Orthogonal spatial coding with stimulated parametric down-conversion.

Orthogonal optical coding is widely used in classical multi-user communication networks. Using the phase conjugation property of stimulated parametric down-conversion, we extend the current time-domain orthogonal optical coding scheme to the spatial domain to encode and decode image information. In this process, the idler beam inherits the complex conjugate of the field information encoded in the seed beam. An encoding phase mask introduced onto the input seed beam blurs the image transferred to the idler. The original image is restored by passing the coded transferred image through a corrective phase mask placed in the momentum space of the idler beam. We expect that this scheme can also inspire new techniques in secure image transmission, aberration cancellation, and frequency conversion imaging.

Stages That Lead to Drop Depinning and Onset of Motion.

In this paper, we consider drops that are subjected to a gradually increasing lateral force and follow the stages of the motion of the drops. We show that the first time a drop slides as a whole is when the receding edge of the drop is pulled by the advancing edge (the advancing edge drags the receding edge). The generality of this phenomenon includes sessile and pendant drops and spans over various chemically and topographically different cases. Because this observation is true for both pendant and sessile cases, we exclude hydrostatic pressure as its reason. Instead, we explain it in terms of the wetting adaptation and interfacial modulus, that is, the difference in the energies of the solid interface at the advancing and receding edges. At the receding edge, a slight motion exposes to the air a recently wetted solid surface whose molecules had reoriented to the liquid and will take time to reorient back to the air. This results in a high surface energy at the solid-air interface which pulls on the triple line, that is, inhibits the motion of the receding edge. On the other hand, at the advancing edge, a slight advancement does not change the nature of the solid interfacial molecules outside the drop, and the advancing side's sliding can continue. Moreover, the solid molecules under the drop at the advancing edge take time to reorient, and hence, their configuration is not yet adapted for the liquid and therefore not adapted for retention of the advancing edge. Therefore, in sliding-drop experiments, the advancing edge moves before the receding one, typically a few times before the receding edge moves. For the same reason, the last motion of the receding edge usually happens as a result of the advancing edge pulling on it.

Comment on "Comparison of the Lateral Retention Forces on Sessile, Pendant, and Inverted Sessile Drops".

Tadmor et al.'s 2009 PRL article shows experiments of pendant drops with ∼30% higher retention forces than their sessile analogues. A recent article (de la Madrid, R. et al. Langmuir 2019, 35, 2871) seemingly explains this result theoretically using a drastically different experimental system that shows a ∼3% higher force that exceeds the scatter in three out of four data points. The differences between the two experimental systems might have allowed the two theories to coexist, but Tadmor's theory, which can explain both, allows an understanding of the solid-liquid interaction, which the newer theory lacks.

Droplets Sliding down a Vertical Surface under Increasing Horizontal Forces.

We have investigated the retention forces of liquid drops on rotating, vertical surfaces. We considered two scenarios: in one, a horizontal, centrifugal force pushes the drop toward the surface (?pushed drop? case), and in the other, a horizontal, centrifugal force pulls the drop away from the surface (?pulled drop? case). Both drops slide down as the centrifugal force increases, although one expects that the pushed drop should remain stuck to the surface. Even more surprising, when the centrifugal force is low, the pushed drop moves faster than the pulled drop, but when the centrifugal force is high, the pushed drop moves much slower than the pulled drop. We explain these results in terms of interfacial modulus between the drop and the surface.

The Functionalized Single-Walled Carbon Nanotubes Gas Sensor With Pd Nanoparticles for Hydrogen Detection in the High-Voltage Transformers.

Single-walled carbon nanotubes (SWCNTs) have been widely discussed and applied as novel gas sensing nanomaterials. Hydrogen is one of the remarkable fault characteristic gases in high-voltage oil-paper insulated transformers. In this paper, 3.07 wt% Pd nanoparticles (NPs) were used to decorate SWCNTs. The unloaded, the carboxylated, and the Pd-doped SWCNTs were fabricated into three planar gas sensors, and their gas sensing properties to hydrogen were studied. Gas sensing mechanism was analyzed. Results show that the optimal operating temperature of a Pd-doped SWCNTs-based gas sensor is 125°C lower than that of the unloaded SWCNTs-based gas sensor, and it shows the highest gas sensing response value. This is attributed to the decreasing work function of Pd, which reduces the hole carries in the nanotubes.

Managing patient complaints in China: a qualitative study in Shanghai.

OBJECTIVES: To examine the handling system for patient complaints and to identify existing barriers that are associated with effective management of patient complaints in China. SETTING: Key stakeholders of the handling system for patient complaints at the national, Shanghai municipal and hospital levels in China. PARTICIPANTS: 35 key informants including policymakers, hospital managers, healthcare providers, users and other stakeholders in Shanghai. PRIMARY AND SECONDARY OUTCOME MEASURES: Semistructured interviews were conducted to understand the process of handling patient complaints and factors affecting the process and outcomes of patient complaint management. RESULTS: The Chinese handling system for patient complaints was established in the past decade. Hospitals shoulder the most responsibility of patient complaint handling. Barriers to effective management of patient complaints included service users' low awareness of the systems in the initial stage of the process; poor capacity and skills of healthcare providers, incompetence and powerlessness of complaint handlers and non-transparent exchange of information during the process of complaint handling; conflicts between relevant actors and regulations and unjustifiable complaints by patients during solution settlements; and weak enforcement of regulations, deficient information for managing patient complaints and unwillingness of the hospitals to effectively handle complaints in the postcomplaint stage. CONCLUSIONS: Barriers to the effective management of patient complaints vary at the different stages of complaint handling and perspectives on these barriers differ between the service users and providers. Information, procedure design, human resources, system arrangement, unified legal system and regulations and factors shaping the social context all play important roles in effective patient complaint management.