Preparation of molecularly imprinted fluorescence sensor based on carbon quantum dots via precipitation polymerization for fluorescence detection of tetracycline

A facile and effective method was proposed to prepare the molecularly imprinted fluorescence sensor with carbon quantum dots, which were modified vinyl groups by acrylic acid on the surface. The obtained fluorescence composite material was investigated by transmission electron microscope and Fourier transform infrared spectra. After the experimental conditions were optimized, a linear range of 1.0–60 μmol L⁻¹ was obtained and the detection limit was 0.17 μmol L⁻¹. The novel fluorescence sensor can be successfully used to detect tetracycline in real samples. This study provides a convenient strategy for selective recognition and rapid detection of tetracycline in the complex environment.     

The growth of oleaginous Rhodotorula glutinis in an internal-loop airlift bioreactor by using mixture substrates of rice straw hydrolysate and crude glycerol

The conversion of lignocellulosic biomass (LCB) to microbial oils is attracting a growing amount of attention. However, the growth of the oleaginous yeast Rhodotorula glutinis on LCB hydrolysate (mainly rice straw) only will lead to a low lipid mass fraction, in the range of 10–20%. This study shows that the addition of crude glycerol to the LCB hydrolysate medium can efficiently raise the lipid mass fraction to the range of 30–40%. Crude glycerol is a by-product in the biodiesel production process. The use of renewable LCB hydrolysate and crude glycerol would greatly reduce the substrate cost for microbial oil production using R. glutinis. In addition, the results of experiments show that a low-cost airlift bioreactor is a more suitable fermentation process for the growth of R. glutinis than the use of a conventional agitation tank. When using mixed carbon sources of LCB hydrolysate with 30 kg m⁻³ of reducing sugars and 30 kg m⁻³ of crude glycerol, a maximal cell mass of 21.4 kg m⁻³ and lipid mass fraction of 58.5 ± 6.2 were achieved in an internal loop airlift bioreactor, and this process may have the potential to be applied in scale-up production.     

DP980+Z烘烤硬化值与退火温度的关系

摘要：为了研究退火温度对镀锌DP980+Z烘烤硬化值的影响，退火温度控制在760～820℃之间，系统分析退火温度对烘烤硬化值的影响。通过准静态拉伸试验机测量烘烤硬化值及抗拉强度，采用lepara试剂对组织中的马氏体进行着色，利用金相显微镜及图像处理软件测量马氏体的体积分数；采用扫描电镜观察DP980+Z的双相组织特点，并且将组织图片通过CAD转化成有限元图进行网格划分，建立代表性体积单元（RVE），通过有限元分析铁素体、马氏体强度对烘烤硬化值的影响。在同样的变形量情况下，DP980+Z的原始屈服强度越高，烘烤硬化值越高。     

碳基采暖电热材料研究进展

近几年,由于节能与环保的需求,电取暖的方式得到大力的推广,电热材料的研究与应用受到人们广泛的重视。非金属碳基电热材料是新型的节能型电热采暖材料,本文重点对影响非金属碳基电热材料中的炭黑基电热材料、碳纤维基电热材料、碳晶电热材料电热性能的因素及相关应用进行了综述。     

Advanced Surface of Fibrous Activated Carbon Immobilized with FeO/TiO2 for Photocatalytic Evolution of Hydrogen under Visible Light

FeO-doped TiO₂ nanoparticle photocatalysts were immobilized onto the surface of fibrous activated carbon (ACF) via a sol-gel process. As an adsorbent and photocatalyst, FeO-TiO₂ on immobilized ACFs (FeO-TiO₂/ACF) greatly improved the photocatalysis rate of hydrogen production as compared with pure TiO₂ and ACF-TiO₂ under UV irradiation and visible light. The addition of ACFs surface significantly reduced the photogenerated pairs of electrons-hole recombination, thereby promoting the photocatalysis action of doped photo-metal oxides of FeO-TiO₂. Co-doping of FeO onto the lattice of the TiO₂ approach can improve the absorption activity of visible light through photo-metal oxide of TiO₂ and further enhance hydrogen production under visible light. The photocatalytic fabrics (FeO-TiO₂/ACF) were effortlessly split out from the experimental solution for re-utilization and exhibited high stability even after five complete regeneration cycles.     

高分散度Pt/C电催化剂的制备

Cabot公司Vulcan XC-72型炭黑，经过H2O2氧化处理后作为Pt的载体，H2PtCl6作为金属前驱体制备了高度分散的Pt/C催化剂。讨论了不同条件下H2PtCl6在炭黑上的吸附性能。载体经过H2O2氧化处理24h,H2PtCl6在pH=9下吸收48h，H2 350℃还原2h，可以制备出铂晶粒平均大小为1.8nm的Pt/C电催化剂。     

Capture of Organic Vapors Using Adsorption and Electrothermal Regeneration

Activated-carbon-fiber cloth (ACFC) is an alternative adsorbent to granular activated carbon (GAC) for removing and recovering organic vapors from gas streams. Electrothermal desorption (ED) of ACFC provides rapid regeneration while requiring less energy compared to traditional regeneration techniques used with GAC. This paper provides proof-of-concept results from a bench-scale ACFC adsorption system. The automated system captured 1,000 ppmv of hazardous air pollutants/volatile organic compounds (HAPs/VOCs) from air streams and demonstrated the use of ED, using ac voltage, to recover the HAP/VOC as a pure liquid. The desorbed HAP/VOC condensed onto the inner walls of the adsorber and was collected at the bottom of the vessel, without the use of ancillary cooling. Seventy percent of the HAP/VOC was collected per cycle as condensate, with the balance being retained in the regenerated adsorber or recycled to the second adsorber. ED with in-vessel condensation results in minimal N2 consumption and short regeneration cycle times allowing the process to be cost competitive with conventional GAC-based adsorption processes. This technology extends the application of carbon adsorption systems to situations that were previously economically and physically impractical.     

Annealing effects on structural and electrical properties of fluorinated amorphous carbon films deposited by plasma enhanced chemical vapor deposition

The annealing effects on the structural and electrical properties of fluorinated amorphous carbon (a-C:F) thin films prepared from C₆F₆ and Ar plasma are investigated in a N₂ environment at 200 mTorr. The a-C:F films deposited at room temperature are thermally stable up to 250 °C, but as the annealing temperature is increased beyond 300 °C, the fluorine incorporation in the film is reduced, and the degree of crosslinking and graphitization in the film appears to be enhanced. At the annealing temperature of 250 °C, the chemical bond structures of the film are unchanged noticeably, but the interface trapped charges between the film and the silicon substrate are reduced significantly. The increased annealing temperature contributes the decrease of both the interface charges and the effective charge density in the a-C:F film. Higher self-bias voltage is shown to reduce the charge density in the film.     

负载型复合载体及其镍基催化剂的性能

采用溶胶-凝胶法制备了负载型ZrO_2/Al_2O_3和ZrO_2/Al_2O_3-SiO_2复合载体,研究了不同复合载体对Ni基催化剂CO_2重整甲烷反应和性能的影响,并用XRD、IR、TPR、TPD和BET等方法对复合载体及催化剂进行了表征。结果表明,ZrO_2负载在基载体后比表面积、碱性、活性组分Ni的分散度和Ni与ZrO_2的相互作用增大。NiO在复合载体表面的分散容量与ZrO_2的负载量有关,ZrO_2的负载量为37．5%时NiO的分散容量达最高值(24．0%)。与Ni/ZrO_2相比,Ni/ZrO_2/Al_2O_3-SiO_2和Ni/ZrO_2/Al_2O_3催化剂对CO_2的吸附能力增大,CO_2吸附量增加,酸强度降低,CO_2重整CH_4反应活性提高,其中以Ni/ZrO_2/Al_2O_3催化剂的活性最好。     

二氧化碳加氢直接合成二甲醚催化剂的研究——沉淀次序对复合催化剂结构和性能的影响

以草酸乙醇溶液为沉淀剂,采用不同的沉淀次序(并流、反加和正加)制备了CuO-ZnO-Al2O3/HZSM-5复合型催化剂,对CO2加氢直接合成二甲醚反应的催化活性顺序为:并流法催化剂>反加法催化剂>正加法催化剂。3种复合催化剂的还原温度由低到高的顺序为:并流法催化剂<反加法催化剂<正加法催化剂。在沉淀过程中,反加法和正加法均形成类胶体沉淀,相应催化剂的比表面积也较大。IR研究发现,催化剂在1101cm-1处表现Cu/Zn/Al氧化物与HZSM-5分子筛之间相互作用的IR吸收峰强度与其催化活性间存在对应关系。XRD结果表明,并流法得到的催化剂前驱体中有铜锌同形取代现象,有利于催化剂活性的发挥。