An approximate analytical model for unconventional reservoir considering variable matrix blocks and simultaneous matrix depletion

In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture network.It has been proven to cause inaccurate production evaluations because of the absence of matrix-macrofracture communication.In addition,most of the existing models are solved analytically based on Laplace transform and numerical inversion.Hence,an approximate analytical solution is derived directly in real-time space considering variable matrix blocks and simultaneous matrix depletion.To simplify the derivation,the simultaneous matrix depletion is divided into two parts:one part feeding the macrofractures and the other part feeding the microfractures.Then,a series of partial differential equations(PDEs)describing the transient flow and boundary conditions are constructed and solved analytically by integration.Finally,a relationship between oil rate and production time in real-time space is obtained.The new model is verified against classical analytical models.When the microfracture system and matrix-macrofracture communication is neglected,the result of the new model agrees with those obtained with the dual-porosity and triple-porosity model,respectively.Certainly,the new model also has an excellent agreement with the numerical model.The model is then applied to two actual tight oil wells completed in western Canada sedimentary basin.After identifying the flow regime,the solution suitably matches the field production data,and the model parameters are determined.Through these output parameters,we can accurately forecast the production and even estimate the petrophysical properties.

Simultaneous Waveform Inverse Modelling for Litho-Fluid Prediction in an Old Marginal, “Agbbo”Field, Onshore Niger Delta, Nigeria

Simultaneous waveform inversion was used to predict lithofacies and fluid type across the field. Very often, characterizing reservoirs in terms of lithology and fluid type using conventional methods is replete with uncertainties, especially in marginal fields. An approach is employed in this study that integrated rock physics and waveform inverse modelling for lithology and fluid-type characterization to appropriately identify potential hydrocarbon saturated zones and their corresponding lithology. Seismic and well-log data were analyzed using Hampson Russel software. The method adopted includes lithofacies and fluid content analysis using rock physics parameters and seismic simultaneous inverse modelling. Rock physics analysis identified 2 broad reservoirs namely: HDZ1 and HDZ2 reservoirs. Results from the inverse modelling showed that low values of acoustic impedance from 19,743 to 20,487 (ft/s)(g/cc) reflect hydrocarbon-bearing reservoirs while medium to high values shows brine and shale respectively, with brine zone ranging from 20,487 to 22,531 (ft/s)(g/cc) and shale above 22,531 (ft/s)(g/cc). Two lithofacies were identified from inversion analysis of Vp/Vs and Mu-Rho, namely: sand and shale with VpVs 1.95 values respectively. Mu-Rho > 12.29 (GPa)(g/cc) and <12.29 (GPa) (g/cc) represent sand and shale respectively. From 3D volume, it was observed that a high accumulation of hydrocarbon was observed to be saturated at the north to the eastern part of the field forming a meandering channel. Sands were mainly distributed around the northeastern to the southwestern part of the field, that tends to be away from Well 029. This was also validated by the volume of rigidity modulus (Mu-Rho) showing high values indicating sands fall within the northeastern part of the field.

A universal probe for simultaneous detection of six pospiviroids and natural infection of potato spindle tuber viroid(PSTVd) in tomato in China

Several viroids in the genus Pospiviroid can infect tomato(Solanum lycopersicum)and cause severe diseases,posing a serious threat to tomato production.For simultaneous detection of six tomato-infecting pospiviroids-columnea latent viroid(CLVd),pepper chat fruit viroid(PCFVd),potato spindle tuber viroid(PSTVd),tomato apical stunt viroid(TASVd),tomato chlorotic dwarf viroid(TCDVd),and tomato planta macho viroid(TPMVd),we developed a universal probe based on a highly conserved 61 nt long sequence shared among them.Compared with their specific probes,the universal probe has a similar,though slightly reduced,detection sensitivity and has the advantages of simple and cost-effective preparation and simultaneous detection of the six pospiviroids.In addition,the universal probe was used in dot-blot hybridization assays for a large-scale survey of viroid(s)in tomato plantings in China.Only PSTVd was detected in a few greenhouse-planted tomato plants.Sequence analysis revealed that these tomato PSTVd isolates may have been introduced from tomato seeds imported from abroad.

A Fiber Optic Sensor for the Simultaneous Measurement of Dual-parameter Based on Hydrogel-immobilized Enzyme Complex

A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic sensor that can continuously detect two kinds of parameters was achieved.By controlling the temperature from high to low,the function of fiber sulfide sensor and fiber DCP sensor can be realized,so as to realize the continuous detection of dual-parameter.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions,the response curves,linear detection ranges,detection limits and response times of the dual-parameter sensor for testing sulfide and DCP were obtained,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing sulfide and DCP concentration of practical water samples.

Simultaneous nitrification and autotrophic denitrification in fluidized bed reactors using pyrite and elemental sulfur as electron donors

In this study, simultaneous nitrification and autotrophic denitrification (SNAD) with either elemental sulfur or pyrite were investigated in fluidized bed reactors in mesophilic conditions. The reactor performance was evaluated at different ammonium (12-40 mg/L of NH4+-N), nitrate (35-45 mg/L of NO3--N), and dissolved oxygen (DO) (0.1-1.5 mg/L) concentrations, with a hydraulic retention time of 12 h. The pyrite reactor supported the SNAD process with a maximum nitrogen removal efficiency of 139.5 mg/(L·d) when the DO concentration was in the range of 0.8-1.5 mg/L. This range, however, limited the denitrification efficiency of the reactor, which decreased from 90.0% ± 5.3% in phases II-V to 67.9% ± 7.2% in phases VI and VII. Sulfate precipitated as iron sulfate (FeSO4/Fe2(SO4)3) and sodium sulfate (Na2SO4) minerals during the experiment. The sulfur reactor did not respond well to nitrification with a low and unstable ammonium removal efficiency, while denitrification occurred with a nitrate removal efficiency of 97.8%. In the pyrite system, the nitrifying bacterium Nitrosomonas sp. was present, and its relative abundance increased from 0.1% to 1.1%, while the autotrophic denitrifying genera Terrimonas, Ferruginibacter, and Denitratimonas dominated the community. Thiobacillus, Sulfurovum, and Trichlorobacter were the most abundant genera in the sulfur reactor during the entire experiment.

Simultaneous resonance of an axially moving ferromagnetic thin plate under a line load in a time-varying magnetic field

In this paper,the simultaneous resonance of a ferromagnetic thin plate in a time-varying magnetic field,having axial speed and being subjected to a periodic line load,is studied.Based on the large deflection theory of thin plates and electromagnetic field theory,the nonlinear vibration differential equation of the plate is obtained by using the Hamilton′s principle and the Galerkin method.Then the boundary condition in which the longer opposite sides are clamped and hinged is considered.The dimensionless nonlinear differential equations are solved by using the method of multiple scales,and the analytical solution is given.In addition,the stability analysis is also carried out by using Lyapunov stability theory.Through numerical analysis,the variation curves of system resonance amplitude with frequency tuning parameter,magnetic field strength and external excitation amplitude are obtained.Different parameters that have significant effects on the response of the system,such as the thickness,the axial velocity,the magnetic field intensity,the position,and the frequency of external excitation,are considered and analyzed.The results show that the system has multiple solution regions and obvious nonlinear coupled characteristics.

Repeat peroral endoscopic myotomy with simultaneous submucosal and muscle dissection as a salvage option for recurrent achalasia

BACKGROUND For recurrent achalasia after initial peroral endoscopic myotomy(POEM)failure,repeat POEM(Re-POEM)has been reported as a treatment option.However,severe esophageal interlayer adhesions caused by previous procedures impede the successful establishment of a submucosal tunnel and lead to aborted Re-POEM procedures.Our team previously described POEM with simultaneous submucosal and muscle dissection(POEM-SSMD)as a feasible solution for achalasia with severe interlayer adhesions.AIM To investigate the effectiveness and safety of Re-POEM with simultaneous submucosal and muscle dissection(Re-POEM-SSMD).METHODS A total of 1049 patients with achalasia who underwent successful endoscopic myotomy at the Digestive Endoscopic Center of Chinese PLA General Hospital from December 2014 to May 2022 were reviewed.Patients with recurrent achalasia who experienced initial POEM clinical failure were retrospectively included in this study.The primary endpoint was retreatment clinical success,defined as an Eckardt score≤3 during the postretreatment follow-up and no need for additional treatment.Procedure-related adverse events,changes in manometric lower esophageal sphincter(LES)pressure and reflux complications,as well as procedure-related parameters,were recorded.RESULTS Sixteen patients underwent Re-POEM(9 patients)or Re-POEM-SSMD(7 patients)successfully at a median of 45.5 mo(range,4-95 mo)after initial POEM.During a median followup period of 31 mo(range,7-96 mo),clinical success(Eckardt score≤3)was achieved in 8(88.9%)and 6(85.7%)patients after Re-POEM and Re-POEM-SSMD,respectively(P=0.849).The median Eckardt score dropped from 4(range,3-8)at preretreatment to 1(range,0-5)at postretreatment in the Re-POEM group(P=0.025)and from 5(range,2-8)to 2(range,0-4)in the Re-POEM-SSMD group(P<0.001).The mean manometric LES pressure decreased from 23.78±9.04 mmHg to 11.45±5.37 mmHg after Re-POEM(P<0.001)and from 26.80±7.48 mmHg to 11.05±4.38 mmHg after Re-POEM-SSMD(P<0.001).No serious adverse events were recorded in both groups.CONCLUSION In conclusion,Re-POEM-SSMD appears to be a safe and effective salvage therapy for recurrent achalasia with severe interlayer adhesions.

Cooperative Sampling Path Planning of Underwater Glider Fleet with Simultaneous Launch and Recovery

As low-cost and highly autonomous ocean observation platforms,underwater gliders encounter risks during their launch and recovery,especially when coordinating multi-glider deployments.This work focuses on cooperative path planning of an underwater glider fleet with simultaneous launch and recovery to enhance the autonomy of sampling and reduce deployment risks.Specifically,the gliders collaborate to achieve sampling considering the specified routines of interest.The overall paths to be planned are divided into four rectangular parts with the same starting point,and each glider is assigned a local sampling route.A clipped-oriented line-of-sight algorithm is proposed to ensure the coverage of the desired edges.The pitch angle of the glider is selected as the optimizing parameter to coordinate the overall progress considering the susceptibility of gliders to currents and the randomness of paths produced by complex navigational strategies.Therefore,a multi-actuation deep-Q network algorithm is proposed to ensure simultaneous launch and recovery.Simulation results demonstrate the acceptable effectiveness of the proposed method.

Simultaneous denoising and resolution enhancement of seismic data based on elastic convolution dictionary learning

Enhancing seismic resolution is a key component in seismic data processing, which plays a valuable role in raising the prospecting accuracy of oil reservoirs. However, in noisy situations, existing resolution enhancement methods are difficult to yield satisfactory processing outcomes for reservoir characterization. To solve this problem, we develop a new approach for simultaneous denoising and resolution enhancement of seismic data based on convolution dictionary learning. First, an elastic convolution dictionary learning algorithm is presented to efficiently learn a convolution dictionary with stronger representation capability from the noisy data to be processed. Specifically, the algorithm introduces the elastic L1/2 norm as a sparsity constraint and employs a steepest gradient descent strategy to efficiently solve the frequency-domain linear system with substantial computational cost in a half-quadratic splitting framework. Then, based on the learned convolution dictionary, a weighted convolutional sparse representation paradigm is designed to encode the noisy data to acquire an optimal sparse approximation of the effective signal. Subsequently, a high-resolution dictionary with a broadband spectrum is constructed by the proposed parameter scaling strategy and matched filtering technique on the basis of atomic spectrum modeling. Finally, the optimal sparse approximation of the effective signal and the constructed high-resolution dictionary are used for data reconstruction to obtain the seismic signal with high resolution and high signal-to-noise ratio. Synthetic and field dataset examples are executed to check the effectiveness and reliability of the developed method. The results indicate that this method has a more competitive performance in seismic applications compared with the conventional deconvolution and spectral whitening methods.

Simultaneous detection of CH_(4)and CO_(2)through dual modulation off-axis integrated cavity output spectroscopy

This study established a novel method for the simultaneous detection of two-component gases.Radio frequency(RF)white noise disturbance laser current and wavelength modulation were simultaneously used to improve the off-axis integrated cavity output spectroscopy technique,and a high-precision dual modulation OA-ICOS(RF-WM-OA-ICOS)system was established.The two laser beams were coupled into one laser beam that was applied incident to the cavity of RF-WM-OA-ICOS system.The second harmonic signals of CH_(4)and CO_(2)gas simultaneously appeared in the rising or falling edge of a triangular wave.This method was used to measure CH_(4)and CO_(2)with different concentrations.The results indicated that the proposed system has high stability and can accurately and simultaneously measure the concentrations of CH_(4)and CO_(2),with an optimal integration time of 220 s.The minimum detection limit was 10 ppb for CH_(4)and 1.5 ppm for CO_(2).The corresponding noise equivalent absorption sensitivity values were calculated as 2.67×10^(-13)cm^(-1)·Hz^(-1/2)and 5.18×10^(-11)cm^(-1)·Hz^(-1/2),respectively.The proposed dual-component gas simultaneous detection method can also be used for high-precision simultaneous detection of other gases.Therefore,this study may serve as a reference for developing portable multicomponent gas analyzers.

Review of Simultaneous Localization and Mapping Technology in the Agricultural Environment

Simultaneous localization and mapping(SLAM)is one of the most attractive research hotspots in the field of robotics,and it is also a prerequisite for the autonomous navigation of robots.It can significantly improve the autonomous navigation ability of mobile robots and their adaptability to different application environments and contribute to the realization of real-time obstacle avoidance and dynamic path planning.Moreover,the application of SLAM technology has expanded from industrial production,intelligent transportation,special operations and other fields to agricultural environments,such as autonomous navigation,independent weeding,three-dimen-sional(3D)mapping,and independent harvesting.This paper mainly introduces the principle,sys-tem framework,latest development and application of SLAM technology,especially in agricultural environments.Firstly,the system framework and theory of the SLAM algorithm are introduced,and the SLAM algorithm is described in detail according to different sensor types.Then,the devel-opment and application of SLAM in the agricultural environment are summarized from two aspects:environment map construction,and localization and navigation of agricultural robots.Finally,the challenges and future research directions of SLAM in the agricultural environment are discussed.

Acute myelomonocytic leukemia and T-lymphoblastic lymphoma as simultaneous bilineage hematologic malignancy treated with decitabine:A case report

BACKGROUND Simultaneous bilineage hematologic malignancies are rare;however,several cases of acute myeloid leukemia(AML)and T-lymphoblastic lymphoma(T-LBL)cooccurrence have been reported.A standard treatment for simultaneous AML and T-LBL has not yet been established,and its prognosis is very poor.Further studies to develop standard treatments are required to increase patient survival rates.CASE SUMMARY A 69-year-old man complaining of pleuritic chest pain visited the emergency room.Computed tomography revealed multiple enlarged lymph nodes(LNs)in the neck and groin and pulmonary thromboembolism with pulmonary infarction.Furthermore,a peripheral blood smear performed due to leukocytosis revealed circulating blasts.Acute myelomonocytic leukemia(AMML)was diagnosed after bone marrow examination,and T-LBL positivity for terminal deoxynucleotidyl transferase,cluster of differentiation(CD)34,and CD4 was confirmed by cervical LN biopsy.Decitabine and dexamethasone were administered because he could not receive intensive chemotherapy due to poor performance status.Complete remission of AMML and T-LBL was achieved after 4 cycles of decitabine plus dexamethasone.CONCLUSION We report the therapeutic effect of decitabine,a hypomethylating agent(HMA),in patients with concurrent bilineage hematologic malignancies and suggest that further studies are required to evaluate the therapeutic effect of HMAs on both lymphoid and bilineage hematologic malignancies.

Simultaneous pancreas-kidney transplantation for end-stage renal failure in type 1 diabetes mellitus: Current perspectives

Type 1 diabetes mellitus(T1DM)is one of the important causes of chronic kidney disease(CKD)and end-stage renal failure(ESRF).Even with the best available treatment options,management of T1DM poses significant challenges for clinicians across the world,especially when associated with CKD and ESRF.Substantial increases in morbidity and mortality along with marked rise in treatment costs and marked reduction of quality of life are the usual consequences of onset of CKD and progression to ESRF in patients with T1DM.Simultaneous pancreas-kidney transplant(SPK)is an attractive and promising treatment option for patients with advanced CKD/ESRF and T1DM for potential cure of these diseases and possibly several complications.However,limited availability of the organs for transplantation,the need for long-term immunosuppression to prevent rejection,peri-and post-operative complications of SPK,lack of resources and the expertise for the procedure in many centers,and the cost implications related to the surgery and postoperative care of these patients are major issues faced by clinicians across the globe.This clinical update review compiles the latest evidence and current recommendations of SPK for patients with T1DM and advanced CKD/ESRF to enable clinicians to care for these diseases.

Empirical Research on the Relationship between Education Poverty Alleviation and Rural Revitalization—Spatial Panel Simultaneous Equation Model Based on Provincial Panel Data

On the basis of using entropy weight method to measure China’s education poverty alleviation and rural revitalization evaluation indicators, using the panel data of 30 provinces in China (excluding Xizang, Hong Kong, Macao and Taiwan) from 2012 to 2021, a spatial panel simultaneous equation model is constructed based on adjacency matrix, geographical distance matrix and economic geographical distance matrix deeply study the interaction mechanism and spatial spillover effects between education poverty alleviation and rural revitalization through the generalized spatial three-stage least squares method (GS3SLS). The results indicate that there is a significant spatial spillover effect and a positive spatial correlation between education poverty alleviation and rural revitalization, and there is a significant interactive effect between the two variables, while promoting each other positively. Therefore, the government should clarify the deep relationship between education poverty alleviation and rural revitalization based on the current background, and better consolidate and expand the effective connection between the achievements of education poverty alleviation and rural revitalization.

MPT-AES在线标准加入法测定中草药黄芪中微量元素

用MPT AES在线标准加入法测定了中草药黄芪中铝、钙、铜、铁、钾、镁、锰、钠、锶和锌10种微量元素。在优化的试验条件下,方法的检出限分别为22.0,1.3,2.4,19.0,5.8,1.6,34.0,0.6,3.7,3.8μg·L-1,相对标准偏差在0.2%～7.6%之间。回收率在94%～118%之间。方法用于美国标准物质1571号橡树叶的分析,测得值与标准参考值较好吻合。

MPT-AES测定矿泉水中的Ca、Mg和Na

用微波等离子体炬 (MPT)为激发光源 ,氩气为等离子体工作气体 ,用气动雾化进样 ,采用标准加入法研究了微波等离子体炬原子发射光谱法 (MPT -AES)测定矿泉水中Ca、Mg和Na的方法。详细考察了溶液中盐酸浓度、微波前向功率、载气流量、工作气流量、氧屏蔽气流量等实验参数对测定的影响 ,同时考察了易电离元素 (EIE)钾和钠对钙和镁发射强度的影响。结果表明 ,MPT -AES测定矿泉水中的Ca、Mg和Na操作简便 ,自动化程度高 ,运转费用低 ,准确快速 。

微波消解MPT-AES测定催化剂中的铈

研究了微波等离子体炬原子发射光谱法(MPT AES)测定催化剂中稀土元素铈的方法。详细考察了测定铈时的实验参数,进行了系统优化。催化剂处理采用了微波消解技术。方法的检出限为2.56μg/mL,相对标准偏差(n=11)为4.37%,线性范围为20～250μg/mL,回收率在90%～110%之间。实验结果表明微波消解和MPT AES联用可成为测定催化剂中铈含量的简单、快速、准确的分析方法。

电热蒸发进样低功率MPT-AES测定铜、锌、镉的研究

微波等离子体炬(MPT)是一种具有类似ICP炬管结构的新型等离子体光源,该光源的基本性质已进行了详细的研究。本文采用自制的低功率MPT为激发光源,以氧为工作气体,用微型电热蒸发装置进样,测得铜、锌和镉的检出限分别为3.3、1.4和1.7ng/mL。考察了碱金属元素对铜、锌和镉发射信号的影响,该方法应用于钢样中铜的测定,结果较好。

微波消解-MPT-AES法测定化妆品中铅、镉和铬含量

建立了微波消解与微波等离子体炬原子发射光谱法(MPT-AES)相结合来同时测定化妆品中铅、镉和铬含量的方法,详细考察了分析波长、微波前向功率、载气流量、工作气流量等参数对元素测定的影响。在最佳试验条件下测得铅、镉和铬的检出限分别为4.7、1.7和4.4ng/mL;线性范围分别为0.04～20、0.02～10和0.04～10μg/mL;样品加标回收率为92.0%～102.4%,精密度为0.52%～4.21%,可满足化妆品行业的日常检测需要,同时节约成本并提高工作效率。

MPT-AES的注射泵-超声雾化器联用进样系统

报道了用于微波等离子体炬原子发射光谱仪(MPT-AES)的新型注射泵-超声雾化器联用进样系统, 考察了影响该系统性能的因素. 分别用气动雾化进样系统和注射泵-超声雾化联用进样系统进样, 测定了Cd, Cu, Mg, Ca和Na等5种元素、浓度均为1×10-4%的混合溶液. 结果表明, 注射泵-超声雾化联用进样系统所得的谱线强度是气动进样所得谱线强度的2～3倍, 而超声雾化进样的检出限比气动雾化进样小2～10倍, 且超声雾化进样系统的记忆效应较强, 所需清洗时间较长.