Artificial Self-Recovery Opens up a New Journey of Autonomous Health of Mechanical Equipments

1.Introduction With the implementation of modern production strategies,such as“Industry 4.0”and“Made in China 2025,”the development of high-end mechanical equipment is gradually reaching a high degree of parameterization,digitalization,networking,and intelligence[1].High-end mechanical equipment no longer consists of traditional single devices,but is closely linked to the overall production process;that is,a variety of devices interact with each other and collectively form a complex system.However,faults can lead to production delays throughout the system and even seriously threaten the safety of workers[2].In addition,equipment operating in unmanned air or space vehicles(including space robots)cannot be repaired by humans if they break down[3].Until recently,the typical method of addressing machine faults was primarily the“fault cure”method,which involves manually shutting down,inspecting,and repairing the equipment to restore normal operation.Accordingly,the maintenance cycle of the traditional“fault cure”method is time-consuming,and the quality of the maintenance depends on the skills of the technician[4].

Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for Lithium-Oxygen Batteries

Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at present.Here,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen battery.On one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox kinetics.On the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic molecules.Therefore,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.

Pure State Feedback Switching Control Based on the Online Estimated State for Stochastic Open Quantum Systems

For the n-qubit stochastic open quantum systems,based on the Lyapunov stability theorem and LaSalle’s invariant set principle,a pure state switching control based on on-line estimated state feedback(short for OQST-SFC)is proposed to realize the state transition the pure state of the target state including eigenstate and superposition state.The proposed switching control consists of a constant control and a control law designed based on the Lyapunov method,in which the Lyapunov function is the state distance of the system.The constant control is used to drive the system state from an initial state to the convergence domain only containing the target state,and a Lyapunov-based control is used to make the state enter the convergence domain and then continue to converge to the target state.At the same time,the continuous weak measurement of quantum system and the quantum state tomography method based on the on-line alternating direction multiplier(QST-OADM)are used to obtain the system information and estimate the quantum state which is used as the input of the quantum system controller.Then,the pure state feedback switching control method based on the on-line estimated state feedback is realized in an n-qubit stochastic open quantum system.The complete derivation process of n-qubit QST-OADM algorithm is given;Through strict theoretical proof and analysis,the convergence conditions to ensure any initial state of the quantum system to converge the target pure state are given.The proposed control method is applied to a 2-qubit stochastic open quantum system for numerical simulation experiments.Four possible different position cases between the initial estimated state and that of the controlled system are studied and discussed,and the performances of the state transition under the corresponding cases are analyzed.

The Effects of the Geometry of a Current Collector with an Equal Open Ratio on Output Power of a Direct Methanol Fuel Cell

The open ratio of a current collector has a great impact on direct methanol fuel cell(DMFC)performance.Although a number of studies have investigated the influence of the open ratio of DMFC current collectors,far too little attention has been given to how geometry(including the shape and feature size of the flow field)affects a current collector with an equal open ratio.In this paper,perforated and parallel current collectors with an equal open ratio of 50%and different feature sizes are designed,and the corresponding experimental results are shown to explain the geometry effects on the output power of the DMFC.The results indicate that the optimal feature sizes are between 2 and 2.5 mm for both perforated and parallel flow field in the current collectors with an equal open ratio of 50%.This means that for passive methanol fuel cells,to achieve the highest output power,the optimal feature size of the flow field in both anode and cathode current collectors is between 2 and 2.5 mm under the operating mode of this experiment.The effects of rib and channel position are also investigated,and the results indicate that the optimum pattern depends on the feature sizes of the flow field.

FURTHER OPENING- UP IS KEY FOR CHINA’S HIGH-QUALITY DEVELOPMENT

The Central Economic Work Conference was held in Beijing from December 11 to 12.The conference discussed the plans,prospects and challenges for China’s economy heading into 2024,as well as evaluating the events of this year.It goes without saying that 2023 has been a challenging year for countries around the world as the global context has been unsatisfactory.Various geopolitical tensions have created a rise in uncertainties which have led to reduced growth worldwide and sent many economies into stagnation.In light of the critical factors affecting the stability of the global economy,China’s primary economic goal corresponds with the promotion and sustaining of free trade.

The Effect of Uterine Artery Occlusion with Tourniquet on Ovarian Reserve during Open Myomectomy at a University Teaching Hospital in Southern Nigeria

Background: The most common surgical treatment for symptomatic uterine fibroids, particularly in women with fertility concerns, is open myomectomy. Given the high vascularity of the uterus, haemorrhage during the procedure is a serious risk that is often mitigated with a uterine tourniquet. Aim and Objectives: To evaluate the effect of uterine artery occlusion with a tourniquet during open myomectomy on ovarian reserve using serial anti-Mullerian hormone (AMH) measurements. Materials and Methods: This was a prospective longitudinal study with a quasi-experimental design and a convenient sampling technique. The study enrolled 47 women who had abdominal myomectomy between September 1, 2021, and March 31, 2022, at the University of Port Harcourt Teaching Hospital. Blood samples were collected before anaesthesia was administered in theatre, on day two, and three months after open abdominal myomectomy for anti-Mullerian hormone assay. The data was collected using a semi-structured proforma, entered into an Excel spreadsheet, and analyzed using SPSS version 25.0 with a 95% confidence interval. Statistical significance level was set at 0.05. Results: The pre-surgery AMH mean value was 1.67 ± 1.44 ng/ml, while the values after using a uterine tourniquet at myomectomy on the second day and three months later were 1.22 ± 1.24 ng/ml and 1.59 ± 1.43 ng/ml, respectively. There was no statistically significant change in AMH levels, and there was no statistically significant relationship between blood loss and tourniquet time and AMH after open abdominal myomectomy. Conclusion: The use of a uterine tourniquet and blood loss during open myomectomy has no effect on ovarian reserve.

Analysis of the Effect of Laparoscopic Versus Open Cholecystectomy in Patients with Cholelithiasis and the Effect on CRP and IL-1βLevels

Objective:To evaluate the therapeutic effect of laparoscopic cholecystectomy(LC)and open cholecystectomy(OC)on cholelithiasis.Methods:92 cases of cholelithiasis patients admitted to the hospital in the past 2 years were selected and grouped by random number table;the observation group was treated with LC;the reference group was treated with OC,and the inflammatory factor and other indexes were compared.Results:The total effective rate of the observation group was higher than that of the reference group,and the perioperative indexes were better than that of the reference group(P<0.05).Preoperatively,the C-reactive protein(CRP)and interleukin-1β(IL-1β)levels and immune function indexes of the two groups were compared,and no difference was seen(P>0.05).At 5 days postoperatively,the CRP and IL-1βlevels of the observation group were lower than those of the reference group,and the immune function indicators were higher than those of the reference group(P<0.05).The complication rate of the observation group was lower than that of the reference group(P<0.05).Conclusion:LC can increase the effective rate of cholelithiasis patients,improve their perioperative indexes,reduce the inflammatory response,protect patients’immune function,and ensure higher surgical safety.

Malawi Opens Tourism Doors No visa’s needed for Chinese tourists and others,as Malawi makes visits more convenient

When Malawian President Lazarus Chakwera delivered a State of the Nation Address at the 50th Parliamentary Session and Budget Meeting in February,tourism was top of mind.

Comparative Analysis of the Efficacy of Transabdominal Pre-Peritoneal Vs Open Tension-Free Hernia Repair in Treating Inguinal Hernia

Objective:To investigate and analyze the clinical outcomes of inguinal hernia patients treated with transabdominal pre-peritoneal repair(TAPP)versus open tension-free hernia repair.Methods:The study was carried out from January 2021 to August 2023,and a total of 50 inguinal hernia patients were selected for this study.The patients were randomly divided into a study group(n=25)and a control group(n=25)by the numerical table method.The patients in the control group were treated with open tension-free hernia repair,whereas the patients in the study group were treated with TAPP.The surgical and postoperative recovery indexes,complication rates,and recurrence rates of the two groups were compared.Results:There was no significant difference in the operative time and intraoperative blood loss between the two groups(P>0.05),and the postoperative feeding time,time out of bed,and hospitalization time of the study group were shorter than those of the control group(P<0.05);the incidence rate of postoperative complications in the study group was lower than that in the control group(P<0.05);and there was no significant difference in the recurrence rate of the two groups after operation(P>0.05).Conclusion:Compared to open tension-free hernia repair,TAPP offers a shorter postoperative recovery duration and hospitalization time,and reduces the incidence of complications.Therefore,this surgical method should be popularized in the treatment of inguinal hernia.

Theory of Flexural Shear, Bending and Torsion for a Thin-Walled Beam of Open Section

Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under transverse shear and axial torsional loading are each considered theoretically. These analyses involve the location of the shear centre at which transverse shear forces when applied do not produce torsion. This centre, when taken to be coincident with the centre of twist implies an equivalent reciprocal behaviour. That is, an axial torsion applied concentric with the shear centre will twist but not bend the beam. The respective bending and shear stress conversions are derived for each action applied to three aluminium alloy extruded channel sections mounted as cantilevers with a horizontal principal axis of symmetry. Bending and shear are considered more generally for other thin-walled sections when the transverse loading axes at the shear centre are not parallel to the section = s centroidal axes of principal second moments of area. The fixing at one end of the cantilever modifies the St Venant free angular twist and the free warping displacement. It is shown from the Wagner-Kappus torsion theory how the end constrained warping generates an axial stress distribution that varies with the length and across the cross-section for an axial torsion applied to the shear centre. It should be mentioned here for wider applications and validation of the Vlasov theory that attendant papers are to consider in detail bending and torsional loadings applied to other axes through each of the centroid and the web centre. Therein, both bending and twisting arise from transverse shear and axial torsion applied to each position being displaced from the shear centre. Here, the influence of the axis position upon the net axial and shear stress distributions is to be established. That is, the net axial stress from axial torsional loading is identified with the sum of axial stress due to bending and axial stress arising from constrained warping displacements at the fixing. The net shear stress distribution overlays the distributions from axial torsion and that from flexural shear under transverse loading. Both arise when transverse forces are displaced from the shear centre.

Understanding the correlation between energy-state mismatching and open-circuit voltage loss in bulk heterojunction solar cells

Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires energy-state matching between the donor and acceptor at the BHJ interfaces.Thus,both geometrically and energetically accessible delocalized state matching at the hot energy level is crucial for achieving efficient PICT.In this study,an effective method for quantifying the hot state matching of OPVs was developed.The degree of energy-state matching between the electron donor and acceptor at BHJ interfaces was quantified using a mismatching factor(MF)calculated from the modified optical density of the BHJ.Furthermore,the correlation between the open-circuit voltage(Voc)of the OPV device and energy-state matching at the BHJ interface was investigated using the calculated MF.The OPVs with small absolute MF values exhibited high Voc values.This result clearly indicates that the energy-state matching between the donor and acceptor is crucial for achieving a high Voc in OPVs.Because the MF indicates the degree of energy-state matching,which is a critical factor for suppressing energy loss,it can be used to estimate the Voc loss in OPVs.

Open-Source Software Defined Networking Controllers:State-of-the-Art,Challenges and Solutions for Future Network Providers

Software Defined Networking(SDN)is programmable by separation of forwarding control through the centralization of the controller.The controller plays the role of the‘brain’that dictates the intelligent part of SDN technology.Various versions of SDN controllers exist as a response to the diverse demands and functions expected of them.There are several SDN controllers available in the open market besides a large number of commercial controllers;some are developed tomeet carrier-grade service levels and one of the recent trends in open-source SDN controllers is the Open Network Operating System(ONOS).This paper presents a comparative study between open source SDN controllers,which are known as Network Controller Platform(NOX),Python-based Network Controller(POX),component-based SDN framework(Ryu),Java-based OpenFlow controller(Floodlight),OpenDayLight(ODL)and ONOS.The discussion is further extended into ONOS architecture,as well as,the evolution of ONOS controllers.This article will review use cases based on ONOS controllers in several application deployments.Moreover,the opportunities and challenges of open source SDN controllers will be discussed,exploring carriergrade ONOS for future real-world deployments,ONOS unique features and identifying the suitable choice of SDN controller for service providers.In addition,we attempt to provide answers to several critical questions relating to the implications of the open-source nature of SDN controllers regarding vendor lock-in,interoperability,and standards compliance,Similarly,real-world use cases of organizations using open-source SDN are highlighted and how the open-source community contributes to the development of SDN controllers.Furthermore,challenges faced by open-source projects,and considerations when choosing an open-source SDN controller are underscored.Then the role of Artificial Intelligence(AI)and Machine Learning(ML)in the evolution of open-source SDN controllers in light of recent research is indicated.In addition,the challenges and limitations associated with deploying open-source SDN controllers in production networks,how can they be mitigated,and finally how opensource SDN controllers handle network security and ensure that network configurations and policies are robust and resilient are presented.Potential opportunities and challenges for future Open SDN deployment are outlined to conclude the article.

Indications of pro-inflammatory cytokines in laparoscopic and open liver resection for early-stage hepatocellular carcinoma

Background:Our clinical practice of laparoscopic liver resection(LLR)had achieved better short-term and long-term benefits for patients with hepatocellular carcinoma(HCC)over open liver resection(OLR),but the underlying mechanisms are not clear.This study was to find out whether systemic inflammation plays an important role.Methods:A total of 103 patients with early-stage HCC under liver resection were enrolled(LLR group,n=53;OLR group,n=50).The expression of 9 inflammatory cytokines in patients at preoperation,postoperative day 1(POD1)and POD7 was quantified by Luminex Multiplex assay.The relationships of the cytokines and the postoperative outcomes were compared between LLR and OLR.Results:Seven of the circulating cytokines were found to be significantly upregulated on POD1 after LLR or OLR compared to their preoperative levels.Compared to OLR,the POD1 levels of granulocytemacrophage colony-stimulating factor(GM-CSF),interleukin-6(IL-6),IL-8,and monocyte chemoattractant protein-1(MCP-1)in the LLR group were significantly lower.Higher POD1 levels of these cytokines were significantly correlated with longer operative time and higher volume of blood loss during operation.The levels of these cytokines were positively associated with postoperative liver injury,and the length of hospital stay.Importantly,a high level of IL-6 at POD1 was a risk factor for HCC recurrence and poor disease-free survival after liver resection.Conclusions:Significantly lower level of GM-CSF,IL-6,IL-8,and MCP-1 after liver resection represented a milder systemic inflammation which might be an important mechanism to offer better short-term and long-term outcomes in LLR over OLR.

RB-DEM Modeling and Simulation of Non-Persisting Rough Open Joints Based on the IFS-Enhanced Method

When the geological environment of rock masses is disturbed,numerous non-persisting open joints can appear within it.It is crucial to investigate the effect of open joints on the mechanical properties of rock mass.However,it has been challenging to generate realistic open joints in traditional experimental tests and numerical simulations.This paper presents a novel solution to solve the problem.By utilizing the stochastic distribution of joints and an enhanced-fractal interpolation system(IFS)method,rough curves with any orientation can be generated.The Douglas-Peucker algorithm is then applied to simplify these curves by removing unnecessary points while preserving their fundamental shape.Subsequently,open joints are created by connecting points that move to both sides of rough curves based on the aperture distribution.Mesh modeling is performed to construct the final mesh model.Finally,the RB-DEM method is applied to transform the mesh model into a discrete element model containing geometric information about these open joints.Furthermore,this study explores the impacts of rough open joint orientation,aperture,and number on rock fracture mechanics.This method provides a realistic and effective approach for modeling and simulating these non-persisting open joints.

BSEC Method for Unveiling Open Clusters and its Application to Gaia DR3:83 New Clusters

Open clusters(OCs) are common in the Milky Way, but most of them remain undiscovered. There are numerous techniques, including some machine-learning algorithms, available for the exploration of OCs. However, each method has its limitations and therefore, different approaches to discovering OCs hold significant values. We develop a comprehensive approach method to automatically explore the data space and identify potential OC candidates with relatively reliable membership determination. This approach combines the techniques of Hierarchical Density-Based Spatial Clustering of Applications with Noise, Gaussian mixture model, and a novel cluster member identification technique, color excess constraint. The new method exhibits efficiency in detecting OCs while ensuring precise determination of cluster memberships. Because the main feature of this technique is to add an extra constraint(EC) for the members of cluster candidates using the homogeneity of color excess,compared to typical blind search codes, it is called Blind Search-Extra Constraint(BSEC) method. It is successfully applied to the Gaia Data Release 3, and 83 new OCs are found, whose color–magnitude diagrams(CMDs) are fitted well to the isochrones. In addition, this study reports 621 new OC candidates with discernible main sequence or red giant branch. It is shown that BSEC technique can discard some false negatives of previous works, which takes about three percentage of known clusters. It shows that as an EC, the color excess(or twocolor) constraint is useful for removing fake cluster member stars from the clusters that are identified from the positions and proper motions of stars, and getting more precise CMDs, when differential reddening of member stars of a cluster is not large(e.g., ΔE(G_(BP)-G_(RP)) < 0.5 mag). It makes the CMDs of 15% clusters clearer(in particular for the region near turnoff) and therefore is helpful for CMD and stellar population studies. Our result suggests that the color excess constraint is more appropriate for clusters with small differential reddening, such as globular clusters or older OCs, and clusters that the distances of member stars cannot be determined accurately.

Development of a DFN-based probabilistic block theory approach for bench face angle design in open pit mining

In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation difficulties.For this reason,bench face angle,as one of the controlling parameters associated with block instabilities,should be carefully designed for sustainable mining.This study introduces a discrete fracture network(DFN)-based probabilistic block theory approach for the fast design of the bench face angle.A major advantage is the explicit incorporation of discontinuity size and spatial distribution in the procedure of key blocks testing.The proposed approach was applied to a granite mine in China.First,DFN models were generated from a multi-step modeling procedure to simulate the complex structural characteristics of pit slopes.Then,a modified key blocks searching method was applied to the slope faces modeled,and a cumulative probability of failure was obtained for each sector.Finally,a bench face angle was determined commensurate with an acceptable risk level of stability.The simulation results have shown that the number of hazardous traces exposed on the slope face can be significantly reduced when the suggested bench face angle is adopted,indicating an extremely low risk of uncontrolled block instabilities.

Efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy

AIM:To evaluate the efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy(MAT).METHODS:Totally 10 eyes of 10 patients with primary open angle glaucoma(POAG)who underwent MAT facilitated by Usights UC100(5 eyes)or iTrack(5 eyes)were reviewed.The success of this surgery was defined as intraocular pressure(IOP)<22 mm Hg with>30%reduction,without oral glaucoma medications,or additional glaucoma surgery.RESULTS:The mean pre-operative IOP was 25.38±10.22 mm Hg in the Usights UC100 group and 19.98±3.87 mm Hg in the iTrack group.MAT was achieved in all eyes in both groups.The success rates for the Usights UC100 group and iTrack groups were in all and 4 eyes,respectively.Both microcatheters produced a statistically significant reduction in IOP,and eyes using Usights UC100 achieved a lower IOP than the iTrack group at 3mo followup(12.58±1.52 and 14.84±1.89 mm Hg,respectively),but no statistical significance was there.No severe side effects were observed in either group.CONCLUSION:MAT using Usights UC100 or iTrack both achieve significant pressure reduction in cases of POAG,and Usights UC100 is as safe as iTrack.

The effects of amino groups and open metal sites of MOFs on polymer-based electrolytes for all-solid-state lithium metal batteries

Metal-organic frameworks(MOFs) are becoming more and more popular as the fillers in polymer electrolytes in recent years. In this study, a series of MOFs(NH_(2)-MIL-101(Fe), MIL-101(Fe), activated NH_(2)-MIL-101(Fe) and activated MIL-101(Fe)) were synthesized and added to PEO-based solid composite electrolytes(SCEs). Furthermore, the role of the —NH_(2) groups and open metal sites(OMSs) were both examined. Different ratios of MOFs vs polymers were also studied by the electrochemical characterizations. At last, we successfully designed a novel solid composite electrolyte containing activated NH_(2)-MIL-101(Fe),PEO, Li TFSI and PVDF for the high-performance all-solid-state lithium-metal batteries. This work might provide new insight to understand the interactions between polymers and functional groups or OMSs of MOFs better.

Variable Stars in the 50BiN Open Cluster Survey.Ⅲ.NGC 884

Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC 884.The target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally bound.From the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were obtained.We detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown types.Two new variable stars were discovered in this work.We also compared the variable star content of NGC 884 with its companion NGC 869.

Impact of open hepatectomy on postoperative bile leakage in patients with biliary tract cancer

BACKGROUND Bile leakage is a common and serious complication of open hepatectomy for the treatment of biliary tract cancer.AIM To evaluate the incidence,risk factors,and management of bile leakage after open hepatectomy in patients with biliary tract cancer.METHODS We retrospectively analyzed 120 patients who underwent open hepatectomy for biliary tract cancer from February 2018 to February 2023.Bile leak was defined as bile drainage from the surgical site or drain or the presence of a biloma on imaging.The incidence,severity,timing,location,and treatment of the bile leaks were recorded.The risk factors for bile leakage were analyzed using univariate and multivariate logistic regression analyses.RESULTS The incidence of bile leak was 16.7%(20/120),and most cases were grade A(75%,15/20)according to the International Study Group of Liver Surgery classification.The median time of onset was 5 d(range,1-14 d),and the median duration was 7 d(range,2-28 d).The most common location of bile leakage was the cut surface of the liver(70%,14/20),followed by the anastomosis site(25%,5/20)and the cystic duct stump(5%,1/20).Most bile leaks were treated conservatively with drainage,antibiotics,and nutritional support(85%,17/20),whereas some required endoscopic retrograde cholangiopancreatography with stenting(10%,2/20)or percutaneous transhepatic cholangiography with drainage(5%,1/20).Risk factors for bile leakage include male sex,hepatocellular carcinoma,major hepatectomy,blood loss,and blood transfusion.CONCLUSION Bile leakage is a frequent complication of open hepatectomy for biliary tract cancer.However,most cases are mild and can be conservatively managed.Male sex,hepatocellular carcinoma,major hepatectomy,blood loss,and blood transfusion were associated with an increased risk of bile leak.