离子膜片碱装置的腐蚀与防腐

介绍了自贡鸿鹤化工股份有限公司离子膜片碱装置主要设备材质的选择情况,分析该装置腐蚀的原因,并提出了设备设计、制造、维修和生产操作控制中的改进意见和防护对策。     

316L 不锈钢在磷酸磷铵装置中的使用情况评述

结合陕西华山化工集团复肥厂130 kt/a磷酸二铵(DAP)和100 kt/a磷酸一铵(MAP)装置的生产特点,介绍了其中主要的磷酸、氟硅酸和硫酸类腐蚀介质及影响其腐蚀性的因素,阐述不锈钢材料316L的耐腐蚀性能,并从磷酸磷铵生产工艺角度重点评述了316L的使用情况.     

Crystallization and dissolution behavior of l(+) calcium and zinc lactate in ethanol-water solvent

Crystallization and dissolution behavior of L(+) calcium and zinc lactate in 50% ethanol-water solution was studied. The effects of stirring, standing, ultrasonic wave, and temperature on the crystallization of L(+) calcium and zinc lactate were evaluated. It was found that standing had a positive effect on crystallization of L(+) calcium and zinc lactate, while stirring promoted dissolution of crystallized particles and resulted in high residual concentration in mother liquor. The application of ultrasonic wave did not influence much on crystallization process. L(+) calcium and zinc lactate crystallized easily at 5 ‡C; however, complete crystallization took more than 72 hours. These two salts dissolved rapidly and reached equilibrium within 1 hour.     

木樨榄属植物中裂环烯醚萜类的提取方法及开发前景

裂环烯醚萜类化合物是木樨榄属植物标记性化合物,尤其是橄榄苦苷具有重要的药理活性。本文作者研究了作者裂环烯醚萜类化合物植物来源、化学结构特征和物化性质及药理作用,提出木樨榄属油橄榄叶提取物加工工艺和橄榄苦苷的检测方法,为我国油橄榄叶中橄榄苦苷的加工利用提供依据。     

手性环(L-苯丙-L-组)和(D-苯丙-D-组)二肽的合成

环二肽是不对称氰醇化反应的重要催化剂。以L 苯丙氨酸、L 组氨酸和D 苯丙氨酸、D 组氨酸为原料,用苄氧羰基保护苯丙氨酸的N端和进一步用硝基苯酚酯活化其C端,再与C端保护的组氨酸甲酯缩合,得直链二肽,再经Pd/C催化氢化脱保护基,闭环,得环(L 苯丙 L 组)二肽和(D 苯丙 D 组)二肽,结构经元素分析、IR、HNMR等证实。     

L-抗坏血酸-2-聚磷酸酯的合成

研究了L 抗坏血酸与磷酸化试剂在水介质中制备L 抗坏血酸 2 一聚磷酸酯和L 抗坏血酸 2 三聚磷酸酯 ,当n(L 抗坏血酸 )∶n(三偏磷酸钠 )∶n(催化剂 ) =1 .0 0 0∶1 2 0 0∶0 1 50、溶液pH值为 8时 ,L 抗坏血酸 2 三聚磷酸酯的收率为 71 34% ,Vc效价为 32 1 0 %。作为饲料添加剂使用 ,可同时给动物补充钙和磷。     

L-甲状腺素的合成

以 L-酪氨酸为起始原料 ,用碘粉和双氧水碘化制备 3,5-二碘 - L-酪氨酸 ,再将氨基和羧基加以保护 ,经孵化反应制备高纯度、具生物活性的 L-甲状腺素     

Comparative Analysis of CREB3 and CREB3L2 Protein Expression in HEK293 Cells

We performed a comparative analysis of two ER-resident CREB3 family proteins, CREB3 and CREB3L2, in HEK293 cells using pharmacological and genome editing approaches and identified several differences between the two. Treatment with brefeldin A (BFA) and monensin induced the cleavage of full-length CREB3 and CREB3L2; however, the level of the full-length CREB3 protein, but not CREB3L2 protein, was not noticeably reduced by the monensin treatment. On the other hand, treatment with tunicamycin (Tm) shifted the molecular weight of the full-length CREB3L2 protein downward but abolished CREB3 protein expression. Thapsigargin (Tg) significantly increased the expression of only full-length CREB3L2 protein concomitant with a slight increase in the level of its cleaved form. Treatment with cycloheximide and MG132 revealed that both endogenous CREB3 and CREB3L2 are proteasome substrates. In addition, kifunensine, an α-mannosidase inhibitor, significantly increased the levels of both full-length forms. Consistent with these findings, cells lacking SEL1L, a crucial ER-associated protein degradation (ERAD) component, showed increased expression of both full-length CREB3 and CREB3L2; however, cycloheximide treatment downregulated full-length CREB3L2 protein expression more rapidly in SEL1L-deficient cells than the full-length CREB3 protein. Finally, we investigated the induction of the expression of several CREB3 and CREB3L2 target genes by Tg and BFA treatments and SEL1L deficiency. In conclusion, this study suggests that both endogenous full-length CREB3 and CREB3L2 are substrates for ER-associated protein degradation but are partially regulated by distinct mechanisms, each of which contributes to unique cellular responses that are distinct from canonical ER signals.     

Long-term effect of nutrient management and cropping system on cotton yield and soil fertility in rainfed vertisols

The effect of different N, P and K combinations with and without FYM on cotton productivity and the changes in soil fertility of three rainfed cotton based cropping systems were analyzed through a field experiment, conducted for 11 yr. Monoculture of G. arboreum (Asiatic) cotton, out-yielded monoculture of G. hirsutum (upland) cotton in 9 out of 11 yr. except in years of heavy rainfall. G. hirsutum cotton in rotation with sorghum produced 8% more yield than monocultured G. hirsutum. Significant responses to N and P application were consistently observed, while the response to K was inconsistent. Substituting half the N dose with FYM, gave 162 kg/ha and 222 kg/ha more seed cotton at low (N60 P13 K25) and high (N90 P20 K38) doses respectively. Also substituting half the N dose with FYM built up soil organic C from 4.2 to 5.4 g/kg, and increased available P from 4.5 to 6.4 mg/kg. The variations in the performance of the cropping systems and the response to fertilizers could not be accounted for by total rainfall alone. However, there was significant positive correlation between cotton yield and post September rainfall. Multiple regression equations were fitted to estimate G. arboreum and G. hirsutum yields based on the monthly distribution of rainfall.     

悬钩子属植物三萜类化学成分及波谱特征研究进展

对悬钩子属植物中三萜类成分研究进行综述,并对其波谱特征进行归纳总结。从悬钩子属植物中已分离得35个三萜类化合物,其中有9个为齐墩果型,26个为乌索烷型,这些化合物的基本骨架、取代基类型及位置均有其波谱特征。     

316L尿素级不锈钢高压管道施工技术

以日产 10 5 0t尿素装置的施工为例 ,对 316L尿素级不锈钢高压管道的焊接、安装、检验、水冲洗和试压等施工艺进行了系统性的介绍。     

轻油气相管管道失效综合分析

通过对管道内介质的化学成分、管道材料成分、裂纹宏观形貌、母材和焊缝热影响区的金相组织、腐蚀产物能谱分析、裂纹断口电镜扫描、管道应力计算等方法,对某厂一期轻油气相管腐蚀机理进行综合分析,并推荐替换材料。     

304、304L、316、316L在化工容器上的应用

通过对304、304L、316、316L性质的比较，对其在化工容器应用上的相同及不同之处进行了简要分析及比较。     

两种湿地植物去除污染物性能研究及其在小型湿地系统中的应用

文章对两种耐寒、易得、具有一定药用和观赏价值的植物石龙芮(Ranunculus sceleratus L.)和酸模(Rumex acetosa L.)进行了研究,以期为提高和稳定人工湿地的净化功能提供基础理论数据。首先对两种植物进行无土栽培的实验,研究其对污水中氮磷的吸收净化效果。然后将其应用到人工湿地系统,研究其实际应用情况。实验表明,在无土栽培实验阶段,两种植物对污水中氮、磷的去除贡献分别为37%、40%,这其中分别有96%、64.4%的氮和磷被植物吸收到体内,适合于构建人工湿地。在实际应用阶段,人工湿地系统中各种污染物的去除率最高为氨氮(NH3-N)64.03%,总氮(TN)66.33%,由于进水磷浓度过低,导致了基质中磷的释放,其释放程度与水中磷浓度有关。根据实验结果,认为石龙芮和酸模属适宜的人工湿地植物,其净化特性还有待于更深层次的研究。     

反相高效液相色谱法测定凤仙花中芦丁、槲皮素和山奈酚的含量

建立反相高效液相色谱测定凤仙花中芦丁、槲皮素和山奈酚含量的方法。采用Shim—pack VP—ODS色谱柱,甲醇—水为流动相,梯度洗脱进行分离,检测波长360 nm。芦丁、槲皮素和山奈酚在选定浓度范围内,线性关系良好,平均回收率分别为102.3%,97.7%,98.90%,RSD分别为1.13%,1.11%,1.85%,方法简单、快速、准确,可作为凤仙花中黄酮的测定方法,以控制其原料的质量。     

牛布鲁菌L7/L12蛋白的原核表达及纯化

目的原核表达并纯化牛布鲁菌L7/L12蛋白。方法提取牛布鲁菌S19基因组DNA,PCR法扩增L7/L12基因,经测序正确后,克隆至pET-28a(+)载体,构建重组原核表达质粒pET-L7/L12,转化大肠杆菌BL21(DE3),IPTG诱导表达。SDS-PAGE分析目的蛋白的表达形式及表达量,经亲和层析纯化后,Western blot鉴定纯化产物。结果所构建的重组原核表达质粒pET-L7/L12经酶切鉴定表明构建正确。重组蛋白以包涵体形式表达,表达量占全菌总蛋白的33%;纯化的重组蛋白纯度可达94%,可与布鲁菌小鼠免疫血清发生特异反应。结论已成功表达并纯化了牛布鲁菌L7/L12蛋白,为建立高特异性的新型布鲁菌检测方法奠定了基础。     

α-L-天门冬氨酰-L-苯丙氨酸甲酯的制备进展

综述了α L 天门冬氨酰 L 苯丙氨酸甲酯的合成新进展 ,并对其加以比较。化学合成法中的内酐法为现阶段的主要生产方法 ;酶合成法现不具有产业化优势 ;基因工程法现处于实验室阶段。     

Assessment of Cosmetic and Dermatological Properties and Safety of Use of Model Skin Tonics with Kombucha-Fermented Red Berry Extracts

Kombucha is a health-promoting beverage that is produced by fermenting sweetened tea using symbiotic cultures of bacteria belonging to the genus Acetobacter, Gluconobacter, and yeast of the genus Saccharomyces. This study compared the cosmetic and dermatological properties of the extracts of the following redberries: R. rubrum, F. vesca, and R. idaeus, and their ferments, which were obtained by fermentation for 10 and 20 days using tea fungus. For this purpose, the fermented and non-fermented extracts were compared in terms of their chemical composition using the HPLC/ESI-MS chromatographic method, demonstrating the high content of biologically active compounds that were present in the ferments. The antioxidant activity of the tested samples was evaluated using DPPH and ABTS tests, as well as by evaluating the scavenging of the external and intracellular free radicals. The cytotoxicity of the extracts and the ferments, as well as the cosmetic formulations, were also determined by conducting Alamar Blue and Neutral Red tests assessing the cell viability and metabolism using skin cell lines: fibroblasts and keratinocytes. In addition, application tests were conducted showing the positive effects of the model cosmetic tonics on the TEWL, the skin hydration, and the skin pH. The results indicate that both the extracts and the ferments that were obtained from kombucha can be valuable ingredients in cosmetic products.     

S-甲基-L-半胱氨酸的合成

以 L-半胱氨酸为原料 ,磷酸三甲酯为甲基化试剂合成了 S-甲基 - L-半胱氨酸。研究了 p H值、温度等反应条件对产品品质和收率的影响。发现在严格控制 p H为 7.0 ,反应温度不高于 37°C的条件下 ,并不出现消旋作用。这一合成路线可用于工业上大规模生产     

L-谷氨酰胺合成及不对称转化

研究了L－谷氨酰胺在不同溶剂、pH、温度、反应时间下的消旋化和不对称转化，并对碱性条件下的消旋化机理做了分析。