桌面弹跳乐的设计与开发

桌面弹跳乐是一款新型机械娱乐产品,它能使玩家充分参与其中并体验到游戏的乐趣。该产品主要由操纵装置、传动机构、弹出机构和计数装置四部分组成,玩家通过手和脚同时进行控制即可实现篮球运动中的传球,带球和投球等动作。其中传动机构采用圆柱凸轮实现了整个活动支架的往复运动,弹出机构由电磁铁和弹簧巧妙的组合而成,计数装置通过89C52单片机进行倒计时和计数。     

A dissipative particle dynamics study on the compatibilizing process of immiscible polymer blends with graft copolymers

The dissipative particle dynamics (DPD) is used to study the compatibilizing process of an immiscible polymer blend using a graft copolymer as a compatibilizer. Polystyrene (PS) and polyamide 6 (PA6) are chosen as the polymer components of the blend. The graft copolymer is composed of PS as the backbone and PA6 as the grafts. Mesoscale morphology, density distribution, end-to-end distance of PA6 and interfacial tension are investigated. Simulations show that the presence of a graft copolymer contributes to the formation of finer and more uniform dispersed domains by preventing them from collision and coalescence. In the presence of a graft copolymer, the density distribution is more uniform and the dynamic equilibrium of the blend morphology is reached more rapidly. For a given backbone and number of grafts per backbone, the compatibilizing efficiency of the graft copolymer first increases with increasing graft length. However, when the graft length exceeds a certain value, it starts decreasing.     

Hydrothermal synthesis of hierarchical hydroxyapatite: Preparation, growth mechanism and drug release property

Hydroxyapatite (HAP) hierarchical microspheres were synthesized by a facile hydrothermal method using calcium nitrate and ammonium dihydrogen phosphate through controlling complexing agents. The influences of two kinds of complexing agents (potassium sodium tartrate tetrahydrate and trisodium citrate) and reaction time on the morphology of HAP crystals have been investigated. These results indicate that complexing agents have a great influence on the morphology of HAP. When potassium sodium tartrate tetrahydrate was used as complexing agent, HAP flowers were composed of the network of nanosheet building blocks. Well-crystallized HAP dandelions with nanorods radiating from the center can be obtained by the introduction of trisodium citrate. Broader XRD diffraction peaks imply a nanometer scale size. Based on XRD and SEM results, the formation mechanism of HAP crystals has been discussed. The hierarchically structured HAP microspheres were explored as drug carriers. The results indicate that HAP flowers and dandelions showed a favorable sustained release property for ibuprofen; thus, they are very promising for application in drug delivery.     

Addition of small amounts of BiFeO3 to (Li,K,Na)(Nb,Ta)O3 lead-free ceramics: Influence on phase structure,microstructure and piezoelectric properties

A small amount of BiFeO₃ (BF) was incorporated into lead-free Li_0.03(Na_0.53K_0.48)_0.97Nb_0.8Ta_0.2O₃ (LKNNT) piezoceramics for the purpose of property improvement via phase structure control. It was found that the addition of BF not only induced a series of phase transformations from orthorhombic to tetragonal and further to pseudocubic in LKNNT ceramics, but also enhanced its sintering densification behavior. Even tiny amount of BF addition down to 0.5 mol% could change the room-temperature phase structure from a dominant orthorhombic state to the coexistence of orthorhombic and tetragonal phases, resulting in peak piezoelectric properties of $d_{33}^{*}～340\text{pm/V}$, k_p ～ 47.0%. When the amount of BF was increased to 0.75 mol%, the tetragonal phase became dominant in the modified LKNNT ceramics, which exhibited excellent temperature stability, despite its slightly lowered piezoelectric coefficients.     

基于STC89C52单片机的可控旋转视觉试验台的设计

为实现对物体的不同角度、不同位置、不同速度的拍照,设计了一种基于STC89C52单片机的可控旋转视觉试验台.试验台由系统软件及硬件共同组成,实现了试验台角度的调节,正反转的控制、速度的控制.将两个CCD摄像机摆放在试验台的两侧,通过对试验台的控制,然后按照既定的条件触发摄像机拍照,将获得的图片传输至图像处理分析软件中进行分析处理.     

重金属离子对烤烟叶片中铜锌超氧化物歧化酶活性的影响

为研究重金属对烟叶铜锌超氧化物歧化酶的作用规律,消除活体烟叶中其它因素的影响,本试验采用离体方法,利用硫酸铵盐析分级分离、乙醇.氯仿沉淀除杂、丙酮再沉淀分级得到只含铜锌超氧化物歧化酶的酶液.研究了不同浓度的Fe2+、Mn2+、Se2+、Sb2+、Cd2+对该酶的影响.结果显示:在浓度为0～100 mg/L范围内,Fe2+、Mn2+、Sb2+、Cd2+都能使铜锌超氧化物歧化酶的活性先降低后升高,但在相同浓度下,Cd2+对酶活性的影响最大,其次是Mn2+、Fe2+.Sb2+使该酶的活性的变化趋势与Cd2+、Mn2+基本一致,仅变化幅度不及Cd2+、Mn2+显著.se2+能降低该酶的活性,当浓度为10 ms/L时,酶活性的降低率为58.78%.当se2+浓度为20 ms/L时,酶活性几乎完全丧失.分析了铜锌超氧化物歧化酶活性受Fe2+、Mn2+等影响的可能机制,以期为烟草重金属污染的酶学指标监测系统的建立提供数据支持.     

Ag/C nanoparticles as an cathode catalyst for a zinc-air battery with a flowing alkaline electrolyte

The cyclic voltammetry indicated that the oxygen reduction reaction (ORR) proceeded by the four-electron pathway mechanism on larger Ag particles (174 nm), and that the ORR proceeded by the four-electron pathway and the two-electron pathway mechanisms on finer Ag particles (4.1 nm), simultaneously. The kinetics towards ORR was measured at a rotating disk electrode (RDE) with Ag/C electrode. The number of exchanged electrons for the ORR was found to be close to four on larger Ag particles (174 nm) and close to three on finer Ag particles (4.1 nm). The zinc-air battery with Ag/C catalysts (25.9 nm) was fabricated and examined.     

Facile synthesis of zinc hydroxide carbonate flowers on zinc oxide nanorods with attractive luminescent and optochemical performance

A simple synthesis route was designed to fabricate a functional composite, zinc hydroxide carbonate (ZHC) flowers on zinc oxide (ZnO) nanorods. The hydrolysis of hexamethylenetetramine (HMT) can generate various species which are slowly released and gradually change reaction modes in a Zn(NO(3))(2)/HMT solution. As a result, ZnO nanorods and ZHC flowers can be sequentially synthesized and connect very well under constant experimental conditions. The obtained composite has the advantages of both components and exhibits attractive properties. For instance, ZHC flowers on ZnO nanorods exhibit strong blue emission under the excitation of ultraviolet light, and dye-sensitized solar cells with the annealed composite as photoanode achieve much higher conversion efficiency than pure nanorod arrays.