Observation of Flowering Process of Grape(Vitis vinifera L.)—Insight into the Starting of Pollination of Flower Hiding in Calyptras(Cap)

It is generally agreed that many Vitis vinifera L.cultivars are self-fertile,where self-pollination often occurs before capfall in a process called cleistogamy.Therefore,it is difficult to identify the right time to remove stamens before self-pollination during the cross-breeding of grape.For this paper,we observed the process of grape flowering and measured the pollen viability and stigma receptivity of grape flowers of‘Shine Muscat’in order to identify the starting time of self-pollination before capfall and to provide useful information for improving the efficiency of cross-breeding.The results demonstrate that the anther is not cracked during the visible clusters and separated clusters stages.Meanwhile,in the separated floral buds,flowering begins,and full bloom stages,the pollen viability is 60.7%,73.2%and 80.3%,respectively;however,at the berry set stage,pollen viability drops to zero.The top of the mature stigma is composed of a layer of nearly cylindrical papillary cells,and the stigma receptivity for pollen changes with the development of flowers:in particular,no reaction was observed in the visible clusters stage;weak positive reaction at the separated clusters stage;strong positive reaction at the separated floral buds,flowering begins,and full bloom stages;and no reaction at the berry set stage.In the separated floral buds stage,pollen tubes were seen germinating in the style.In the flowering begins stage,more pollen tubes were observed at the entry of the ovary.During the full bloom stage,most pollen tubes elongated into the ovary base and some entered the pearl hole.At the berry set stage,newborn endosperm nucleus could be seen in the ovule.From the above,we can conclude that the initiation time of closed fertilization for‘Shine Muscat’grape can be judged as the separated floral buds stage,and it is best to discard the stamen before the separated floral buds stage when conducting cross-breeding.

An Interactive Online Platform for Algorithms Teaching

Learning programming has become an important part of education.However,most students have extreme difficulty learning programming and complex algorithms.This is because programming has a hierarchical logic.Solving complex problems requires students to develop skills in decomposing problems.To this end,this paper describes an effective method to develop an online platform for teaching complex algorithms.

A quantum federated learning framework for classical clients

Quantum federated learning(QFL)enables collaborative training of a quantum machine learning(QML)model among multiple clients possessing quantum computing capabilities,without the need to share their respective local data.However,the limited availability of quantum computing resources poses a challenge for each client to acquire quantum computing capabilities.This raises a natural question:Can quantum computing capabilities be deployed on the server instead?In this paper,we propose a QFL framework specifically designed for classical clients,referred to as CC-QFL,in response to this question.In each iteration,the collaborative training of the QML model is assisted by the shadow tomography technique,eliminating the need for quantum computing capabilities of clients.Specifically,the server constructs a classical representation of the QML model and transmits it to the clients.The clients encode their local data onto observables and use this classical representation to calculate local gradients.These local gradients are then utilized to update the parameters of the QML model.We evaluate the effectiveness of our framework through extensive numerical simulations using handwritten digit images from the MNIST dataset.Our framework provides valuable insights into QFL,particularly in scenarios where quantum computing resources are scarce.

Controlled Step-Growth Polymerization

Conjugated polymers are attractive components of modern plastic electronics and photovoltaic devices.They are synthesized mainly through a step-growth polymerization(SGP)mechanism.However,due to the uncontrollable characteristic of classical SGP,this effort leads to batch-to-batch variations in solubility,uncontrolled molecular weight,and broad polydispersity of the polymers obtained,thus,severely limiting their processing properties and performance.Here we demonstrate a general theoretical model of controlled SGP process by examining the possibility of the polymer chains further involvement in the SGP and how this correlated with their respective molecular weights.Subsequently,we proposed a practical method by which the SGP system was confined in nano-sized reactors.This method enabled the synthesis of a variety of polymers,having precisely controlled molecular weights with narrow polydispersity.We anticipate that this venture would exemplify a starting point for a more sophisticated molecular and structural design of functional polymers in widespread applications.