A Hybrid Integrated and Low-Cost Multi-Chip Broadband Doherty Power Amplifier Module for 5G Massive MIMO Application

In this paper,a hybrid integrated broadband Doherty power amplifier(DPA)based on a multi-chip module(MCM),whose active devices are fabricated using the gallium nitride(GaN)process and whose passive circuits are fabricated using the gallium arsenide(GaAs)integrated passive device(IPD)process,is proposed for 5G massive multiple-input multiple-output(MIMO)application.An inverted DPA structure with a low-Q output network is proposed to achieve better bandwidth performance,and a single-driver architecture is adopted for a chip with high gain and small area.The proposed DPA has a bandwidth of 4.4-5.0 GHz that can achieve a saturation of more than 45.0 dBm.The gain compression from 37 dBm to saturation power is less than 4 dB,and the average power-added efficiency(PAE)is 36.3%with an 8.5 dB peak-to-average power ratio(PAPR)in 4.5-5.0 GHz.The measured adjacent channel power ratio(ACPR)is better than50 dBc after digital predistortion(DPD),exhibiting satisfactory linearity.

Prediction of Meteorological Drought in the Lower Nu River by Statistical Model

Global climate change, temperature rise and some kinds of extreme meteorological disaster, such as the drought, threaten the development of the natural ecosystem and human society. Forecasting in drought is an important step toward developing a disaster mitigation system. In this study, we utilized the statistical, autoregressive integrated moving average (ARIMA) model to predict drought conditions based on the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI) in a major tributary in the lower reaches of Nu River. We employed data from 2001 to 2010 to fit the model and data from 2011 to 2013 for model validation. The results showed that the coefficients of determination (R2) was over 0.85 in each index series, and the root-mean-square error and mean absolute error were low, implying that the ARIMA model is effective and adequate for this region.

Changes of protein oxidation,lipid oxidation and lipolysis in Chinese dry sausage with different sodium chloride curing salt content

The effect of sodium chloride(NaCl)curing salt content on protein oxidation,lipid oxidation and lipolysis of Chinese dry sausage was investigated.Two groups Chinese dry sausages with 2%and 4%(m/m)salt content were studied.The degree of protein oxidation increased during the processes in two groups sausages,while the content of phospholipids decreased,neutral lipids and free fatty acids increased.The degree of protein oxidation,lipid oxidation and lipolysis in 4%NaCl content group was higher than those in 2%NaCl content group,while 4%NaCl content group has higher lipase activity.In conclusion,4%NaCl may facilitate the protein oxidation,lipid hydrolysis and oxidation in Chinese dry sausage,and the protein oxidation had strong correlation with lipid oxidation and lipolysis.The results could provide a basis for improving the technology of industrial production.

Time-dependent categorization of volatile aroma compound formation in stewed Chinese spicy beef using electron nose profile coupled with thermal desorption GC–MS detection

In the present study,flavor profiles of Chinese spiced beef in the cooking process were comparatively analyzed by electronic nose,gas chromatography–mass spectrometry(GC–MS)with a thermal desorption system(TDS),and solid-phase microextraction(SPME).A total of 82 volatile compounds were identified,and 3-methyl-butanal,pentanal,hexanal,-xylene,heptanal,limonene,terpinene,octanal,linalool,4-terpinenol,-terpineol,and(E)-anethole were identified as the characteristic flavor compounds in Chinese spiced beef.Variation in the content of volatile components produced by different cooking processes was observed.In general,a cooking time of 4 h resulted in optimal flavor quality and stability.Results indicated that the electronic nose could profile and rapidly distinguish variation among different cooking time.The volatile profiling by TDS-GC–MS and responses from the electronic nose,in combination with multivariate statistical analysis,are a promising tool for control the cooking process of spiced beef.

Non-covalently Functionalized Graphene Oxide-Based Coating to Enhance Thermal Stability and Flame Retardancy of PVA Film

The synergistic effect of conventional flame-retardant elements and graphene has received extensive attention in the development of a new class of flame retardants. Compared to covalent modification, the noncovalent strategy is simpler and expeditious and entirely preserves the original quality of graphene. Thus, non-covalently functionalized graphene oxide(FGO) with a phosphorus–nitrogen compound was successfully prepared via a one-pot process in this study. Polyethyleneimine and FGO were alternatively deposited on the surface of a poly(vinyl alcohol)(PVA) film via layer-by-layer assembly driven by electrostatic interaction, imparting excellent flame retardancy to the coated PVA film. The multilayer FGO-based coating formed a protective shield encapsulating the PVA matrix, effectively blocking the transfer of heat and mass during combustion. The coated PVA has a higher initial decomposition temperature of about 260 °C and a nearly 60% reduction in total heat release than neat PVA does. Our results may have a promising prospect for flame-retardant polymers.

Effect of proteolytic starter culture isolated from Chinese Dong fermented pork(Nanx Wudl)on microbiological,biochemical and organoleptic attributes in dry fermented sausages

The effect of a proteolytic starter culture isolated from Nanx Wudl,on microbiological,biochemical and organoleptic attributes of dry fermented sausages was investigated during processing.Based on preliminary screening,the combination of Staphylococcus xylosus SX16 and Lactobacillus plantarum CMRC6,showing excellent proteolytic activity in vitro,was selected as the multi-strain starter(starter LS).For comparison,the single-strain starter culture of L.plantarum CMRC6(starter LB)and non-inoculated control were also tested.During fermentation,lactic acid bacteria and staphylococci dominated the microbiota and suppressed the Enterobacteriaceae growth in LS-inoculated sausages.The addition of LS starter accelerated acidification and proteolysis during ripening,improving the contents of total free amino acids and several essential free amino acids(Phe,Ile and Leu).Volatile compounds analysis revealed that LS-fermented sausage showed the highest abundance of 3-methyl-1-butanol,probably due to the inoculated S.xylosus.The inoculation of LS starter improved the sensory properties of sausages,especially the flavor attribute.Therefore,S.xylosus SX16 and L.plantarum CMRC6 are promising candidates for inclusion as multi-strain starters in the manufacture of gourmet fermented dry sausage.

Predominant yeasts in Chinese Dong fermented pork(Nanx Wudl)and their aroma-producing properties in fermented sausage condition

Yeasts are one of the predominant microbial groups in fermented meats.In this study,yeast communities of Chinese Dong fermented pork(Nanx Wudl)were investigated and the technological properties of 73 yeast isolates were evaluated.Through culture-dependent and high-throughput sequencing methods,the main yeast species identified included Pichia membranifaciens,Kazachstania bulderi,Millerozyma farinosa,Candida zeylanoides,Kazachstania exigua,Candida parapsilosis and Saccharomyces cerevisiae.Among these yeasts,P.membranifaciens,M.farinosa,K.exigua and K.bulderi were detected in fermented meats for the first time.A total of 73 yeast isolates was investigated for their lipolytic and proteolytic activities.All yeast species showed lipolytic activity,while proteolytic activity against meat protein was only detected in S.cerevisiae.Assay of aroma-producing potential was performed in a model simulating fermented sausage condition.Inoculation of yeast strains increased volatiles production,especially esters and alcohols.The highest ester production was observed in S.cerevisiae Y70 strain,followed by K.exigua Y12 and K.bulderi Y19.C.zeylanoides Y10 and S.cerevisiae Y70 were the highest producers of benzeneethanol and 3-methyl-1-butanol.S.cerevisiae Y70 with its highest production of branched alcohols and esters could be a promising candidate as aroma enhancer in the manufacture of fermented sausages.

Applications of multislice CT angiography in the surgical clipping and endovascular coiling of intracranial aneurysms

Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography （CTA） in the surgical and endovascular treatment of intracranial aneurysms.A total of 195 cases with 206 intracranial aneurysms underwent CTA.Fifty （24%） aneurysms underwent surgical clipping while 156 （76%） aneurysms underwent endovascular coiling.In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas,surgical treatment was successfully performed based on 16-slice CTA alone,and the other 36 aneurysms were clipped on the main basis of the CTA.The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully.Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms.

The clinical application of multi-slice spiral CT angiography in abdominal aortic disease

Objective： To evaluate the clinical application of multi-slice spiral CT angiography（MSCTA） in the assessment of abdominal aortic disease. Methods： Fifty-four patients underwent multi-slice spiral CT angiography of abdomen. Contrast agent （Omnipaque 300 I g/L） 1.5 ml/kg was injected and the injection rate was 3 ml/s. The delay time was determined by bolus tracking technique, Tll level abdominal aorta was set as the target vessel and the threshold was 180-200Hu, slice width was 3mm and with a pitch of 4-6. Original data were transferred to working-station to perform functional reconstruction. Results： Ten cases were normal, twenty-eight cases were abdominal aortic aneurysms, five abdominal aortic dissecting aneurysms （Debakay type Ⅲ） and eleven aortic sclerosis. SSD showed the body of aneurysm and the relationship between aneurysm and adjacent blood vessel, MIP better displayed calcification of blood vessel wall and condition of the stent, MPR demonstrated true and false lumen, rapture site of abdominal aorta intima and mural thrombus. Conelusion： MSCTA axial and reconstruction image can show the extent of abdominal aortic disease and the relationship with adjacent blood vessels. It is a safe, simple and non-invasive examination method.

Influence of Axial Loads to Propagation Characteristics of the Elastic Wave in a Non-Uniform Shaft

The vibration propagates through the shaft in the form of elastic waves. The propagation characteristics of the elastic waves are a ected by the axial loads. The influence of the axial loads to the propagation characteristics of the elastic waves is studied in this paper. Firstly, the transfer matrix of the elastic waves for the non-uniform shaft with axial loads is deduced by combining the transfer matrix without axial load and the additional equation caused by the axial load. And then, a numerical method is used to study the influence of the axial load, non-uniformity and the rotating speed to the propagation characteristics of the elastic waves. It’s found that a new Stop Band will appear due to the axial force, and the central frequency of which will decrease as the increase of the force, while the band width of which remains the same. The central frequency of the new Stop Band will also increase as the increase of the cross-section area ratio;however, the rotating speed of the shaft doesn’t a ect the propagation characteristics of the elastic waves obviously. Finally, an experimental rig is built up for further study, even though there are some small local errors, the results of experiments match well with the numerical ones, which indicates the validation of the theoretical results. The result can help to study the influence of the axial load to the dynamics of a non-uniform shaft and help to reveal the vibration propagating mechanism in such a shaft.

Corner Transition Toolpath Generation Based on Velocity-Blending Algorithm for Glass Edge Grinding

Sharp corners usually are used on glass contours to meet the highly increasing demand for personalized products,but they result in a broken wheel center toolpath in edge grinding.To ensure that the whole wheel center toolpath is of G1 continuity and that the grinding depth is controllable at the corners,a transition toolpath generation method based on a velocity-blending algorithm is proposed.Taking the grinding depth into consideration,the sharp-corner grinding process is planned,and a velocity-blending algorithm is introduced.With the constraints,such as traverse displacement and grinding depth,the sharp-corner transition toolpath is generated with a three-phase motion arrangement and with confirmations of the acceleration/deceleration positions.A piece of glass with three sharp corners is ground on a three-axis numerical-control glass grinding equipment.The experimental results demonstrate that the proposed algorithm can protect the sharp corners from breakage efficiently and achieve satisfactory shape accuracy.This research proposed a toolpath generation method based on a velocity-blending algorithm for the manufacturing of personalized glass products,which generates the transition toolpath as needed around a sharp corner in real time.

A 600W Broadband Doherty Power Amplifier with Improved Linearity for Wireless Communication System

An asymmetric Doherty architecture based on three identical transistors is proposed in this paper. This proposed three.way topology reduces the difficulty in designing matching networks brought by the low optimal impedance of high power transistors. And the inverted Doherty topology as well as carefully chosen value of load impedance makes it possible to extend the bandwidth of high power amplifiers. Besides, bias networks of this proposed three.way architecture are also carefully considered to improve the linearity. The proposed high power three.way Doherty power amplifier(3W.DPA) is designed and fabricated based on theoretic analysis. Its maximum output power is about 600 Watts and the drain efficiency is above 35.5% at 9d B back off output power level from 1.9GHz to 2.2 GHz and the saturated drain efficiency is above 47% across the whole frequency band. The measured concurrent two.tone results suggest that the linearity of DPA is improved by at least 5d B.

A spring-like interface between saturated frozen soil and circular tunnel lining under the moving load in cold regions without considering frost heave

The vibration of underground or buried piping during construction and long-term operation causes secondary disasters,and becomes more complex when tubes are buried in cold regions.The interface between saturated frozen soil and lining is regarded as a thin spring-like layer whose thickness could be negligible.In this paper,the dynamic response of saturated frozen soil is studied in frequency domain by using the Helmholtz composition and Fourier transform to obtain analytical solutions of the radial and axial displacement,as well as expressions of the stiffness coefficient(Kr)and damping coefficient(Cr)of the spring-like interface.Numerical results indicate that Krand Crare related to physical properties of the lining and its surrounding soil,and the coefficients of the springlike model could be changed by adjusting lining parameters to improve structure stability under the same load conditions.Also,the viscoelastic contact surface of the spring-like model is considered to have less effect on the surrounding soil than that when the lining has complete contact with the soil under load.The degree of soil freezing significantly affects the axial and radial displacement of the soil when the interface between lining and unsaturated frozen soil is taken into consideration.

A Survey of Development and Features of Ganzhou Orange Industrial Clusters in China

Ganzhou Orange Industrial Clusters （GOIC for short） is mainly characterized as follows. （1）The Government＇s driving force is the key factor for the formation and development of GOIC; （2）the interaction between market and industry; （3）the specific geography and natural resources act as a carrier; （4）with a strong sense of innovation; （5）it is still at the early stage of development, with a certain high cost.

Pathological progression of osteoarthritis:a perspective on subchondral bone

Osteoarthritis(OA)is a degenerative bone disease associated with aging.The rising global aging population has led to a surge in OA cases,thereby imposing a significant socioeconomic burden.Researchers have been keenly investigating the mechanisms underlying OA.Previous studies have suggested that the disease starts with synovial inflammation and hyperplasia,advancing toward cartilage degradation.Ultimately,subchondral-bone collapse,sclerosis,and osteophyte formation occur.This progression is deemed as“top to bottom.”However,recent research is challenging this perspective by indicating that initial changes occur in subchondral bone,precipitating cartilage breakdown.In this review,we elucidate the epidemiology of OA and present an in-depth overview of the subchondral bone’s physiological state,functions,and the varied pathological shifts during OA progression.We also introduce the role of multifunctional signal pathways(including osteoprotegerin(OPG)/receptor activator of nuclear factor-kappa B ligand(RANKL)/receptor activator of nuclear factor-kappa B(RANK),and chemokine(CXC motif)ligand 12(CXCL12)/CXC motif chemokine receptor 4(CXCR4))in the pathology of subchondral bone and their role in the“bottom-up”progression of OA.Using vivid pattern maps and clinical images,this review highlights the crucial role of subchondral bone in driving OA progression,illuminating its interplay with the condition.

Targeted mutagenesis in Arabidopsis and medicinal plants using transposon-associated TnpB^(FA)

Medicinal plants produce valuable compounds, but often at low concentrations. Genome editing could be used to increase the production of valuable secondary metabolites in medicinal plants. The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9(Cas9) system has emerged as a simple, widely used method for gene editing in plants.

功放数字预失真线性化技术发展趋势与挑战

射频功率放大器是发射机的核心器件之一,它在提供高效率的同时也成为了发射机非线性失真的主要来源.因此,发射机往往采用额外的功放线性化技术以兼顾效率和线性度,其中,数字预失真技术以其高精度、稳定、可灵活配置等优势成为目前应用最广泛、应用效果最好的一类线性化技术.本文从数字预失真的基本原理和关键技术出发,回顾了数字预失真技术近三十年的发展历程,探讨了目前数字预失真发展面临的关键技术挑战,为今后的研究提供了参考.

Novel dual inhibitors against FP-2 and PfDHFR as potential antimalarial agents: Design, synthesis and biological evaluation

Resistance to malaria parasites has quickly developed to almost all used antimalarial drugs. Cysteine protease falcipain-2(FP-2) and Plasmodium falciparum dihydrofolate reductase(PfDHFR) have crucial roles, which are absolutely necessary, in the parasite life cycle. In this study, based on the uniform pharmacophores of reported PfDHFR inhibitors and the first-generation dual inhibitors against FP-2 and PfDHFR, we identified a novel series of dual inhibitors through fragments assembly. Lead optimization led to the identification of 14, which showed potent inhibition against FP-2 and PfDHFR enzyme(IC_(50)= 6.8 + 1.8 mmol/L and IC_(50)= 8.8 + 0.3 mmol/L) and P. falciparum 3D7 strain(IC50= 2.9mmol/L).Additionally, 14 exhibited more potent inhibition to the proliferation of chloroquine-resistant P.falciparum Dd2 strain(IC_(50)= 1.1 mmol/L) than pyrimethamine(IC_(50)>10 mmol/L), and 14 displayed micromolar inhibitory activities against two clinical isolated strains Fab9(IC_(50)= 2.6 mmol/L) and GB4(IC_(50)= 1.0 mmol/L). Collectively, these data demonstrated that 14 might be a good lead compound for the treatment of malaria.

需求与资源的“拔河”:中国台湾地区《长照2.0计划》资格规则评析与启示

中国台湾地区的长期照顾制度自20世纪80年代开始实施,历经近40年的发展,逐步形成了以老年人为中心的多层次照顾体系。该制度通过整合照顾系统,提供从居家、社区到机构照顾的多元连续服务。服务对象在坚持以失能者为主体的同时,也逐步惠及健康、衰弱等老人及家庭照顾者。《长照2.0计划》是台湾地区现行的主导性照顾政策,自2017年正式施行,至今已有三年。为评析该计划的效果,本文从资格规则这一政策元素切入,整合吉尔伯特和特勒尔及钱伯斯和邦克的理论构建分析框架,以进行全面评析。研究发现,在描述性分析上,《长照2.0计划》资格规则综合采用长照需要等级、收入、年龄、地理分布、非正式照顾、民族六个操作标准,体现了归因性需求、补偿、诊断差异、资产调查需求四个福利分配原则,建立了一套多层分类的准普及差异化资格规则体系;而在评价性分析上,其社会效益比较明显,但因受制于资源的有限性,其成本效益堪忧。总体而言,《长照2.0计划》陷入了照顾需求满足最大化与照顾资源有限的"拔河"中。最后,本文参考台湾地区经验并考察中国大陆实况,提出几项具体建议。