3～5 GHz超宽带无电感CMOS低噪声放大器设计

基于TSMC O.18μm RFCMOS工艺设计了一种无电感并联负反馈的超宽带低噪声放大器(LNA).在3～5 GHz工作频率范围内,电阻电流复用技术为整体电路提供自偏置,使其在足够的带宽范围内均可实现较高增益;同时噪声相消技术又可消除部分沟道热噪声,在很大程度上降低了放大器的噪声系数,由仿真结果可以看到:LNA在3～5 GHz内实现了良好输入输出匹配和较好的线性度,同时得到了较好的电压增益和噪声性能;并且其在整个频带范围内增益达到11～13.9 dB,噪声系数小于4.6 dB.整个设计最大的优点是没有用到片上电感,使得芯片面积大大缩小,这对商业应用具有极大的吸引力。     

小波分解求取含噪混沌时间序列的关联维数

关联维数是一个混沌时间序列分析中很重要的参数,在分析了噪声对关联维数求取的影响后,提出了一种应用小波分解求取含噪混沌时间序列关联维数的方法,数值试验证实了我们这种方法的正确性与可行性.     

Network-Pharmacology-Based Study on Active Phytochemicals and Molecular Mechanism of Cnidium monnieri in Treating Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a malignancy with a high mortality rate globally. For thousands of years, Cnidium monnieri has been used to treat human ailments and is regarded as a veritable treasure trove for drug discovery. This study has investigated the key active phytochemicals and molecular mechanisms of Cnidium monnieri implicated in curing HCC. We utilized the TCMSP database to collect data on the phytochemicals of Cnidium monnieri. The SwissTargetPrediction website tool was used to predict the targets of phytochemicals of Cnidium monnieri. HCC-related genes were retrieved from OncoDB.HCC and Liverome, two liver-cancer-related databases. Using the DAVID bioinformatic website tool, Gene Ontology (GO) and KEGG enrichment analysis were performed on the intersecting targets of HCC-related genes and active phytochemicals in Cnidium monnieri. A network of active phytochemicals and anti-HCC targets was constructed and analyzed using Cytoscape software. Molecular docking of key active phytochemicals was performed with anti-HCC targets using AutoDock Vina (version 1.2.0.). We identified 19 active phytochemicals in Cnidium monnieri, 532 potential targets of these phytochemicals, and 566 HCC-related genes. Results of GO enrichment indicated that Cnidium monnieri might be implicated in affecting gene targets involved in multiple biological processes, such as protein phosphorylation, negative regulation of the apoptotic process, which could be attributed to its anti-HCC effects. KEGG pathway analyses indicated that the PI3K–AKT signaling pathway, pathways in cancer, proteoglycans in cancer, the TNF signaling pathway, VEGF signaling pathway, ErbB signaling pathway, and EGFR tyrosine kinase inhibitor resistance are the main pathways implicated in the anti-HCC effects of Cnidium monnieri. Molecular docking analyses showed that key active phytochemicals of Cnidium monnieri, such as ar-curcumene, diosmetin, and (E)-2,3-bis(2-keto-7-methoxy-chromen-8-yl)acrolein, can bind to core therapeutic targets EGFR, CASP3, ESR1, MAPK3, CCND1, and ERBB2. The results of the present study offer clues for further investigation of the anti-HCC phytochemicals and mechanisms of Cnidium monnieri and provide a basis for developing modern anti-HCC drugs based on phytochemicals in Cnidium monnieri.     

典型固废资源化与无害化处置技术

2021年我国产出约110亿吨固体废弃物,其中40亿吨为工业固体废弃物,12亿吨不同程度含有价金属,具有一定的回收利用价值。重点针对复杂多金属典型固废,介绍了国内外资源化与无害化处置技术,包括铜冶炼过程含砷物料、铅锌冶炼渣、废锂离子动力电池、废催化剂、电镀污泥和氰化渣等典型固废。目前,我国已初步建立了典型固废特别是危废的处置体系,但存在处置能力不足、技术装备参差不齐、处理不彻底、经济性差等问题,未来发展趋势将向着规模化、高温无害化、协同冶炼等方向发展。     

Efficient branch-and-bound algorithms on a two-level memory system

Branch-and-bound algorithms in a system with a two-level memory hierarchy were evaluated. An efficient implementation depends on the disparities in the numbers of subproblems expanded between the depth-first and best-first searches as well as the relative speeds of the main and secondary memories. A best-first search should be used when it expands a much smaller number of subproblems than that of a depth-first search, and the secondary memory is relatively slow. In contrast, a depth-first search should be used when the number of expanded subproblems is close to that of a best-first search. The choice is not as clear for cases in between these cases are studied. Two strategies are proposed and analyzed: a specialized virtual-memory system that matches the architectural design with the characteristics of the existing algorithm, and a modified branch-and-bound algorithm that can be tuned to the characteristic of the problem and the architecture. The latter strategy illustrates that designing a better algorithm is sometimes more effective that tuning the architecture alone     

Hybrid Electrolyte Design for High-Performance Zinc–Sulfur Battery

Rechargeable aqueous Zn/S batteries exhibit high capacity and energy density. However, the long-term battery performance is bottlenecked by the sulfur side reactions and serious Zn anode dendritic growth in the aqueous electrolyte medium. This work addresses the problem of sulfur side reactions and zinc dendrite growth simultaneously by developing a unique hybrid aqueous electrolyte using ethylene glycol as a co-solvent. The designed hybrid electrolyte enables the fabricated Zn/S battery to deliver an unprecedented capacity of 1435 mAh g⁻¹ and an excellent energy density of 730 Wh kg⁻¹ at 0.1 Ag⁻¹. In addition, the battery exhibits capacity retention of 70% after 250 cycles even at 3 Ag⁻¹. Moreover, the cathode charge–discharge mechanism studies demonstrate a multi-step conversion reaction. During discharge, the elemental sulfur is sequentially reduced by Zn to S²⁻ (${\mathrm{S}}_8\to {\mathrm{S}}_{\mathrm{x}}^{2-}\to {\mathrm{S}}_2^{2-}+{\mathrm{S}}^{2-})$, forming ZnS. On charging, the ZnS and short-chain polysulfides will oxidize back to elemental sulfur. This electrolyte design strategy and unique multi-step electrochemistry of the Zn/S system provide a new pathway in tackling both key issues of Zn dendritic growth and sulfur side reactions, and also in designing better Zn/S batteries in the future.     

Fault coupling in finite bijective functions

Fault-based testing attempts to show that particular faults cannot exist in software by using test sets that differentiate between the original program (hypothesized to be correct) and faulty alternate programs. The success of this approach depends on a number of assumptions, notably that programmers are competent insofar as they only commit relatively trivial faults, and that faults only couple infrequently. Fault coupling occurs when test sets are able to differentiate between the original program and faulty alternate programs when faults occur in isolation, but not when they occur in combination; it is a complicating factor in fault-based testing. Fault coupling is studied here within the context of finite bijective functions. A complete mathematical solution of the problem is possible in this simplified case; the results indicate that fault coupling does indeed occur infrequently, and are thus in agreement with the empirical results obtained by others in the field. One surprising result is that certain kinds of test set are able to avoid fault coupling altogether.     

分银炉富氧精炼贵铅梯级脱杂试验研究

基于贵铅中杂质元素与氧亲和力的差异，采用富氧熔炼技术梯级脱除分银炉内贵铅中的杂质，考察氧气浓度对分银炉氧化精炼脱砷锑段、脱铋段、脱铜段的炉期、炉渣、脱杂速率的影响。结果表明：在脱砷锑段氧气浓度25%～30%、脱铋段氧气浓度50%～70%、脱铜段氧气浓度70%～88%的条件下，脱砷锑段、脱铋段、脱铜段的炉期分别为2.48、2.48、0.81 d,炉渣分别为0.78、4.77、0.52 t,砷、锑、铋、铜脱除速率分别为8.75、43.75、80.00、27.34 kg/h;贵铅在分银炉上采用富氧精炼梯级脱杂，可缩短分银炉炉期2～3 d,提高分银炉的处理能力，降低银精炼生产作业成本。     

搅拌摩擦焊过程数学模型建立的影响因素及现状

在此主要研究搅拌摩擦焊过程数学模型建立的几个重要影响因素，并结合工艺试验对国内外的研究现状和模型建立过程中涉及到的问题进行了阐述。结果发现，搅拌摩擦焊的焊接工艺参数、搅拌头探针产生的热量等都对温度场模型的建立起着重要作用。另外，轴肩与工件的摩擦系数、搅拌头轴肩的压力、搅拌头探针的形状都影响着焊缝的成形质量和焊缝区流场模型的建立。