不同有机物对硝酸盐氮测试的影响

研究了红糖、葡萄糖、乙酸钠、甲醇、乙醇、乙酸、丙酸、丁酸、正戊酸、混合有机溶剂等10种不同有机物对麝香草酚光谱法和离子色谱法测试硝酸盐氮的影响。结果表明,溶液中含有红糖或葡萄糖时,均会对麝香草酚法测试硝酸盐氮造成影响,使得测试结果偏大;在无硝酸根离子存在时,红糖和葡萄糖的质量浓度与硝酸盐氮的测试浓度非线性相关;而乙酸钠、甲醇、乙醇、乙酸、丙酸、丁酸、正戊酸和混合有机溶剂则对麝香草酚法测试硝酸盐氮没有影响。实验发现,红糖和葡萄糖在浓硫酸的作用下与麝香草酚发生Molisch反应,形成有色复合物和红棕色不溶性沉淀。实验采用离子色谱法测试硝酸盐氮时,红糖和葡萄糖等糖类有机物对测试结果均无影响。     

预分散酚醛树脂硫化CIIR性能的研究

分别研究了预分散酚醛树脂HY-2045(预)、HY-2055(预)和SP-1055(预)对CIIR胶料硫化特性、力学性能及100℃×72h热空气老化性能的影响,并与原树脂HY-2045(原)、HY-2055(原)和SP-1055(原)的影响效果进行了对比。结果表明,与原酚醛树脂相比,预分散酚醛树脂在CIIR橡胶中的分散性、硫化胶拉伸强度和拉断伸长率均获得提高。加入SP-1055(预)可明显缩短CIIR胶料的t90;加入HY-2045(预)可使胶料的t10和t90延长,交联密度、硬度、100%定伸应力和拉伸强度均最小,拉断伸长率最大;加入HY-2055(预)可使胶料的t90延长,其他性能与加入SP-1055(预)的胶料相差不大。加入HY-2055(预)的硫化胶100℃×72h热空气老化后性能变化最小。     

某高硫难处理金精矿超细磨提金试验研究

针对某高硫难处理金精矿中金大部分被黄铁矿包裹、直接氰化浸出金浸出率低的问题,采用超细磨-碱预处理-氰化浸出工艺处理金精矿,通过条件优化可获得金浸出率84.50%,氰化钠耗量控制在3 kg/t以内,该工艺简单、流程短、安全环保。     

Prediction of hot tearing susceptibility of direct chill casting of AA6111 alloys via finite element simulations

To predict hot tearing susceptibility (HTS) during solidification and improve the quality of Al alloy castings, constitutive equations for AA6111 alloys were developed using a direct finite element (FE) method. A hot tearing model was established for direct chill (DC) casting of industrial AA6111 alloys via coupling FE model and hot tearing criterion. By applying this model to real manufacture processes, the effects of casting speed, bottom cooling, secondary cooling, and geometric variations on the HTS were revealed. The results show that the HTS of the billet increases as the speed and billet radius increase, while it reduces as the interfacial heat transfer coefficient at the bottom or secondary water-cooling rate increases. This model shows the capabilities of incorporating maximum pore fraction in simulating hot tearing initiation, which will have a significant impact on optimizing casting conditions and chemistry for minimizing HTS and thus controlling the casting quality.     

Processing of CaLa2S4 infrared transparent ceramics: A comparative study of HP and FAST/SPS techniques

The densification of CaLa₂S₄ (CLS) powders prepared by combustion method was investigated by the use of Field-Assisted Sintering Technique (FAST) and Hot Pressing (HP). CLS powders were sintered using FAST at 1000°C at different pressures and heating rates and sintered by HP under 120 MPa from 800°C to 1100°C for 6 hours with a heating rate of 10°C/min. Comparison of both techniques was further realized by use of the same conditions of pressure, dwell time, and heating rate. Complementary techniques (XRD, SEM-EDS, density measurements, FTIR spectroscopy) were employed to correlate the sintering processes/parameters to the microstructural/compositional developments and optical transmission of the ceramics. Both sintering techniques produce ceramics with submicrometer grain size and relative density of about 99%. Nevertheless, HP is more suitable to densify CLS ceramics without fragmentation and also reach higher transmission than FAST. Transmission of 40%–45% was measured out of a possible maximum of 69% based on the Fresnel losses in the 8-14 μm window when HP is applied at 1000°C for 6 hours under 120 MPa. In both techniques, ceramics undergo reduction issues that originate from graphitic sintering atmosphere.     

集成式铁基质生物膜反应器自养反硝化深度脱氮

以污水厂处理水为研究对象，采用铁基质生物载体与生物膜耦合实现高效自养反硝化脱氮。考察停留时间（HRT）对系统脱氮效能的影响，通过动力学及微生物群落结构分析，揭示耦合技术的脱氮机理。结果表明：HRT为8 h，对一级A和一级B污水厂处理水，总氮(TN)平均去除率分别为95.41%和92.55%，TN处理负荷分别为0.48 kg TN/(m³·d）和0.58 kg TN/(m³·d），硝化过程氨氮(NH₄⁺-N)饱和常数分别为1.17 mg/L和0.72 mg/L，反硝化过程硝氮(NO₃^--N)饱和常数分别为0.87 mg/L和0.67 mg/L。出水水质分别达到《地表水环境质量标准》Ⅲ类、Ⅴ类水质标准。铁基质生物载体与生物膜耦合系统中微生物优势菌属为Maritimimonas、Rhodobacter和Sphaerotilus, 均为自养反硝化菌，证实了铁基质生物载体可为自养反硝化菌提供电子，实现生物自养反硝化脱氮。     

游戏机手柄热流道立式注塑4层叠层注塑模设计

设计了一种4层叠层模用于实现游戏机手柄的高效率注塑生产，解决了塑件成型时在保证塑件成型精度的基础上，单次注塑量产数量4倍倍增难题。4层叠层模的结构由4层结构相同的单层模具通过一定的空间组序排列组装后，应用立式注塑机来进行注射成型。单层模结构设计采用两板式2次开模热流道浇注两板模形式，第一次开模用于热流道嘴与塑件的冷流道部分分离，第二次开模用于塑件从型腔镶件中脱模脱出。为解决单层模做4层叠层组合后，顶出板无动力顶出的问题，在单层模的模架模板侧边对称设置了拉杆，将单层模在开模动力转化为单层模中顶出板的顶出拉力，巧妙地解决了单层模做4层叠层安装后各单层模的顶出元件顶出板无推动力的问题。模具结构布局及机构的驱动设置设计合理，有较好的工程设计参考意义。     

Feasibility of CANON process for treating nitrogenous wastewater containing heavy metals

The appearance of heavy metals in wastewater brings a major burden to wastewater treatment plants, due to the high toxicity to microorganisms. Several commonly used heavy metals, including Zn(II), Cd(II), Hg(II), and Pb(II) were adopted to clear the individual and joint toxicity to the completely autotrophic nitrogen removal over nitrite (CANON) process in six sequencing batch reactors. The obtained results suggested that the nitrogen removal performances were transiently inhibited, but rapidly recovered. The restoration period under the stress of Hg(II) and Pb(II) was shorter than that under Zn(II), Cd(II), and the joint heavy metals. During the long-term exposure, Cd(II) in 1mg L⁻¹ slightly inhibited the nitrogen removal, while Zn(II), Hg(II), Pb(II), and mixture showed a negligible impact on CANON process. The defense of extracellular polymeric substances (EPS), the good adaptability of functional bacteria, and the inducement of resistant genera by heavy metals all contributed to the robustness and stability of CANON process. Therefore, it is feasible to treat nitrogenous wastewater containing low heavy metals using CANON process. © 2020 Society of Chemical Industry     

煤磨热风管道改造的效果

中联万基水泥有限公司4500t/d熟料生产线采用SCLW4-12×13.4第四代篦冷机,煤磨热风取风口和余热发电AQC热风取风口在篦冷机同一对称位置,煤磨与余热发电系统存在争风现象,开停煤磨对余热发电系统影响较大。通过从废气管道处开孔,加装管道和电动阀,与热风管道汇合通往煤磨沉降室,调整相应阀门开度,可以控制入煤磨烟气温度,这样不但提高了余热发电量,而且提高了煤磨产量,同时也降低了窑头排风机的负荷,降低了熟料生产电耗。     

Ca对Mg-Gd-Y-Zn-Zr合金热变形行为及热加工性能的影响

利用Gleeble3500热模拟试验机研究了Ca对Mg-Gd-Y-Zn-Zr合金在变形温度573～723 K,应变速率0.001～1 s-1的热变形行为及热加工性能的影响。结果表明:Ca增大了合金的流变应力及变形激活能,扩宽了加工安全区及最佳加工区范围,但降低了最大功率耗散因子及动态再结晶程度。结合激光共聚焦显微镜分析了合金热压缩后组织,验证了热加工图的准确性,并制定了合理的热加工工艺,Mg-Gd-Y-Zn-Zr合金的最佳加工区域为:应变速率0.001～0.01 s~(-1),温度623～723 K。根据最佳加工工艺参数获得了表面质量良好,无变形缺陷的等温锻造合金。