Three-dimensional cell culture provides an efficient way to simulate the in vivo tumorigenic microenvironment where tumor-stroma interaction intrinsically plays a pivotal role. Conventional three-dimensional (3D) culture is inadequate to address precise coexistential heterogeneous pairing and quantitative measurement in a parallel algorithm format. Herein, we implemented a set of microwell array microfluidic devices to study the cell spheroids-based tumor-stromal metastatic process in vitro. This approach enables accurate one-to-one pairing between tumor and fibroblast spheroid for dissecting 3D tumor invasion in the manner of high-content imaging. On one single device, 240 addressable tumor-stroma pairings can be formed with convenient pipetting and centrifugation within a small area of 1 cm2. Consequential confocal imaging analysis disclosed that the tumor spheroid could envelop the fibroblast spheroid. Specific chemicals can effectively hamper or promote this 3D metastasis. Due to the addressable time-resolved measurements of the merging process of hundreds of doublets, our approach allows us to decipher the metastatic phenotype between different tumor spheroids. Compared with traditional protocols, massive heterogeneous cellular spheroids pairing and merging using this method is well-defined with microfluidic control, which leads to a favorable high-content tumor-stroma doublet metastasis analysis. This simple technique will be a useful tool for investigating heterotypic spheroid-spheroid interactions.Van der Waals (vdW) heterostructures are the fundamental blocks for two-dimensional (2D) electronic and optoelectronic devices. In this work, a high-quality 2D metal-semiconductor NiTe2/MoS2 heterostructure is prepared by a two-step chemical vapor deposition (CVD) growth. The back-gated field-effect transistors (FETs) and photodetectors based on the heterostructure show enhanced electronic and optoelectronic performance than that of a pristine MoS2 monolayer, owing to the better heterointerface in the former device. Especially, this photodetector based on the metal-semiconductor heterostructure shows 3 orders faster rise time and decay time than that of the pristine MoS2 under the same fabrication procedure. The enhancement of electronic behavior and optoelectronic response by the epitaxial growth of metallic vdW layered materials can provide a new method to improve the performance of optoelectronic devices.To prevent the corrosion of carbon and to enhance corrosion resistance, charge transfer and mass transfer, graphene, which exhibits a high surface area and good conductivity, was applied as an electrocatalyst support for a fuel cell. Pt3Sn/G electrocatalysts for oxygen reduction reaction (ORR) were prepared with alcohol reduction. The characterization of synthesized catalysts were analyzed according to the EDS, XRD, HRTEM and EXAFS. The electrochemical performance was analyzed with CV, LSV (linear sweep voltammetry) and accelerated degradation test (ADT) measurements. The Pt3Sn/G electrocatalysts showed more positive onset potential and larger ORR mass activity than commercial Pt/C catalysts after 5000 cycles ADT, indicating that in an acidic environment Pt3Sn/G is more chemically stable than Pt/C. Graphene has effective acid tolerance and is more stable against corrosion, and shows increased stability through preventing the PtSn nanoparticles from detaching from the surface. According to the in-situ QEXAFS under a CV test to clarify the potential-dependent state of the Pt3Sn/G electrocatalyst, the results show that the electrode surface is reproducible; there is no perceptible change of oxidation state of the Pt3Sn/G electrocatalyst. The radial distribution function (RDF) of the EXAFS spectra shows that the adsorption and desorption of H+ and OH- cause no structural change in the Pt3Sn crystallites. This work provides insight into the reaction mechanism of proton electroreduction and hydrogen adsorption on a Pt3Sn/G electrocatalyst surface.Using the nanoindentation technique, we probed the mechanical properties of tape cast and sintered thin doped Li7La3Zr2O12 garnet electrolytes. For comparison, a bulk garnet sample fabricated by die pressing and sintering was also studied. The results indicate that the thin sample has significantly higher elastic modulus (~155GPa), hardness (~11GPa), and indentation fracture toughness (~1.12±0.12 MPa*m1/2than the bulk sample (~142GPa, ~10GPa, and ~0.97±0.10 MPa*m1/2, respectively). The above results demonstrate the thin sample can more effectively prevent lithium dendrite penetration due to its higher mechanical properties. Deformation and creep behavior analysis further indicates that the thin sample (1) has higher resistance to withhold the charge/discharge stress and consequently deformation; (2) lower creep exponent and likely high resistance to brittle failure.Suitable intercalation cathodes and fundamental insights into the Zn-ion storage mechanism are the crucial factors for the booming development of aqueous zinc-ion batteries. Herein, a novel nickel vanadium oxide hydrate (Ni0.25V2O5·0.88H2O) is synthesized and investigated as a high-performance electrode material, which delivers a reversible capacity of 418 mA h g-1 with 155 mA h g-1 retained at 20 A g-1 and a high capacity of 293 mA h g-1 in long-term cycling at 10 A g-1 with 77% retention after 10,000 cycles. Lonafarnib supplier More importantly, multistep phase transition and chemical-state change during intercalation/deintercalation of hydrated Zn2+ are illustrated in detail via in situ/ex situ analytical techniques to unveil the Zn2+ storage mechanism of the hydrated and layered vanadium oxide bronze. Furthermore, morphological development from nanobelts to hierarchical structures during rapid ion insertion and extraction is demonstrated and a self-hierarchical process is correspondingly proposed. The unique evolutions of structure and morphology, together with consequent fast Zn2+ transport kinetics, are of significance to the outstanding zinc storage capacity, which would enlighten the mechanism exploration of the aqueous rechargeable batteries and push development of vanadium-based cathode materials.