Palladium‐Catalyzed Decarbonylative Dehydration of Fatty Acids for the Production of Linear Alpha Olefins

A highly efficient palladium‐catalyzed decarbonylative dehydration reaction of carboxylic acids is reported. This method transforms abundant and renewable even‐numbered natural fatty acids into valuable and expensive odd‐numbered alpha olefins. Additionally, the chemistry displays a high functional group tolerance. The process employs a low loading of palladium catalyst and proceeds under solvent‐free and relatively mild conditions.

     

软件形式化开发方法的选择策略研究

随着软件形式化方法的不断发展,各种各具特色的形式化方法涌现出来,为了解决在具体的系统开发中如何选取合适的形式化方法,对目前较为流行的几种形式化方法RSL,B,VDM,Z的特点进行对比分析,然后针对不同的软件开发人员和所需开发系统的不同,给出了适合用形式化方法开发的情况和如何选择合适的形式化开发方法。     

热轧卷取温度对HC340LAD+Z带钢力学性能的影响

为了研究热轧卷取温度对热镀锌HC340LAD+Z带钢力学性能的影响规律,对同一炉次、相同规格的3批次钢坯,分别采用580、620、660 ℃3个卷取温度,以及相同的冷轧、热镀锌、退火工艺进行了试验研究。结果表明,随着卷取温度的升高,成品带钢的屈服强度、抗拉强度降低,伸长率稍有增加,均满足EN10346标准对HC340LAD+Z带钢力学性能的要求。热轧卷取温度为620 ℃时,HC340LAD+Z带钢的屈服强度为389.2 MPa,抗拉强度为474.3 MPa,伸长率A80为26.5%,其综合力学性能对比标准指标,富裕量最佳。     

邯钢光伏支架用热镀锌S390GD(S450GD)+Z产品的开发

环保节能领域光伏支架用有锌花镀锌产品是邯钢市场开发的重点,但用户对其表面质量、力学性能、耐蚀性能和变形延展性有较高的要求。从热轧备料,酸洗工艺,热镀锌退火温度及锌层控制等方面阐述了开发光伏支架用热镀锌S390GD(S450GD)+Z产品的质量保证措施。通过降C、增Mn的化学成分设计,板坯出炉温度1 100～1 150℃、粗轧压下率40%～45%、终轧温度(850±20)℃、卷取温度降至(580±20)℃ 的热轧工艺优化,保证了热轧原料强度。通过酸液温度、酸洗速度、缓蚀剂添加量的优化,以及热镀锌退火温度、锌液成分的优化改进,实现了锌花结晶均匀性控制,产品质量满足用户要求。     

Comprehensive Molecular Dissection of Dermatophilus congolensis Genome and First Observation of tet(Z) Tetracycline Resistance

Dermatophilus congolensis is a bacterial pathogen mostly of ruminant livestock in the tropics/subtropics and certain temperate climate areas. It causes dermatophilosis, a skin disease that threatens food security by lowering animal productivity and compromising animal health and welfare. Since it is a prevalent infection in ruminants, dermatophilosis warrants more research. There is limited understanding of its pathogenicity, and as such, there is no registered vaccine against D. congolensis. To better understanding the genomics of D. congolensis, the primary aim of this work was to investigate this bacterium using whole-genome sequencing and bioinformatic analysis. D. congolensis is a high GC member of the Actinobacteria and encodes approximately 2527 genes. It has an open pan-genome, contains many potential virulence factors, secondary metabolites and encodes at least 23 housekeeping genes associated with antimicrobial susceptibility mechanisms and some isolates have an acquired antimicrobial resistance gene. Our isolates contain a single CRISPR array Cas type IE with classical 8 Cas genes. Although the isolates originate from the same geographical location there is some genomic diversity among them. In conclusion, we present the first detailed genomic study on D. congolensis, including the first observation of tet(Z), a tetracycline resistance-conferring gene.     

Z/M对RFCC催化剂反应性能的影响

以稀土超稳Y型分子筛和拟薄水铝石为主要原料制备了重油催化裂化(RFCC)模型催化剂,通过N 2物理吸附和高级裂化评价装置研究了水热减活RFCC模型催化剂中Y型分子筛与基质比表面积之比(Z/M)及其对催化裂化反应性能的影响。结果表明,拟薄水铝石含量越高,Y型分子筛抵御高温水热破坏的能力越差,Z/M越小。拟薄水铝石质量分数为30%时,水热减活后分子筛比表面积仅为减活前的28.3%,Z/M仅为0.8。拟薄水铝石含量不仅影响催化剂的水热稳定性,还影响催化剂的形貌。拟薄水铝石含量越高,催化剂微球形貌规整性越差,当其质量分数为30%时,催化剂微球表面不仅产生了大量的孔洞,还出现了许多裂纹。随着模型催化剂Z/M下降,目标产物液化石油气和汽油产率之和逐渐降低,轻循环油产率升高,焦炭选择性变差。     

基于 TTP 参数法的25Cr20NiNbN 钢持久寿命评估方法

结合常规时间－温度（TTP）参数法和粒子群优化算法（PSO）,建立了 Larson －Miller（LM）, Orr －Sherby －Dorn（OSD）和 Manson －Harferd（MH）模型,然后利用这3种模型对25Cr20NiNbN 钢的持久寿命进行了评估,并利用 Z 参数对3种参数模型的预测准确度进行分析。通过分析3种模型的预测结果,发现 MH 法的预测结果准确度最高。对不同可靠度下材料的持久寿命进行计算,保证了预测结果的可靠性。     

Amtshaftung bei Bauführung im Hochwassergebiet; fehlerhafter Flächenwidmungsplan; Nachforschungspflichten der Gemeinde

Bestehen ausreichende Anhaltspunkte für die Hochwassergef?hrdung, ist die Gemeinde verpflichtet, sich durch Nachforschungen Gewissheit über das Vorliegen oder Nichtvorliegen eines Hochwasserabflussgebietes gem § 38 Abs 3 WRG zu verschaffen. Liegt ein solches vor, hat sie gem § 12 Abs 1 Z 2 krnt GplG dieses im Fl?chenwidmungsplan ersichtlich zu machen. Erteilt die Gemeinde eine Baubewilligung ohne diese von der Erteilung einer wasserrechtlichen Bewilligung abh?ngig zu machen, haftet sie für die Kosten der Bauführung, die bei gesetzes-konformer Vorgangsweise unterlassen worden w?re.     

High-pressure hydriding of Zircaloy cladding by the thermogravimetry and tube-burst techniques

Hydriding kinetics of modified Zircaloy claddings was studied by the thermogravimetric method at 400 °C and the tube-burst technique at 315 °C. Some specimens were prefilmed with a thin oxide layer by air oxidation on both the inner and outer surfaces which were either pickled or blasted. In the thermogravimetric test, the hydriding rates of bare cladding specimens (no oxide prefilm) were in the range 0.9-1.6 mg/cm² h with little effect of the surface treatment. Incubation times were less than 1 h or even zero. In the tube-burst test, immediate and extensive hydrogen uptake was observed for these non-coated specimens. On the other hand, the cladding specimens with oxide prefilm exhibited lower hydriding rates ranging from 0.01 to 0.05 mg/cm² h and incubation times increased to 42 h. In addition, no hydrogen uptake was observed for all oxide-coated specimens for 100-750 h.     

制氢转化催化剂损坏原因分析及对策

通过对胜利炼油厂第二制氢装置Z417/4 18制氢转化催化剂的使用情况及损坏情况进行分析,认为Z417/4 18转化催化剂具有较强的抗波动性能、灵活的原料适应性和抗毒物性能。但在大面积停电时,含水的饱和蒸汽进入温度在63 0～780℃之间的转化催化剂床层,低温水汽和高温催化剂接触,发生剧烈的热传递,使上层催化剂崩裂粉碎,从而导致了催化剂的粉化损坏。据此提出了装置异常时的对策,取得了明显的效果