Achieving Rich and Active Alkaline Hydrogen Evolution Heterostructures via Interface Engineering on 2D 1T‐MoS2 Quantum Sheets

Large‐scale production of hydrogen from water‐alkali electrolyzers is impeded by the sluggish kinetics of hydrogen evolution reaction (HER) electrocatalysts. The hybridization of an acid‐active HER catalyst with a cocatalyst at the nanoscale helps boost HER kinetics in alkaline media. Here, it is demonstrated that 1T–MoS₂ nanosheet edges (instead of basal planes) decorated by metal hydroxides form highly active ${\text{edge}}_{{\text{1T‐MoS}}_{\text{2}}}$/ ${\text{edge}}_{\text{Ni}{(\text{OH})}_{\text{2}}}$ heterostructures, which significantly enhance HER performance in alkaline media. Featured with rich ${\text{edge}}_{{\text{1T‐MoS}}_{\text{2}}}$/ ${\text{edge}}_{\text{Ni}{(\text{OH})}_{\text{2}}}$ sites, the fabricated 1T–MoS₂ QS/Ni(OH)₂ hybrid (quantum sized 1T–MoS₂ sheets decorated with Ni(OH)₂ via interface engineering) only requires overpotentials of 57 and 112 mV to drive HER current densities of 10 and 100 mA cm^?2, respectively, and has a low Tafel slope of 30 mV dec^?1 in 1 m KOH. So far, this is the best performance for MoS₂‐based electrocatalysts and the 1T–MoS₂ QS/Ni(OH)₂ hybrid is among the best‐performing non‐Pt alkaline HER electrocatalysts known. The HER process is durable for 100 h at current densities up to 500 mA cm^?2. This work not only provides an active, cost‐effective, and robust alkaline HER electrocatalyst, but also demonstrates a design strategy for preparing high‐performance catalysts based on edge‐rich 2D quantum sheets for other catalytic reactions.     

锅炉异种钢管焊接接头焊缝稀释率试验

异种钢焊接的稀释率对焊接质量有影响,通过焊缝的稀释率与接头坡口形式、焊接工艺关系试验与分析,采用试验推荐的坡口形式及焊接参数可将焊缝稀释率控制在所要求的范围内.     

同振式三轴向矢量水听器设计与实现

根据实际工程需要,设计、制作同振式三轴向矢量水听器,其外形为柱体两端带半球帽的圆柱体,声压通道和矢量通道在结构上结合为一体。矢量水听器外形尺寸为Φ54×72 mm、工作频带为20 Hz~2000 Hz。在国防科技工业水声一级计量站驻波管对研制的矢量水听器进行了测试,测试结果表明：声压通道声压灵敏度级为-192.7 dB（0 dB=1 V/mPa）、具有全指向性;矢量通道声压灵敏度级为-185.3 dB（测试频率500 Hz,0 dB=1 V/mPa）、具有余弦指向性。设计、制作的矢量水听器灵敏度高、通道一致性好、使用方便,满足工程应用需求。     

西部地区三网融合发展模式研究

"三网融合"对促进西部地区信息产业发展、带动经济增长和社会发展具有重要意义。运用比较分析法,在借鉴我国"三网融合"发展模式成功经验的基础上,针对西部地区自身的社会经济状况和信息基础设施发展水平,提出适合西部地区"三网融合"的发展模式。     

IPv4/IPv6双栈防火墙的设计与实现

IPv6的新特点和应用对现有的安全设备结构提出了挑战。同时，从IPv4升级到IPv6是一个长期的过程，两种协议在一定时间内将共同存在。因此，需要设计支持IPv4、IPv6双协议的防火墙以适应过渡时期的需要和IPv6新特点对防火墙的要求。论述了IPv4／IPv6防火墙的设计需要考虑的防火墙位置、IPv6与IPv4的差异及性能，然后介绍防火墙实现的步骤和将要进行的工作。     

Accelerating photocatalytic hydrogen evolution of Ta2O5/g-C3N4 via nanostructure engineering and surface assembly

Despite that several strategies have been demonstrated to be effective for improving the catalytic hydrogen evolution activity of bulky g-C₃N₄, the large-scale hydrogen production over g–C₃N₄–based photocatalysts still confronts a big challenge. Here, a two-step calcination method is presented in constructing metal oxide/two-dimensional g-C₃N₄, i.e., Ta₂O₅/2D g-C₃N₄ photocatalyst. Thanks to the superiority of the synthetic method, nanostructure engineering forming 2D structure, and surface assembly with another semiconductor, can be realized simultaneously, in which ultrathin structure of 2D g-C₃N₄ and strong interfacial coupling between two components are two important characteristics. As a result, the structure engineered Ta₂O₅/2D g-C₃N₄ induces high photocatalytic hydrogen evolution half reaction rate of ~19,000 μmol g^?1 h^?1 under visible light irradiation (λ > 400 nm), and an external quantum efficiency (EQE) of 25.18% and 12.48% at 405 nm and 420 nm. The high photocatalytic performance strongly demonstrates the advance of the synchronous engineering of nanostructure and construction of heterostructure with tight interface, both of which are beneficial for the fast charge separation and transfer.     

卤化银感光片的单浴显影

介绍了一种单浴显影的实验方法，它不同于目前广泛采用的将显影、定影分两步走的传统的处理方法，而是将显影剂和定影剂集于一液，使感光片经一种药液处理即获得原显影和定影的功效。     

几种不同元素与45~#钢混合的耐蚀性比较

离子束混合对金属耐蚀性影响的研究已屡见报道。该技术以其固有的特点正引起人们的重视。已有一些报道肯定了它对金属腐蚀研究的作用。 4S~#钢是一种用途广泛的碳素钢。本文用离子束混合技术将Cr、Ti、Mo和Cr+Ni等元素分别引入其基体,企图形成不同的表面新合金,以观察其对基体腐蚀性能的影响。用线性极化法评价各试样在充气的3％NaCl溶液中的腐蚀速率;在0.5mol/1 H_2SO_4和3％NaCl溶液中分别测试了各试样的阳极极化曲线,比较了它们在这两种介质中的电化学行为。     

奥普图系统在水处理装置中的运用

介绍奥普图(OPT022)系统在贵州赤天化水处理生产装置中的应用实例情况,主要包括OPT022系统的硬件配置,重要控制回路的应用及在实践中对OPT022系统的开发。     

响应面法优化枸杞无硫促干护色工艺及其对品质的影响

为研究鲜枸杞促干护色工艺,选取碳酸钠、柠檬酸和浸泡时间为自变量,以水分含量和色差值为响应值,采用响应面优化法对此工艺进行优化,并测定各品质指标。结果表明,枸杞最佳促干护色条件为:碳酸钠1.1%,柠檬酸0.6%,浸泡时间10 min,浸泡温度为30 ℃,经50 ℃热风干燥42 h后,枸杞含水量降至12.41%,色差值为11.09,颜色较好且干制速度快,相比未处理的枸杞干燥速度提高42%。测得枸杞多糖2%,总糖52.89%,总类胡萝卜素0.54 g/100 g,总酚7.16 mg/g,总黄酮1.57 mg/g。得到的枸杞干中总类胡萝卜素、总酚和总黄酮含量显著高于未处理的枸杞干（P<0.05）,多糖和总糖含量与未处理的枸杞无显著差异（P>0.05）。相比对照组,此促干护色方法可使枸杞干制过程中保留较多营养成分,具有实际参考价值。