国外需求促进了中国出口企业创新吗?

本文运用详细的海关数据构建了中国出口企业面临的国外需求指标,并进一步按目的国类型与贸易方式细分,研究了国外需求与中国出口企业创新之间的关系。结果表明:总体上,来自发达国家的需求显著抑制了中国出口企业的创新。异质性分析表明,国外需求与出口企业创新的关系在不同要素密集度以及不同所有制企业中表现各有不同。在发达国家的需求中,加工贸易是抑制中国出口企业创新的重要原因。在一般贸易方式下,来自发达国家与发展中国家的“需求引致创新”效应依然有效,体现为,发达国家的需求对中国出口企业创新的影响偏向于过程创新,而发展中国家的需求对中国出口企业创新的影响偏向于产品创新。本文为中国当前的双循环发展战略调整提供了有价值的参考依据。

含碳纳米管包覆Co9S8微球的高性能铵离子电池正极材料

构建Co9S8/碳纳米管(Co9S8/2CNTs)涂层微球,并成功将其应用于水性铵离子电池。在Co9S8微球中引入碳纳米管可增加电子传导性,缩短NH4+离子的扩散距离,并提高对循环过程中体积变化的缓冲能力。因此,Co9S8/2CNTs微球在0.1A/g条件下具有112mA·h/g的可逆容量。此外,研究了Co9S8/2CNTs中伴随着可逆相变产物CoSO_(4)·6H_(2)O的形成和分子间氢键的形成/断裂的铵离子储能机理。

CD4^(+)CD25^(+) regulatory T cells decreased future liver remnant after associating liver partition and portal vein ligation for staged hepatectomy

BACKGROUND Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS)is an innovative surgical approach for the treatment of massive hepatocellular carcinoma(HCC),the key to successful planned stage 2 ALPPS is future liver remnant(FLR)volume growth,but the exact mechanism has not been elucidated.The correlation between regulatory T cells(Tregs)and postoperative FLR regeneration has not been reported.AIM To investigate the effect of CD4^(+)CD25^(+)Tregs on FLR regeneration after ALPPS.METHODS Clinical data and specimens were collected from 37 patients who developed massive HCC treated with ALPPS.Flow cytometry was performed to detect changes in the proportion of CD4^(+)CD25^(+)Tregs to CD4^(+)T cells in peripheral blood before and after ALPPS.To analyze the relationship between peripheral blood CD4^(+)CD25^(+)Treg proportion and clinicopathological information and liver volume.RESULTS The postoperative CD4^(+)CD25^(+)Treg proportion in stage 1 ALPPS was negatively correlated with the amount of proliferation volume,proliferation rate,and kinetic growth rate(KGR)of the FLR after stage 1 ALPPS.Patients with low Treg proportion had significantly higher KGR than those with high Treg proportion(P=0.006);patients with high Treg proportion had more severe postoperative pathological liver fibrosis than those with low Treg proportion(P=0.043).The area under the receiver operating characteristic curve between the percentage of Tregs and proliferation volume,proliferation rate,and KGR were all greater than 0.70.CONCLUSION CD4^(+)CD25^(+)Tregs in the peripheral blood of patients with massive HCC at stage 1 ALPPS were negatively correlated with indicators of FLR regeneration after stage 1 ALPPS and may influence the degree of fibrosis in patients’livers.Treg percentage was highly accurate in predicting the FLR regeneration after stage 1 ALPPS.

Corneal infection in Shandong peninsula of China: a10-year retrospective study on 578 cases

AIM：To determine the epidemiological characteristics,clinical signs,laboratory findings,and outcomes in patients with corneal infection in Shandong peninsula of China.·METHODS：The medical records of 578 inpatients（578eyes）with corneal infection were reviewed retrospectively for demographic characteristics,risk factors,seasonal variation,clinical signs,laboratory findings,and treatment strategy.Patient history,ocular examination findings using slit-lamp biomicroscopy,laboratory findings resulted from microbiological cultures,and treatment.·RESULTS：Fungal keratitis constituted 58.48%of cases of infectious keratitis among the inpatients,followed by herpes simplex keratitis（20.76%）,bacterial keratitis（19.03%）and acanthamoeba keratitis（1.73%）.The most common risk factor was corneal trauma（71.80%）.The direct microscopic examination（338 cases）using potassium hydroxide（KOH）wet mounts was positive in296 cases（87.57%）.Among the 298 fungal culturepositive cases,Fusarium species were the most common isolates（70.47%）.A total of 517 cases（89.45%）received surgical intervention,including 255（44.12%）cases of penetrating keratoplasty,74（12.80%）cases of lamellar keratoplasty which has become increasingly popular,and77 cases（13.32%）of evisceration or enucleation.·CONCLUSION：At present,infectious keratitis is a primary corneal disease causing blindness in China.With Fusarium species being the most commonly identified pathogens,fungal keratitis is the leading cause of severe infectious corneal ulcers in Shandong peninsula of China.

Direct Patterning of Carbon Nanotube via Stamp Contact Printing Process for Stretchable and Sensitive Sensing Devices

Flexible and wearable sensing devices have broad application prospects in bio-monitoring such as pulse measurement,motion detection and voice recognition.In recent years,many significant improvements had been made to enhance the sensor’s performance including sensitivity,flexibility and repeatability.However,it is still extremely complicated and difficult to prepare a patterned sensor directly on a flexible substrate.Herein,inspired by typography,a lowcost,environmentally friendly stamping method for the mass production of transparent conductive carbon nanotube(CNT)film is proposed.In this dry transfer strategy,a porous CNT block was used as both the seal and the ink;and Ecoflex film was served as an object substrate.Welldesigned CNT patterns can be easily fabricated on the polymer substrate by engraving the target pattern on the CNT seal before the stamping process.Moreover,the CNT film can be directly used to fabricate ultrathin(300μm)strain sensor.This strain sensor possesses high sensitivity with a gauge factor(GF)up to 9960 at 85%strain,high stretchability(>200%)and repeatability(>5000 cycles).It has been used to measure pulse signals and detect joint motion,suggesting promising application prospects in flexible and wearable electronic devices.

Shape reconstructions and morphing kinematics of an eagle during perching manoeuvres

The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video.A shape reconstruction method is proposed to describe wing contours and tail contours during perching.The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3D laser scanner.The wing planform,chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3D wing geometry.A three-jointed arm model is proposed to associate with the 3D wing geometry,while a one-joint arm model is proposed to describe the kinematics of tail.Therefore,a 3D bird model is established.The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3D bird model.A quasi-steady aerodynamic model is applied in the aerodynamic predictions,a four-step Adams-Bashforth method is used to calculate the ordinary differential equations,thus a BFGS based optimization method is established to predict the perching motions.

Measuring the flexibility matrix of an eagle’s flight feather and a method to estimate the stiffness distribution

Flight feathers stand out with extraordinary mechanical properties for flight because they are lightweight but stiff enough.Their elasticity has great effects on the aerodynamics, resulting in aeroelasticity.Our primary task is to figure out the stiffness distribution of the feather to study the aeroelastic effects.The feather shaft is simplified as a beam, and the flexibility matrix of an eagle flight feather is tested.A numerical method is proposed to estimate the stiffness distributions along the shaft length based on an optimal Broyden–Fletcher–Goldfarb–Shanno(BFGS) method with global convergence.An analysis of the compressive behavior of the shaft based on the beam model shows a good fit with experimental results.The stiffness distribution of the shaft is finally presented using a 5 th order polynomial.

New fossil seeds of Eurya （Theaceae） from East Asia and their paleobiogeographic implications

Eurya has an excellent fossil record in Europe,but it has only a few fossil occurrences in East Asia though this vast area houses the highest modern diversity of the genus.In this study,three-dimensionally preserved fossil seeds of Euiya stigmosa(Ludwig) Mai from the late Pliocene of northwestern Yunnan,southwestern China are described.The seeds are compressed and flattened,slightly campylotropous,and nearly circular to slightly angular in shape.The surface of the seeds is sculptured by a distinctive foveolate pattern,consisting of funnel-shaped and finely pitted cells.Each seed valve contains a reniform or horseshoe-shaped embryo cavity,a characteristic condyle structure and an internal raphe.These fossil seeds represent one of the few fossil records of Eurya in East Asia.This new finding therefore largely extends the distributional ranges of Eurya during Neogene.Fossil records summarized here show that Euiya persisted in Europe until the early Pleistocene,but disappeared thereafter.The genus might have first appeared in East Asia no later than the late Oligocene,and dispersed widely in regions such as Japan,Nepal,and southwestern China.

Dispersion of exciton-polariton based on ZnO/MgZnO quantum wells at room temperature

We report observation of dispersion for coupled exciton-polariton in a plate microcavity combining with ZnO/MgZnO multi-quantum well (QW) at room temperature. Benefited from the large exciton binding energy and giant oscillator strength, the room-temperature Rabi splitting energy can be enhanced to be as large as 60 meV. The results of excitonic polariton dispersion can be well described using the coupling wave model. It is demonstrated that mode modification between polariton branches allowing, just by controlling the pumping location, to tune the photonic fraction in the different detuning can be investigated comprehensively. Our results present a direct observation of the exciton-polariton dispersions based on two-dimensional oxide semiconductor quantum wells, thus provide a feasible road for coupling of exciton with photon and pave the way for realizing novel polariton-type optoelectronic devices.

Large eddy simulation of water flow over series of dunes

Large eddy simulation was used to investigate the spatial development of open channel flow over a series of dunes. The three-dimensional filtered Navier-Stokes （N-S） equations were numerically solved with the fractional-step method in sigma coordinates. The subgrid-scale turbulent stress was modeled with a dynamic coherent eddy viscosity model proposed by the authors The computed velocity profiles are in good agreement with the available experimental results. The mean velocity and the turbulent Reynolds stress affected by a series of dune-shaped structures were compared and analyzed. The variation of turbulence statistics along the flow direction affected by the wavy bottom roughness has been studied. The turbulent boundary layer in a complex geographic environment can be simulated well with the proposed large eddy simulation （LES） model.

Rapid Detection of β-lactam Antibiotic Residue in Milk Using Biolayer Interferometry

[ Objective] This study aimed to establish a high-sensitivity method for rapid detection of^-lactam antibiotic residue in milk. [Method] Based on bio- layer interferometry technology, ampicillin-BSA conjugate was fixed on the bottom of APS fiber optic biosensor probe through hydrophobic interaction and bound to 40 mn colloidal gold-labeled/3-1actam antibiotic receptor, to detect β-lactam antibiotics in milk. [ Result] The sensitivity of colloidal gold-labeled BLI method was twice as high as that of immunechromatographic test strip in detection of β-1actam antibiotic residue in milk. Colloidal gold-labeled BLI method exhibited good speci- ficity and had no cross-reaction with 1 000 ng/ml aflatoxin M1, gentamicin, kanamycin, streptomycin, tylosin, chloromycetin and melamine. [Condusion] The colloidal gold-labeled BLI method is not suitable for quantitative detection in actual production due to its small quantitative range in detection of β-lactam antibiot- ics, but it is a simple and rapid qualitative detection method that can be used in rapid detection of β-1actam antibiotic residue in milk.

Change of tumor-infiltrating lymphocyte of associating liver partition and portal vein ligation for staged hepatectomy for hepatocellular carcinoma

BACKGROUND The role of tumor-infiltrating lymphocytes(TILs)in the growth and progression of hepatocellular carcinoma(HCC)has attracted widespread attention.AIM To evaluate the feasibility of associating liver partition and portal vein ligation for staged hepatectomy(ALPPS)for massive HCC by exploring the role of TIL in the tumor microenvironment.METHODS Fifteen massive HCC patients who underwent ALPPS treatment and 46 who underwent hemi-hepatectomy were selected for this study.Propensity score matching was utilized to match patients in ALPPS and hemi-hepatectomy groups(1:1).Quantitative analysis of TILs in tumor and adjacent tissues between the two groups was performed by immunofluorescence staining and further analyses with oncological characteristics.In the meantime,trends of TILs in peripheral blood RESULTS Continuous measurement of tumor volume and necrosis volume showed that the proportion of tumor necrosis volume on the seventh day after stage-I ALPPS was significantly higher than the pre-operative value(P=0.024).In the preoperative period of stage-I ALPPS,the proportion of tumor necrosis volume in the high CD8+T cell infiltration group was significantly higher than that in the low group(P=0.048).CONCLUSION TIL infiltration level maintained a dynamic balance during the preoperative period of ALPPS.Compared with right hemi-hepatectomy,the ALPPS procedure does not cause severe immunosuppression with the decrease in TIL infiltration and pathological changes in immune components of peripheral blood.Our results suggested that ALPPS is safe and feasible for treating massive HCC from the perspective of immunology.In addition,high CD8+T cell infiltration is associated with increasing tumor necrosis in the perioperative period of ALPPS.

Ionospheric disturbance analysis of the January 15,2022 Tonga eruption based on GPS data

Hunga Tonga-Hunga Ha’apai climactic eruption on January 15,2022,released enormous energy that affected the ionosphere over the Pacific Rim.We analyzed ionospheric disturbance following volcanic eruptions using near-field(<1000 km),regional(1000–5000 km),and far-field(5000–12000 km) global positioning system(GPS) observations.The results indicate that the near-field ionospheric perturbation that occurred 8–15 min after the cataclysmic eruption was mainly derived from the shock wave(~1000 m/s) generated by the blast,while the low-frequency branch with long-distance propagation characteristics over the regional and the far-field was mainly associated with atmospheric Lamb waves(~330 m/s).Moreover,the amplitude of disturbance and background total electron content(TEC) are related proportionally.The intensity of the volcanic eruption and the background ionospheric conditions determine the magnitude of ionospheric responses.TEC perturbations were invisible on the reference days.Furthermore,the source location and onset time were calculated using the ray tracing technique,which confirms that the Tonga event triggered the ionospheric anomaly beyond the crater.Finally,the change in the frequency of the perturbations coincided with the arrival of the initial tsunami,implying the generation of a meteotsunami.

Pulmonary Vein Stenosis:A Review

Pulmonary vein stenosis(PVS)is an extremely rare and lethal disease caused by multiple etiologies.PVS has a bimodal distribution in the population,affecting children and adults.Congenital PVS is the usual PVS type in children,which sometimes develops after cardiothoracic surgery.Acquired PVS,in turn,is the most common PVS type in adults.A review of the relevant literature has shown that PVS after radiofrequency ablation of atrial fibrillation is the most common,as well as that caused by compression of proliferative fibrous tissues or tumor in the mediastinum(eg,PVS caused by fibrosing mediastinitis,lung tumors,metastases,etc).This article provides a comprehensive review of PVS in terms of embryology and anatomy,etiology and triggers,classification,clinical symptoms and signs,treatment,and prognosis,intending to promote the understanding and treatment of this disease.

Edge computing powers aerial swarms in sensing, communication, and planning

The last decade has witnessed significant progress and extensive applications of unmanned aerial vehicles(UAVs),thanks to their exceptional mobility,cost-effectiveness,and versatile deployment capabilities.1 With continuous advances in sensing,communication,and processing technologies,using UAV swarms to provide cost-effective services in future smart cities is expected to become ubiquitous.These services encompass a wide spectrum of applications,ranging from large-scale infrastructure inspection,geospatial land surveying,and traffic/crowd monitoring,to three-dimensional terrain mapping.2 In these scenarios,UAVs are typically equipped with onboard sensors such as cameras and LiDARs,to gather environmental information by analyzing the sensor data such as captured videos and point clouds.The key technologies to achieve autonomous information-gathering flight for UAV swarms include information extraction from sensor data,transmission and fusion of the extracted information among UAVs,and planning and coordination of their trajectories to ensure safe and efficient mission accomplishment.

Extended pancreatoduodenectomy with portal vein and inferior vena cava resection and reconstruction combined with sorafenib for hepatoid carcinoma of the pancreas:a strategy of superextended surgery combined with targeted therapy

Hepatoid carcinoma of the pancreas(HCP)is an extremely rare pancreatic cancer resembling hepatocellular carcinoma,a type of liver cancer(1).Most reports have shown that it has an aggressive behavior and is associated with early metastasis.There is no standardized treatment for HCP due to its rarity,and the limited number of cases reported in the literature(2,3).However,treatment options for this type of rare cancer include surgery,chemotherapy,and radiation therapy,depending on the stage of the cancer.Nevertheless,the prognosis of HCP is poor.

Functional polymer brushes for anti-microplastic pollution

Microplastic fibers(MPFs)featuring mean sizes of 11-5,000μm and lengths of less than 500μm have been regarded as ubiquitous and hazardous contaminants in the ecosystem[1,2].Nowadays,nearly 35% of MPFs come from textile washing[3],threatening freshwater,marine fauna,human life,and even ecological balance on multiple scales.The controllable release of MPFs during garment washing has become increasingly urgent[4].

横断山南段上新世的植被多样性与分布格局

横断山南段复杂的地形地貌和多样的气候环境造就了高度丰富的植被多样性。这种植被多样性的演化与形成是植物学、生态学等领域共同关注的科学问题,而植物化石是回答这一科学问题的重要媒介。本文基于横断山南段的9个上新世化石植物群,根据其植物组成和优势成分,分析其所代表的植被类型,总结了该地区上新世的植被多样性与空间分布,并结合古环境研究资料,探讨该地区植被多样性的兴起,植被分布格局的形成,及其与环境变迁之间的关联。结果显示,横断山南段在上新世时期已经具有了多种植被类型,包括亚热带常绿阔叶林、亚热带落叶阔叶林、硬叶常绿阔叶林、针阔叶混交林、灌丛草地等,体现了丰富的植被多样性;植被类型从南面的偏热性植被向北面的偏温性植被逐渐转变,反映了当时随纬度变化的海拔梯度,植被类型与分布呈现出与现在高度相似的格局。同时,小范围内也具有适应于不同气候的植被类型,反映了当地较大的海拔落差,可能与高大山体的存在有着密切关联。我们推测,横断山南段现在丰富的植被多样性和随纬度变化的植被面貌最晚在上新世就已基本形成,但形成时间是否更早则需要更多、更老化石植物群的发现与研究。

Understanding the Separations of Oil/Water Mixtures from Immiscible to Emulsions on Super-wettable Surfaces

As the frequent oil spill accidents happens and large quantities of oily wastewater from all kinds of industries are being discharged, the environment has been seriously polluted and our living areas have been horribly threatened. To deal with these issues, attentions have been aroused on the treatments of the oily wastewater. Recently, numerous superwettable materials have been fabricated. In this review, we summarize the new development of the materials for the separation of oil/water mixtures, mainly including the immiscible and emulsified mixtures. For the separation of immiscible ones, special materials with fixed wettability are firstly detailed, where three types of materials can be classified based on their wettability, i.e. superhydrophobic and superoleophilic materials, superhydrophilic and underwater superoleophobic materials, and superhydrophilic and su- peroleophobic materials. Then, the smart materials with switchable wettabilities responsive to external stimulus, for instance, light, solvent, pH, temperature, and electrical potential, are presented. Meanwhile, the single, dual, and multiple stimu- lus-responsive materials are also described. As for the separation of emulsified oil/water mixtures, the materials for the sepa- ration of water-in-oil （W/O）, oil-in-water （O/W）, and both water-in-oil （W/O） and oil-in-water （O/W） emulsions are sequen- tially introduced. Finally, some challenges are discussed and the outlook in this filed is proposed.

Wetting Characterizations of Oilseed Rapes

Oilseed rape, widely cultivated all over the world, plays an important role for our daily life due to its high nutritional and economic values. In this paper, for the first time we discuss the surlhce wettability of oilseed rapes with special surface structures. It is found that the fresh rape flowers are superhydrophobic with a low Adhesion Force （AF）, showing the self-cleaning properties similar to lotus leaves. In contrast, the fresh rape leaves also exhibit hydrophobicity but a high AF, which resemble rose petals. Furthermore, we study the effect of storage time on the wetting properties of rape leaves. The high hydrophobicity of rape leaves gradually switches to hydrophilicity. Meanwhile, the AF intensely increases after placement at room temperature for 10 days. This research offers a profound inspiration to artificially fabricate biomimetic materials with high hydrophobicity and different adhesion characterizations.