A FRET-based multifunctional fluorescence probe for the simultaneous detection of sulfite and viscosity in living cells.

Viscosity and sulfur dioxide derivatives were significant indicators for the assessment of health threat and even cancers, therefore, on-site and real time detection of viscosity and sulfur dioxide derivatives has obtained considerable attentions. An FRET-based fluorescence probe JZX was designed and synthesized based on a novel energy donor of N,N-diethyl-4-(1H-phenanthro[9,10-d]imidazol-2-yl)benzamide fluorophore. JZX exhibited a large Stokes shift (230 nm), high energy transfer efficiency, wide emission channel gap (135 nm) and excellent stability and biocompatibility. JZX detected sulfur dioxide with low detection limit (55 nM), fast responding (16 min), high selectivity and sensitivity. Additionally, JZX tend to target endoplasmic reticulum of which normal metabolism will be disturbed by the abnormal levels of viscosity and sulfur dioxide derivatives. Prominently, JZX could concurrently detect viscosity and sulfur dioxide derivatives depending on different fluorescence signals in living cells for the screening of cancer cells. Hence, probe JZX will be a promising candidate for the detection of viscosity and sulfur dioxide derivatives, and even for the diagnosis of liver cancers.

Conformal smoothing of mid-spatial frequency surface error for nano-accuracy Continuous Phase Plates (CPP).

This paper presented a conformal smoothing theory, and smoothing capability evaluation was established on the proposed theory. According to pressure distribution model, processing parameters have been optimized and the CPP sample with a size of 340 × 340 mm was applied in conformal smoothing. The middle spatial frequency was effectively corrected with the total polishing time of 750 min, and energy was constringed 32.2 times (improved from 57.68 nm2·mm to 1.79 nm2·mm). Meanwhile, surface roughness RMS (root mean square) maintained at the same scale (changed from 265.4 nm to 265.2 nm). Parametric conformal smoothing was proven to be an effective method to control the middle spatial frequency error of CPPs.

Detailed subsurface damage measurement and efficient damage-free fabrication of fused silica optics assisted by ion beam sputtering.

Formation of subsurface damage has an inseparable relationship with microscopic material behaviors. In this work, our research results indicate that the formation process of subsurface damage often accompanies with the local densification effect of fused silica material, which seriously influences microscopic material properties. Interestingly, we find ion beam sputtering (IBS) is very sensitive to the local densification, and this microscopic phenomenon makes IBS as a promising technique for the detection of nanoscale subsurface damages. Additionally, to control the densification effect and subsurface damage during the fabrication of high-performance optical components, a combined polishing technology integrating chemical-mechanical polishing (CMP) and ion beam figuring (IBF) is proposed. With this combined technology, fused silica without subsurface damage is obtained through the final experimental investigation, which demonstrates the feasibility of our proposed method.

Control of mid-spatial frequency errors considering the pad groove feature in smoothing polishing process.

Mid-spatial frequency error (MSFR) should be strictly controlled in modern optical systems. As an effective approach to suppress MSFR, the smoothing polishing (SP) process is not easy to handle because it can be affected by many factors. This paper mainly focuses on the influence of the pad groove, which has not been researched yet. The SP process is introduced, and the important role of the pad groove is explained in detail. The relationship between the contact pressure distribution and the groove feature including groove section type, groove width, and groove depth is established, and the optimized result is achieved with the finite element method. The different kinds of groove patterns are compared utilizing the numerical superposition method established scrupulously. The optimal groove is applied in the verification experiment conducted on a self-developed SP machine. The root mean square value of the MSFR after the SP process is diminished from 2.38 to 0.68 nm, which reveals that the selected pad can smooth out the MSFR to a great extent with proper SP parameters, while the newly generated MSFR due to the groove can be suppressed to a very low magnitude.

Generalized numerical pressure distribution model for smoothing polishing of irregular midspatial frequency errors.

The smoothing effect of the rigid lap plays an important role in controlling midspatial frequency errors (MSFRs). At present, the pressure distribution between the polishing pad and processed surface is mainly calculated by Mehta's bridging model. However, this classic model does not work for the irregular MSFR. In this paper, a generalized numerical model based on the finite element method (FEM) is proposed to solve this problem. First, the smoothing polishing (SP) process is transformed to a 3D elastic structural FEM model, and the governing matrix equation is gained. By virtue of the boundary conditions applied to the governing matrix equation, the nodal displacement vector and nodal force vector of the pad can be attained, from which the pressure distribution can be extracted. In the partial contact condition, the iterative method is needed. The algorithmic routine is shown, and the applicability of the generalized numerical model is discussed. The detailed simulation is given when the lap is in contact with the irregular surface of different morphologies. A well-designed SP experiment is conducted in our lab to verify the model. A small difference between the experimental data and simulated result shows that the model is totally practicable. The generalized numerical model is applied on a Φ500 mm parabolic surface. The calculated result and measured data after the SP process have been compared, which indicates that the model established in this paper is an effective method to predict the SP process.