利用假单胞菌天冬氨酸－β－脱羧酶高效生产L－丙氨酸

通过诱变筛选得到一株具有高活性Ｌ－Ａｓｐ－β－脱羧酶的菌株ＰｓｅｕｄｏｍｏｎａｓＮＸ－１，对该株酶形成和酶反应的条件进行了详细研究，该株可以高效地转化Ｌ－Ａｓｐ生成Ｌ－ＡＩａ，转化４～５山每Ｌ培养液可转化Ｌ－Ａｓｐ量高达１４００ｇ左右，生成Ｌ－Ａｌａ浓度高达９０％以上，摩尔转化率近１００％。     

Na－α′－Sialon的形成

合成了Ｎａ－α’－Ｓｉａｌｏｎ，并研究了它的生成随温度变化的关系，发现Ｎａ－α’－Ｓｉａｌｏｎ不稳定，易发生分解，分解产物为β’－Ｓｉａｌｏｎ、ＡＩＮ和１５Ｒ等；在Ｎａ－α’－Ｓｉａｌｏｎ的生成过程中，发现一个不稳定的过渡新相：Ｎａ－Ｏ’－Ｓｉａｌｏｎ，并给出了它的点阵常数．     

2－氨基－4－氯苯酚的合成研究

提出了以对二氯苯为原料，经硝化，水解和还原三步合成２－氨基－４－氯苯酚的讨了影响反应的因素。产品总收率达７７％。     

Al－Li－Cu－Mg－Zr合金的晶界断裂

本文通过室温拉伸试验，利用扫描电镜和透射电镜研究了Ａｌ－Ｌｉ－Ｃｕ－Ｍｇ－Ｚｒ合金不同时效状态下的拉伸性能和断裂行为。结果表明，该合金的力学性能与主要强化相δ＇（Ａｌ３Ｌｉ）的尺寸有关，其断裂行为决定于位错的共面滑移程度和滑移与晶界沉淀相的交互作用。     

A－稳定等价于B－收敛

本文对线性多步法证明了Ｂ－收敛蕴含Ａ－稳定，从而Ａ－稳定等价于Ｂ－收敛。对于单支方法则Ａ－稳定、Ｇ－稳定、Ｂ－收敛三者等价。     

Ti－15－3钛合金的应用研究

研究了冷加工对Ｔｉ－１５－３合金时效性能的影响，并研究了该合金的冷成形性能及零件制造工艺，为Ｔｉ－１５－３高强钛合金钣金零件的应用提供了经验。     

PP－g－AA的制备和表征

用熔融接枝方法制备了聚丙烯－ｇ－丙烯酸（ＰＰ－ｇ－ＡＡ）。用光电子能谱，广角Ｘ射线衍射，红外光谱和化学滴定方法对接枝物进行了定性和定量表征。讨论了单体和引发剂浓度对接枝率的影响，确定了用红外光谱法测定接枝物含量的经验公式     

Y－Ba－Cu－O熟粉和生粉与油酸化学作用的研究

采用ＣＮＤＯ／２量子化学计算方法，研究了Ｙ－Ｂａ－Ｃｕ－Ｏ熟粉及生粉的化学成键特征。计算表明，ＹＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）高温超导相形成后，其中各化学键发生变化，化学键的反应活性趋于平均化。因此，Ｙ－Ｂａ－Ｃｕ－Ｏ熟粉可以与油酸发生均匀化学反应，得到的膏状物能用来焊接高ＴｃＹＢＣＯ超导线材及器件。     

在热处理过程中α－β－Sialon的相变

Ｓｉａｌｏｎ陶瓷在热处理过程中经常发生α－Ｓｉａｌｏｎ→β－Ｓｉａｌｏｎ的相变．晶界中液相的结晶化是导致热处理时α－Ｓｉａｌｏｎ→β－Ｓｉａｌｏｎ相变的原因．这种相交的程度随组份中液相量增加而变大，而且与稀土元素的原子序数有关．对于轻稀土的α－Ｓｉａｌｏｎ材料，这种相变更易发生．本文依据Ｌｎ－Ｓｉ－Ａｌ－Ｏ－Ｎ系统的相关系和α－Ｓｉａｌｏｎ的形成特性对α－Ｓｉａｌｏｎ→β－Ｓｉａｌｏｎ相变的机理作了探讨．     

P－S－N曲线测定法比较研究

本文介绍了七种测定Ｐ－Ｓ－Ｎ曲线的方法。并且用五种材料的实验数据对上述测定方法作了分析比较。在比较了几种方法的优缺点的基础上，提出了选择试验方法的建议和结论。     

Fatigue behavior of AZ31 magnesium alloy produced by solid-state recycling

Mechanical properties of AZ31 Mg alloy produced from machined chips by the solid-state recycle method were compared to those of the reference alloy which was produced from an as-received AZ31 Mg alloy block under the same conditions with the recycled alloy. Tensile properties of the recycled alloy were comparable to those of the reference alloy, however, the recycled alloy exhibited poorer fatigue resistance than the reference alloy.     

高抗冲聚苯乙烯对改性国产聚苯醚性能的影响

研究了不同高抗冲聚苯乙烯(HIPS)对聚苯醚/高抗冲聚苯乙烯(PPO/HIPS)合金力学性能和流动性能的影响,并探讨了两种聚苯醚原粉对合金性能的影响;采用阿基米德螺旋线流动长度表征合金注塑成型的流动性能,观察了合金冲击断面的微观形貌,分析了其韧性差异的原因。结果发现:HIPS-HI425制备的合金流动性能最好,HIPS-470制备的合金综合性能最佳;PPO-40原粉制备的合金流动性能较好,PPO-45原粉制备的合金韧性较好。     

电沉积Ni-W合金在NaCl溶液中的腐蚀行为

通过电沉积的方法制备了Ni-W晶态合金与Ni-W非晶态合金.采用极化曲线与电化学阻抗谱测试了Ni-W合金在0.5mol/L NaCl溶液中的腐蚀行为.结果表明,Ni-W非晶态合金在0.5mol/L NaCl溶液中的极化曲线与Ni-W晶态合金相比,腐蚀电位较正,且钝化区间明显.Ni-W非晶态合金在0.5mol/L NaCl溶液中的电化学阻抗谱容抗弧半径远远大于Ni-W晶态合金,并且随着浸泡时间的延长Ni-W非晶态合金的表面生成一层钝化膜,容抗弧半径变化较小,而Ni-W晶态合金的容抗弧半径随浸泡时间的延长而越来越小,表面腐蚀越来越严重.总体来说,Ni-W非晶态合金的耐蚀性能要远远优于Ni-W晶态合金.     

聚丙烯/聚苯乙烯共混合金Ⅱ.结晶和性能

用偏光显微镜、DSC、DMA分析法和拉伸试验等方法对PP／PS／PP-g-PS熔融共混合金的结晶行为、形态和拉伸强度进行了研究。结果表明，PP-g-PS减轻了PS相对PP相结晶行为的干扰，合金的拉伸强度明显上升。上述变化均与PP-g-PS在合金中的含量有关。     

Combined effects of cerium and boron on the mechanical properties and oxidation behaviour of Ni3Al alloy

The combined effects of cerium and boron additions on the room-temperature tensile properties and high-temperature oxidation behaviour of Ni3Al alloys: alloy 1 doped with cerium, alloy 2 doped with boron, and alloy 3 doped with both cerium and boron. The strength, ductility and oxidation behaviour of the alloy are more effectively improved by combined cerium and boron additions than by cerium or by boron addition alone. Of the three alloys, alloy 3 exhibits comprehensively the best mechanical properties and oxidation resistance. Alloy 2 presents the better mechanical properties than alloy 1; nevertheless, alloy 1 has the better oxidation resistance than alloy 2.     

Dynamic mechanical properties of a near-nano aluminum alloy processed by equal-channel-angular-extrusion

Microstructure of AA5056 AlMg alloy is refined drastically to nano-scale by the equal-channel-angular-extrusion(ECAE) process. Dynamic mechanical properties at room temperature in the ECAE processed 5056 AlMg alloy (5056-ECAE) are characterized by a modified Hopldnson-bar method. Yield stress (YS) in 5056-ECAE exhibits remarkably higher value than that of a fully annealed 5056 alloy(5056-0). Hall-Petch(H-P) relation of 5056 alloy is compared with those of a binary AlMg alloy and Aluminum. The slope of the H-P relation in the granular 5056 alloy is almost equal to that of a binary AlMg alloy with a similar content of magnesium, and larger than that of Aluminum. On the other hand, the slope of the sub-grained alloy exhibits lower value than that of the granular alloy. The result indicates that grains effectively refined by the ECAE process, however, the grain boundary strength of the sub-grained alloy is relatively lower than that of the granular alloy. The elongation-to-failure of 5056-ECAE exhibits a larger value than those of some fine-grained bulk aluminum alloys such as a mechanically alloyed aluminum. Fractography of 5056-ECAE revealed that this alloy was fractured with ductile dimples. The result supports the possibility that this alloy exhibits the high speed impact performance and capability for high-rate forming.     

Optimizing mechanical property and cytocompatibility of the biodegradable Mg-Zn-Y-Nd alloy by hot extrusion and heat treatment

The Mg-Zn-Y-Nd alloy is a new type of degradable material for biomedical application. In the present study, Mg-6Zn-1.2Y-0.8Nd alloy was fabricated, and then extrusion and heat treatment were conducted to optimize its mechanical properties and cytocompatibility. The microstructure observation, mechanical property, degradation behavior and cytocompatibility tests were conducted on the Mg-Zn-Y-Nd alloy with three different states: as-cast (alloy C), as-extruded (alloy E) and extruded + heat treated (alloy EH). The results show that alloy C consists of coarse grains and continuous secondary phases. The extrusion process has caused incomplete recrystallization, and results in a mixed grain structure of elongated grains and small equiaxed grains (alloy E). The heat treatment process has promoted the recrystallization and homogenized the grain structure (alloy EH). Both the strength and ductility of the alloy has been improved by extrusion, but the following heat treatment has decreased the strength and increased the ductility. The degradation behavior of the alloy C and E alloys does not show much difference, but improves slightly in alloy EH, because the heat treatment has homogenized the microstructure and released the residual stress in the alloy. The directly and indirectly cell viability tests indicate that alloy EH exhibits the best cytocompatibility, which should be ascribed to its relative uniform degradation and low ion releasing rate. In summary, the combination of hot extrusion and heat treatment could optimize the mechanical property and cytocompatibility of the Mg-Zn-Y-Nd alloy together, which is beneficial for the future application of the alloy.     

Al-Cu-Mg-Ag合金与ZL205A合金性能与微观组织对比

采用半连续铸造法分别制备了Al-Cu-Mg-Ag合金与ZL205A合金。对两种铝合金的流动性能、室温及高温拉伸性能、拉伸断口形貌、晶间腐蚀性能和微观组织进行了对比分析。结果表明:浇铸温度为720℃和740℃时,Al-Cu-Mg-Ag合金的流动性能均优于ZL205A合金的。室温、150℃、200℃、250℃下,Al-Cu-Mg-Ag合金的强度均高于ZL205A合金的,且随着温度的升高,其强度降低的幅度要明显低于ZL205A合金的,两种材料的室温伸长率基本相当。Al-Cu-Mg-Ag合金的晶间腐蚀深度在182～246 μm之间,优于ZL205A合金的274～337 μm。Al-Cu-Mg-Ag合金无析出带的宽度要窄于ZL205A合金的。      

Tribological Behavior of Al CoCrFeNi(Ti_(0.5)) High Entropy Alloys under Oil and MACs Lubrication

The tribological properties of AlCoCrFeNi and AlCoCrFeNiTi_(0.5) high entropy alloys under gear oil and multiply alkylated cyclopentanes(MACs)lubrication condition have been studied.The equiaxed crystal structure of AlCoCrFeNi alloy is obtained after heat-treatment.The AlCoCrFeNiTi_(0.5) alloy keeps dendrite structure.Under the gear oil with good lubrication action,AlCoCrFeNiTi_(0.5) alloy preserves better tribological properties than AlCoCrFeNi alloy.The delamination and crack behaviors tend to occur in the grain boundary of AlCoCrFeNi alloy and along the interdendrite region of AlCoCrFeNiTi_(0.5) alloy.Under the MACs with relatively poor lubrication action,the applied load slightly influences the wear behavior of AlCoCrFeNi alloy,but seriously impacts the wear mechanism of AlCoCrFeNiTi_(0.5) alloy.Compared with AlCoCrFeNi alloy,AlCoCrFeNiTi_(0.5) alloy keeps better wear-resistance at low applied load of 100 N,but preserves less wearresistance at high applied load of 200 N.     

铸态及快淬态Ni50Mn26Ga19Fe5合金的磁致应变

研究了铸态及快淬Ni50Mn26Ga19Fe5掺杂合金的磁致应变性能.结果表明,掺Fe的Ni-Mn-Ga合金也具有典型的热弹性马氏体相变过程和磁转变过程,但铸态合金的结构为7层调制型马氏体(7M),而快淬合金的结构为14层调制型马氏体(14M).铸态合金最大磁致应变可达0.1%,快淬薄带合金最大磁致应变只能达到0.0095%.Ni50Mn26Ga19Fe5铸态合金比快淬合金有更大的磁致应变,说明掺杂元素Fe在Ni-Mn-Ga合金中的作用较为复杂.