MPP CCD扩散暗电流温度特性分析

研究了MPP CCD扩散暗电流的温度特性,分析了扩散暗电流在不同温度下对器件总暗电流的贡献和不同处理方式对评估器件高温暗电流的影响,并对此进行了实验验证。结果表明,扩散暗电流在高温下对器件总暗电流的影响很大,占据支配地位,是器件高温暗电流的主要来源。提出了两种优化方法,以降低扩散暗电流对器件高温暗电流的影响,提高MPP CCD的高温环境工作能力。     

4A分子筛对MPP阻燃PA6性能的影响

以恒温聚合得到的三聚氛胺聚磷酸盐(MPP)为阻燃剂,4A分子筛为协效剂,制备了阻燃PA6.研究了4A分子筛用量对阻燃PA6性能的影响.结果表明,少量的分子筛便可以显著提高PA6的阻燃性能,在加速体系成炭的同时使炭层结构发生变化.当MPP、4A分子筛质量分数分别为20%、4%时,阻燃PA6的氧指数可以达到30%,拉伸强度...     

三聚氰胺聚磷酸盐的合成及其在阻燃聚乙烯中的应用

以磷酸和三聚氰胺(ME)为原料,水为溶剂,合成出了高纯度的三聚氰胺磷酸盐(MP),确定了最佳的工艺条件。MP经热聚合得到三聚氰胺聚磷酸盐(MPP)。对MPP进行了氮含量测定、红外光谱分析和热失重分析。研究表明,添加适量份数三聚氰胺与纯MP一起煅烧制得的MPP1热稳定性优于MPP;通过氧指数测试、热重分析和锥形量热法考察了MPP和MPP1对聚乙烯(PE)阻燃性能的影响,发现分别添加20%MPP和MPP1的阻燃PE的极限氧指数(LOI)分别由纯PE的17.6提升到21.56和22.19,600℃时的残炭率均超过10%。     

High rate deposition of thick CrN and Cr2N coatings using modulated pulse power (MPP) magnetron sputtering

As a variation of high power pulsed magnetron sputtering technique, modulated pulse power (MPP) magnetron sputtering can achieve a high deposition rate while at the same time achieving a high degree of ionization of the sputtered material with low ion energies. These advantages of the MPP technique can be utilized to obtain dense coatings with a small incorporation of the residual stress and defect density for the thick coating growth. In this study, the MPP technique has been utilized to reactively deposit thick Cr₂N and CrN coatings (up to 55 μm) on AISI 440C steel and cemented carbide substrates in a closed field unbalanced magnetron sputtering system. High deposition rates of 15 and 10 μm per hour have been measured for the Cr₂N and CrN coating depositions, respectively, using a 3 kW average target power (16.7 W/cm² average target power density), a 50 mm substrate to target distance and an Ar/N₂ gas flow ratio of 3:1 and 1:1. The CrN coatings showed a denser microstructure than the Cr₂N coatings, whereas the Cr₂N coatings exhibited a smaller grain size and surface roughness than those of the CrN coatings for the same coating thickness. The compressive residual stresses in the CrN and Cr₂N coatings increased as the coating thickness increased to 30 μm and 20 μm, respectively, but for thicker coatings, the stress gradually decreased as the coating thickness increased. The CrN coatings exhibited an increase in the scratch test critical load as the thickness was increased. Both CrN and Cr₂N coatings showed a decrease in the hardness and an increase in the sliding coefficient of friction as the coating thickness increased from 2.5 to 55 μm. However, the wear rate of the CrN coatings decreased significantly as the coating thickness was increased to 10 μm or higher. The 10-55 μm CrN coating exhibited low wear rates in the range of 3.5-5 × 10⁻⁷ mm³ N⁻¹ m⁻¹. To the contrary, the Cr₂N coating exhibited relatively low wear resistance in that high wear rates in the range of 3.5 to 7.5 × 10⁻⁶ mm³ N⁻¹ m⁻¹ were observed for different thicknesses.     

气相色谱仪结合数据分析软件鉴别橄榄油掺杂

目的基于气相色谱仪和数据分析软件来鉴别橄榄油掺杂。方法取5种橄榄油分别与市售葵花籽油、大豆油、菜籽油、玉米油和花生油以不同的比例混合来模拟掺杂。运用气相色谱-氢火焰检测器检测其脂肪酸甲酯含量,结合数据分析软件(mass profiler professional,MPP)进行数据处理,以偏最小二乘判别分析法建立预测模型。结果 1%(体积比)掺杂样品的鉴别准确率在90%以上。结论通过此方法对各类掺杂橄榄油都能很好地鉴别是否掺杂。     

金黄色葡萄球菌金属磷酸酶的遗传特征分析及功能鉴定

目的对金黄色葡萄球菌(简称金葡菌)一种新型金属磷酸酶(metallophosphatase,MPP)SA1662进行遗传特征分析及生物学功能鉴定。方法从金葡菌基因组DNA中克隆SA1662基因,通过序列比对和构建进化树分析其遗传特征;构建重组表达质粒,转化大肠埃希菌BL21,IPTG诱导表达,表达的重组蛋白经Ni柱纯化后,测定酶活性。应用同源重组技术构建SA1662基因缺失株,分析SA1662基因缺失对金葡菌生长、万古霉素敏感性、细菌自溶性和细菌生物菌膜形成的影响,探讨SA1662的生物学功能。结果 SA1662蛋白具有MPP类蛋白结构域,并含有特征性金属离子结合位点,与金葡菌和施维茨葡萄球菌中相关蛋白有更近的亲缘关系。该蛋白酶活性依赖于Mg^2+和Mn^2+,特别是Mg^2+。与野生型菌株相比,SA1662基因缺失后,细菌生长速度减慢,万古霉素敏感性、TritonX-100诱导下的细菌自溶性和细菌生物菌膜形成能力均下降。结论 SA1662蛋白为一种新型的金葡菌MPP,在细菌抗逆性中起着重要作用。     

The structure and properties of chromium nitride coatings deposited using dc, pulsed dc and modulated pulse power magnetron sputtering

The time averaged ion energy distributions and ion fluxes of continuous dc magnetron sputtering (dcMS), middle frequency pulsed dc magnetron sputtering (PMS), and modulated pulse power (MPP) magnetron sputtering plasmas were compared during sputtering of a Cr target in an Ar/N₂ atmosphere in a closed field unbalanced magnetron sputtering system. The results showed that the dcMS plasma exhibited a low ion energy and ion flux; the PMS plasma generated a moderate ion flux of multiple high ion energy regions; while the MPP plasma exhibited a significantly increased number of target Cr⁺ and gas ions with a low ion energy as compared to the dcMS and PMS plasmas. Cubic CrN coatings were deposited using these three techniques with a floating substrate bias. The structure and properties of the coatings were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nanoindentation, microscratch and ball-on-disk wear tests. It was found that the deposition rate of the MPP CrN depositions was slightly lower than those of the dcMS depositions, but higher than in the PMS depositions at similar average target powers. The coatings deposited in the dcMS and PMS conditions without the aid of the substrate bias exhibited large columnar grains with clear grain boundaries. On the other hand, the interruption of the large columnar grain growth accompanied with the renucleation and growth of the grains was revealed in the MPP CrN coatings. The MPP CrN coatings exhibited a dense microstructure, fine grain size and smooth surface with high hardness (24.5 and 26 GPa), improved wear resistance (COF = 0.33 and 0.36) and adhesion, which are the results of the low ion energy and high ion flux bombardment from the MPP plasma.     

MPP微孔发泡材料缓冲性能研究

为降低对产品的冲击,对新型MPP(Microcellular Polypropylene foam)材料的性能进行研究。通过对MPP材料的试验,利用MATLAB对数据进行分析处理,得到其不同发泡倍数的应力-应变曲线;通过换算,得出其应力-缓冲系数的分布图。试验数据表明,缓冲系数随着应力的增大,呈现出先增大后减小,再增大趋势;缓冲系数随着发泡倍数的增加而减小,且缓冲系数最大时对应的应力为0.3~0.6 MPa。结果表明:MPP作为一种新型缓冲材料,根据其缓冲系数-应力曲线图,可以计算出对应所需材料的厚度,对其在缓冲包装设计时提供了设计依据,同时对以后的相关试验和优化具有重要的参考意义。     

纳米SiO_2对MPP/PEPA阻燃PP性能的影响

采用多聚磷酸蜜胺(MPP)和笼状季戊四醇磷酸酯(PEPA)为复配阻燃剂,制备了无卤阻燃聚丙烯(PP)。研究了MPP/PEPA质量比和纳米SiO2用量对PP复合材料阻燃性能和力学性能的影响。结果表明:当MPP:PEPA=3:2时,协效阻燃效果最好,添加少量的纳米SiO2即可提高PP复合材料的阻燃和力学性能;当MPP、PEPA、纳米SiO2添加量分别为12%、8%和1%时,阻燃PP的氧指数达28.5%,并具有较好的力学性能。TGA和EDX结果表明:添加少量纳米SiO2可以催化MPP/PEPA间的酯化反应,促进PP复合材料成炭,保留更多的磷。SEM分析表明:添加少量的纳米SiO2可稳定炭层和加固泡孔,增强炭层隔热隔氧的能力。     

CCD MPP结构制作工艺技术研究

在1024×1024可见光电荷耦合器件(CCD)的基础上增加了MPP(Multi-PinnedPhase)结构设计和工艺制作.制得的1024×1024可见光MPP CCD实现了MPP功能,有效抑制了CCD表面暗电流的产生.当MPP注入剂量为(6±2)×10~(11)cm~(-2)时,其暗电流密度下降了2/3,满阱电荷下降了1/2.

Abstract：

Multi-Pinned Phase (MPP) structure is designed and fabricated on the base of 1024×1024 visible light CCD. The 1024×1024 visible light MPP CCD achieves MPP function and suppresses the surface dark current effectively. Its dark current density and full well capacity decrease 2/3 and 1/2, respectively, when MPP implant dose is(6±2)×10~(11) cm~(-2).