Corrections of shipboard GPS radiosonde soundings and applications on historical records in the eastern tropical Indian Ocean and South China Sea

Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Global Positioning System(GPS)soundings in the eastern tropical Indian Ocean and South China Sea through a simultaneous balloon-borne inter-comparison of different radiosonde types.Our results indicate that the temperature and relative humidity(RH)measurements of GPS-TanKong(GPS-TK)radiosonde(used at most stations before 2012)have larger biases than those of ChangFeng-06-A(CF-06-A)radiosonde(widely used in current observation)when compared to reference data from Vaisala RS92-SGP radiosonde,with a warm bias of 5℃and dry bias of 10%during daytimes,and a cooling bias of-0.8℃and a moist bias of 6%during nighttime.These systematic biases are primarily attributed to the radiation effects and altitude deviation.An empirical correction algorithm was developed to retrieve the atmospheric temperature and RH profiles.The corrected profiles agree well with that of RS92-SGP,except for uncertainties of CF-06-A in the stratosphere.These correction algorithms were applied to the GPS-TK historical sounding records,reducing biases in the corrected temperature and RH profiles when compared to radio occultation data.The correction of GPS-TK historical records illustrated an improvement in capturing the marine atmospheric structure,with more accurate atmospheric boundary layer height,convective available potential energy,and convective inhibition in the tropical ocean.This study contributes significantly to improving the quality of GPS radiosonde soundings and promotes the sharing of observation in the eastern tropical Indian Ocean and South China Sea.

A Novel Competition-Based Coordination Model With Dynamic Feedback for Multi-Robot Systems

Dear Editor, Task allocation strategies are important in multi-robot systems and have been intensely investigated by researchers because they are critical in determining the performance of the system. In this letter, a novel competition-based coordination model is proposed to solve the multi-robot task allocation problem and applied to a multi-robot object tracking scenario.

铋基光催化剂的金属或非金属改性研究进展

随着经济的快速增长,环境和能源问题日益突出。太阳能作为一种可再生、环保的能源,受到了许多研究人员的关注,最大限度地利用太阳能资源成为未来的研究热点。众所周知,光催化技术可以将太阳能转化为化学能或电能,为环境污染提供解决方案。因此,半导体光催化技术被认为是解决能源危机和环境问题的最环保的技术之一。铋基半导体材料由于合适的能带结构、丰富的种类、无毒性和低成本,在光催化领域受到欢迎。然而,纯Bi基光催化剂存在光激发电子-空穴对复合效率高、量子产率低和光吸收能力有限的问题,导致光催化性能低。为了克服这些限制,人们设计了各种策略,比如金属或非金属掺杂、金属沉积、异质结构建和诱导缺陷生成来提高它们的光催化活性。在这些策略中,元素掺杂或金属沉积被认为是调整铋基材料能带结构和物化性质的有效方法。这个方法拓宽了光响应范围和提高了光催化性能。这篇综述总结了金属掺杂、非金属掺杂、金属和非金属共掺杂以及金属沉积改性铋基材料的最新研究进展。它也探索了它们在光催化降解污染物和重金属离子、氮气还原、二氧化碳还原、光催化抗菌等各个领域的应用。关于金属掺杂,我们将其分为三类:碱金属或碱土金属掺杂、过渡金属掺杂和稀土金属掺杂,并详细介绍了每种掺杂的优缺点。非金属掺杂则被分为卤素掺杂和非卤素掺杂,并重点研究非金属掺杂对铋基材料的影响。此外,我们还纵向比较了每个元素的优点。结合最近的研究进展,简要介绍了结合金属和非金属元素优点的共掺杂。对于金属沉积,我们主要从肖特基势垒和局域表面等离子体共振(LSPR)效应两个方面介绍了对Bi基材料的影响。最后,我们也呈现了金属或非金属改性Bi基光催化剂目前面临的挑战和前景。

Influence of layer thickness on formation quality,microstructure,mechanical properties,and corrosion resistance of WE43 magnesium alloy fabricated by laser powder bed fusion

Laser powder bed fusion(L-PBF)of Mg alloys has provided tremendous opportunities for customized production of aeronautical and medical parts.Layer thickness(LT)is of great significance to the L-PBF process but has not been studied for Mg alloys.In this study,WE43 Mg alloy bulk cubes,porous scaffolds,and thin walls with layer thicknesses of 10,20,30,and 40μm were fabricated.The required laser energy input increased with increasing layer thickness and was different for the bulk cubes and porous scaffolds.Porosity tended to occur at the connection joints in porous scaffolds for LT40 and could be eliminated by reducing the laser energy input.For thin wall parts,a large overhang angle or a small wall thickness resulted in porosity when a large layer thicknesses was used,and the porosity disappeared by reducing the layer thickness or laser energy input.A deeper keyhole penetration was found in all occasions with porosity,explaining the influence of layer thickness,geometrical structure,and laser energy input on the porosity.All the samples achieved a high fusion quality with a relative density of over 99.5%using the optimized laser energy input.The increased layer thickness resulted to more precipitation phases,finer grain sizes and decreased grain texture.With the similar high fusion quality,the tensile strength and elongation of bulk samples were significantly improved from 257 MPa and 1.41%with the 10μm layer to 287 MPa and 15.12%with the 40μm layer,in accordance with the microstructural change.The effect of layer thickness on the compressive properties of porous scaffolds was limited.However,the corrosion rate of bulk samples accelerated with increasing the layer thickness,mainly attributed to the increased number of precipitation phases.

动态外载荷工况下风力机法兰螺栓相对刚度研究

螺栓相对刚度决定了工作中螺栓拉力大小。为探究风力机法兰盘螺栓拉力与外载荷关系,基于法兰单元等效圆柱模型与等效压缩变形体模型,结合有限元仿真,研究了不同工况下螺栓相对刚度的变化情况。研究结果表明,螺栓相对刚度与外载荷的性质和施加位置有关;与上下法兰单元间接触面积和螺栓初始预紧力呈负相关;动态外载荷工况下表现出明显的非线性特性。研究结论可为风力机法兰盘螺栓组设计与装配以及螺栓组松动故障预警诊断提供参考。

Improving corrosion resistance of additively manufactured WE43 magnesium alloy by high temperature oxidation for biodegradable applications

Laser powder bed fusion(L-PBF)has been employed to additively manufacture WE43 magnesium(Mg)alloy biodegradable implants,but WE43 L-PBF samples exhibit excessively rapid corrosion.In this work,dense WE43 L-PBF samples were built with the relativity density reaching 99.9%.High temperature oxidation was performed on the L-PBF samples in circulating air via various heating temperatures and holding durations.The oxidation and diffusion at the elevated temperature generated a gradient structure composed of an oxide layer at the surface,a transition layer in the middle and the matrix.The oxide layer consisted of rare earth(RE)oxides,and became dense and thick with increasing the holding duration.The matrix was composed ofα-Mg,RE oxides and Mg_(24)RE_(5) precipitates.The precipitates almost disappeared in the transition layer.Enhanced passivation effect was observed in the samples treated by a suitable high temperature oxidation.The original L-PBF samples lost 40%weight after 3-day immersion in Hank’s solution,and broke into fragments after 7-day immersion.The casted and solution treated samples lost roughly half of the weight after 28-day immersion.The high temperature oxidation samples,which were heated at 525℃ for 8 h,kept the structural integrity,and lost only 6.88%weight after 28-day immersion.The substantially improved corrosion resistance was contributed to the gradient structure at the surface.On one hand,the outmost dense layer of RE oxides isolated the corrosive medium;on the other hand,the transition layer considerably inhibited the corrosion owing to the lack of precipitates.Overall,high temperature oxidation provides an efficient,economic and safe approach to inhibit the corrosion of WE43 L-PBF samples,and has promising prospects for future clinical applications.

Physical mechanism of oxygen diffusion in the formation of Ga_(2)O_(3) Ohmic contacts

The formation of low-resistance Ohmic contacts in Ga_(2)O_(3) is crucial for high-performance electronic devices. Conventionally, a titanium/gold(Ti/Au) electrode is rapidly annealed to achieve Ohmic contacts, resulting in mutual diffusion of atoms at the interface. However, the specific role of diffusing elements in Ohmic contact formation remains unclear.In this work, we investigate the contribution of oxygen atom diffusion to the formation of Ohmic contacts in Ga_(2)O_(3). We prepare a Ti/Au electrode on a single crystal substrate and conduct a series of electrical and structural characterizations.Using density functional theory, we construct a model of the interface and calculate the charge density, partial density of states, planar electrostatic potential energy, and I–V characteristics. Our results demonstrate that the oxygen atom diffusion effectively reduces the interface barrier, leading to low-resistance Ohmic contacts in Ga_(2)O_(3). These findings provide valuable insights into the underlying mechanisms of Ohmic contact formation and highlight the importance of considering the oxygen atom diffusion in the design of Ga_(2)O_(3)-based electronic devices.

Ganoderma lucidum:a comprehensive review of phytochemistry,efficacy,safety and clinical study

Ganoderma lucidum,one of the most well-known edible fungi,is believed to be very beneficial for longevity and vitality.A long usage history suggests that G.lucidum has various clinical therapeutic effects.And experimental studies have confirmed that G.lucidum has multiple pharmacological effects,including antitumor,anti-microbial,anti-HIV protease,and antidiabetic activity and so on.With the deepening of research,more than 300 compounds have been isolated from G.lucidum.There is an increasing population of G.lucidum-based products,and its international development is expanding.Currently,G.lucidum has drawn much attention to its chemical composition,therapeutic effect,clinical value,and safety.This paper provides a comprehensive review of these aspects to enhance the global promotion of G.lucidum.

晚期肾上腺皮质癌靶向治疗和免疫治疗的研究进展

肾上腺皮质癌(adrenocoritical carcinoma,ACC)是肾上腺最常见的恶性肿瘤,晚期ACC预后较差,手术切除肿瘤仅限于临床Ⅰ、Ⅱ期的患者,且术后复发率高。对于晚期ACC,米托坦(mitotane,M)联合依托泊苷(etoposide,E)、阿霉素(doxorubicin,D)、顺铂(cisplatin,P)(EDP-M)是目前唯一批准可行的一线治疗方案,但化疗和放疗等治疗效果有限,EDP-M方案失败后尚无标准或一致的二线全身治疗选择。近年来随着对ACC发病分子机制的深入研究与认识,针对表皮生长因子受体(epidermal growth factor receptor,EGFR)、内皮细胞上血管内皮生长因子受体(vascular endothelial growth factor receptor,VEGFR)、哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)等靶点的酪氨酸激酶抑制剂(tyrosine kinase inhibitors,TKIs)、mTOR抑制剂和免疫检查点抑制剂(immune checkpoint inhibitors,ICIs)正在研究中。此外,多项针对ACC的研究发现CTNBB1、TP53、KDM5A、CENP-H等突变,有望成为潜在的治疗靶点或生物标志物,为ACC治疗提供更多可能的选择。ICIs已经被证实对非小细胞肺癌、肝癌、肾细胞癌、尿路上皮细胞癌等多种肿瘤有效,积极探索靶向、免疫治疗、特别是联合疗法对延长患者生存期和改善患者生活质量展现出良好的发展潜力。

Gas microchannel plate-pixel detector for X-ray polarimetry

POLAR-2 is a gamma-ray burst(GRB)polarimeter that is designed to study the polarization in GRB radiation emissions,aiming to improve our knowledge of related mechanisms.POLAR-2 is expected to utilize an on-board polarimeter that is sensitive to soft X-rays(2-10 keV),called low-energy polarization detector.We have developed a new soft X-ray polari-zation detector prototype based on gas microchannel plates(GMCPs)and pixel chips(Topmetal).The GMCPs have bulk resistance,which prevents charging-up effects and ensures gain stability during operation.The detector is composed of low outgassing materials and is gas-sealed using a laser welding technique,ensuring long-term stability.A modulation factor of 41.28%±0.64% is obtained for a 4.5 keV polarized X-ray beam.A residual modulation of 1.96%±0.58% at 5.9 keV is observed for the entire sensitive area.

A Unified Model Fusing Region of Interest Detection and Super Resolution for Video Compression

High-resolution video transmission requires a substantial amount of bandwidth.In this paper,we present a novel video processing methodology that innovatively integrates region of interest(ROI)identification and super-resolution enhancement.Our method commences with the accurate detection of ROIs within video sequences,followed by the application of advanced super-resolution techniques to these areas,thereby preserving visual quality while economizing on data transmission.To validate and benchmark our approach,we have curated a new gaming dataset tailored to evaluate the effectiveness of ROI-based super-resolution in practical applications.The proposed model architecture leverages the transformer network framework,guided by a carefully designed multi-task loss function,which facilitates concurrent learning and execution of both ROI identification and resolution enhancement tasks.This unified deep learning model exhibits remarkable performance in achieving super-resolution on our custom dataset.The implications of this research extend to optimizing low-bitrate video streaming scenarios.By selectively enhancing the resolution of critical regions in videos,our solution enables high-quality video delivery under constrained bandwidth conditions.Empirical results demonstrate a 15%reduction in transmission bandwidth compared to traditional super-resolution based compression methods,without any perceivable decline in visual quality.This work thus contributes to the advancement of video compression and enhancement technologies,offering an effective strategy for improving digital media delivery efficiency and user experience,especially in bandwidth-limited environments.The innovative integration of ROI identification and super-resolution presents promising avenues for future research and development in adaptive and intelligent video communication systems.

Endoscopic ultrasound features of rectal melanoma:A case report and review of literature

BACKGROUND Rectal mucosal melanoma is a rare and highly aggressive disease.Common symptoms include anal pain,an anal mass,or bleeding.As such,the disease is usually detected on rectal examination of patients with other suspected anorectal diseases.However,due to its rarity and nonspecific symptoms,melanoma of the rectal mucosa is easily misdiagnosed.CASE SUMMARY This report describes the case of a 58-year-old female patient who presented with a history of blood in her stool for the prior one or two months,without any identifiable cause.During colonoscopy,a bulge of approximately 2.2 cm×2.0 cm was identified.Subsequently,the patient underwent endoscopic ultrasound(EUS)to characterize the depth of invasion of the lesions.EUS suggested a hypoechoic mucosal mass with involvement of the submucosal layer and heterogeneity of the internal echoes.Following surgical intervention,the excised tissue samples were examined and confirmed to be rectal malignant melanoma.The patient recovered well with no evidence of recurrence during follow-up.CONCLUSION This case shows that colonoscopy with EUS and pathological examination can accurately diagnose rare cases of rectal mucosal melanoma.

A time-space network-based model for transportation service optimization of China Railway Express

This paper describes the development and optimization plans for the China Railway Express(CR Express).As a new type of international land transport organization,CR Express has emerged with the continuous expansion of China toward European investment and trade,and in particular,has expanded with the continuous progress of the One Belt and One Road(OBOR)initiative.In addition to improving the service quality of CR Express,the operating costs must be reduced for developing“smart railways”that serve“smart cities”.We propose a dualobjective-based function mathematical optimization model;the satisfaction of the cargo owner is considered,and the timeliness,transportation capacity,and goods category constraints of CR Express transportation are designed.Moreover,we present the normalized equivalent method of the two-objective function of the model.Finally,a case study is conducted against the background of certain trains in the western corridor of CR Express to validate the effectiveness of the model and research methods proposed in this study.

Strain-Insensitive Fiber Bragg Grating Composite Structure for Wide-Range Temperature Sensing

This paper reports on the design,fabrication,and temperature strain sensing performance of a fiber Bragg grating composite structure for surface mounted temperature measurements over a wide temperature range,with highly reduced strain cross-sensitivity.The fiber Bragg grating sensor is encapsulated in a polyimide tube filled with epoxy resin,forming an arc-shaped cavity.This assembly is then placed between two layers of glass fiber prepreg with a flexible pad in between and cured into shape.Experimental results,supported by finite element simulations,demonstrate an enhanced temperature sensitivity is 26.3 pm/°C over a wide temperature range of–30°C to 70°C,and high strain transfer isolation of about 99.65%.

A Method for Detection of Main Metabolites in Aromatic Rice Seeds

[ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry （GC-MS）. [ Method] The main metabolites in seeds of 9 different aromatic rice varieties were compared and analyzed with two methods. Method 1 ： the compound was extracted by the mixture of anhydrous ethanol and methylene chloride （ WV = 1：1 ） at 60 ℃ for 3 h in water bath; the extract was isolated and detected by gas chromatography-mass spectrometry using HP-5 capillary column with scan monitoring mode. Method 2： the main metabolites in aromatic rice seeds were detected using headspaee solid phase micro-extraction and gas chromatography mass spectrometry （GC-MS）. [ Result ] Fifteen types of common metabolites were found in 9 different aromatic rice varieties. Method 1 was more effective than method 2 in detecting the main metabolites in aromatic rice seeds. [ Conclusion] This study provides an important reference for clarifying the metabolic pathway of main metabolites in aromatic rice and lays the foundation for further rice breeding.

面向航天器型号的COTS元器件选用策略

为了实现COTS元器件在航天器中低成本高效应用,文章调研了商用塑封器件的工业基础、应用风险以及国内外各航天机构对COTS元器件的应用策略;针对COTS元器件的选用策略,系统性提出了元器件需求分析、选择、供应、应用结合的选用程序,并在此基础上设计了元器件供应方选择、执行标准选择和产品选择的选用要素。最后结合元器件应用实践需求,提出了面向航天器型号的COTS元器件选用控制建议。

航天器3D打印金属材料可靠性评估方案设计

随着航天器对3D打印金属材料需求的不断增长,航天器对3D打印金属材料的可靠性也提出了更高的要求。通过对航天器服役环境、3D打印材料特点以及在航天器中的应用功能等因素的分析,从3D打印金属原材料、典型构件和最终产品着手,设置了性能评价技术指标体系、设计了方案实施技术路线、明确了性能指标评价方式,最终形成了航天器3D打印金属材料可靠性评估技术方案,为3D打印材料在航天领域中安全可靠的应用提供了技术支撑。

柔性端电极多层瓷介电容器失效模式分析与改进措施

柔性端电极多层陶瓷电容器(Flexible Termination Multilayer Ceramic Capacitors,FTMLCCs)在典型三层端电极基础上,引入由树脂和导电填充物构成的柔性电极层,在不增加电容尺寸或削减容量的前提下,降低瓷体开裂风险。但FTMLCC引入柔性层结构,降低瓷体开裂风险的同时也可能引入新的失效风险。选取两种1812尺寸FTMLCC产品为研究对象,利用扫描电子显微镜、聚焦离子束剖切与三维重构等技术进行了柔性层物理结构和结合界面特性的详细表征。通过装联、抗弯曲与环境试验评价的方法,对柔性电极结构、柔性层相关缺陷和失效模式进行了深入研究。研究表明,柔性端电极虽增强了MLCC抗弯性,但柔性层内空洞或弱层间结合力可能诱发电极内开裂或界面剥离等新失效模式,造成容量下降。因此,生产或使用FTMLCC产品时,需提升柔性层耐焊性,控制装联条件,并适当除湿,以保护瓷体,提升其装联可靠性。

Measuring moisture content of dead fine fuels based on the fusion of spectrum meteorological data

Dead fine fuel moisture content(DFFMC)is a key factor affecting the spread of forest fires,which plays an important role in evaluation of forest fire risk.In order to achieve high-precision real-time measurement of DFFMC,this study established a long short-term memory(LSTM)network based on particle swarm optimization(PSO)algorithm as a measurement model.A multi-point surface monitoring scheme combining near-infrared measurement method and meteorological measurement method is proposed.The near-infrared spectral information of dead fine fuels and the meteorological factors in the region are processed by data fusion technology to construct a spectral-meteorological data set.The surface fine dead fuel of Mongolian oak(Quercus mongolica Fisch.ex Ledeb.),white birch(Betula platyphylla Suk.),larch(Larix gmelinii(Rupr.)Kuzen.),and Manchurian walnut(Juglans mandshurica Maxim.)in the maoershan experimental forest farm of the Northeast Forestry University were investigated.We used the PSO-LSTM model for moisture content to compare the near-infrared spectroscopy,meteorological,and spectral meteorological fusion methods.The results show that the mean absolute error of the DFFMC of the four stands by spectral meteorological fusion method were 1.1%for Mongolian oak,1.3%for white birch,1.4%for larch,and 1.8%for Manchurian walnut,and these values were lower than those of the near-infrared method and the meteorological method.The spectral meteorological fusion method provides a new way for high-precision measurement of moisture content of fine dead fuel.

A novelα-ketoamide reactivity-based two-photon fluorogenic probe for visualizing peroxynitrite in Parkinson's disease models

Peroxynitrite(ONOO^(-))contributes to oxidative stress and neurodegeneration in Parkinson's disease(PD).Developing a peroxynitrite probe would enable in situ visualization of the overwhelming ONOO^(-)flux and understanding of the ONOO^(-)stress-induced neuropathology of PD.Herein,a novelα-ketoamide-based fluorogenic probe(DFlu)was designed for ONOO^(-)
monitoring in multiple PD models.The results demonstrated that DFlu exhibits a fluorescence turn-on response to ONOO^(-)with high specificity and sensitivity.The efficacy of DFlu for intracellular ONOO^(-)
imaging was demonstrated systematically.The results showed that DFlu can successfully visualize endogenous and exogenous ONOO^(-)in cells derived from chemical and biochemical routes.More importantly,the two-photon excitation ability of DFlu has been well demonstrated by monitoring exogenous/endogenous ONOO^(-)production and scavenging in live zebraflsh PD models.This work provides a reliable and promising
α-ketoamide-based optical tool for identifying variations of ONOO^(-)in PD models.