《中国腐蚀与防护学报》1987—1988年总目录

1 987年第7卷期a一Fe:03、Fe:0;和Cr20:在熔融Na:50‘中的溶解度...........................……,..................................……张允书RobertA。RaPP热浸镀55多Al一Zn合金过程中化合物层生长动力学分析.........................................................…….........................·.··.……孟荣祥杨熙珍(Fa一3终51单晶I型试样的氢致开裂.................................................·.……”.“.“·~……张统一褚式扬马仁燕肖纪美(19不锈钢裸表面在氯化物溶液中钝化的动力学规律和机理研究”.....…     

Restorable Type Conversion of Carbon Nanotube Transistor Using Pyrolytically Controlled Antioxidizing Photosynthesis Coenzyme

Here, a pyrolytically controlled antioxidizing photosynthesis coenzyme, β‐Nicotinamide adenine dinucleotide, reduced dipotassium salt (NADH) for a stable n‐type dopant for carbon nanotube (CNT) transistors is proposed. A strong electron transfer from NADH, mainly nicotinamide, to CNTs takes place during pyrolysis so that not only the type conversion from p‐type to n‐type is realized with 100% of reproducibility but also the on/off ratio of the transistor is significantly improved by increasing on‐current and/or decreasing off‐current. The device was stable up to a few months with negligible current changes under ambient conditions. The n‐type characteristics were completely recovered to an initial doping level after reheat treatment of the device.     

Fabrication of a Superhydrophobic Surface from a Smectic Liquid‐Crystal Defect Array

A novel fabrication method is developed for the preparation of superhydrophobic surfaces. The procedure uses focal conic structures of semi‐fluorinated smectic liquid crystals (LCs) whose periodic toric focal conic domains (TFCDs) are prepared on a surface modified substrate. Reactive ion etching (RIE) on the periodic TFCD surface leads to a superhydrophobic surface with a water contact angle of ～160° and a sliding angle of ～2° for a 10 µL water droplet. The results show that this phenomenon is due to the development of a dual‐scale surface roughness arising from the nanoscale protuberance caused by applying the RIE process to the top of the microscale TFCD arrays. The unique surface behavior is further verified by demonstrating that RIE on a flat lamellar liquid crystal film, in which the director is aligned parallel with surface, results in a relatively low hydrophobicity as compared to when periodic TFCDs are subjected to REI. The observations made in this publication suggest that a new approach exists for selecting potential candidates of superhydrophic surface formation based on spontaneous self‐assembly in smectic liquid‐crystalline materials.     

A multicarrier CDMA system with adaptive subchannel allocation forforward links

Multicarrier transmission schemes have been introduced into code-division multiple access (CDMA) systems to gain advantages for high data rate transmission. One of the methods is to transmit identical narrowband direct-sequence (DS) waveforms in parallel over a number of subchannels using frequency diversity. In this paper, we propose a multicarrier CDMA system with an adaptive subchannel allocation method for forward links. In the proposed system, instead of identical DS waveforms being transmitted over a number of subchannels in parallel, each user's DS waveform is transmitted over the user's favourite subchannel which has the largest fading amplitude among all the subchannels. We analyze the performance characteristics of the system when orthogonal and random signature sequences are used. The proposed system is shown to have performance gain over the conventional multicarrier CDMA system. We also investigate how the performance is influenced when the signal is not perfectly allocated into the best subchannel     

Covalent 0D–2D Heterostructuring of Co9S8–MoS2 for Enhanced Hydrogen Evolution in All pH Electrolytes

Ultrasmall Co₉S₈ nanoparticles are introduced on the basal plane of MoS₂ to fabricate a covalent 0D–2D heterostructure that enhances the hydrogen evolution reaction (HER) activity of electrochemical water splitting. In the heterostructure, separate phases of Co₉S₈ and MoS₂ are formed, but they are connected by Co–S–Mo type covalent bonds. The charge redistribution from Co to Mo occurring at the interface enhances the electron‐doped characteristics of MoS₂ to generate electron‐rich Mo atoms. Besides, reductive annealing during the synthesis forms S defects that activates adjacent Mo atoms for further enhanced HER activity as elucidated by the density functional theory (DFT) calculation. Eventually, the covalent Co₉S₈–MoS₂ heterostructure shows amplified HER activity as well as stability in all pH electrolytes. The synergistic effect is pronounced when the heterostructure is coupled with a porous Ni foam (NF) support to form Co₉S₈–MoS₂/NF that displays superior performance to those of the state‐of‐the‐art non‐noble metal electrocatalysts, and even outperforms a commercial Pt/C catalyst in a practically meaningful, high current density region in alkaline (>170 mA cm^?2) and neutral (>60 mA cm^?2) media. The high HER performance and stability of Co₉S₈–MoS₂ heterostructure make it a promising pH universal alternative to expensive Pt‐based electrocatalysts for practical water electrolyzers.     

Proposal for an Inundation Hazard Index of Road Links for Safer Routing Services in Car Navigation Systems

Inundation of roads by heavy rainfall has attracted more attention than traffic accidents, traffic congestion, and construction because it simultaneously causes travel delays and threatens driver safety. For these reasons, in this paper, we propose an inundation hazard index (IHI) of road links, which shows the possibility of inundation of road links caused by rainfall. To generate the index, we have used two key data sources, namely the digital elevation model (DEM) and past rainfall records of when inundation has occurred. IHI is derived by statistically analyzing the relationships between the normalized relative height of the road links calculated from DEM within the watershed and past rainfall records. After analyzing the practical applicability of the proposed index with a commercial car navigation system through a set of tests, we confirmed that the proposed IHI could be implemented to choose safer routes, with reduced chances of encountering roads having inundation risks.s     

Design of 24 GHz Radar with Subspace‐Based Digital Beam Forming for ACC Stop‐and‐Go System

For an adaptive cruise control (ACC) stop‐and‐go system in automotive applications, three radar sensors are needed because two 24 GHz short range radars are used for object detection in an adjacent lane, and one 77 GHz long‐range radar is used for object detection in the center lane. In this letter, we propose a single sensor‐based 24 GHz radar with a detection capability of up to 150 m and ±30° for an ACC stop‐and‐go system. The developed radar is highly integrated with a high gain patch antenna, four channel receivers with GaAs RF ICs, and back‐end processing board with subspace based digital beam forming algorithm.     

Suppressing Lithium Dendrite Growth by Metallic Coating on a Separator

Lithium (Li) metal is one of the most promising candidates for the anode in high‐energy‐density batteries. However, Li dendrite growth induces a significant safety concerns in these batteries. Here, a multifunctional separator through coating a thin electronic conductive film on one side of the conventional polymer separator facing the Li anode is proposed for the purpose of Li dendrite suppression and cycling stability improvement. The ultrathin Cu film on one side of the polyethylene support serves as an additional conducting agent to facilitate electrochemical stripping/deposition of Li metal with less accumulation of electrically isolated or “dead” Li. Furthermore, its electrically conductive nature guides the backside plating of Li metal and modulates the Li deposition morphology via dendrite merging. In addition, metallic Cu film coating can also improve thermal stability of the separator and enhance the safety of the batteries. Due to its unique beneficial features, this separator enables stable cycling of Li metal anode with enhanced Coulombic efficiency during extended cycles in Li metal batteries and increases the lifetime of Li metal anode by preventing short‐circuit failures even under extensive Li metal deposition.     

A design of a high-speed and high-efficiency capsule endoscopy system

This paper presents a high-speed and high-efficiency capsule endoscopy system. Both a transmitter and a receiver were optimized for its application through an analysis of the human body channel. ON-OFF keying modulation is utilized to achieve low power consumption of the in-body transmitter. A low drop output regulator is adopted to prevent performance degradation in the event of a voltage drop in the battery. The receiver adopts superheterodyne structure to obtain high sensitivity, considering the link budget from the previous analysis. The receiver and transmitter were fabricated using the CMOS 0.13-μm process. The output power of the transmitter is -1.6 dB·m and its efficiency is 27.7%. The minimum sensitivity of the receiver is -80 dB·m at a bit error ratio (BER) of 3 × 10 (-6). An outer wall loop antenna is adopted for the capsule system to ensure a small size. The integrated system is evaluated using a liquid human phantom and a living pig, resulting in clean captured images.