Pb)and sulfur(S)precursors,and the concentration of sulfur and Pb Se NCs in solvent have a significant effect on the efficient Pb S shell growth.The infrared light-emitting diodes(IR-LEDs)fabricated with the Pb Se/Pb S core/shell NCs exhibit an external quantum efficiency(EQE)of 1.3%at 1280 nm.The ligand exchange to optimize the distance between NCs and chloride treatment are important processes for achieving high performance on Pb Se/Pb S NC-LEDs.Our results provide evidence for the promising potential of Pb Se/Pb S NCs over the wide range of infrared optoelectronic applications.

A Novel System for Recognizing Recording Devices from Recorded Speech Signals

The field of digital audio forensics aims to detect threats and fraud in audio signals.Contemporary audio forensic techniques use digital signal processing to detect the authenticity of recorded speech,recognize speakers,and recognize recording devices.User-generated audio recordings from mobile phones are very helpful in a number of forensic applications.This article proposed a novel method for recognizing recording devices based on recorded audio signals.First,a database of the features of various recording devices was constructed using 32 recording devices(20 mobile phones of different brands and 12 kinds of recording pens)in various environments.Second,the audio features of each recording device,such as the Mel-frequency cepstral coefficients(MFCC),were extracted from the audio signals and used as model inputs.Finally,support vector machines(SVM)with fractional Gaussian kernel were used to recognize the recording devices from their audio features.Experiments demonstrated that the proposed method had a 93.4%accuracy in recognizing recording devices.

Bipolar membrane electrodialysis integrated with in-situ CO_(2)absorption for simulated seawater concentrate utilization,carbon storage and production of sodium carbonate

In the context of carbon capture,utilization,and storage,the high-value utilization of carbon storage presents a significant challenge.To address this challenge,this study employed the bipolar membrane electrodialysis integrated with carbon utilization technology to prepare Na_(2)CO_(3)products using simulated seawater concentrate,achieving simultaneous saline wastewater utilization,carbon storage and high-value production of Na_(2)CO_(3).The effects of various factors,including concentration of simulated seawater concentrate,current density,CO_(2)aeration rate,and circulating flow rate of alkali chamber,on the quality of Na_(2)CO_(3)product,carbon sequestration rate,and energy consumption were investigated.Under the optimal condition,the CO_(3)^(2-)concentration in the alkaline chamber reached a maximum of 0.817 mol/L with 98 mol%purity.The resulting carbon fixation rate was 70.50%,with energy consumption for carbon sequestration and product production of 5.7 k Whr/m^(3)CO_(2)and1237.8 k Whr/ton Na_(2)CO_(3),respectively.This coupling design provides a triple-win outcome promoting waste reduction and efficient utilization of resources.

In Situ Analysis of Tobacco Leaves Based on Microwave Plasma Torch Desorption Ionization Mass Spectrometry

Tobacco is an important economic crop worldwide.Tobacco leaves contain a large number of natural products.Therefore,the analysis of tobacco composition is crucial for the control of tobacco safety and quality assessment.Microwave plasma torch desorption ionization mass spectrometry(MPT-MS) is an emerging ambient mass spectrometry(AMS) technique that can be used for rapid real-time analysis of s amples without pretreatment.Our work focuses on the chemical composition analysis of tobacco using MPT-MS,and 14 compounds were detected in green flue-cured tobacco leaves,while 30 compounds were detected in cured flue-cured tobacco leaves,which confirms that curing can enhance the flavor of cigarettes.Furthermore,we successfully in situ identified characteristic fragment ions of α/β-CBD(α/β-cembranoids),an important aroma compound in tobacco by MPT-MS.The results demonstrate the capability of MPT-MS for in situ analysis of tobacco components and its potential for evaluating tobacco quality.

Dynamic ageing research of cross‐linked polyethylene cable insulation based on temporal‐spatial dimension under combined electro‐thermal effect

Dynamic ageing process of cross‐linked polyethylene(XLPE)cable insulation under combined electro‐thermal effect is investigated by the construction of theoretical analysis model and the practice of operation‐simulated ageing test.Firstly,theoretical analysis model is constructed from time and spatial dimensions.From the time dimension,in the light of the impeding trend of internal stress to external stress,the XLPE ageing process of Steady state‐Transition state‐Steady state(STS)is proposed to illustrate the dynamic ageing process of XLPE.From the spatial dimension,the insulation is divided into three scales to quantify the ageing.Secondly,to practice the theoretical analysis model,an operation‐simulated ageing test was conducted on two high voltage alternating current cables with service years of 15 and 30 for 540 days.Subsequently,relevant diagnostic measurements were applied to analyse the influence of physicochemical characteristics on the dielectric and heat transfer performances of the cables.The results show that the degradation of the actual operating cable is an extremely slow process.On the one hand,the response in physical changes of morphology counterbalances the external stress,maintaining the stability.On the other hand,once the chemical changes occur,negative feedback mechanism tends to impede the occurrence of further degradation by regulating fields distribution.

Hinge Majorana flat band in type-Ⅱ Dirac semimetals

Type-Ⅱ Dirac semimetals exhibit a unique Fermi surface topology,which allows them to host novel topological superconductivity(TSC).We reveal a novel inter-orbital superconducting state,corresponding to the B_(1u) and B_(2u) pairings under the D_(4h) point group.Intriguingly,we find that both first-and second-order TSC coexist in this novel state.It is induced by a dominant inter-orbital attraction and possesses surface helical Majorana cones and hinge Majorana flat bands,spanning the entire z-directed hinge Brillouin zone.Further investigation uncovers that these higher-order hinge modes are robust against the C_(4z) symmetry-breaking perturbation.

Species of Botryosphaeriaceae involved in grapevine dieback in China

Botryosphaeria dieback is a serious disease problem for table and grape wine production worldwide.The disease however,has been less well-studied in China.In this study,we surveyed Botryosphaeria dieback in 72 vineyards of 20 grape-growing regions in China and found that Botryosphaeria dieback occurs in 18 out of 20 provinces.Morphological and multi-gene phylogenetic analyses confirmed that Botryosphaeria dothidea,Diplodia seriata,Lasiodiplodia theobromae and Neofusicoccum parvum are associated with different grapevine dieback symptoms.This study also revealed considerable differences in the geographical distribution of Botryosphaeriaceae species in China with Lasiodiplodia theobromae and Neofusicoccum parvum occurring only in subtropical monsoon climate regions,Diplodia seriata occurring only in temperate monsoon climate regions,and Botryosphaeria dothidea occurring in both temperate and subtropical monsoon climate regions.Analysis of 26 isolates showed that there is little genetic variation within species.Koch’s postulates were satisfied for all species,and pathogenicity testing showed that among the 25 major cultivars growing in China,none was resistant to the four taxa.The current paper represents the first detailed report on Botryosphaeria dieback of grapevines in China.

Clinical characteristics and effectiveness of antiviral agents in hospitalized children with infectious mononucleosis in China:A multicenter retrospective study

Importance:The clinical characteristics of infectious mononucleosis(IM)in Chinese children have not been evaluated in multicenter studies,and the effectiveness of antiviral treatment are controversial.Objective:To investigate the clinical characteristics of Chinese children with IM and current status of antiviral therapy for affected patients.Methods:Hospitalized patients with IM were enrolled between 2018 and 2020 in five children’s hospitals in China.The clinical characteristics were compared among four age groups:<3 years,3-<6 years,6-<10 years,and≥10 years.The clinical characteristics of IM and effectiveness of antiviral therapy were compared among patients receiving acyclovir(ACV),ganciclovir(GCV),and no antiviral therapy(i.e.,non-antiviral group).Results:In total,499 patients were analyzed;most patients were 3-<6 years of age.The most common symptoms and signs included fever(100%),lymphadenopathy(98.6%),pharyngitis(86.4%),eyelid edema(76.8%),and snoring(72.9%).There were significant differences in rash,hepatomegaly,and liver dysfunction among the four age groups.Patients aged<3 years had a lower incidence of liver dysfunction and a higher incidence of rash.Among the 499 patients,50.1%were treated with GCV,26.3%were treated with ACV,and 23.6%received no antiviral therapy.Compared with the non-antiviral group,patients in the ACV and GCV groups had longer durations of fever(P<0.001).There were no significant differences in the incidences of complications among the three treatment groups.Interpretation:The incidence of IM in Chinese children peaked at 3-<6 years of age.Clinical features of IM varied according to age.Patients receiving antiviral therapy exhibited more serious clinical manifestations than did patients without antiviral therapy.The effectiveness of antiviral therapy for IM requires further analysis.

Support-free interior carving for 3D printing

Recent interior carving methods for functional design necessitate a cumbersome cut-and-glue process in fabrication.Wepropose a method to generate interior voids which not only satisfy the functional purposes but are also support-free during the 3D printing process.We introduce a support-free unit structure for voxelization and derive the wall thicknesses parametrization for continuous optimization.Wealso design a discrete dithering algorithm to ensure the printability of ghost voxels.The interior voids are iteratively carved by alternating the optimization and dithering.We apply our method to optimize the static and rotational stability,and print various results to evaluate the efficacy.

Sensitive Analysis and Pharmacokinetic Study of Berberrubine Using LC-MS/MS

Objective To develop a sensitive and reproducible liquid chromatography-tandem mass spectrometry（LC-MS/MS） method to evaluate the pharmacokinetic behavior of berberrubine（BRB） and its glucuronide（BRBG） in rats. Methods BRB, BRBG and tetrahydroberberine（THB, internal standard） were isolated by liquid-liquid extraction in rat biological samples. Chromatographic separation was achieved on an Agilent Zorbax Eclipse Plus C_（18）（2.1 mm × 50 mm, 3.5-Micron） with a gradient mobile phases primarily containing acetonitrile, water with 0.1% formic acid and 5 mm ammonium acetate. The analytes were monitored by MS/MS in positive electrospray ionization mode. Herein, the feasibility of new developed method was validated with respect to specificity, linearity, precision, accuracy, stability, extraction efficiency and matrix effect. The appropriate method was used for the pharmacokinetic study in rats.Results The new developed method could be applied to the pharmacokinetic study of BRB in rats. BRB and BRBG showed good linearity over the ranges of 2-1000 ng/mL and 5-2000 ng/mL, respectively, and precision was no more than 15%. The accuracy, specificity and stability could be acceptable. Conclusion The new method is sensitive and reproducible. In pharmacokinetic study, BRB showed nonlinear elimination property. Meanwhile, BRB was rapidly absorbed and widely distributed in various tissues with the highest exposure of BRB in kidney and liver. The absolute bioavailability of BRB was determined to be 8.2% and at the dose of 40 mg/kg, a total of 44% BRB was excreted in urine and feces.

Efficacy and safety of decitabine combined with low-dose cytarabine, aclarubicin, and granulocyte colony-stimulating factor compared with standard therapy in acute myeloid leukemia patients with TP53 mutation

Tumor suppressor gene P53(TP53)is a critical tumor suppressor gene.The mutant p53 protein enhances the activity,invasion and metastasis of tumor cells.Acute myeloid leukemia(AML)patients with TP53 mutations respond poorly to conventional chemotherapy and have poor clinical outcomes.We previously conducted a multi-center phase II clinical trial(No.ChiCTRONC-11001700)in elderly AML patients with decitabine,low-dose cytarabine,aclarubicin,and granulocyte colony-stimulating factor(G-CSF)(DCAG regimen),which showed an overall response rate(ORR)of 82.4%and a complete remission(CR)rate of 64.7%.[1]Given this satisfactory effect of DCAG regimen,the present study has been designed to compare the efficacy and safety of DCAG regimen with standard therapy in AML patients with TP53 mutations.