5G候选波形Filtered-OFDM技术子带滤波器设计与分析

Filtered-OFDM是中国华为公司提出来的一种5G波形技术,它采用子带级滤波来减少带外泄露,且各个子带参数可灵活配置,能适应5G多样化的应用场景。Filtered-OFDM子带滤波器的设计对系统性能有着重要的影响,研究和分析了不同子带滤波器类型和滤波器长度下的系统性能,结果表明滤波器长度越长,系统误码率越低,但系统设计也更加复杂。     

Pluronic lecithin organogel of 5-aminosalicylic acid for wound healing

5-Aminosalicylic acid (5-ASA) is an aminosalicylate anti-inflammatory drug, which is also known as mesalazine or mesalamine. Currently employed in treating inflammatory bowel disease, ulcerative colitis, inflamed anus or rectum, and maintain remission in Crohn's disease. Evidence from the researchers highlighted its significant re-epithelization in allergic asthma, aphthous, and gastric ulcerative conditions. The objective of the study was to formulate the pluronic lecithin organogel (PLO) containing 5-ASA and evaluate its wound-healing ability in a full thickness excision wound rat model. The data obtained from in silico docking studies revealed 5-ASA is having an affinity towards the transforming growth factor-beta (TGF-β) specifically towards beta1. Among various formulations prepared (F1 to F8), F1, and F6 have shown a maximum in vitro drug release with optimum pH and viscosity. From MTT assay it was found that selected PLO formulations showed no toxicity and enhanced cell proliferation in HaCaT cell lines. In vivo wound-healing studies in albino Wistar rats has revealed that PLO accelerates wound closure and reepithelization to the statistically significant level on day 3 (p?相似文献   

CDM-系列开窗导流式催化精馏模块在C4/C5醚化等反应中的工业应用

CDM-系列开窗导流式催化精馏模块具有优异的"催化反应"和"组分分离"双重功能,综合性能优于催化蒸馏组件CDP,是其升级换代产品。可应用于甲基叔丁基醚、轻汽油醚化、异丁烯叠合和叔丁醇脱水等工艺中,主要介绍CDM-系列开窗导流式催化精馏模块产品特点及在工业装置中的应用情况。     

钽表面铜掺杂Ta2O5纳米棒的制备及抗菌性能研究

本实验采用两步水热法在钽基体表面制备出掺杂Cu_²⁺的Ta₂O₅纳米棒薄膜。采用XRD、SEM、XPS等方法分析了材料的物相和表面微观结构。用ICP检测了样品在生理盐水中离子析出浓度,最后通过平板计数法检验了不同含量铜掺杂Ta₂O₅薄膜的抗菌能力。结果表明,通过两步水热处理,在钽表面生成了简单斜方晶体结构的Ta₂O₅纳米棒阵列,Cu_²⁺的掺杂不会对纳米棒薄膜的微观形貌和物相造成显著影响。随时间的增加,掺铜薄膜的铜离子析出速率逐渐趋于平缓。平板计数法表明,Cu_²⁺ 的掺杂量达到2.68At%时,铜掺杂Ta₂O₅纳米棒薄膜的抗菌性能最好,抗菌率达99.2%。     

Effect of α phase morphology on fatigue crack growth behavior of Ti−5Al−5Mo−5V−1Cr−1Fe alloy

Taking a Ti−5Al−5Mo−5V−1Cr−1Fe alloy as exemplary case, the fatigue crack growth sensitivity and fracture features with various tailored α phase morphologies were thoroughly investigated using fatigue crack growth rate (FCGR) test, optical microscopy (OM) and scanning electron microscopy (SEM). The tailored microstructures by heat treatments include the fine and coarse secondary α phase, as well as the widmanstatten and basket weave features. The sample with coarse secondary α phase exhibits better comprehensive properties of good crack propagation resistance (with long Paris regime ranging from 15 to 60 MPa·m^1/2), high yield strength (1113 MPa) and ultimate strength (1150 MPa), and good elongation (11.6%). The good crack propagation resistance can be attributed to crack deflection, long secondary crack, and tortuous crack path induced by coarse secondary α phase.     

Comprehensive mutagenesis on yeast cytosine deaminase yields improvements in 5-fluorocytosine toxicity in HT1080 cells

Improved prodrug-activating enzymes have the potential to increase the therapeutic efficacy of gene-directed enzyme prodrug therapy (GDEPT). Yeast cytosine deaminase (yCD) is commonly used to convert the prodrug 5-fluorocytosine (5-FC) to the chemotherapeutic 5-fluorouracil for GDEPT. Mutagenesis studies on yCD aimed at improving its application in GDEPT have been limited to subsets of residues or have sought to improve a single property of the enzyme. We performed comprehensive site-saturation mutagenesis (CSM) on yCD designed to create all 2,983 possible unique protein mutants with a single amino acid substitution. We identified active variants through Escherichia coli genetic complementation and screened these mutants, and combinations thereof, for increased ability to sensitize E. coli and HT1080 fibrosarcoma cells to 5-FC. Several mutants identified in this study showed increased sensitization ability for both E. coli and HT1080 cells indicating that CSM is an effective directed evolution tool for identifying unexpectedly beneficial mutations.     

胡尖山地区长4+5层油气富集控制因素研究

胡尖山地区长4+5油层组储层非均质性强、物性差异较大,开展该区储层地质特征研究,尤其是针对胡尖山地区长4+5油层组的构造形态、储层特征、孔隙类型、油藏类型的研究,分析原油的分布特征,总结原油富集区的聚集特征、重点分析分布特征及控制因素,得到胡尖山地区长4+5层油气富集的规律,可加深对优质储层形成机理和分布规律的认识,为油藏勘探开发提供有利的方向。     

Nonoxidative methane activation,coupling, and conversion to ethane,ethylene, and hydrogen over Fe/HZSM‐5, Mo/HZSM‐5, and Fe–Mo/HZSM‐5 catalysts in packed bed reactor

A high abundance of methane and its relatively low price make it an attractive raw feedstock for the production of ethylene, which is in the consumer demand in recent years. Direct catalytic nonoxidative conversion is interesting, because it could be utilized on natural gas well sites. Monometallic and bimetallic Fe and Mo catalysts were prepared for the purpose of the coupling to ethane and ethene. Three supported materials were synthesized with the following loading of metal: 2.5‐wt% Fe, 5.0‐wt% Fe, and 2.5‐wt% Mo on HZSM‐5. Process' chemical reactions were also catalyzed with a constant 2.5‐wt% Mo/HZSM‐5, which had different amounts of Fe, namely, 0.5, 1.0, and 2.5 wt%. Fourier transform infrared (FTIR), N₂ adsorption/desorption, NH₃ temperature‐programmed desorption (TPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X‐ray diffraction (XRD) were applied for characterization. Coke, accumulated on spent solids, was determined by thermogravimetric analysis (TGA). Activity was evaluated in quartz‐packed bed reactor. All surfaces suffered from deactivation due to carbon formation. The addition of Fe to Mo increased CH₄ reacted. The highest selectivity for alkenes was achieved over 1.0‐wt% Fe to 2.5‐wt% Mo/HZSM‐5. At the peak of performance, the C‐based reactivity was 52% for olefins and 2% for alkanes. Stability was accomplished over 2.5‐wt% Fe/HZSM‐5, where the rate of C₂ synthesis was comparatively stable for 20 hours of the time on stream. The selective C‐basis yield for C₂H₄ and C₂H₆ was 36% and 23%, respectively. The lowest measured quantity of (carbonaceous) by‐products was deposited on 2.5‐wt% Fe/HZSM‐5 after 26 hours. Propylene was detected very limitedly.