14,828 research outputs found

    High Current Matching over Full-Swing and Low-Glitch Charge Pump Circuit for PLLs

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    A high current matching over full-swing and low-glitch charge pump (CP) circuit is proposed. The current of the CP is split into two identical branches having one-half the original current. The two branches are connected in source-coupled structure, and a two-stage amplifier is used to regulate the common-source voltage for the minimum current mismatch. The proposed CP is designed in TSMC 0.18µm CMOS technology with a power supply of 1.8 V. SpectreRF based simulation results show the mismatch between the current source and the current sink is less than 0.1% while the current is 40 µA and output swing is 1.32 V ranging from 0.2 V to 1.52 V. Moreover, the transient output current presents nearly no glitches. The simulation results verify the usage of the CP in PLLs with the maximum tuning range from the voltage-controlled oscillator, as well as the low power supply applications

    Efficiency of Hybrid Algorithms for Estimating the Shear Strength of Deep Reinforced Concrete Beams

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    Earthquakes occurred in recent years have highlighted the need to examine the strength of reinforced concrete (RC) members. RC beams are one of the elements of reinforced concrete structures. Due to the dramatic increase in the population and the number of medium/high-rise buildings, in recent years, the beams of buildings have been mainly designed and executed in the type of deep beams. In this study, the artificial neural network (ANN) with optimization algorithms, including particle swarm optimization (PSO), Archimedes optimization algorithm (AOA), and sparrow search algorithm (SSA), are used to determine the shear strength of reinforced concrete deep (RCD) beams. 271 samples from experimental tests are employed to develop algorithms. The results of this study, design codes equations, and previous research are compared. Comparison between the results shows that the PSO-ANN algorithm is more accurate than previous methods. Finally, SHApley Additive exPlanations (SHAP) method is utilized to explain the predictions. SHAP reveals that the beam span and the ratio of the beam span to beam depth have the highest impact in predicting shear strength

    4-(1H-Pyrazol-3-yl)pyridine–terephthalic acid–water (2/1/2)

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    In the title compound, 2C8H7N3·C8H6O4·2H2O, the pyridine and pyrazole rings are approximately coplanar, the dihedral angle between them being 4.69 (9)°. The asymmetric unit consists of half of the terephthalic acid (an inversion centre generates the other half of the mol­ecule), one 4-(1H-pyrazol-3-yl)pyridine (4pp) mol­ecule and one water mol­ecule. In the crystal, two 4pp and one terephthalic acid mol­ecules form a linear three-molecule unit as a result of O—H⋯N hydrogen bonds. These units are further assembled into a three-dimensional network by two types of hydrogen bonds, viz. O—H⋯O and N—H⋯O

    Three-Dimensional Waveguide Splitters Inscribed in Nd:YAG by Femtosecond Laser Writing: Realization and Laser Emission

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    n this paper, we report on a three-dimensional beam splitter monolithically integrated in an Nd:YAG laser crystal wafer by applying the direct femtosecond laser writing technique with the photonic-lattice-like cladding approach, capable of 1 to 2 and 1 to 4 beam splitting. Using the pump at 808 nm, 1064-nm splitting lasers with slope efficiencies of 34% and 22% for 1 to 2 and 1 to 4 configurations were realized. This study paves a way to fabricate direct-pump compact laser devices in a single chip for light guiding and beam dividing in Nd:YAG crystals for various photonic applications.This work was supported by National Natural Science Foundation of China (No. 11274203) and Ministerio de Economía y Competitividad under Project FIS2013–44174-P, Spain

    Superficial waveguide splitters fabricated by femtosecond laser writing of LiTaO 3 crystal

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    We report on Y-branch superficial depressed-cladding waveguides fabricated by femtosecond laser writing of MgO∶LiTaO3 crystal. The cladding waveguides with a rectangular cross-section are single mode for both transverse electric and transverse magnetic polarization, and show good transmission properties at a telecommunication wavelength of 1.55 μm. Divergence angles as large as 2.6 deg are successfully achieved in the splitters with nearly equalized splitting ratios (1:1). The fabricated shallow structures are excellent photonic elements for optoelectronic applications.This work was supported by the National Natural Science Foundation of China (Grant No. U1332121) and Ministerio de Economía y Competitividad under Project FIS2013-44174-P, Spain

    Refined Partition Functions for Open Superstrings with 4, 8 and 16 Supercharges

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    We analyse the perturbative massive open string spectrum of even dimensional superstring compactifications with four, eight and sixteen supercharges. In each of such cases, we focus on universal states that exist independently on the internal geometry and other compatification details. We analytically compute refined partition functions that count these states at each mass level. Such refined partition functions are written in a super-Poincare covariant form, providing information on how supermultiplets transform under the little group and the R symmetry. Various asymptotic limits of the partition functions and their associated quantities, such as the leading and subleading Regge trajectories, are studied empirically and analytically. In the phenomenologically relevant case of four supercharges, the partition function can be cast into the most compact form and the asymptotic formula in the large spin limit is derived explicitly.Comment: 65 pages (with 26 pages of appendices) and 7 figure

    Protective Mechanism of Luteinizing Hormone and Follicle-Stimulating Hormone Against Nicotine-Induced Damage of Mouse Early Folliculogenesis

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    Previous studies have shown that nicotine could impair the germ cell cyst breakdown and the primordial follicle assembly by autophagy. In this paper, we discovered that luteinizing hormone (LH) and follicle-stimulating hormone (FSH) could counteract the damage caused by nicotine of mouse germ cell cyst breakdown. The neonatal mice were separately intraperitoneally injected with nicotine, nicotine plus LH, nicotine plus FSH, and saline (control) for 4 days. Compared with the nicotine group, the quality of oocytes and the number of follicles were remarkably increased in the nicotine plus LH group or nicotine plus FSH group. LH and FSH could alleviate nicotine-induced oocyte autophagy by different pathways. LH reduced the nicotine-induced autophagy by restoring the phosphorylation level of adenosine 5 '-monophosphate-activated protein kinase alpha-1, while FSH by downregulating the phosphorylation level of Forkhead box class O 1. In addition, in a subsequent study of 6-week mice in different treated groups, we found that LH and FSH supplementation significantly improved normal maturation rates, fertilization rates, and embryo's developmental potential of oocytes in oocytes exposed to nicotine. Taken together, these results suggested that LH and FSH could counteract the damage caused by nicotine and finally ensure normal germ cell cyst breakdown and early embryo development

    Association of Intrarenal B-Cell Infiltrates with Clinical Outcome in Lupus Nephritis: A Study of 192 Cases

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    Background. Lupus nephritis (LN) remains a major cause of morbidity and end-stage renal disease. Dysfunction of B lymphocytes is thought to be important in the pathogenesis of SLE/LN. Intrarenal B cells have been found in several forms of inflammatory kidney diseases although their role in LN renal is not well defined. Methods. Intrarenal B cells were analyzed in 192 renal biopsies from patients diagnosed with lupus nephritis. Immunohistochemical staining of serial sections was performed for each LN patient using CD20, CD3, and CD21 antibodies. Results. Intrarenal B cells were more likely to be associated with class IV LN and were mainly distributed in the renal interstitium, with very few in the glomerulus. The systemic lupus erythematosus disease activity index (SLEDAI), blood urea nitrogen, and serum creatinine levels were all significantly greater in the LN-B cell groups (all P<0.05). LN renal activity and chronicity indices correlated with B-cells infiltrates (all P<0.0001). Renal biopsies were classified into four distinct categories according to the organizational grade of inflammatory cell infiltrates. Germinal center- (GC-) like structures were not identified in any LN biopsies. Conclusion. It is hypothesized that intrarenal B cells enhance immunological responses and exaggerate the local immune response to persisting autoimmune damage in the tubulointerstitium
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