白芨胶间歇式提取工艺条件的探讨

以白芨块茎为基本原料,采用浸泡、回流、蒸馏回收等工艺过程提取了白芨胶,对提取的白芨胶进行了HPLC、DTA、熔点等方面的测试和表征工作;探讨了浸泡时间、回流时间、回流温度、回流方法、料液配比等工艺条件对白芨胶提取率的影响。研究结果表明,间歇式提取白芨胶较佳的工艺条件为：浸泡时间7～10h、回流时间8～10h、回流温度90℃、料液比1／15-1／8,在此工艺条件下,得到的白芨胶采用蒸馏法回收,提取率达45．06％。     

双醛纤维素的制备及表征

以微晶纤维素(MCC)为原料,高碘酸钠为氧化剂,用正交实验考察了各种条件对氧化效率的影响。结果表明,影响醛基含量的顺序依次是投料比、反应时间、pH及反应温度。最佳氧化条件为:高碘酸钠和微晶纤维素投料质量比为1.0,反应温度30℃,pH=3,反应时间8 h。通过FTIR,XRD和SEM等对产物双醛纤维素在微粒形态、光谱特征、功能基团含量、晶体结构进行了表征。     

SWRH72B-S绞线钢连铸小方坯凝固温度场数值模拟

为研究适于6号连铸机的凝固传热模型,通过实际生产数据对相关参数进行修正,并通过低碳焊丝钢铸坯白亮带、液芯宽度、空冷段铸坯表面温度进行分析研究,验证了准确性。并且对拉速、过热度以及比水量进行计算分析,得出它们对铸坯表面温度、液芯末端位置的影响程度。结果表明,采用符合特定连铸机的凝固传热模型,并利用模型对生产工艺进行了探讨,可以提高铸坯内部质量。     

Molecular docking simulations for macromolecularly imprinted polymers

Molecularly imprinted polymers are fully synthetic antibody mimics prepared via the crosslinking of organic monomers in the presence of an analyte. This general procedure is now well developed for small molecule templates; however, attempts to extend the same techniques to the macromolecular regime have achieved limited success to date. We employ molecular docking simulations to investigate the interactions between albumin, a common protein template, and frequently employed ligands used in the literature at the molecular level. Specifically, we determine the most favorable binding sites for these ligands on albumin and determine the types of non-covalent interactions taking place based on the amino acids present nearby this binding pocket. Our results show that hydrogen bonding, electrostatic interactions, and hydrophobic interactions occur between amino acids side chains and ligands. Several interactions are also taking place with the polypeptide backbone, potentially disrupting the protein's secondary structure. We show that several of the ligands preferentially bind to the same sites on the protein, which indicates that if multiple monomers are used during synthesis then competition for the same amino acids could lead to non-specific recognition. Both of these results provide rational explanations for the lack of success to date in the field.     

A New Electrospray Aerosol Generator with High Particle Transmission Efficiency

A new single-capillary electrospray (ES) aerosol generator has been developed for monodisperse particle production with maximal transmission efficiency. The new generator consists of both a spray chamber in a point-to-orifice-plate configuration and a charge reduction chamber that can hold up to 4 Nuclespot ionizers (Model P-2042, NRD Inc.). The 2 chambers are partitioned by an orifice plate. To optimize the particle transmission efficiency of the prototype, a systematic study was performed on the generator by varying the system setup and operation. Two key dimensions of the generator setup, the orifice diameter and the distance from the capillary tip to the orifice plate, were varied. Fluorescence analysis was applied to characterize the loss of ES-generated particles at different locations of the prototype. It was found that particle loss in the generator could be reduced by either increasing the orifice diameter or decreasing the distance between the capillary tip and the orifice plate. Increasing either the total radioactivity of the ionizers or the flowrate of the particle carrier gas also further decreased the particle loss in the system. The maximum particle transmission efficiency of 88.0% was obtained with the spray chamber fully opened to the charge reduction chamber, the capillary tip at the same level as the orifice plate, and 4 bipolar ionizers installed.     

TMSN3/NfF:一种有机胺叠氮化试剂的制备和应用

伯胺的重氮转移反应是制备有机叠氮化物的重要手段。高毒、易爆的金属叠氮化物(NaN₃)一直是制备重氮转移试剂的必需原料。以安全性更高的TMSN₃和NfF为原料,制备得到重叠转移试剂NfN₃,进而开发出一种制备有机叠氮化合物的新方法。该TMSN₃/NfF试剂制备有机叠氮的方法,具有良好的底物适用性、官能团兼容性和安全性,且放大至10克级规模,产率无明显下降。所有15个芳香胺、脂肪胺、氨基酸衍生底物都以60%～95%的产率得到了目标叠氮产物。     

54例浆细胞性乳腺炎钼靶X线诊断分析

目的 评价高频超声、钼靶X线及其联合试验对于浆细胞性乳腺炎(plasmacellmastitis,PCM)的诊断效能,以期找出首选诊断方法以提高诊断效率。方法 回顾性分析93例临床疑似PCM并且进行穿刺活检或手术治疗的患者,所有患者术前均行高频超声和钼靶X线检查,术后病理证实为PCM54例。结果 高频超声各项统计指标均优于钼靶X线检查。结论 高频超声对于PCM具有较高的诊断价值,故适于作为本病的首选检查。     

食物废弃物培养菌体蛋白的菌种筛选与参数优化研究

研究了多组霉菌和酵母菌之间的复配及其对泔水样培养单细胞蛋白 SCP菌体干重的影响 ,利用正交实验对培养条件进行了优化。结果表明 ,选用黑曲霉 As3.462 7和白地霉 As2 .498,接种时间间隔 2 4 h,接种量为 1 0 % ,初始 p H值为 5 ,培养时间为 72 h,可获得最佳的菌体干重 2 9.33g/L,菌体粗蛋白含量达 5 4 .71 %。根据优化条件对细胞的生长代谢特性进行了比较研究 ,为进一步的反应器研究打下基础     

蒸发冷却塔循环系统的化学处理方案

对一生产磷酸和硫酸设备的两套循环冷却系统提出了化学处理方案。选择方案时，在考虑了设备与补水的特点的同时还考虑了当地的特殊环境。在用软件和中试冷却塔进行了实际和理论的研究后确定了处理方案。     

抽油泵失效机理研究

从抽油泵工况情况着手,提出了磨损、油井出砂、阀罩断裂、阀罩结构不合理、材质不过关等原因是抽油泵失效的主要原因,并就原因做了详细的分析。