Numerical Solution for the Helmholtz Equation with Mixed Boundary Condition

We consider the numerical solution for the Helmholtz equation in R^2 with mixed boundary conditions.The solvability of this mixed boundary value problem is estab- lished by the boundary integral equation method.Based on the Green formula,we express the solution in terms of the boundary data.The key to the numerical real- ization of this method is the computation of weakly singular integrals.Numerical performances show the validity and feasibility of our method.The numerical schemes proposed in this paper have been applied in the realization of probe method for inverse scattering problems.

Organic-inorganic hybrid hole transport layers with SnS doping boost the performance of perovskite solar cells

Perovskite solar cells(PSCs) have demonstrated excellent photovoltaic performance which currently rival the long-standing silicon solar cells’ efficiency. However, the relatively poor device operational stability of PSCs still limits their future commercialization. Binary sulfide is a category of materials with promising optoelectrical properties, which shows the potential to improve both the efficiency and stability of PSCs.Here we demonstrate that the inorganic tin monosulfide(Sn S) can be an efficient dopant in 2,2’,7,7’-tet rakis(N,N-di-p-methoxy-phenylamine)-9,9’-spirobifluorene(spiro-OMe TAD) to form a composite hole transport layer(HTL) for PSCs. Sn S nanoparticles(NPs) synthesized through a simple chemical precipitation method exhibit good crystallization and suitable band matching with the perovskites. The introduction of Sn S NPs in Spiro-OMTAD HTLs enhanced charge extraction, reduced trap state density, and shallowed trap state energy level of the devices based on the composite HTLs. Therefore, the resulting solar cells employing Sn S-doped spiro-OMe TAD HTLs delivered an improved stabilized power output efficiency of 21.75% as well as enhanced long-term stability and operational stability. Our results provide a simple method to modify the conventional spiro-OMe TAD and obtain PSCs with both high efficiency and good stability.

家庭医生团队结合分级诊疗在社区糖尿病足危险人群中的应用效果

目的探讨家庭医生团队结合分级诊疗在社区糖尿病足危险人群中的应用效果。方法采用方便取样的方法,选取2017年1月-2019年1月东莞松山湖高新技术产业开发区社区卫生服务中心和东莞市东城社区卫生服务中心两个中心的糖尿病患者100例为研究对象,为社区居民构建完善的健康管理档案,实施家庭医生团队健康管理及指导,并在家庭医生团队中加强社区护士护理干预,观察患者足溃疡的发生情况、足部风险分级情况、下肢动脉血供及足部自我护理能力。结果干预后,有8例患者发生糖尿病足1级溃疡,糖尿病足的危险因素评分比干预前降低,差异具有统计学意义(P<0.05);下肢动脉踝肱指数得分高于干预前,同时,干预后患者的糖尿病足自我护理能力得分为(55.4±7.5)分,高于干预前,差异具有统计学意义(P<0.05)。结论家庭医生团队结合分级诊疗的实施有助于缓解糖尿病足危险因素,改善周围血管病变,同时提高患者的足部自我护理能力及生活质量。

Unveiling the key factor affecting the illumination deterioration and response measures for lead halide perovskite solar cells

So far,it's been widely acknowledged that the Pb I2decomposition under illumination mainly accounts for the degradation of perovskite solar cells(PSCs)under maximum power point(MPP)tracking condition.However,PSCs without excess Pb I2were also reported to deteriorate rapidly under the same condition.Here,we demonstrate that the key to enhance PSCs stability under MPP tracking condition is not to have fascinating surface morphology with effective suppression of nonradiative recombination traps but to prevent the migration of iodine ion(I-)under light illumination.By partially substituting methylammonium chloride(MACl)with methylammonium iodide(MAI)and simutaneouly introducing I2during the sequential deposition,the iodine vacancies in perovskite films are substantially suppressed,thereby limiting the pathways for I^(-)migration.As a consequence,PSCs with efficiency of 24.28%are fabricated with remarkably enhanced working stability.

建设新西康:民国时期刘文辉治康方略述论

刘文辉的治康方略包含建省、经边、对藏三个层面。争取生存权是建设新西康的根本动机和出发点,发展经济、加强民族联系、促进边民教育、健全基层组织、培训干部、澄清吏治、加强西康与中央及四川的联系等是建设新西康的主要内容。在经边方面,刘文辉采取“三化政策”和“因教制宜”原则。政治吸引、宗教联系、经济运用、军事戍防则是刘文辉对藏工作的主要策略。这些治康方略的推行,稳定了刘文辉在康区的统治,促进了康区经济社会发展和康、藏关系改善,对于维护国家统一、巩固西南边防起到了重要作用。

戈壁风沙运动及其对下垫面砾石盖度影响的风洞模拟

通过风沙环境风洞模拟测定不同风速、不同砾石盖度下戈壁近地表风沙流输沙量、风沙流结构和粒度特征,分析床面砾石盖度在不同风速下的变化规律,揭示戈壁地表风沙运动及其对下垫面砾石盖度变化影响。结果表明:(1)将床面砾石盖度以12%为界分为低、高盖度,低砾石盖度高风速下(18~24m·s^(-1))戈壁地表输沙量随风速变化明显,输沙量曲线出现拐点,呈“象鼻效应”,随风速增加拐点上移,砾石盖度越小输沙廓线曲率越大,相较于高风速,低风速下(6~18 m·s^(-1))戈壁地表输沙量大小变化不明显,说明低砾石盖度下输沙量变化主要受风速调控,高砾石盖度对风沙流有抑制作用。(2)随床面砾石盖度增加,输沙粒度频率分布曲线有下移趋势,砾石盖度对输沙颗粒频率分布规律影响较小,均表现为单峰分布,只对曲线峰值粒径所占质量百分含量有所影响,说明风速一定时,风沙流中输沙颗粒粒度分布受砾石盖度影响较小。(3)在风沙运动过程中,随作用风速增大,戈壁床面砾石盖度呈线性增加,且二者呈线性强相关,高风速下不同盖度变化量大于低风速下盖度变化量。

库布齐沙漠地表沉积物常量元素与粒度的关系

地表沉积物的风化过程引起元素在各粒级间的迁移或富集,采用粒度分级可以深度解释元素与粒度的关系。选取库布齐沙漠不同植被盖度测定粒度分布特征分级情况下的元素含量。结果表明:(1)库布齐沙漠以细砂和极细砂为主(二者占比85%以上),常量元素以SiO_(2)、Al_(2)O_(3)为主(二者占比80%以上且呈相反关系),其他元素含量较低;不同粒级组分元素富集情况不同。(2)表层沉积物的化学蚀变指标CPA(60.2~85.9)、CIA(28.08~53.06)值显示该区域处于未风化或弱风化状态;研究区表现为富SiO_(2)、CaO、Fe_(2)O_(3)、K_(2)O、TiO_(2)贫Al_(2)O_(3)、Na2O现象;SiO_(2)、K_(2)O与粒径段呈显著正相关,Fe_(2)O_(3)、CaO、Al_(2)O_(3)、MgO、TiO_(2)与粒径段呈显著负相关,Na2O不受粒度控制。(3)分级前,CaO、SiO_(2)、MgO、TiO_(2)与粒径有相关性;分级后,SiO_(2)、K_(2)O、Fe_(2)O_(3)、CaO、Al_(2)O_(3)、MgO、TiO_(2)均与粒径段具有一定的相关性,细化分级后确实能解读更多蕴含在元素中的信息。

Risk-averse Market Clearing for Coupled Electricity, Natural Gas and District Heating System

Multiple energy carriers can be coupled as an Integrated Energy System (IES) through interconnection tech- nologies. Unexpected risks will be transferred with the growing coupling of energy systems, mainly stemming from the uncertain- ties in different energy sectors. It is imperative to coordinate the operation of different energy systems to improve energy efficiency and ensure energy security. With the close integration of different energy systems, it is necessary to couple these different energy markets to achieve the holistic energy supply economy. On the other hand, uncertainties in the energy systems will bring the financial risk for the operator of IES. A risk-averse stochastic market clearing model for the IES is proposed to study the operating strategy aiming at minimizing the operation cost. While the financial risk imposed by the wind power uncertainties is restricted to a predefined level. Simulations results are provided to verify that the proposed model can improve market efficiency and handle the trade-off between cost and risk.

Comparing Competition Equilibrium with Nash Equilibrium in Electric Power Market

The Nash equilibrium and competition equilibrium have been widely studied in the electric power market up to now.In this paper,it is explained that the Nash equilibrium can be achieved by using marginal cost pricing and the com-petition equilibrium can be performed by using accounting cost pricing based on the model of the power market system.The comparison between the Nash equilibrium and competition equilibrium indicates that surplus and unfair allocation of market benefits may be obtained by the Nash equilibrium,and the competition equilibrium realizes the optimization in economics with maximum market efficiency and fairness for market benefit allocations while the optimization in mathematics is achieved by the Nash equilibrium.There is sameness between the Nash equilibrium and competition equilibrium at the point when the power network characteristics are disregarded.The case study is made on a IEEE 30-bus system,and the calculation results indicate that it is the key issue to perform the competition equilibrium by using accounting cost pricing.

Lipopolysaccharide-induced podocyte injury is regulated by calcineurin/NFAT and TLR4/MyD88/NF-κB signaling pathways through angiopoietin-like protein 4

Podocyte injury is an important cause of proteinuria.Angiopoietin-like protein 4(Angptl4)is a secreted glycoprotein and has a role in proteinuria.However,the exact role of Angptl4 in podocyte injury and its upstream regulators has not been clarified.In this study,we used lipopolysaccharide(LPS)-induced mice and cultured podocytes as podocyte injury models.Our results indicated that LPS increased the expression of podocyte Angptl4 in vivo and in vitro.Furthermore,we showed that Angptl4 overexpression deteriorated LPS-induced podocyte injury by inducing podocyte cytoskeleton rearrangement,reducing the expression of synaptopodin while Angptl4 knockdown alleviated LPS-induced podocyte injury.In addition,we found that inhibitors and siRNA targeting TLR4/MyD88/NF-κB signaling inhibited the upregulation of Angptl4 in LPS-induced podocytes.Moreover,inhibitors and siRNA targeting calcineurin/NFAT signaling also relieved LPS-induced Angptl4 expression and podocyte injury in vivo and in vitro.Taken together,our study has elucidated that both of the TLR4/MyD88/NF-κB and calcineurin/NFAT signaling mediate the upregulation of Angptl4 in LPS-induced podocytes,which has important implications for further understanding the molecular mechanism of LPS-induced podocyte injury.

On the Well-Posedness of Determination of Two Coefficients in a Fractional Integrodifferential Equation

The authors study an inverse problem for a fractional integrodifferential equation, which aims to determine simultaneously two time varying coefficients, a kernel function and a source function, from the additional integral overdetermination condition. By using the fixed point theorem in suitable Sobolev space, the global existence and uniqueness results of this inverse problem are obtained.

Determining the Planning Period of a Distribution Substation Based on Acceptable Errors

The distribution substation planning is faced with numerous uncertainties so that the planning result can only be a“rough outline,”and the problem of determining the planning period arises.On the basis of the assessment of uncertainties in distribution planning,a specific approach to determine the planning period of a distribution substation based on acceptable errors is proposed,indicating that the load forecast error is the key factor to affect the planning period.In order to provide a clearer understanding of this paper’s primary objective,the proposed approach is applied to determining the planning period of a power supply radius optimization(PSRO)model in distribution substation planning.Finally,an example is illustrated which validates the suggested approach of this paper.

Corrigendum to“Lipopolysaccharide-induced podocyte injury is regulated by calcineurin/NFAT and TLR4/MyD88/NF-kB signaling pathways through Angiopoietin-like protein 4”[Genes&Diseases 9(2022)443e455]

The authors regret that some statistical errors were made in“Lipopolysaccharide-induced podocyte injury is regulated by calcineurin/NFAT and TLR4/MyD88/NF-kB signaling pathways through Angiopoietin-like protein 4”(Genes Dis,https://doi.org/10.1016/j.gendis.2020.07.005)at Figure 2G,Figure 3B and F,and Figure 4C and D for Angptl4 expression,Figure 5E for CaN expression.