绩效反馈如何影响政府绩效?--问责压力的调节作用

从绩效反馈角度探究绩效提升是绩效管理研究的一项新兴命题,而构建绩效差距对基层政府绩效的完整影响机制是亟待探索的问题。绩效反馈理论认为绩效差距影响绩效水平,而该研究试图探究上级问责压力在这个过程中发挥的调节作用。基于北京市“接诉即办”的政策背景,该研究收集了2019年16个区333个街乡镇分数和排名等数据,实证检验市、区两级问责压力对绩效差距的调节作用。研究发现,上级问责压力会调节绩效差距对绩效水平的作用,且市、区两级问责压力的调节效应不同。区级问责压力调节社会绩效差距对绩效水平的影响,增强正向绩效差距的正向影响,减弱负向绩效差距的负向影响。市级问责压力对正向历史绩效差距的影响产生正向调节作用。上述研究结果深化了对绩效差距影响绩效水平的机制的理解,为加强政府绩效管理与提高基层治理绩效提供了政策建议。

Amending Research on the Expression of the Contact Force of the Spindle Barrel Finishing Based on EDEM Simulation

The spindle barrel finishing is commonly used to improve the surface integrity of the important parts of the high-end equipment while it is difficult to provide enough test artifacts for the traditional trial and error experiment to obtain the desirable processing technology.The EDEM simulation of the spindle barrel finishing can provide effective help for the process design,however,the difference between the simulation and experiment is closely related to the selection of the contact model during simulation.In this paper,simulations and experiments are conducted based on the identical apparatus and conditions to facilitate the comparison and validation between each other.Based on the Hertz contact theory,the effect of the material properties of contact objects and the relative position of the workpiece on the contact force is qualified.The expression of the correlation coefficient of the contact model is deduced.Then the formula for calculating the contact force between the barrel finishing abrasive and the workpiece that includes influence coefficient of the material properties and the relative positions is established.Finally,the contact force calculation formula is verified by changing the rotating speed.The result shows that the material correction coefficient ranges from 1.41 to 2.38,which is inversely related to the equivalent modulus E.The position correction coefficient ranges from 2.0 to 2.3.The relative error value between the calculation result and the experimental test result is from 0.58%to 14.07%.This research lay a theoretical foundation for the correction theory of the core elements of the spindle barrel finishing process.

Electronic structure and spatial inhomogeneity of iron-based superconductor FeS

Iron-based superconductor family FeX(X=S,Se,Te)has been one of the research foci in physics and material science due to their record-breaking superconducting temperature(FeSe film)and rich physical phenomena.Recently,FeS,the least studied Fe X compound(due to the difficulty in synthesizing high quality macroscopic crystals)attracted much attention because of its puzzling superconducting pairing symmetry.In this work,combining scanning tunneling microscopy and angle resolved photoemission spectroscopy(ARPES)with sub-micron spatial resolution,we investigate the intrinsic electronic structures of superconducting FeS from individual single crystalline domains.Unlike FeTe or FeSe,FeS remains identical tetragonal structure from room temperature down to 5 K,and the band structures observed can be well reproduced by our ab-initio calculations.Remarkably,mixed with the 1×1 tetragonal metallic phase,we also observe the coexistence of √5×√5 reconstructed insulating phase in the crystal,which not only helps explain the unusual properties of FeS,but also demonstrates the importance of using spatially resolved experimental tools in the study of this compound.

The prospects for bioprinting tumor models:recent advances in their applications

Three-dimensional(3D)tumor models prepared from patient-derived cells have been reported to imitate some of the biological development processes of in situ tumors in vitro.These 3D tumor models share several important characteristics with their in vivo tumor counterparts.Accordingly,their applications in tumor modeling,drug screening,and precision-targeted treatment are promising.However,the establishment of tumormodels is subject to several challenges,including advancements in scale size,repeatability,structural precision in time and space,vascularization,and the tumor microenvironment.Recently,bioprinting technologies enabling the editorial arrangement of cells,factors,and materials have improved the simulation of tumormodels in vitro.Among the 3D bioprinted tumor models,the organoidmodel has been widely appreciated for its advantages of maintaining high heterogeneity and capacity for simulating the developmental process of tumor tissues.In this review,we outline approaches and potential prospects for tumor model bioprinting and discuss the existing bioprinting technologies and bioinks in tumor model construction.The multidisciplinary combination of tumor pathology,molecular biology,material science,and additive manufacturing will help overcome the barriers to tumor model construction by allowing consideration of the structural and functional characteristics of in vitro models and promoting the development of heterogeneous tumor precision therapies.

Earthquake early warning system in Liaoning,China based on PRESTo

Liaoning is located in northeast China with a high level of seismic activity,and earthquake early warning is important for the mitigation of seismic hazard.In this work,we implement PRESTo,an open-source software platform for earthquake early warning based on regional seismic records,to the Liaoning seismic network.For the early warning of earthquakes in Liaoning,a travel-time table is created for event detection and location using an average crustal model,and the empirical relation is established between the earthquake magnitude and the initial P-wave amplitudes.Using archived seismic records of past earthquakes,we determine the optimal values for Liaoning using the core algorithms of PRESTo.Based on the optimal parameters,the uncertainty in event location is generally less than 5 km,and the lead time of the early warning is~15 s at 100-km epicentral distance.The implemented system can be directly put into routine earthquake early warning operation by linking it with the real-time data stream from the Liaoning seismic network.

LiCoO_(2) sintering aid towards cathode-interface-enhanced garnet electrolytes

Garnet-type Li_7La_(3)Zr_(2)O_(12)(LLZO) has high ionic conductivity and good compatibility with lithium metal.High-temperature processing has been proven an effective method to decrease the interface resistance of cathodeILLZO.However,its application is still hindered by the interlayer co-diffusion with the cathode and high sintering temperature(>1200℃).In this work,a new garnet-type composite solid-state electrolyte(SSE) Li_(6.54)La_(2.96)Ba_(0.04)Zr_(1.5)Nb_(0.5)O_(12)-LiCoO_(2)(LLBZNO-LCO) is firstly proposed to improve the chemical stability and electrochemical properties of garnet with high-temperature processing.Small doses of LCO(3%) can significantly decrease the LCOISSE interface resistance from 121.2 to 10.1 Ω cm~2,while the sintering temperature of garnet-type LLBZNO decreases from 1230 to 1000℃.The all-solid-state battery based on the sintered LLBZNO-LCO SSE exhibits excellent cycling stability.Our approach achieves an enhanced LCOISSE interface and an improved sintering activity of garnet SSE,which provides a new strategy for optimizing the comprehensive performance of garnet SSE.

Therapeutic effect of acupuncture and massage for shoulder-hand syndrome in hemiplegia patients:a clinical two-center randomized controlled trial

OBJECTIVE:To evaluate the therapeutic effects of acupuncture and massage for shoulder-hand syndrome in hemiplegia patients.METHODS:One hundred and twenty hemiplegia patients with stage I shoulder-hand syndrome were randomly divided into a group treated with standardized electric acupuncture and massage,and a group treated with rehabilitation therapy for 6 weeks.The primary indices evaluated were pain on passive movement of the shoulder using the numeric pain rating scale(NPRS),and the number of patients with shoulder-hand syndrome at Steinbrocker stage II or III after treatment.The secondary indices were Fugl-Meyer evaluation of functional movement of the upper limb and hand using the modified rankin scale(MRS).RESULTS:At post-treatment evaluation and a 12-week follow-up visit,NPRS score,number of patients with stage II or III shoulder-hand syndrome,and MRS score were all improved in the acupuncture-massage group compared with the rehabilitation group(P<0.05).On Fugl-Meyer evaluation,functional movement of the upper limb was also improved in the acupuncture-massage group compared with the rehabilitation group(P<0.05).CONCLUSION:Standardized acupuncture-massage therapy may have curative effects on shoulder-hand syndrome in hemiplegia patients.

Clinical curative effect of electric acupuncture on acute cerebral infarction:a randomized controlled multicenter trial

OBJECTIVE: To examine whether electric acupuncture can improve the daily life of patients with ischemic cerebral apoplexy at acute stage.METHODS: A stratified-block randomized controlled multicenter trial was designed for this study.Totally 340 patients with acute ischemic cerebral apoplexy were randomly divided into an electric acupuncture group and a control group. In the electric acupuncture group, 170 patients were treated with electric acupuncture and routine therapy, and170 patients in the control group with routine therapy alone. Major indexes for judging curative effect were Barthel index at 3- and 6- months follow-up visits and number of re-hospitalized patients. Mi-nor indexes for judging curative effect were change in the score for nervous dysfunction at 4and 12 weeks follow-up visits and number of patients persisting in rehabilitation treatment with acupuncture during follow-up visit.RESULTS: Baseline data at the time of case selection between the two groups were similar. The odds ratio(OR) was 0.92, and the 95% confidence interval(CI) was 0.49-1.73 in disabled rate and 0.73 and 0.51-1.05 in the number of re-hospitalized patients in the electric acupuncture group at 6-month follow up visit compared with the control group.There was no difference in the score for nervous dysfunction at the end of 12-week follow-up visit between the two groups. The score for nervous dysfunction at the end of 4-week treatment in the electric acupuncture group was significantly higher than that in the control group(P<0.05). The number of patients discharged from hospital who persisted in rehabilitation treatment with acupuncture in the acupuncture group was significantly higher than that in the control group.CONCLUSION: Using electric acupuncture to treat patients with acute ischemic cerebral apoplexy can effectively improve the nervous dysfunction scores after 4-week treatment and their ability to deal with daily life after 6-month follow-up visit. Systematic treatment with acupuncture may also reduce the number of patients with secondary apoplexy.

Well-aligned carbon nanotube array membrane synthesized in porous alumina template by chemical vapor deposition

A new simple approach was developed for preparing well-aligned and monodispersed carbon nanotuoe (CNT) array membrane within the cylindrical pores of anodic aluminum oxide (AAO) template by chemical vapor deposition (CVD). Acetylene and hydrogen were used in the CVD process with Fe-catalyzer at 700℃ under 250 Pa. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed to characterize the resulting highly-oriented uniform hollow tube array which had a diameter of about 250 nm, a tube density of 5.3×108cm2 and a length of about 60 μm. The length and diameter of the tubes depend on the thickness and pore diameter of the template. The growth properties of the CNT array film can be achieved by controlling the structure of the template, the particle size of Fe-catalyzer, the temperature in the reactor, the flow ratio and the deposition time. The highly-oriented and uniform CNT array membrane fabricated by this simple method is very much useful in a variety of

Generation of enhanced stability of SnO/In(OH)_(3)/InP for photocatalytic water splitting by SnO protection layer1 Generation of enhanced stability of SnO/In(OH)_(3)/InP for photocatalytic water splitting by SnO protection layer1

InP shows a very high efficiency for solar light to electricity conversion in solar cell and may present an expectation property in photocatalytic hydrogen evolution.However,it suffers serious corrosion in water dispersion.In this paper,it is demonstrated that the stability and activity of the InP-based catalyst are effectively enhanced by applying an anti-corrosion SnO layer and In(OH)_(3)transition layer,which reduces the crystal mismatch between SnO and InP and increases charge transfer.The obtained Pt/SnO/In(OH)_(3)/InP exhibits a hydrogen production rate of 144.42μmol/g in_(3)h under visible light illumination in multi-cycle tests without remarkable decay,12_(3)times higher than that of naked In(OH)_(3)/InP without any electron donor under visible irradiation.

Synthesis of ordered Si nanowire arrays in porous anodic aluminum oxide templates

Highly ordered poly crystalline Si nanowire arrays were synthesized in porous anodic aluminum oxide (AAO) templates by the chemical vapor deposition (CVD) method. The morphological structure, the crystal character of Si nanowire arrays and the individual nanowire were analyzed by the transmission electron microscopy (TEM), scanning electron microscopy (SEM), atom force microscopy (AFM) and the X-ray diffraction spectrum (XRD), respectively. It is shown that most fabricated silicon nanowires (SiNWs) tend to be assembled parallelly in bundles and constructed with highly orientated arrays. This method provides a simple and low cost fabricating craftwork and the diameters and lengths of SiNWs can be controlled, the large area Si nanowire arrays can be achieved easily under such a way. The curling and twisting SiNWs are fewer than those by other synthesis methods.

Modification of wettability of stainless steel by picosecond laser surface microstructuring

We report on the modification of the wettability of stainless steel by picosecond laser surface microstructuring in this paper. Compared with traditional methods, picosecond laser-induced surface modification provides a fast and facile method for surface modification without chemical damage and environmental pollution. As a result of treatment by 100 ps laser pulses, microstructures are fabricated on the stainless steel sample surface, contributing to the increase of the contact angle from 88° to 105°, which realizes a transformation from hydrophilicity to hydrophobicity. The morphological features of fabricated microstructures are characterized by scanning electron microscopy and optical microscopy.

Bio-inspired, bio-degradable adenosine 5′ -diphosphate-modified hyaluronic acid coordinated hydrophobic undecanal-modified chitosan for hemostasis and wound healing

Uncontrolled hemorrhage and wound infection are crucial causes of trauma-associated death in both the military and the clinic. Therefore, developing an efficient and rapid hemostatic method with biocompatibility, easy degradation, and wound healing is of great importance and desirability. Inspired by spontaneous blood cell plug formation in the hemostasis process, an adenosine 5′-diphosphate modified pro-coagulation hyaluronic acid (HA-ADP) coordinated with enhanced antibacterial activity of undecanal-modified chitosan (UCS) was fabricated through physical electrostatic cross-linking and freeze-drying. The as-prepared hydrogel sponges showed a porous structure suitable for blood cell adhesion. In particular, the hydrogel exhibited excellent antibacterial ability and promoted the adhesion of platelets and red blood cells, thus inducing a prominent pro-coagulation ability via platelet activation, which exhibits a shorter hemostasis time (58.94% of control) in vitro. Compared with commercially available CELOX and gelatin sponge (GS), HA-ADP/UCS accelerates hemostasis and reduces blood loss in both rat tail amputation and rat artery injury models. Furthermore, all the samples exhibited su-perior cytocompatibility and biodegradability. Due to these performances, HA-ADP/UCS promoted full-thickness skin defect healing significantly in vivo. All the properties of HA-ADP/UCS suggest that it has great potential for translation as a clinical application material for hemostatic and wound healing.

Electrospun nanofiber/hydrogel composite materials and their tissue engineering applications

Electrospun nanofiber/hydrogel composites combine the excellent biochemical properties of hydrogel with the biomimetic nature of electrospun fibers,and have attracted widespread attention in the last few years.Besides,nanofiber/hydrogel composites with tunable mechanical properties can mimic the microstructure of extracellular matrix(ECM)of various tissues and the microenvironment of different cells.These features enable electrospun fiber/hydrogel composites have uniquely advantageous for tissue repair.However,a comprehensive review of electrospun fiber/hydrogel composites as tissue engineering scaffolds is still lacking.Thus,this article systematically reviewed the preparation of electrospun fiber/hydrogel composites and their application in tissue engineering.First,the preparation strategies of electrospun fiber/hydrogel composites are classified and discussed.Second,the application of electrospun fiber/hydrogel-based scaffolds in tissue engineering,involving skin,blood vessel,nerve,bone and other tissue engineering,are summarized.Finally,future research directions for functional electrospun fiber/hydrogel scaffold materials are proposed.

Facile preparation of silver nanoparticles in bulk silicate glass by high-repetition-rate picosecond laser pulses

One-step precipitation of Ag nanoparticles in Ag+-doped silicate glasses was achieved through a focused picosecond laser with a high repetition rate. Absorption spectra and transmission electron microscopy(TEM) confirmed that metallic Ag nanoparticles were precipitated within glass samples in the laser-written domain. The surface plasmon absorbance fits well with the experimental absorption spectrum. The nonlinear absorption coefficient β is determined to be 2.47 × 10-14 m/W by fitting the open aperture Z-scan curve, which originated from the intraband transition in the s-p Ag band. The formation mechanism of Ag-glass nanocomposites is discussed as well.

Electroactive and antibacterial wound dressings based on Ti_(3)C_(2)T_(x)MXene/poly(ε-caprolactone)/gelatin coaxial electrospun nanofibrous membranes

Endogenous electric fields(EFs)are capable of regulating the behaviors of skin cells in wound healing.However,majority of current dressings are primarily engaged in the passive repair of defective tissue,as they lack the ability to actively respond to physiological electrical signals.In this work,a series of nanofibrous membranes(NFMs)were fabricated by coaxial electrospinning,combining the good mechanical properties of poly(ε-caprolactone)(PCL),the bioactivity of gelatin and the electroactivity of Ti_(3)C_(2)T_(x)MXene,as electroactive and antibacterial dressings for cutaneous wound healing.The obtained NFMs exhibited suitable mechanical properties and hydrophilicity,excellent electroactivity,antibacterial activity,and biocompatibility.Especially,Ti_(3)C_(2)T_(x)MXene/PCL/gelatin-6(MPG-6,6 wt.%of Ti_(3)C_(2)T_(x)MXene in sheath spinning liquids)showed the optimal conductivity and antibacterial activity.Excitingly,this scaffold significantly promoted the adhesion,proliferation,and migration of NIH 3T3 cells under the electrical stimulation(ES).The in vivo evaluation in a full-thickness wounds defect model demonstrated that the MPG-6 films significantly accelerated wound closure,increased granulation tissue formation,increased collagen deposition,and promoted wound vascularization.In summary,the versatile scaffold is expected to be an ideal candidate as wound dressings due to its ability to promote the transmission of physiological electrical signals and thus improved the therapeutic outcomes of wound regeneration.

Flexoelectricity-enhanced photovoltaic effect in trapezoid-shaped NaNbO_(3)nanotube array composites

In this work,we successfully prepared vertically aligned NaNbO_(3)nanotube(NN-NT)with trapezoidal shapes,in which the orthorhombic and monoclinic phases coexisted.According to the structure analysis,the NN-NT/epoxy composite film had excellent flexoelectric properties due to the lattice distortion caused by defects and irregular shape.The flexoelectric effect is the greatest in the vertical direction in the flexible NN-NT/epoxy composite film,and the flexoelectric coefficient()is 2.77×10^(−8)C·m^(−1),which is approximately 5-fold higher than that of the pure epoxy film.The photovoltaic current of the NN-NT/epoxy composite film increased from 39.9 to 71.8 nA·cm^(−2)in the direction of spontaneous polarization when the sample was bent upward due to the flexoelectricity-enhanced photovoltaic(FPV)effect.The flexoelectric effect of the NN-NT/epoxy composite film could modulate the photovoltaic response by increasing it by 80%or reducing it to 65%of the original value.This work provides a new idea for further exploration in efficient and lossless ferroelectric memory devices.