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Objective To investigate the relationship between oral glucose tolerance test (OGTT) findings and short-term adverse pregnancy outcomes among women with gestational diabetes mellitus. Methods We retrospectively collected 387 cases of pregnant womenwith gestational diabetes mellitus from 2020 to 2021 at the Maternity & Child Care Center of Dezhou and analyzed laboratory results. According to OGTT values, patients were divided into three groups, and pregnancy outcomes were analyzed; these included gestational weight gain, gestational hypertension, cesarean section, preterm birth, dead fetus, fetal distress, fetal growth restriction, congenital disabilities, macrosomia, and low birth weight. In group 1, 277 patients had abnormal OGTT values, and short-term adverse outcomes were studied. Results Three abnormal OGTT points were accompanied by significant gestational weight gain, gestational hypertension incidence, and low birth weight incidence; the risks of cesarean section and preterm birth increased. Abnormal fasting plasma glucose was associated with gestational hypertension. Conclusion OGTT findings can be used to alert clinicians to short-term adverse outcomes in mothers and infants. Clinicians should be aware of abnormal OGTT findings.

The fall armyworm (Spodoptera frugiperda), a destructive pest that originated in South and North America, spread to China in early 2019. Controlling this invasive pest requires an understanding of its population structure and migration patterns, yet the invasion genetics of Chinese S. frugiperda is not clear. Here, using the mitochondrial cytochrome oxidase subunit I (COI) gene, triose phosphate isomerase (Tpi) gene and eight microsatellite loci, we investigated genetic structure and genetic diversity of 16 S. frugiperda populations in China. The Tpi locus identified most S. frugiperda populations as the corn-strains, and a few were heterozygous strains. The microsatellite loci revealed that the genetic diversity of this pest in China was lower than that in South America. Furthermore, we found moderate differentiation among the populations, distinct genetic structures between adjacent populations and abundant genetic resources in the S. frugiperda populations from China sampled across 2 years. The survival rate of S. frugiperda was significantly higher when it was fed on corn leaves than on rice leaves, and the larval stage mortality rate was the highest under both treatments. Our results showed that S. frugiperda probably invaded China via multiple independent introductions and careful pesticide control, continuous monitoring and further studies will be needed to minimize its potential future outbreak.

Zhong Wang,1,* Kai Yuan,1,* Yan-Bin Ji,2,* Su-Xia Li,3 Le Shi,1 Zhe Wang,1 Xin-Yu Zhou,4 Yan-Ping Bao,3 Wen Xie,5 Ying Han,3 Jie Shi,3 Lin Lu,1,3,6 Wei Yan,1 Wen-Hao Chen1 1Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Peking University, Beijing, 100191, People’s Republic of China; 2Department of Neurology, Qilu Hospital of Shandong University, Shandong University, Jinan, 250012, People’s Republic of China; 3National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, 100191, People’s Republic of China; 4Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People’s Republic of China; 5Mental Health Center of Anhui Province, Hefei, 230032, People’s Republic of China; 6Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wen-Hao Chen; Wei Yan Peking University Sixth Hospital/Peking University Institute of Mental Health, 51 Huayuanbei Road, Haidian District, Beijing, 100191, People’s Republic of ChinaTel +86-10-82801342; Tel +86-10-62723704Email chenwenhao@bjmu.edu.cn; weiyan@bjmu.edu.cnIntroduction: Accumulating evidence suggests that both sleep loss and gut dysbiosis can lead to metabolic disorders. However, less is known about the impact of total sleep deprivation (SD) and sleep recovery on the composition, function, and metabolic dynamics of the gut microbiota.Methods: Specific-pathogen free Sprague–Dawley rats were subjected to 48 h of SD with gentle handling and then allowed to recover for 1 week. Taxonomic profiles of fecal microbiota were obtained at baseline, 24 h of SD, 48 h of SD, and 1 week of recovery. We used 16S rRNA gene sequencing to analyze the gut microbial composition and function and further characterize microbiota-derived metabolites in rats.Results: The microbiota composition analysis revealed that gut microbial composition and metabolites did not change in the rats after 24 h of SD but were significantly altered after 48 h of SD. These changes were reversible after 1 week of sleep recovery. A functional analysis was performed based on Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations, indicating that 19 KEGG pathways were significantly altered in the gut microbiota in SD rats. These functional changes occurred within 24 h of SD, were more apparent after 48 h of SD, and did not fully recover after 1 week of sleep recovery.Conclusion: These results indicate that acute total SD leads to significant compositional and functional changes in the gut microbiota, and these changes are reversible.Keywords: gut microbiota, sleep deprivation, short-chain fatty acid, function prediction

AimsHuman skin is the first barrier against pathogens and environmental hazards and the highest contact frequency occurs with the hands. Environmental and personal metabolic factors may affect skin microbes. This study was conducted to clarify the diversity in the skin microbial community that was mainly due to individual skin metabolites rather than lifestyle and environmental factors.Methods and ResultsSkin microbiota samples were collected from 11 volunteers who met similar lifestyle inclusion criteria. The V3-V4 region of the 16S rRNA gene was amplified. After library construction and sequencing, we compared the composition and diversity of the hand skin microbiota in different sexes and BMI groups with bioinformation analysis. The whole sequence data were annotated as 42 phyla, 538 families, and 1215 genera. Four dominant phyla accounted for 97% of the total including Actinobacteriota (50.18%), Firmicutes (23.85%), Proteobacteria (21.64%) and Bacteroidota (2.05%). The genera that were detected in all subjects with high relative abundance were Cutibacterium, Staphylococcus, Corynebacterium, Streptococcus, Lawsonella, Enhydrobacter, Escherichia-Shigella, Asaia and Micrococcus.ConclusionsThe diversity and richness of the microbiota of male hand skin in our study was higher than that of females. Interestingly, Cutibacterium, Staphylococcus, and Corynebacterium might serve as important skin microbiota to distinguish sexes.

Phomopsis vexans, which causes Phomopsis blight of eggplant, has been reported worldwide. To study the biocontrol of this disease, 162 leaf and fruit samples of eggplant Phomopsis blight were collected from Hunan, Hubei, Jiangxi, Sichuan, Zhejiang, Fujian, Guangdong and Anhui Provinces from 2017 to 2019. Eighty-seven pathogenic fungus isolates were identified as P. vexans. The following studies were conducted: screening of sporulation medium, spore morphology analysis, mycovirus detection and identification of novel mycoviruses in these isolates. The results showed that eggplant tissue medium was the most suitable medium for rapid sporulation, and all isolates had mycoviruses consisting of mainly mixed infections. The genome of these mycoviruses varied from 1-15 kb. Five novel mycoviruses infecting P. vexans were obtained, including “Phomopsis vexans fusarivirus 1” (PvFV1), “Phomopsis vexans ourmia-like virus 1” (PvOLV1), “Phomopsis vexans endornavirus 2” (PvEV2), “Phomopsis vexans partitivirus 1” (PvPV1) and “Phomopsis vexans victorivirus L1” (PvVVL1). Thus, PvVVL1 displays a unique genome structure, and this is the first report of a victorivirus consisting of two segments and of a deltapartitivirus infecting the fungus host.

Background Patients with locally advanced oral squamous cell carcinoma (OSCC) failed to benefit from docetaxel, cisplatin and 5-fluorouracil (TPF) neoadjuvant chemotherapy prior to surgery and postoperative radiotherapy in our previous phase 3 trial (NCT01542931). The aim of the present study was to explore the prognostic value of Ki67 expression for individualized TPF neoadjuvant therapy. Methods Immunohistochemical staining of Ki67 was performed in the biopsies before treatment in the experimental arm of our previous phase 3 trial. A total of 65 patients with Ki67 expression below 25% or above 50% were retrospectively reviewed in this study. Kaplan‑Meier analysis, log-rank test and Cox proportional hazards model were used for survival analysis. Results Among the 65 patients enrolled in the study, the patients with high Ki67 expression (n = 41) before treatment exhibited higher overall survival (OS) (P = 0.041) and distant metastasis–free survival (DMFS) (P = 0.049) than those with low expression (n = 24). The 5-year OS of the two groups were 70.7% and 45.8% respectively (high vs low). Cox proportional hazards model showed that high Ki67 expression before TPF neoadjuvant chemotherapy had a positive impact on the OS (HR = 0.399, 95% CI: 0.178–0.893, P = 0.025). Conclusions High Ki67 expression before treatment could predict the survival benefits from TPF neoadjuvant chemotherapy prior to standard therapy in patients with locally advanced OSCC, which could act as a biomarker for individualized treatment.

BACKGROUND Forkhead box protein 1 (FOXP1) (OMIM: 605515) at chromosomal region 3p14.1 plays an important regulatory role in cell development and functions by regulating genetic expression. Earlier studies have suggested that FOXP1, an oncogene, is capable of initiating tumorigenicity depending on the cell type. FOXP1 also plays an important role in regulating the cell development and functions of the immune system, e.g., regulating B-cell maturation and mononuclear phagocyte differentiation, and in the occurrence and development of various immune diseases. The mRNA of this gene is widely expressed in humans, and its differential expression is related to numerous diseases. CASE SUMMARY A 5-year-old boy mainly presented with attention deficit and hyperactivity disorder and developmental retardation accompanied by gait instability and abnormal facial features (low-set ears). DNA samples were extracted from the child’s and his parents’ peripheral blood to detect whole-exome sequences and whole-genome copy number variations. Results revealed heterozygous deletions of exon 6-21 of FOXP1 gene in the child. Physical examination upon admission showed that the child was generally in good condition, had a moderate nutritional status, a slightly slow response to external stimuli, equally large and equally round bilateral pupils, was sensitive to light reflection, and had poor eye contact and joint attention. He had no meaningful utterance and could not pronounce words properly. He was able to use gestures to simply express his thoughts, to perform simple actions, and to listen to instructions. He had no rash, cafe-au-lait macules, or depigmentation spots. He had thick black hair and low-set ears. He had highly sensitive skin, especially on his face and palms. He had no abnormal palm fingerprint. Cardiopulmonary and abdominal examinations revealed no abnormalities. He had normal limb muscle strength and tension. He showed normal tendon reflexes of both knees. His bilateral Babinski and meningeal irritation signs were negative. He had a normal male vulva. CONCLUSION We report the characteristic features of autism with dysphasia accompanied by mental retardation caused by FOXP1 exon deletion. This study provides a molecular basis for etiological diagnosis and treatment of the child, as well as for genetic counseling for the pedigree.

Doherty power amplifiers (DPAs) [1] are widely used as basestation PAs in modern wireless communication systems and have been well-reviewed [2]. Due to its mechanism of load modulation, the DPA exhibits an additional efficiency peak at a certain output power back-off (OBO). This makes the DPA highly desirable for amplifying modulated signals with high peak-to-average power ratios (PAPRs). However, there still are limitations that restrict its use in modern and future wireless communication systems. To meet the insatiable demand for higher data rates, modulated signal formats require an everhigher PAPR (g6 dB). This, in turn, means that the DPA needs to operate at a greater OBO g6 dB). Hence, the design of extended back-off DPAs is of great interest to engineers. Broadband operation is also required, but, unfortunately, the DPA?s efficiency at back-off decreases with an increase in bandwidth. Therefore, a technique to achieve high efficiency at back-off, not at the expense of the bandwidth, is urgently needed.

This brief presents a novel design method of broadband continuous-mode Doherty power amplifier (CM-DPA) using compensation susceptance. In particular, at power back-off point, the compensation susceptance is added at the current source plane of the carrier PA to make it operates in continuous mode, which thus enhances the back-off efficiency and extends the bandwidth. Meanwhile, considering the influence of the parasitic parameters of the PA in practical design, the designed compensation susceptance at the current source plane is equivalently transformed into the compensation susceptance at the package plane of the carrier PA. Additionally, at saturation point, the load impedances at the package plane of both carrier and peaking PAs can meet the impedance conditions of drain efficiency more than 60%. Based on the proposed method, a 74% fractional bandwidth CM-DPA operating from 1.1 to 2.4 GHz is designed and measured. Under the continuous-wave excitation, the measured 6-dB back-off efficiency is 46.8%–63% and the saturation efficiency is 59.1%–78.8%. The measured small-signal gain and back-off gain are 10–12 dB and 9.1–10 dB, respectively.

Two compact and high selectivity balanced bandpass filters with excellent common mode rejection are designed in this brief. Compared with the half-wavelength microstrip transmission line, 180° phase shift is realized by two small swap structures, which are composed by double-sided parallel-strip line (DSPSL), and this way can easily realize a wideband common mode rejection with compact circuit size. Two out-of-band transmission zeros are introduced by the dual-mode ring resonator in the first proposed structure; thus, high selectivity can be achieved. In the second filter, shorted/open coupled microstrip lines are added between the dual-mode ring resonator and 180° swap structure, two additional transmission zeros can be achieved. Finally, two prototypes center at 2.2 GHz are fabricated, and the measured 3-dB bandwidths for the differential mode are 23.6% and 11.8%, respectively.

The study aimed to investigate the effects of galangin on learning and memory impairments and Akt/MEF2 D/Beclin-1 signaling pathway in APP/PS1 double-transgenic mice. The mice in this experiment were divided into the normal group, model group, low-(25 mg·kg~(-1)), medium-(50 mg·kg~(-1)), and high-dose(100 mg·kg~(-1)) galangin groups, donepezil(3 mg·kg~(-1)) group, Akt inhibitor(25 mg·kg~(-1)) group, and autophagy inhibitor(30 mg·kg~(-1)) group, with ten in each group, and administered with the corresponding drugs for 30 successive days. On the 24 th day of medication, the water maze and dark avoidance tests were performed. The levels of p-tau, β-amyloid peptide 1-42(Aβ_(42)), acetylcholinesterase(AChE), β-site amyloid precursor protein cleaving enzyme 1(BACE1), and amyloid precursor protein(APP) in hippocampus were detected by ELISA, the Beclin-1 mRNA expression by RT-PCR, the expression of Aβ_(42) and glial fibrillary acidic protein(GFAP) by immunohistochemistry, and the expression of myocyte enhancer factor 2 D(MEF2 D) by immunofluorescence assay. The pathological changes in hippocampus were observed after HE staining, and the expression of Akt, MEF2 D, and Beclin-1 in hippocampus were assayed by Western blot. These results showed that compared with the normal group, the model group exhibited prolonged swimming time, increased number of errors and electric shocks, up-regulated p-tau, Aβ_(42), APP, AChE, BACE1, GFAP, and Beclin-1, shortened incubation period, decreased p-Akt and MEF2 D, and obvious hippocampal injury. Compared with the model group, donepezil and galangin shortened the swimming time, reduced the number of errors and electric shocks, down-regulated the expression of p-tau, Aβ_(42), APP, AChE, BACE1, GFAP, and Beclin-1, prolonged the incubation period, up-regulated p-Akt and MEF2 D, and improved the pathological changes in hippocampus. Compared with the autophagy inhibitor group, galangin prolonged the swimming time, elevated the number of errors and electric shocks, enhanced the expression of p-tau, Aβ_(42), APP, AChE, BACE1, GFAP, and Beclin-1, shortened the incubation period, and diminished the expression of p-Akt and MEF2 D. In conclusion, galangin improves the learning and memory impairments and hippocampal neuron injury of APP/PS1 mice, which may be related to its regulation of Akt/MEF2 D/Beclin-1 signaling pathway.

This paper presents a new methodology for designing a broadband three-way Doherty power amplifier (DPA), which utilizes a reactance compensation generated by parallel peaking amplifiers to extend the bandwidth and improve the back-off efficiency. By analyzing the load impedance and efficiency of the reactance-compensated DPA, the optimal reactance at the output of the peaking amplifier required for bandwidth extension can be obtained. Then, a structure using two parallel peaking amplifiers is proposed to reduce the output reactance for the desired distribution. Using a $\lambda _{0}$ /4 transmission line, a sufficiently large output reactance of the peaking branch can be realized at the combining point over a wider frequency band, which can compensate the effective load impedance of the carrier amplifier and improve its efficiency and bandwidth. A wideband three-way DPA is designed and fabricated to verify the proposed method. Measurement results indicate that an efficiency of 50–53% at 10 dB output power back-off and a saturated efficiency of 54–68% can be achieved over the frequency range from 1.6 to 2.7 GHz.

Lithium-sulfur (Li-S) battery is a promising candidate for high-energy storage devices due to its high theoretical capacity and energy density. However, both structural change and drastic phase transfer arising from irreversible and unstable conversion between S/Li2S and polysulfides during cycling would lead rapid capacity decay and short cycle-life for lithium-sulfur battery. Herein, inspired by such principle of zippers, a self-healing zipper-like sulfur electrode was designed, which was fabricated by organo-polysulfide (-Sx-) polymer binder (PSPEG) and sulfur nanocomposite with organo-polysulfide (-Sx-) chains grafted on carbon host (CPS/S). The organo-polysulfide (-Sx-) chains on/in the carbon host or binder can not only function as redox mediator to control phase transfer between S/Li2S and polysulfides but also act as “zipper teeth” and “zipper sliders” respectively to repair the electrode spontaneously as the sulfur electrode suffered from mechanical damages and cracks. Owing to this unique zipper-like electrode design, the structural collapse and the agglomeration of S/Li2S were effectively suppressed. Consequently, the sulfur electrode exhibits both high capacity and excellent cycling stability, showing a specific capacity of 812 mA h g − 1 at 1.0 C after 300 cycles. Moreover, as the sulfur loading was increased to 7.6 mg cm−2, the CPS/S+PSPEG electrode can still deliver a high areal capacity of 6.47 mA h cm−2 with a low electrolyte/sulfur ratio (4.5:1, µL:mg) after 60 cycles, which verifies the feasibility of the zipper-like electrode design.

A novel polymycovirus isolating from plant-pathogenic fungus Colletotrichum gloeosporioides was identified. The virus were composed nine RNA segments, ranging from 699 bp to 2,444 bp, and except that RNA5 contains two open reading frames (ORF5-1 and ORF5-2), other RNA segement contain only one ORF. In addition,the proteins encoded by ORFs 1-8 were homologous to the protein encoded by ORFs 1-8 in Colletotrichum camelliae filamentous virus 1(CcFV-1) by BLASTp. The amino acid sequence between the RNA-dependent RNA polymerase (RdRp) encoded by ORF1 and the viral methyltransferase encoded by ORF3 shared 87.6% and 83.3% identity with CcFV-1. The proline-alanine-serine-rich protein (PASrp) encoded by ORF4 shows 86.6% sequence homology to that of CcFV-1. The sequence homology of proteins encoded by ORFs2, 5-1, 6, 7 and 8 with the corresponding proteins of CcFV-1 was 86.6%, 82.5%, 89.0%, 45.7% and 95.5%, respectively. However, RNA9 is a defective RNA of RNA2, missing the 1556 bp (nt 519 to nt 2074) intermediate fragment of RNA2. Phylogenetic analysis based on RdRp protein indicated that the virus, which is the phylogenetically closest relative of CcFV-1, clustered with members of the family Polymycoviridae, so we tentatively named it "Colletotrichum gloeosporioides polymycovirus virus 1" (CgPmV1). To our knowledge, this is the first report of a defective polymycovirus in C. gloeosporioides.

Previously, the bandwidth of conventional Doherty power amplifiers (DPAs) is limited by the phase dispersion of the microstrip impedance transformer (IT). To overcome this phase dispersion, minimization of the phase delay of the IT is required, however at the expense of load modulation bandwidth, which limits further bandwidth extension. In this article, we present a broadband Doherty-like PA topology that, for the first time, uses parallel right- and left-handed ITs. This satisfies the minimal phase delay requirement while simultaneously maintaining wideband load modulation. Consequently, the frequency range for load modulation can be significantly extended. For demonstration purposes, a Doherty-like PA prototype is realized using two identical 10-W GaN HEMTs. Measurement results show that a drain efficiency of at least 40% is achieved at 5.2–6-dB back-off from 1.25 to 2.30 GHz, which corresponds to a very wide bandwidth of ~60%.

Fifth-generation (5G) communication techniques are growing in popularity, and 5G will become the commercial operation standard for mainland China in 2020 [1]. As the next-generation mobile communication network, 5G will not only greatly improve communication efficiency; it will also change the way people live and work. The 5G communication system contains the millimeter-wave and sub-6-GHz bands. For the sub-6-GHz band, circuits are becoming ever more compact and multifunction; thus, electromagnetic interference and multicoupling problems will greatly affect the entire system's performance [2]-[4]. In response, balanced circuits with higher immunity to environmental noises [5]-[8], lower electromagnetic interference [9]-[11], and better dynamic range [12]-[15] have attracted increasing attention in the past few years, and a large number of balanced circuits are being conceived [16], [17]. Currently, all feature differential-mode input and output terminals, so they cannot be connected directly to single-ended circuits. Balanced filters, antennas, and power dividers that can be cointegrated with balanced active circuits are required for the development of fully balanced transmitter and receiver RF chains, such as the balanced power dividers that can be connected to a Doherty power amplifier in a balanced system. In this case, balancing is only necessary at the input and output stages. It is expected that the transistor stage is still a single-ended structure, where only two amplifier devices are needed [18].

Two dual-band branch line couplers with arbitrary power division are proposed in this brief. By adopting half-wavelength open/short-ended stubs in improved couplers, the dual-band operations could effectively be implemented while ensuring a compact size. Furthermore, the frequency is tunable by changing the characteristic impedance of the transmission line. For practical verification, two branch line coupler ( ${\varepsilon }_{r} = 2.65$ , ${h}= 0.5$ mm) operating at 0.9/1.8GHz and 0.9/1.57GHz are constructed in microstrip technology and tested. The measured results are in good agreement with the simulated ones.

A novel leaky wave endfire filtering antenna based on spoof surface plasmon polaritons (SSPPs) is proposed. The structure of leaky wave antenna consists of multiple radiating elements and one double-sided parallel strip line (DSPSL), and the filtering performance is realized by adding stubs with via holes. The structure with a periodic arrangement of the radiating elements has similar dispersion curves of SSPPs, which has low-pass transmission characteristic and also can radiate energy to the free space. According to the measured results, a peak gain of 8.65 dBi at a center frequency of 7.7 GHz and a bandwidth of 36.36% can be achieved for the leaky wave endfire filtering antenna based on SSPPs. The out-of-band rejection is over 13 dB.

Lithium–sulfur (Li–S) battery can satisfy the need of the future power battery market because of its high energy density, but the hidden dangers caused by lithium anode have seriously hindered their commercialization. Herein, an innovative gel polymer electrolyte (GPE) composed of polyvinylidene fluoride (PVDF) and organo-polysulfide polymer (PSPEG) is proposed, which could be used in semi-solid-state Li–S batteries for protection of Li anodes. Particularly, organo-polysulfide polymer could chemically/electrochemically generate both inorganic and organic components simultaneously in-situ once contacting fresh Li metal surface and/or during discharging processes. And these inorganic/organic components could participate in the formation of the SEI layer and finally constitute a stable and flexible hybrid SEI layer on the surface of Li metal anode. Moreover, the organic components were permselective to lithium ions against anions. Therefore, PVDF/PSPEG GPE ensures the ideal chemical and electrochemical properties for Li–S batteries. Our work demonstrates an effective solution to solve the problems about Li anodes and contributes to the development of the safe Li metal batteries.

To study the tensile strength of rock under different loading rates, direct tensile test is the most accurate method. However, the eccentric tension in the process of rock direct tensile test has a significant influence on the test results. In this paper, firstly, a self-developed centering device for rock direct tensile test is introduced, which can effectively eliminate the eccentric tension in the process of rock direct tensile test. Then, with the aid of the self-developed centering device, the direct tensile tests of red sandstone under the loading rates of 0.001 mm/s, 0.01 mm/s and 0.1 mm/s are successfully carried out. After tests, both the macro failure characteristics and the scanning electron microscope micrograph show that the fracture pattern of the rock is caused by pure tensile loading. The stress-strain curves of the direct tensile test of the red sandstone show that the process of the direct tensile test can be roughly divided into four stages. With the increase of loading rate, both of the tensile strength and the peak tensile strain of the rock increase obviously. The direct tensile test of the red sandstone shows obvious loading rate effect.

This article proposes a design methodology of dual-band outphasing power amplifier (OPA) based on two noncommensurate transmission lines (NCTLs). The devised NCTLs are used to replace the imperative reactance compensation and impedance matching networks in a conventional design. In virtue of this, the overall complexity of the combiner can be greatly reduced without sacrificing the load modulation effect. To support operations at two distinct frequencies, the conceptual NCTLs are further realized using two dual-band stub-loaded transmission lines. Comprehensive theoretical analysis is given to describe the proposed scheme and to illustrate how the electrical parameters of essential elements are determined. As a proof of concept, an OPA prototype operating at 2.6 and 3.5 GHz is fabricated. The implemented PA based on two 10-W GaN high electron mobility transistor (HEMTs) achieves 44.8 and 44.2-dBm maximum output power, and 74.5% and 62.1% peak drain efficiencies under continuous wave excitation at these two independent frequencies. At 6-dB output back-off points, the corresponding efficiencies reach 63.8% and 54.9%, respectively.

Bandpass power amplifiers (PAs) are typically implemented by a cascade of second-order topologies. To achieve a wide and flat passband response, the number of resonators must be increased, which leads to large size, high loss and low efficiency, especially at high frequencies. In this paper, a wideband Class-F−1 PA based on a microstrip multimode bandpass impedance transformer (BPIT) is proposed. The modified quad-mode BPIT operation enables the creation of multiple transmission poles using only a single resonator, thus simultaneously achieving a flat wideband response in a small size. In addition, the drain bias and input feed line of the BPIT are arranged to satisfy the harmonic-impedance requirement of the Class-F−1 amplifier. Two PA prototypes have been designed, fabricated, and measured, which exhibit desirable filtering characteristics centered at 3.5 and 3.6 GHz for 5G applications. The fabricated dual- and quad-mode circuits demonstrate large-signal gains of 11.5 dB and 12.6 dB, maximum power added efficiencies (PAEs) of 67.4% and 66.3%, respectively and, with output powers greater than 38.5 dBm. For operation with a PAE larger than 60%, the PAs achieve bandwidths of 150 and 250 MHz, respectively.

In a conventional Doherty Power Amplifier (DPA), harmonic isolation is typically required between the two transistors to prevent them from modulating each other at harmonic frequencies. Normally, the current is clipped at saturation, which results in poor in-band non-linearity, e.g. IMD3. Hence, mutual harmonic interaction is desirable when properly used to prevent current clipping in the active devices, thus improving linearity. In this paper, for the first time, a linearity enhancement technique for Doherty-like power amplifier (DLPA) based on harmonic interaction is presented. The proposed DLPA achieves an excellent trade-off between efficiency and in-band linearity. For demonstration purposes, a DLPA prototype is devised based on two identical 6-Watts gallium nitride HEMTs (CGH 40006P). Within the frequency band of 1.75 to 2.45 GHz, the DLPA achieves a measured power added efficiency (PAE) of greater than 45.0% and 61.9% at 6 dB output back-off and saturation, respectively. An IMD3 below −30 dBc and a PAE of greater than 53% is achieved near saturation under a two-tone signal excitation.

Because of its good stability, high strength and low permeability, granite is considered as an ideal surrounding rock for geological disposal of high-level radioactive waste, which is also the main candidate surrounding rock for high-level radioactive waste disposal project in China. Rock mechanics is one of the important problems for site selection, design, construction and operation of geological repository. It is of great theoretical and practical value to study the failure law of rock from the microcosmic aspect, to link the microcosmic failure morphology characteristics with the mechanical mechanism of rock macro fracture failure, and finally to establish a bridge between microcosmic failure mechanism and macro fracture analysis of rock. We carried out uniaxial compression test, triaxial compression test under different confining pressures, Brazilian splitting test and direct tensile test for the deep granite from the core of No. BS28 hole in Beishan area with depth of 560–680 m. SEM and EDS was carried out for the fracture surface under different test conditions. The macro and micro failure characteristics of granite under different test conditions are analyzed: It is basically the splitting failure phenomenon dominated by tensile failure after the uniaxial compression test, while the failure of the triaxial test specimen are basically all form a large inclined failure surface which show the shear failure phenomenon. It shows obvious brittle tensile failure under direct tensile test, while not simply tensile failure under Brazil split test. The micro structure and mineral composition of rocks are closely related to their macro mechanical properties. Due to the existence of other impurities, Beishan granite has a certain degree of discreteness, and because of the different composition, its fracture presents different forms. These studies provide the necessary basis for the design and construction of the geological disposal of high-level radioactive waste.

Modern wireless communication systems with large bandwidth and high peak-to-average power ratios (PAPRs) have been and will continue to be in high demand. This puts a strain on the transmitter, which has to operate with its average power in the output back-off (OBO) region. The Doherty power amplifier (Doherty PA) was invented in 1936 as an alternative to the highly inefficient linear amplifiers used in radio transmitters. The Doherty PA has recently undergone a renaissance, becoming the PA architecture of choice for mobile radio base stations. The additional efficiency peak at the OBO point makes it ideal for high PAPR signals. However, the main drawback of conventional Doherty PAs is its narrow bandwidth, which significantly limits its applicability. Recently, broadband Doherty PAs have been realized using a technique called "post-matching" and have attracted much attention. In this paper, the operating principles of conventional and broadband Doherty PAs are reviewed, followed by an analysis of recently reported prototypes, current technical challenges, and application in 5G wireless communication systems. As a comparison, process technologies for the implementation of Doherty PAs are also surveyed.

In this article, various types of six-port balanced rat-race couplers with wideband common-mode suppression characteristics are presented. In these couplers, the input and output ports can functionalize either as single-ended or differential terminals to realize different operational modes. The power-splitting ratio for these balanced couplers can be flexibly adjusted by means of the values of the characteristic-impedance parameters of their constituent transmission-line segments. Furthermore, the employment of double-sided-parallel-strip-line-(DSPSL)-based 180° phase inverters instead of half-wavelength transmission-line-based ones allows for the considerable enlargement of their operation bandwidth in more-compact circuits with lower in-band insertion-loss levels. For experimental-validation purposes, two microstrip prototypes at $f_{0}=0.9$ GHz with equal and unequal power division are fabricated and characterized. They exhibit common-mode rejection levels higher than 15 dB from 0 to 1.8 GHz (i.e., 0– $2f_{0}$ ) and differential-to-common- mode-conversion suppression levels above 15 dB within the spectral range 0–1.49 GHz (i.e., 0– $1.65f_{0}$ ).

Li–S batteries are considered as one of the most promising battery systems because of their large theoretical capacity and high energy density. However, the “shuttle effect” of soluble polysulfides and sluggish electrochemical redox kinetics of Li–S batteries could cause a broken electrode structure and poor electrochemical performance. Herein, a high-performance and stable Li–S battery has been demonstrated by employing organo-polysulfide chain modified acetylene black (ABPS) as the coating layer on the separator. In addition to the traditional advantages of fast electron transport and polysulfide-interception ability of the carbon coating layer, the grafted organo-polysulfide chain endows the ABPS coating layer with permselectivity for lithium ion against polysulfides, electrocatalytic ability for the sluggish redox kinetics and self-repairing ability for the broken electrode. Hence, the battery prepared using an ABPS-coated separator delivers the best cycling performance (970 mA h g−1 at 0.2 C after 100 cycles) and rate performance (805 mA h g−1 at 2 C) as compared to the cells using acetylene black (AB)-coated or Celgard separators. Moreover, the Li–S battery prepared using an ABPS-coated separator exhibits a stable cycling performance at 1 C over 500 cycles with a low degradation of 0.04% per cycle, and a high coulombic efficiency (near 100%). Furthermore, as the sulfur loading was increased to 6.8 mg cm−2, the Li–S battery using the ABPS-coated separator still could deliver a high areal capacity of 6.03 mA h cm−2 with a low electrolyte/sulfur ratio (E/S = 4, μLelectrolyte mgS−1) after 170 cycles. Significantly, ABPS is an effective coating layer material for improving and stabilizing Li–S batteries.