全固态锂电池正极/电解质界面电阻:从空间电荷层模型到表征及模拟

采用无机固体电解质的全固态锂电池以其高安全性和长寿命等优点,已经成为动力电池领域的重要发展方向之一。随着高室温离子电导率(大于10^(-3)S·cm^(-1))的固体电解质的涌现,锂离子在其中的迁移动力学问题不再是全固态锂电池发展的主要瓶颈。相比之下,正极和固体电解质界面处因空间电荷层等复杂效应导致的高界面电阻成为当前急需解决的难题。本文从(电)化学势及电势的基本概念出发,对描述正极和固体电解质之间化学势差异所导致的空间电荷层的理论模型进行严格推导,以揭示其影响界面电阻的物理本质。接着,本文从实验表征和理论模拟角度出发,综述了当前在观测空间电荷层状态、计算正极/固体电解质界面及其体相锂离子浓度,以及预测界面电阻等方面存在的问题。在此基础上,本文提出了融合空间电荷层模型、数值模拟以及基于实际正极和固体电解质接触处费米能级状态和位置的方法,从而定量评估界面电阻。最后,本文展望了通过优化正极/固体电解质界面来提升全固态锂电池电化学性能的未来发展趋势。通过深入理解界面电阻的物理机制,未来可以采用新的材料设计、界面工程等策略来改善全固态锂电池的性能。这些研究将有助于推动全固态锂电池技术的发展,实现更高效、更安全的能源存储解决方案。

Combining systemic inflammatory response index and albumin fibrinogen ratio to predict early serious complications and prognosis after resectable gastric cancer

BACKGROUND Gastric cancer has a high incidence and fatality rate,and surgery is the preferred course of treatment.Nonetheless,patient survival rates are still low,and the incidence of major postoperative complications cannot be disregarded.The systemic inflammatory response,nutritional level,and coagulation status are key factors affecting the postoperative recovery and prognosis of gastric cancer patients.The systemic inflammatory response index(SIRI)and the albumin fibrinogen ratio(AFR)are two valuable comprehensive indicators of the severity and prognosis of systemic inflammation in various medical conditions.AIM To assess the clinical importance and prognostic significance of the SIRI scores and the AFR on early postoperative outcomes in patients undergoing radical gastric cancer surgery.METHODS We conducted a retrospective analysis of the clinicopathological characteristics and relevant laboratory indices of 568 gastric cancer patients from January 2018 to December 2019.We calculated and compared two indicators of inflammation and then examined the diagnostic ability of combined SIRI and AFR values for serious early postoperative complications.We scored the patients and categorized them into three groups based on their SIRI and AFR levels.COX analysis was used to compare the three groups of patients the prognostic value of various preoperative SIRI-AFR scores for 5-year overall survival(OS)and disease-free survival(DFS).RESULTS SIRI-AFR scores were an independent risk factor for prognosis[OS:P=0.004;hazards ratio(HR)=3.134;DFS:P<0.001;HR=3.543]and had the highest diagnostic power(area under the curve:0.779;95%confidence interval:0.737-0.820)for early serious complications in patients with gastric cancer.The tumor-node-metastasis stage(P=0.001),perioperative transfusion(P=0.044),positive carcinoembryonic antigen(P=0.014)findings,and major postoperative complications(P=0.011)were factors associated with prognosis.CONCLUSION Preoperative SIRI and AFR values were significantly associated with early postoperative survival and the occurrence of severe complications in gastric cancer patients.

Systemic inflammatory response index is a predictor of prognosis in gastric cancer patients: Retrospective cohort and meta-analysis

BACKGROUND The systemic inflammatory response index(SIRI)has been demonstrated to make a significant difference in assessing the prognosis of patients with different solid neoplasms.However,research is needed to ascertain the accuracy and reliability of applying the SIRI to patients who undergo robotic radical gastric cancer sur-gery.AIM To validate the applicability of the SIRI in assessing the survival of gastric cancer patients and evaluate the clinical contribution of preoperative SIRI levels to predicting long-term tumor outcomes in patients,who received robotic radical gastric cancer surgery.METHODS Initially,an exhaustive retrieval was performed in the PubMed,the Cochrane Library,EMBASE,Web of Science,and Scopus databases to identify relevant studies.Subsequently,a meta-analysis was executed on 6 cohort studies iden-tifying the value of the SIRI in assessing the survival of gastric cancer patients.Additionally,the clinical data of 161 patients undergoing robotic radical gastric cancer surgery were retrospectively analyzed to evaluate their clinicopathological characteristics and relevant laboratory indicators.The association between preoperative SIRI levels and 5-year overall survival(OS)and disease-free survival(DFS)was assessed.RESULTS The findings demonstrated an extensive connection between SIRI values and the outcome of patients with gastric cancer.Preoperative SIRI levels were identified as an independent hazard feature for both OS and DFS among those who received robotic surgery for gastric cancer.SIRI levels in gastric cancer patients were observed to be associated with the presence of comorbidities,T-stage,carcinoembryonic antigen levels,the development of early serious postoperative complications,and the rate of lymph node metastasis.CONCLUSION SIRI values are correlated with adverse in the gastric cancer population and have the potential to be utilized in predicting long-term oncological survival in patients who undergo robotic radical gastric cancer surgery.

Micro-power negative pressure wound technique reduces risk of incision infection following loop ileostomy closure

BACKGROUND Prophylactic loop ileostomy is an effective way to reduce the clinical severity of anastomotic leakage following radical resection of rectal cancer.Incisional surgical site infection(SSI)is a common complication after ileostomy closure.AIM To evaluate the efficacy and safety of the micro-power negative pressure wound technique(MPNPWT)in preventing incisional SSI.METHODS This was a prospective,randomized controlled clinical trial conducted at a single center.A total of 101 consecutive patients who underwent ileostomy closure after rectal cancer surgery with a prophylactic ileostomy were enrolled from January 2019 to December 2021.Patients were randomly allocated into an MPNPWT group and a control group.The MPNPWT group underwent intermittent suturing of the surgical incision with 2-0 Prolene and was covered with a micro-power negative pressure dressing.The surgical outcomes were compared between the MPNPWT(n=50)and control(n=51)groups.Risk factors for incisional SSI were identified using logistic regression.RESULTS There were no differences in baseline characteristics between the MPNPWT(n=50)and control groups(n=51).The incisional SSI rate was significantly higher in the control group than in the MPNPWT group(15.7%vs 2.0%,P=0.031).However,MPNPWT did not affect other surgical outcomes,including intra-abdominal complications,operative time,and blood loss.Postoperative hospital stay length and hospitalization costs did not differ significantly between the two groups(P=0.069 and 0.843,respectively).None of the patients experienced adverse effects of MPNPWT,including skin allergy,dermatitis,and pain.MPNPWT also helped heal the infected incision.Our study indicated that MPNPWT was an independent protective factor[odds ratio(OR)=0.005,P=0.025)]and diabetes was a risk factor(OR=26.575,P=0.029)for incisional SSI.CONCLUSION MPNPWT is an effective and safe way to prevent incisional SSI after loop ileostomy closure.

拉斯维加斯史上最贵的“球”MSG Sphere版“楚门的世界”

MSG Sphere,即拉斯维加斯碗形剧场。这座球状建筑的外观类似一颗夜空中的繁星,由120万颗LED光源构成万象外观,再加上绚丽多彩的色彩和独特的形态,成为了拉斯维加斯最新的标志性建筑。不过,除了华丽的外观,该建筑的内在或许才是真正令人心动的所在。

Effect of Anisotropic Impurity Scattering in D-Wave Superconductors

In d_(x^(2)-y^(2))-wave superconductors,the effect of s-wave point disorder has been extensively studied in literature.We study the anisotropic disorder in the form of V_(kk')^(imp)=V_(if)_(kf)_(k')with f_(k)=cos(2θ)(θthe azimuthal angle of k),as proposed to be caused by apical oxygen vacancies in overdoped La-based cuprate films,under the Born approximation.The disorder self-energy and d-wave pairing affect each other and must be solved simultaneously self-consistently.We find that the self-energy is reduced at low frequencies and thus weakens the pair-breaking effect.This frequency dependence vanishes in the dirty limit for which the disorder is well described by a scattering rateΓ_(k)=Γ_(if)_(k)^(2).One consequence of the disorder effect is that the gap-to-T_c ratio 2Δ(0)/T_(c) is greatly enhanced by the d-wave disorder,much larger than the s-wave disorder and the clean BCS value 4.28.Lastly,we generalize the d-wave scattering rate to a general formΓ_(θ)=Γ_α|θ-θ_(0)|^(α) around each nodal direction θ_(0).We find the density of statesρ(ω)-ρ(0)∝|ω|(ω^(2)) for allα≥1(α<1)in the limit ofω→0.As a result,the superfluid densityρ_(s) exhibits two and only two possible scaling behaviors:ρ_(s)(0)-ρ_(s)(T)∝T(T^(2))forα≥1(α<1)in the low temperature limit.

塑料齿轮及其成型制造技术进展

以传递运动和动力为主要功能的齿轮在机械装备中具有举足轻重的作用。与金属齿轮相比,塑料齿轮具有质量轻、运行噪音小、耐磨性好、自润滑性能好、耐腐蚀等诸多优点,而且具有易成型、制造成本低、设计灵活等特点。与传统金属齿轮的成型制造方法相比,塑料齿轮因塑料原料种类及性能差别较大,成型制造方法也有很大差异。通过查阅塑料齿轮相关文献资料,总结了不同塑料齿轮的特点、性能及应用,分析了注塑成型、3D打印和机加工成型等塑料齿轮的主要制造方法。

Staging laparoscopy improves treatment decision-makingfor advanced gastric cancer

AIM To evaluate the clinical value of staging laparoscopyin treatment decision-making for advancedgastric cancer （GC）.METHODS： Clinical data of 582 patients with advancedGC were retrospectively analyzed. All patientsunderwent staging laparoscopy. The strength ofagreement between computed tomography （CT） stage,endoscopic ultrasound （EUS） stage, laparoscopic stage,and final stage were determined by weighted Kappastatistic （Kw）. The number of patients with treatmentdecision-changes was counted. A χ 2 test was used toanalyze the correlation between peritoneal metastasisor positive cytology and clinical characteristics.RESULTS： Among the 582 patients, the distributions ofpathological T classifications were T2/3 （153, 26.3%）,T4a （262, 45.0%）, and T4b （167, 28.7%）. Treatmentplans for 211 （36.3%） patients were changed after staging laparoscopy was performed. Two （10.5%） of19 patients in M1 regained the opportunity for potentialradical resection by staging laparoscopy. Unnecessarylaparotomy was avoided in 71 （12.2%） patients. Thestrength of agreement between preoperative T stageand final T stage was in almost perfect agreement （Kw= 0.838; 95% confidence interval （CI）： 0.803-0.872;P 〈 0.05） for staging laparoscopy; compared with CTand EUS, which was in fair agreement. The strengthof agreement between preoperative M stage andfinal M stage was in almost perfect agreement （Kw= 0.990; 95% CI： 0.977-1.000; P 〈 0.05） for staginglaparoscopy; compared with CT, which was in slightagreement. Multivariate analysis revealed that tumorsize （≥ 40 mm）, depth of tumor invasion （T4b）, andBorrmann type （Ⅲ or Ⅳ） were significantly correlatedwith either peritoneal metastasis or positive cytology.The best performance in diagnosing P-positive wasobtained when two or three risk factors existed.CONCLUSION： Staging laparoscopy can improvetreatment decision-making for advanced GC anddecrease unnecessary exploratory laparotomy.

Understanding the Li diffusion mechanism and positive effect of current collector volume expansion in anode free batteries

In anode free batteries(AFBs), the current collector acts as anode simultaneously and has large volume expansion which is generally considered as a negative effect decreasing the structural stability of a battery. Moreover, despite many studies on the fast lithium diffusion in the current collector materials of AFB such as copper and aluminum, the involved Li diffusion mechanism in these materials remains poorly understood. Through first-principles calculation and stress-assisted diffusion equations, here we study the Li diffusion mechanism in several current collectors and related alloys and clarify the effect of volume expansion on Li diffusion respectively. It is suggested that due to the lower Li migration barriers in aluminum and tin, they should be more suitable to be used as AFB anodes, compared to copper, silver, and lead. The Li diffusion facilitation in copper with a certain number of vacancies is proposed to explain why the use of copper with a thickness≤100 nm as the protective coating on the anode improves the lifetime of the batteries. We show that the volume expansion has a positive effect on Li diffusion via mechanical–electrochemical coupling. Namely, the volume expansion caused by Li diffusion will further induce stress which in turn affects the diffusion. These findings not only provide in-depth insight into the operating principle of AFBs, but also open a new route toward design of improved anode through utilizing the positive effect of mechanical–electrochemical coupling.

Strongly coupled Te-SnS_(2)/MXene superstructure with self-autoadjustable function for fast and stable potassium ion storage

Potassium-ion batteries(PIBs)are a promising candidate for next-generation electric energy storage applications because of the abundance and low cost of potassium.However,the development of PIBs is limited by sluggish kinetics and huge volume expansion of anodes,leading to poor rate capability and cycling stability.Herein,an advanced superstructure anode,including Te-doped SnS_(2) nanosheets uniformly anchored on MXene surface(Te-SnS_(2)/MXene),is rationally designed for the first time to boost K^(+)storage performance.Featuring with strong interface interaction and self-autoadjustable interlayer spacings,the Te-SnS_(2)/MXene can efficiently accelerate electron/ion transfer,accommodate volume expansion,inhibit crack formation,and improve pseudocapacitive contribution during cycling.Thus,the novel Te-SnS_(2)/MXene anode delivers a high reversible capacity(343.2 mAh g^(-1) after 50 cycles at0.2 A g^(-1)),outstanding rate capability(186.4 mAh g^(-1) at 20 A g^(-1)),long cycle stability(165.8 mAh g^(-1)after 5000 cycles at 10 A g^(-1) with a low electrode swelling rate of only 15.4%),and reliable operation in flexible full battery.The present Te-SnS_(2)/MXene becomes among the best transition metal-based anode materials for PIBs reported to date.

Generalized Drude model and electromagnetic screening in metals and superconductors

Electromagnetic screening is studied from the perspective of fluid mechanics by generalizing the Drude theory, which unifies three known results： Thomas–Fermi screening of the longitudinal field in both metals and superconductors, the skin effect of the transverse field in metals, and the Meissner effect in superconductors. In the special case of superfluid electrons, we slightly generalize the London equations to incorporate the longitudinal electric fields. Moreover, regarding the experiments, our study points out that the dynamical measurement may overestimate the superfluid density.

Superconductivity,Pair Density Wave,and Neel Order in Cuprates

We investigate in underdoped cuprates possible coexistence of the superconducting order at zero momentum and pair density wave(PDW)at momentum Q=(Л,Л)in the presence of a Neel order.By symmetry,the d-wave uniform singlet pairing dS0 can coexist with the d-wave triplet PDW dTq,and the p-wave singlet PDW pSq can coexist with the p-wave uniform triplet pT0.At half filling,we find that the novel pSq+pT0 state is energetically more favorable than the dS0+dTQ state.At finite doping,however,the dS0+dTq state is more favorable.In both types of states,the variational triplet parameters cITq and pT0 are of secondary significance.Our results point to a fully symmetric Z2 quantum spin liquid with spinon Fermi surface in proximity to the Neel order at zero doping,which may not be adiabatically connected to the d-wave singlet superconductivity at finite doping with intertwining d-wave triplet PDW fluctuations and spin moment fluctuations.The results are obtained by variational quantum Monte Carlo simulations.

A Deep Learning Approach for Detecting Colorectal Cancer via Raman Spectra

Objective and Impact Statement.Distinguishing tumors from normal tissues is vital in the intraoperative diagnosis and pathological examination.In this work,we propose to utilize Raman spectroscopy as a novel modality in surgery to detect colorectal cancer tissues.Introduction.Raman spectra can reflect the substance components of the target tissues.However,the feature peak is slight and hard to detect due to environmental noise.Collecting a high-quality Raman spectroscopy dataset and developing effective deep learning detection methods are possibly viable approaches.Methods.First,we collect a large Raman spectroscopy dataset from 26 colorectal cancer patients with the Raman shift ranging from 385 to 1545 cm^(−1).Second,a one-dimensional residual convolutional neural network(1D-ResNet)architecture is designed to classify the tumor tissues of colorectal cancer.Third,we visualize and interpret the fingerprint peaks found by our deep learning model.Results.Experimental results show that our deep learning method achieves 98.5%accuracy in the detection of colorectal cancer and outperforms traditional methods.Conclusion.Overall,Raman spectra are a novel modality for clinical detection of colorectal cancer.Our proposed ensemble 1D-ResNet could effectively classify the Raman spectra obtained from colorectal tumor tissues or normal tissues.

Regulating ion transport behaviors toward dendrite-free potassium metal batteries:recent advances and perspectives

With abundant potassium resources and high capacity,potassium metal batteries(PMBs)present a compelling option for the next generation of energy storage technology.However,PMBs suffer from an unstable anode interface caused by uncontrolled dendrite growth,which results in unsatisfactory cyclability and safety concerns.Extensive investigations suggest that significant progress has been made in enhancing the interfacial stability of PMBs.The various effective strategies for stabilizing interfaces can ultimately be attributed to the regulation of the sluggish ion transfer kinetics and irregular deposition,i.e.,the arrangement of ion transport behaviors at the interface.Rational modulation of ions transport rate and ions deposition directions makes it possible to obtain a dendrite-free and smooth deposition plane.Herein,the influencing factors and action mechanism of K^(+)interface transport behaviors are discussed to understand the nature of material design for constructing stable anode interfaces,including regulating the solvation and desolvation structures,accelerating K^(+)transport kinetics and controlling K^(+)deposition direction.In addition,the deficiencies and prospects of the research on electrolyte,separators and designed electrode involved in the manufacturing and testing and ion transport process of PMBs are discussed.This review is expected to provide some possible directions for constructing dendrite-free interfaces in advanced PMBs-related research and offer significant insights for prospective experimental research and commercial applications.

Quantized bound states around a vortex in anisotropic superconductors

The bound states around a vortex in anisotropic superconductors is a longstanding yet important issue.In this work,we develop a variational theory on the basis of the Andreev approximation to obtain the energy levels and wave functions of the low-energy quantized bound states in superconductors with anisotropic pairing on arbitrary Fermi surface.In the case of circular Fermi surface,the effective Schr¨odinger equation yielding the bound state energies gets back to the theory proposed by Volovik and Kopnin many years ago.Our generalization here enables us to prove the equidistant energy spectrum inside a vortex in a broader class of superconductors.More importantly,we are now able to obtain the wave functions of these bound states by projecting the quasiclassical wave function on the eigenmodes of the effective Schr¨odinger equation,going beyond the quasiclassical Eilenberger results,which,as we find,are sensitive to the scattering rate.For the case of isotropic Fermi surface,the spatial profile of the low-energy local density of states is dominated near the vortex center and elongates along the gap antinode directions,in addition to the ubiquitous Friedel oscillation arising from the quantum inteference neglected in the Eilenberger theory.Moreover,as a consequence of the pairing anisotropy,the quantized wave functions develop a peculiar distribution of winding number,which reduces stepwise towards the vortex center.Our work provides a flexible way to study the vortex bound states in the future.

An Efficient Network-on-Chip Router for Dataflow Architecture

Dataflow architecture has shown its advantages in many high-performance computing cases. In dataflow computing, a large amount of data are frequently transferred among processing elements through the network-on-chip （NoC）. Thus the router design has a significant impact on the performance of dataflow architecture. Common routers are designed for control-flow multi-core architecture and we find they are not suitable for dataflow architecture. In this work, we analyze and extract the features of data transfers in NoCs of dataflow architecture： multiple destinations, high injection rate, and performance sensitive to delay. Based on the three features, we propose a novel and efficient NoC router for dataflow architecture. The proposed router supports multi-destination; thus it can transfer data with multiple destinations in a single transfer. Moreover, the router adopts output buffer to maximize throughput and adopts non-flit packets to minimize transfer delay. Experimental results show that the proposed router can improve the performance of dataflow architecture by 3.6x over a state-of-the-art router.

A Non-Stop Double Buffering Mechanism for Dataflow Architecture

Double buffering is an effective mechanism to hide the latency of data transfers between on-chip and off-chip memory. However, in dataflow architecture, the swapping of two buffers during the execution of many tiles decreases the performance because of repetitive filling and draining of the dataflow accelerator. In this work, we propose a non-stop double buffering mechanism for dataflow architecture. The proposed non-stop mechanism assigns tiles to the processing element array without stopping the execution of processing elements through optimizing control logic in dataflow architecture. Moreover, we propose a work-flow program to cooperate with the non-stop double buffering mechanism. After optimizations both on control logic and on work-flow program, the filling and draining of the array needs to be done only once across the execution of all tiles belonging to the same dataflow graph. Experimental results show that the proposed double buffering mechanism for dataftow architecture achieves a 16.2% average efficiency improvement over that without the optimization.

A Pipelining Loop Optimization Method for Dataflow Architecture

With the coming of exascale supercomputing era, power efficiency has become the most important obstacle to build an exascale system. Dataflow architecture has native advantage in achieving high power efficiency for scientific applications. However, the state-of-the-art dataflow architectures fail to exploit high parallelism for loop processing. To address this issue, we propose a pipelining loop optimization method （PLO）, which makes iterations in loops flow in the processing element （PE） array of dataflow accelerator. This method consists of two techniques, architecture-assisted hardware iteration and instruction-assisted software iteration. In hardware iteration execution model, an on-chip loop controller is designed to generate loop indexes, reducing the complexity of computing kernel and laying a good f（mndation for pipelining execution. In software iteration execution model, additional loop instructions are presented to solve the iteration dependency problem. Via these two techniques, the average number of instructions ready to execute per cycle is increased to keep floating-point unit busy. Simulation results show that our proposed method outperforms static and dynamic loop execution model in floating-point efficiency by 2.45x and 1.1x on average, respectively, while the hardware cost of these two techniques is acceptable.

Accelerating Data Transfer in Dataflow Architectures Through a Look-Ahead Acknowledgment Mechanism

The dataflow architecture,which is characterized by a lack of a redundant unified control logic,has been shown to have an advantage over the control-flow architecture as it improves the computational performance and power efficiency,especially of applications used in high-performance computing(HPC).Importantly,the high computational efficiency of systems using the dataflow architecture is achieved by allowing program kernels to be activated in a simultaneous manner.Therefore,a proper acknowledgment mechanism is required to distinguish the data that logically belongs to different contexts.Possible solutions include the tagged-token matching mechanism in which the data is sent before acknowledgments are received but retried after rejection,or a handshake mechanism in which the data is only sent after acknowledgments are received.However,these mechanisms are characterized by both inefficient data transfer and increased area cost.Good performance of the dataflow architecture depends on the efficiency of data transfer.In order to optimize the efficiency of data transfer in existing dataflow architectures with a minimal increase in area and power cost,we propose a Look-Ahead Acknowledgment(LAA)mechanism.LAA accelerates the execution flow by speculatively acknowledging ahead without penalties.Our simulation analysis based on a handshake mechanism shows that our LAA increases the average utilization of computational units by 23.9%,with a reduction in the average execution time by 17.4%and an increase in the average power efficiency of dataflow processors by 22.4%.Crucially,our novel approach results in a relatively small increase in the area and power consumption of the on-chip logic of less than 0.9%.In conclusion,the evaluation results suggest that Look-Ahead Acknowledgment is an effective improvement for data transfer in existing dataflow architectures.

0D/3D direct Z-scheme heterojunctions hybridizing by MoS2 quantum dots and honeycomb conjugated triazine polymers (CTPs) for enhanced photocatalytic performance

Herein,a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS2 quantum dots(MSQDs)and 3D honeycomb-like conjugated triazine polymers(CTP)(namely,CTP-MSQD).The unique 0D/3D hierarchical structure significantly enhanced the exposure of active sites and light harvesting property,while the formed p-n junction enabled the direct strong interface coupling without the necessity of any mediators.The optimized CTP-MSQD3 exhibited continuously increased visible-light-driven photocatalytic activity and strong durability both in Cr(VI)reduction and H2 evolution,featured a rate of 0.069 min^(-1) and 1070μmol/(hr•g),respectively,which were 8 times than those of pure 3D-CTP(0.009 min^(−1) and 129μmol/(hr•g)).We believe that this work provides a promising photocatalyst system that combines a 0D/3D hierarchical structure and a Z-scheme charge flow for efficient and stable photocatalytic conversion.