SO_4~(2-)/炼锌水淬渣固体酸的制备及催化性能研究

用炼锌水淬渣废物为原料,采用半湿法浸渍和干法老化结合的方法制备了SO2-4/水淬渣固体酸催化剂,考察了浸渍浓度、焙烧温度、老化温度等制备条件对其催化油酸和甲醇酯化制备生物柴油催化性能的影响,并对SO2-4/水淬渣和硫酸处理水淬渣絮凝体烘干物进行NH3-TPD酸性测试和比表面积分析。实验结果表明,制备条件对SO2-4/水淬渣固体酸的催化性能有很大的影响,将最佳制备条件下得到的催化剂用于油酸和甲醇的酯化反应,在催化剂用量18%,醇油比15∶1,温度120℃,反应时间8h的反应条件下,酯化率可达90%以上,且该催化剂重复使用4次后,酯化率仍在50%以上,经H2SO4活化后其催化活性又可恢复。     

竹炭基固体酸催化剂的制备及其催化性能研究

以4年生慈竹为炭源制备新型碳基固体强酸催化剂,以油酸与甲醇的酯化反应为模型反应主要考察了炭化温度、炭化时间、磺化温度和磺化时间等因素对其催化剂性能的影响。研究结果表明,以竹子作为碳源,利用硫酸合成碳基固体酸催化剂的最佳工艺条件为:碳化温度650℃,碳化时间6h,磺化温度140℃和磺化时间10h,在此条件下油酸与甲醇的酯化反应的转化率达到94.70%。竹炭基固体酸催化剂制备简单,催化酯化反应条件温和,克服了传统液体酸催化剂的缺点,具有良好的稳定性,且通过简单的过滤即可回收重复利用具有很好的应用前景。     

磁性碳基固体酸微球催化剂的制备及其催化性能研究

采用水热法制备得到具有磁响应性能的碳基固体酸微球催化剂,采用扫描电镜、振动样品磁强计、X射线衍射仪、红外光谱仪、热重分析仪和Boehm滴定等手段对其进行表征,并探讨了催化剂制备条件对碳基固体酸微球催化剂催化性能的影响。结果表明:微球直径为1.1～1.3μm时,其饱和磁化强度为4.25emu/g,具有Fe_3O_4的特征衍射峰,且表面具有大量的酸性官能团;在磺化温度为120℃、磺化时间为8h、浓硫酸用量为15mL时,催化剂酸量达到2.84mmol/g。将催化剂应用于油酸与甲醇的酯化反应,当催化剂质量为油酸质量的7.5%,甲醇与油酸摩尔比为24∶1,酯化温度为90℃,酯化时间为3h时,酯化率达到89.43%。     

玉米粉炭基固体酸催化剂的制备及表征

通过炭化-磺化的方法,以玉米粉为原料,制备了玉米粉炭基固体酸催化剂,并催化油酸与甲醇酯化反应制备生物柴油。通过XRD、FE-SEM、FT-IR对催化剂表征,实验结果证明,经过不完全炭化和磺化过程生成的为磺酸基负载的芳香族炭结构的化合物。通过单因素和正交试验得出该催化剂的最优制备条件为450℃,炭化恒温时间2h,磺化温度140℃,磺化时间3h,此催化剂催化的酯化反应转化率高达72.04%。     

秸秆炭质固体酸催化剂的制备及应用

以秸秆为原料,采用炭化和磺化方法制备炭质磺酸化固体酸催化剂,并通过XRD、SEM和FT-IR对所制备催化剂的结构进行表征。通过催化油酸和甲醇酯化反应制备生物柴油,考察炭化温度、炭化时间、磺化温度和磺化时间对催化剂性能的影响。并研究了不同条件对油酸转化率的影响,优化了制备生物柴油的最佳工艺条件,结果表明:在炭化温度为350℃、炭化时间1h、磺化温度140℃、磺化时间1h的条件下,所制备催化剂具有较高的活性;在反应温度为68℃、反应时间为5h、催化剂质量为油酸质量的7%、甲醇与油酸的物质的量比为12∶1的条件下,生物柴油转化率可达94.83%。     

固体超强酸催化合成丁酸戊酯的研究

以Ti(OC4H9)4为原料,采用溶胶-凝胶法制备固体超强酸SO4 2-/TiO2,并利用XRD、IR及DRS对催化剂进行表征,然后,以SO4 2-/TiO2为催化剂,通过丁酸与戊醇反应合成了丁酸戊酯.探讨了SO4 2-/TiO2催化酯化反应机理及SO4 2-/TiO2的结构,讨论了影响酯化率的主要因素,实验结果表明,当催化剂用量为0.6g,醇酸摩尔比为1.4:1,反应温度为125℃,反应时间为6h时,平行实验的平均酯化率可达96.4%.     

SO_4~(2-)/TiO_2-SiO_2固体超强酸失活原因及再生方法研究

以SO42-/TiO2-SiO2固体超强酸催化剂为例,选择松香与甘油酯化这一高粘度有机反应体系,通过IR、TPD、XRD和BET等检测方法,研究了SO42-/TiO2-SiO2的失活原因。研究表明,催化剂表面吸附有机物、酸中心减少、酸量下降是导致该催化剂失活的主要原因。在此基础上研究了再生方法,优化了再生条件:在500℃焙烧脱去吸附物,再用H2SO4浸渍对失活催化剂进行再生。再生催化剂的催化性能与新鲜催化剂性能基本相同。     

催化乳酸铵酯化的改性树脂的制备与表征

为降低酯化催化剂的制备成本,提高催化酯化反应的性能,以磺酸型阳离子交换树脂和FeCl3·6H2O为原料,采用液固溶剂法制备了固体酸催化剂.利用XRF,FTIR,XRD,NH3-FTIR对催化剂进行表面酸性、元素含量等性质的测试表征.研究表明,FeCl3与阳离子交换树脂的Bronsted酸中心(SO3H)发生化学反应形成了新的Lewis酸中心,络合到树脂上的Fe3+量为11.8%.测试了催化剂促进乳酸铵和正丁醇酯化反应的催化活性,当催化剂用量为1.5%时,酯化率高达96.1%.     

SO4^2-／ZrO2-SiO2的制备及其催化性能研究

用共沉淀法制备了SO4^2-／ZrO2-SiO2固体酸催化剂，通过XRD、BET、IR、SEM等综合实验手段考察了SiO2的加入量不同对固体酸的晶体结构的影响，并以乙酸正丁酯的酯化反应为探针实验考察了SO4^2-／ZrO2-SiO2的催化性能。结果表明，SiO2的加入抑制了ZrO2晶型的转变，提高了催化剂的活性。     

磺化椰壳炭固体酸催化剂的制备及催化酯化反应研究

以海南椰壳纤维为原料,采用浸渍法活化、管式炉炭化等过程制备椰壳活性炭,然后以浓硫酸为磺化剂,磺化制备了具有多孔特征的椰壳炭固体酸。并对制得的椰壳炭固体酸进行了结构表征。通过乙酸和正丁醇的酯化反应,对催化剂的性能进行了测试,考察了催化剂制备过程中物料比、灼烧温度、炭化时间、磺化剂用量等因素对催化反应的影响。结果表明:在椰壳纤维原料与活化剂氢氧化钾的质量配合比为1∶1,炭化温度为450℃,炭化时间为2h,椰壳活性炭与磺化剂投量配合比为1g∶20mL,磺化时间为2h条件下,制得的磺化椰壳固体酸的催化性能最好,并在催化乙酸与正丁醇的酯化反应中2h转化率达到96.6%。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from