A Stiffness Modeling Approach for Multi-Leaf Spring Mechanism Supporting Coupling Error Analysis of Nano- Stages

Shuai-Shuai Lu,Peng Yan 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.6

In the present paper, we take the multi-leaf spring mechanism as a particular element to develop a modeling approach for the stiffness by considering the coupling effects of the cross axis force. With this, a more accurate model of the multi-leaf spring based nano-stage is derived by incorporating the effect of cross axis input force, which can better predict the coupling error. The new analytical model indicates that the total axial stiffness is an inverse-quadratic function of the cross axis input load instead of a constant value, which can be used to analyze the cross axis coupling error of multi-leaf spring based nano-stages. The proposed analysis method is then verified by FEA and experiments, where excellent results are demonstrated in predicting the cross axis coupling effects of nano-stages such as stiffness variation and coupling error. The proposed approach offers a new look into the design and manipulation of multileaf spring based nano-stages.

Protein-based soft micro-optics fabricated by femtosecond laser direct writing

Sun, Yun-Lu,Dong, Wen-Fei,Niu, Li-Gang,Jiang, Tong,Liu, Dong-Xu,Zhang, Lu,Wang, Ying-Shuai,Chen, Qi-Dai,Kim, Dong-Pyo,Sun, Hong-Bo Nature Publishing Group 2014 Light, science & applications Vol.3 No.1

<P>In this work, we report a novel soft diffractive micro-optics, called 'microscale kinoform phase-type lens (micro-KPL)', which is fabricated by femtosecond laser direct writing (FsLDW) using bovine serum albumin (BSA) as building blocks and flexible polydimethylsiloxane (PDMS) slices as substrates. By carefully optimizing various process parameters of FsLDW (e. g., average laser power density, scanning step, exposure time on a single point and protein concentration), the as-formed protein micro-KPLs exhibit excellent surface quality, well-defined three-dimensional (3D) geometry and distinctive optical properties, even in relatively harsh operation environments (for instance, in strong acid or base). Laser shaping, imaging and other optical performances can be easily achieved. More importantly, micro-KPLs also have unique flexible and stretchable properties as well as good biocompatibility and biodegradability. Therefore, such protein hydrogel-based micro-optics may have great potential applications, such as in flexible and stretchable photonics and optics, soft integrated optical microsystems and bioimplantable devices.</P>

BMB Reports : Heat shock protein 90β inhibits apoptosis of intestinal epithelial cells induced by hypoxia through stabilizing phosphorylated Akt

( Shuai Zhang ),( Yong Sun ),( Zhi Qiang Yuan ),( Ying Li ),( Xiao Lu Li ),( Zhen Yu Gong ),( Yi Zhi Peng ) 생화학분자생물학회(구 한국생화학분자생물학회) 2013 BMB Reports Vol.46 No.1

Intestinal epithelial cell (IEC) apoptosis induced by hypoxia compromise intestinal epithelium barrier function. Both Akt and Hsp90 have cytoprotective function. However, the specific role of Akt and Hsp90β in IEC apoptosis induced by hypoxia has not been explored. We confirmed that hypoxia-induced apoptosis was reduced by Hsp90β overexpression but enhanced by decreasing Hsp90β expression. Hsp90β overexpression enhanced BAD phosphorylation and thus reduced mitochondrial release of cytochrome C. Reducing Hsp90β expression had opposite effects. The protective effect of Hsp90β against apoptosis was negated by LY294002, an Akt inhibitor. Further study showed that Akt phosphorylation was enhanced by Hsp90β, which was not due to the activation of upstream PI3K and PDK1 but because of stabilization of pAkt via direct interaction between Hsp90β and pAkt. These results demonstrate that Hsp90β may play a significant role in protecting IECs from hypoxia-induced apoptosis via stabilizing pAkt to phosphorylate BAD and reduce cytochrome C release. [BMB Reports 2013; 46(1): 47-52]

Mathematical Model and Tooth Contact Analysis of an Internal Helical Gear Pair with Selectable Contact Path

Shuai Peng,Bingkui Chen,Dong Liang,Lu-he Zhang,Si-ling Qin 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.6

An internal helical gear pair with point contact pattern based on the space meshing theory is proposed which consists of an involute internal gear and a pinion with quadratic curve profile. Particularly, the contact path of the tooth surface is selectable, which can inherit the characteristic of the surface. Moreover, this type of internal gear pair has lower sensitivity to assembly errors. The generation principle and mathematical model is presented. The motion simulation and adaptability to center distance error of the internal gear pair are discussed. The gear pair is manufactured. Based on the mathematical model and tooth contact analysis (TCA) method, the locations of contact points and kinematic errors are determined under different center distance variation and axial misalignments. The simulated results reveal that the locations of contact points of the gear and pinion change under assembly errors. Little kinematic error occurs under axial misalignment. No edge contact occurs under any assembly error condition. Experiment study is performed and the result is consistent with the theoretical analysis.

RECOMMENDING THE “RIGHT” PRODUCT TO THE “RIGHT” CUSTOMER WITH THE “RIGHT” MESSAGE VIA STRUCTURAL NEURAL RECOMMENDER

Shuai Zhang,Lina Yao,Tianying Song,Jake An,Steven Lu 글로벌지식마케팅경영학회 2023 Global Marketing Conference Vol.2023 No.07

In this paper, we propose a new neural network architecture for item recommendation with structural information. Our model, structural neural recommender (SNR) is based on neural networks and operates on a hierarchy paradigm, aiming to explore the effectiveness of incorporating different structural information for recommendation. Many recent state-of-the-art neural network based recommendation models exploit the nonlinear transformations for modeling the complex user-item interaction patterns and user historical behaviors, ignoring the item-item structural relationship. This structural information, however, is uncomplicated to derive and useful for inferring item characteristics. To utilize this information, SNR simultaneously learns representation from user-item interactions and item-item relationships. Empirical studies on eight real-world datasets demonstrate the effectiveness of incorporating such structural information, by outperforming classic and recent baselines. We also conduct detail ablation studies and hyper-parameter analysis to provide further understanding towards the behaviors of our model. Following the model development, we conduct a field experiment to demonstrate that the effectiveness of algorithmic recommender systems can further increase by using different types of message framing when communicating recommendations to consumers. Our results suggest that recommendations framed with a relevance appeal (e.g. “Top 5 brands for you”) are more effective in general, yet recommendations that are framed with a popularity appeal (“Top 5 most popular brands”) are more effective for customers who were acquired via social media (versus non-social media) advertising or for those who have stronger (versus weaker) social orientation.

The characteristic of Cu2ZnSnS4 thin film solar cells prepared by sputtering CuSn and CuZn alloy targets

Yilei Lu,Shurong Wang,Xun Ma,Xin Xu,Shuai Yang,Yaobin Li,Zhen Tang 한국물리학회 2018 Current Applied Physics Vol.18 No.12

Recent study shows that the main reason for limiting CZTS device performance lies in the low open circuit voltage, and crucial factor that could affect the Voc is secondary phases like ZnS existing in absorber layer and its interfaces. In this work, the Cu2ZnSnS4 thin film solar cells were prepared by sputtering CuSn and CuZn alloy targets. Through tuning the Zn/Sn ratios of the CZTS thin films, the crystal structure, morphology, chemical composition and phase purity of CZTS thin films were characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) and Raman spectroscopy. The statistics data show that the CZTS solar cell with a ratio of Zn/Sn=1.2 have the best power convention efficiency of 5.07%. After HCl etching process, the CZTS thin film solar cell with the highest efficiency 5.41% was obtained, which demonstrated that CZTS film solar cells with high efficiency could be developed by sputtering CuSn and CuZn alloy targets.

Synergistic effect of single-wall carbon nanotubes and MoS2 on tribological performance of polyether MDI polyurethane elastomer

Gang Lu,Changgeng Shuai,Yinsong Liu,Xue Yang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.1

Synergistic effects have been extensively investigated in the modification of polymer materials. To gain complete insights into the effect of two-component synergy on the tribology performance of thermoplastic polyurethane (TPU), this study selected single-wall carbon nanotubes (SWNTs) and MoS 2 as the solid additives to prepare several composite materials. Subsequently, the tribology property of the composites was analyzed. It was reported that the agglomeration phenomenon could be improved by regulating the ratio of SWNTs and MoS 2 . In addition, SWNTs could effectively improve the friction and wear properties exhibited by the composites and promote the mechanical properties exhibited by the composites. Moreover, the positive effect on tribological properties was increasingly significantly as the contact load increased.

Microfluidic Synthesis of Hybrid Nanoparticles with Controlled Lipid Layers: Understanding Flexibility-Regulated Cell–Nanoparticle Interaction

Zhang, Lu,Feng, Qiang,Wang, Jiuling,Zhang, Shuai,Ding, Baoquan,Wei, Yujie,Dong, Mingdong,Ryu, Ji-Young,Yoon, Tae-Young,Shi, Xinghua,Sun, Jiashu,Jiang, Xingyu American Chemical Society 2015 ACS NANO Vol.9 No.10

<P>The functionalized lipid shell of hybrid nanoparticles plays an important role for improving their biocompatibility and <I>in vivo</I> stability. Yet few efforts have been made to critically examine the shell structure of nanoparticles and its effect on cell–particle interaction. Here we develop a microfluidic chip allowing for the synthesis of structurally well-defined lipid-polymer nanoparticles of the same sizes, but covered with either lipid-monolayer-shell (MPs, monolayer nanoparticles) or lipid-bilayer-shell (BPs, bilayer nanoparticles). Atomic force microscope and atomistic simulations reveal that MPs have a lower flexibility than BPs, resulting in a more efficient cellular uptake and thus anticancer effect than BPs do. This flexibility-regulated cell–particle interaction may have important implications for designing drug nanocarriers.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-10/acsnano.5b05792/production/images/medium/nn-2015-05792e_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b05792'>ACS Electronic Supporting Info</A></P>

New insights into separating wolframite from calcium bearing minerals by flotation

Yuxi Lu,Shuai Wang,Hong Zhong 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

Wolframite is often associated with calcium bearing minerals, leading to low grade, while conventionalanionic collectors are hard to realize their efficientflotation separation, thus the effective structuralmodification of cationic collectors provides a new insight into enhancing the comprehensivedevelopment of wolframite resources. In this study, a surfactant 3-dodecyloxy propyl amidoxime(DOPA) was designed andfirst used as the collector inflotation separation of wolframite fromfluorite andcalcite. Computational calculations basically proved the correctness of predictions about the performancesof DOPA. Micro-flotation tests indicated that compared to DDA and conventional anionic collectorbenzohydroxamic acid (BHA), DOPA possessed superior collecting ability to wolframite and excellentselectivity againstfluorite and calcite at low concentration, with no frother or activator employed, whichis supposed to be an efficient collector for separating wolframite from calcium bearing minerals. Theseparation mechanisms of DOPA between wolframite andfluorite/calcite were further probed, revealingthat besides the electrostatic attraction between DOPA and wolframite, DOPA could chemisorb ontowolframite surfaces by formingfive-membered ring toward the surface cation site Fe or Mn, with nosignificant interaction observed onfluorite/calcite surfaces, resulting to the excellent separationperformance.

Redox zonation for different groundwater flow paths during bank filtration: a case study at Liao River, Shenyang, northeastern China

Su, Xiaosi,Lu, Shuai,Yuan, Wenzhen,Woo, Nam Chil,Dai, Zhenxue,Dong, Weihong,Du, Shanghai,Zhang, Xinyue Springer-Verlag 2018 Hydrogeology journal Vol.26 No.5