The nature of electron density enhancement over a wide altitude range during ionosphere heating experiments at EISCAT

During the course of ionospheric heating experiments, researchers at the European Incoherent Scatter Scientific Association (EISCAT) observed an apparent electron density enhancement. The enhancement extended over a wide range of altitudes, above the reflection altitude of the high-frequency pump wave. However, whether this enhancement actually corresponds to a true enhancement in electron density remains an open question. When the dispersion relation of ion acoustic waves is followed, the frequency ratio of the enhanced ion line to the background ion line suggests that the profile of the effective ion mass may have remained unchanged. Furthermore, the solar radio flux and ion drift velocity indicate no significant changes in the ion species and their densities. In conclusion, the electron density enhancement observed at EISCAT should not, in fact, be considered a true enhancement.

The Effects of a Hyperinsulinemic-Euglycemic Clamp on Milk Fat Synthesis and the Expression of Fat Synthesis-Related Genes in the Mammary Gland Tissues of Lactating Goats

To determine whether insulin exerts an effect on milk fat yield through the direct regulation of milk fat synthesis in the mammary gland, the hyperinsulinemic-euglycemic clamp procedure was performed in lactating goats in the present study. The effects of the hyperinsulinemic-euglycemic clamp on milk yield, milk composition, milk fatty acid yield and the expression levels of mRNAs of milk fat synthesis-related genes were examined. The results revealed that the hyperinsulinemiceuglycemic clamp had no significant effect on the milk yield, the milk protein yield, the yield and content of lactose or the yield and content of solids-not-fat (SNF) (P > 0.05). In contrast, the milk fat percentage and milk fat yield were decreased by 35.3% and 33.6%, respectively (P < 0.01). Among the 19 fatty acids examined, the yields of 9 fatty acids were significantly reduced (P < 0.05) following the clamp procedure, including C16:0 (hexadecanoic acid), 3 fatty acids derived from blood (>C16) and 5 fatty acids synthesized de novo in the mammary gland ( 0.05), including acetyl-coenzyme A carboxylase (ACC), fatty acid synthase (FAS), fatty acidbinding protein (FABP), lipoprotein lipase (LPL), stearoyl-CoA desaturase (SCD) and glycerol-3-phosphate acyltransferase (GPAT). However, the expression level of the SCD gene was significantly reduced during the post-procedure period (P < 0.05) but returned to a normal level at 48 h after termination of the clamp procedure. It was concluded that the hyperinsulinemic-euglycemic clamp exerted a direct effect on milk fatty acid desaturation.

Constructing nanocomposites with robust covalent connection between nanoparticles and polymer for high discharged energy density and excellent tensile properties

High discharged energy density and excellent flexible properties in dielectric materials are significantly sought to meet the rapid advancements in the electronics industry. In this study, covalent bonds are constructed between poly(vinylidene fluoride-chlorotrifluoroethylene), which contains olefinic bonds, and thiol-modified BaTiO_(3) at the interface before the nanocomposite films are fabricated. The presence of the covalent bonds is proved to promote the dispersibility of the modified BaTiO_(3) and enhance the interfacial adhesion between the modified BaTiO_(3) and the polymer, followed by a remarkably positive effect in suppressing the dielectric loss(tanδ) and increasing the breakdown strength(Eb) of the nanocomposite films. In addition, the cross-linking treatment in the preparation process is found to be favourable for improving the mechanical properties of the nanocomposite films, which benefits the enhancement of Eb. Furthermore, at 400% elongation, the stretched nanocomposite film doped with 5 vol% modified BaTiO_(3) exhibits an Eb15.6% greater than that of the unstretched film, and the discharged energy density reaches 11.4 J/cm^(3) with a high discharge energy efficiency of 84.5%. This study provides a novel strategy for preparing flexible nanocomposites with powerful interfacial adhesion at high filler content to achieve high discharged energy density.

MHSS ARAIM Algorithm Combined with Gross Error Detection

Due to some shortcomings in the current multiple hypothesis solution separation advanced receiver autonomous integrity monitoring(MHSS ARAIM)algorithm,such as the weaker robustness,a number of computational subsets with the larger computational load,a method combining MHSS ARAIM with gross error detection is proposed in this paper.The gross error detection method is used to identify and eliminate the gross data in the original data first,then the MHSS ARAIM algorithm is used to deal with the data after the gross error detection.Therefore,this makes up for the weakness of the MHSS ARAIM algorithm.With the data processing and analysis from several international GNSS service(IGS)and international GNSS monitoring and assessment system(iGMAS)stations,the results show that this new algorithm is superior to MHSS ARAIM in the localizer performance with vertical guidance down to 200 feet service(LPV-200)when using GPS and BDS measure data.Under the assumption of a single-faulty satellite,the effective monitoring threshold(EMT)is improved about 22.47%and 9.63%,and the vertical protection level(VPL)is improved about 32.28%and 12.98%for GPS and BDS observations,respectively.Moreover,under the assumption of double-faulty satellites,the EMT is improved about 80.85%and 29.88%,and the VPL is improved about 49.66%and 18.24%for GPS and BDS observations,respectively.

油墨粘度对卷对卷印刷有机光活性层的油墨转移速率和薄膜缺陷的影响机理

卷对卷(R2R)凹版印刷具有高的边缘分辨率、可图案化、高加工速度等优势,是制备大面积柔性有机太阳能电池(FOSCs)的一种可行技术.有机光活性层的薄膜质量是决定有机太阳能电池器件性能的关键.对于凹版印刷过程而言,墨水的转移是影响印刷薄膜厚度和质量的关键.本文深入研究了有机光活性层的墨水粘度对墨水转移率和薄膜缺陷的影响.我们开发了紫外可见光谱法,量化凹版印刷过程中墨水的转移率.通过对墨水的流变行为分析、流体动力学模拟和实验验证,深入研究了油墨粘度与油墨转移率、膜厚和膜均匀性之间的关系.结果表明,油墨粘度约为25 m Pa·s是R2R凹版印刷有机光活性层薄膜的适合粘度.通过对油墨配方的优化,我们制备了全R2R印刷FOSCs,其中1 cm^(2);电池的效率超过12%.

信息不对称下二手电商平台三方动态博弈分析——基于贝叶斯模型

随着我国二手电商市场的快速发展,如何构建买卖双方与二手电商平台的监管机制促进二手电商行业健康发展,是亟待解决的问题。本文基于贝叶斯模型刻画信息不对称下的二手商品买卖双方与电商平台的动态博弈过程,通过求解均衡策略分析影响各方策略选择的因素。结果表明:平台加强检查、加大对劣质二手商品卖家的惩罚力度,减少消费者购买二手商品的成本,降低卖家提供低质量二手商品的收益等措施均有利于提高二手商品的质量。

地域文化生态对京津冀远程教育协同发展软实力形成的社会影响

远程教育的协同发展是助推京津冀区域产业可持续发展的重要人才保障,而地域文化生态又对京津冀区域远程教育协同发展的文化软实力形成有着十分深远的影响。本文采用文化学中常用的民族志和知识考古方法进行研究后认为,地域文化生态对京津冀远程教育协同发展软实力形成的社会影响主要表现在三个方面:一是地域地理文化生态对京津冀区域远程教育协同发展凝聚力的形成产生了非常重要的社会影响;二是地域创新文化生态对京津冀区域远程教育协同发展感召力的形成产生了非常重要的社会影响;三是地域共享文化生态对京津冀区域远程教育协同发展行动力的形成产生了非常重要的社会影响。文章最后指出,软实力正是京津冀开放大学远程教育最重要的核心竞争力之一。

内生模型下财政分权对政府规模的影响机制——支出端分权与地方政府规模的非线性关系

本文旨在从理论和实证两个方面探究财政分权对政府规模影响的内在机制。研究表明,从中央政府角度看,财权下放不利于控制中央政府规模,而事权下放表现出显著的正向作用;从地方政府角度看,收入端分权有利于控制地方政府规模,但支出端分权和地方政府规模呈非线性关系,并依据转移支付依赖度、公共支出结构参数和地方性公共品供给能力呈现不同程度的门槛效应,这一效应对控制地方政府规模具有重要的指导意义。

Survival outcomes in older patients with different stages of acute kidney injury defined by the addition of urine output criteria

To the Editor:Globally,acute kidney injury(AKI)is a common life-threatening condition.AKI is more prevalent in elderly patients,with increasing mortality rates.Compared with younger patients,older patients with AKI have a higher risk of persistent injury and poorer prognoses.[1]Older individuals often have comorbidities,increasing their susceptibility to AKI.Kidney Disease:Improving Global Outcomes(KDIGO)criteria define and stage AKI based on the higher stage of AKI defined by either serum creatinine(SCr)level or urine output(UO).[2]However,the record of UO is difficult to access in clinic,the data on the value of UO combined with SCr for AKI diagnosis or prognosis in elderly patients are lacking.Therefore,the objectives of this study were to investigate whether UO would influence the classification of AKI and improve the accuracy of prediction of the clinical prognosis in elderly patients.

Dynamic Changes of China’s Functional Specialization in Export and International Comparison under Global Value Chains

The functional specialization in export of a country(and its sectors)in different activities,such as fabrication,R&D,management and marketing,is crucial to its governance and control on the value chains,which magnifies the shortage of the existing aggregate value added studies on our understanding of global value chains(GVCs).Considering production fragmentation at both the spatial and functional levels,this paper defines the modified functional specialization indicators at the national and sectoral levels from the forward linkage(rather than backward linkage).Based on the World Input-Output Database together with the newly compiled Labor Occupations Database,this paper re-estimates and analyzes the functional specialization and changes in China and major developed economies’exports.The results show that China’s export is mainly specialized in fabrication activity,which is among the world leading level,while it is weak in headquarter activities(especially R&D and management),which is almost locked at the lowest level in the world and could not pose an export threat to the developed economies.China’s manufacturing basically follows the functional development path of“relying on fabrication,entering market,targeting management and R&D”,featuring the coexistence of“strong”fabrication and“weak”management and R&D.The fabrication specialization of the typical processing sector“electronic and optical equipment”has reached the international leading level.The level of functional specialization of China’s service industry is generally lower than that of manufacturing and generally lags behind in the world,indicating that China still has a long way to go before becoming a major power of service in the world.Finally,this paper proposes policy implications and further researches that can be extended.