Xiaopeng Li’s Quantum AMO Theory Group,Department of Physics,Fudan University

We are a quantum theory group working on quantum simulation and quantum computation.The quantum experiments of our primary interest are about atomic,molecular,and optical systems.We aim at developing theories,algorithms,architectures for programmable quantum simulations,with a particular focus on the schemes accessible to present or near-term quantum technology.One direction we are currently pushing is to exploit the computation power of programmable quantum simulations in resolving computation challenges that arise in both fundamental quantum science and nontrivial applications,including correlated quantum many-body physics,classical optimization,and simulating complex chaotic dynamics.This may revolutionize computational science or even the entire field of computation itself.

Enzyme activities and gene expression of starch metabolism provide insights into grape berry development

Grapes are categorized as a non-climacteric type of fruit which its ripening is not associated to important rises in respiration and ethylene synthesis.The starch metabolism shares a certain role in the carbohydrate metabolic pathways during grape berry development,and is regarded as an important transient pool in the pathway of sugar accumulation.However,the comprehensive role of starch and its contribution to the quality and flavor of grape berry have not been explored thoroughly.In this study,the expression levels of genes enzyme activities and carbohydrate concentrations related to starch metabolism,were analyzed to understand the molecular mechanism of starch accumulation during grape berry development.The results indicated that starch granules in grape berry were located at the chloroplast in the sub-epidermal tissues,acting as the temporary reserves of photosynthetic products to meet the needs for berry development,and relatively high starch contents could be detected at véraison stage.Moreover,both ADP-glucose pyrophosphorylase(EC 2.7.7.27)and sucrose phosphate synthase(EC 2.3.1.14)involved in starch synthesis displayed elevated gene expression and enzymes activities in the sub-epidermal tissue,whileα-andβ-amylases involved in its degradation were highly transcribed and active in the central flesh,explaining the absence of starch in this last tissue.Change in the gene expression and activities of ADP-glucose pyrophosphorylase,β-amylase and sucrose phosphate synthase revealed that they were regulated by the circadian rhythms in the fruitlets compared with those in the leaves.Both the morphological,enzymological and transcriptional data in this study provide advanced understandings on the function of starch during berry development and ripening that are so important for berry quality.This study will further facilitate our understanding of the sugar metabolism in grape berry as well as in other plant species.

Low temperature surface oxygen activation in crystalline MnO_(2) triggered by lattice confined Pd single atoms

Tuning the coordination environment is the research axis of single atom catalysts (SACs). SACs are commonly stabilized by various defects from support. Here, we report a lattice confined Pd SAC using MnO_(2) as support. Compared with the Pd clusters anchored on the surface, the lattice confined Pd single atoms allows spontaneous exaction of surrounding lattice oxygen at room temperature when employed in CO oxidation. The MnO_(2) supported Pd SAC exhibited a high turnover frequency of 0.203 s^(−1) at low reaction temperature, which is higher than that of recently reported Pd SACs. Theoretical calculations also confirmed the confined monatomic Pd activate lattice oxygen with an ultralow energy barrier. Our results illustrate that the unique coordination environment of single atom provided by lattice confinement is promising to boost the activity of SACs.

Busbar Differential Relaying Method Based on Combined Amplitude and Phase Information of High Frequency Transient Currents

Busbar differential relaying method based on combined amplitude and phase information of high frequency transient currents is put forward in this paper for the speed and reliability problems of busbar protection based on fundamental frequency. Under the analysis of features of bus high frequency differential currents, complex wavelet analysis is used to extract the amplitude and phase features of 1/4 period high frequency differential currents, and amplitude and phase information are used to form the polar coordinates. Bus fault is identified intuitively and precisely according to polar locus differences. This polar coordinates represented busbar differential protection scheme based on high frequency transient signals can not only avoid TA saturation, realizing quick protection, lots of PSCAD/EMTDC simulations also show that this busbar differential protection scheme works well under different fault conditions.

Optimization of Processing Technology for Roasted Licorice with Water by Orthogonal Method

[Objectives]To optimize the processing technology for roasted licorice with water.[Methods]Through the orthogonal experimental design,taking the water added,moistening time,frying temperature and frying time as the factors,and the content of glycyrrhizin and glycyrrhizic acid as the evaluation index,the processing technology for roasted licorice with water was optimized.[Results]The best processing technology of licorice was as follows:Pure licorice slices were mixed with water and moistened for 3 h,and then fried at 160℃for 6 min.20 kg of water was added to every 100 kg of licorice.[Conclusions]The best processing technology for roasted licorice with water was established,laying a foundation for the research and application of roasted licorice with water and its preparation.

Meningeal melanocytoma in the cerebellopontine angle:A rare case report and review of the literature

Primary meningeal melanocytoma(MM)in the cerebellopontine angle(CPA)region is an extremely rare neoplasm that originates from the melanocytes in the leptomeninges.These lesions are usually misdiagnosed as they mimic other common CPA lesions through their nonspecific presenting symptoms,signs,and radiological characteristics.Here,we report a 47-year-old Chinese female patient who presented with a 1-month history of the right-sided tongue numbness and 1-week history of the right-sided face numbness that had been worsening for 2 days.The tumor,in the right CPA region,showed a slight isointensity on T1-weighted image and mixed signal intensity on T2-weighted image.The clinical presentation,surgical treatment,and pathologic characteristics were determined.The tumor was microsurgically resected and gross-total resection was achieved.The tumor revealed a solid,capsulated,brown-black lesion.Immunohistochemistry showed that the tumor cells were positive for human melanoma black-45(HMB-45),melanoma antigen(MelanA),S100,SOX10,and BRAF,confirming the final diagnosis of meningeal melanocytoma.Ultimately,no signs of radiological local recurrence were observed during the two-year follow-up.Collectively,meningeal melanocytoma is difficult to distinguish from common tumors in the CPA region before operation due to the lack of specificity in imaging and symptoms.Complete surgical resection is the best therapeutic option for this tumor.Although the tumor is commonly considered as a benign lesion,recurrence and metastasis are common,and pathogenesis remains unclear.

Expression of N-myc downstream regulatory gene 4(NDRG4)in glioma and its relationship with glioma prognosis

Objective:the N-myc downstream regulatory gene 4(NDRG4)is involved in cell growth,cell proliferation,cell survival and tumor invasion.In this paper,the role of NDRG4 in glioma was explored.Method:the expression of NDRG4 in glioma clinical specimens and its relationship with the prognosis of glioma patients were analyzed by the Cancer Genome Atlas(TCGA)and the Chinese Glioma Genome Atlas(CGGA),and the expression of NDRG4 protein and mRNA in glioma cell lines were tested and verified by Western blot and quantitative real-time fluorescence polymerase chain reaction(qRT-PCR).Result:it showed that the expression of NDRG4 in glioma tissues and cell lines is closely related to the prognosis of glioma patients.Conclusion:NDRG4 is a highly potential target gene for glioma therapy.

光照条件下AuPd合金纳米颗粒上原位形成缺电子Pd位点促进高效的光催化Heck反应

光催化技术通过直接利用太阳光来驱动一系列化学反应,被认为是合成精细化学品的有效手段.光催化反应条件简单温和,避免了传统热催化有机反应所需要的苛刻条件,且有效减少副反应的发生,提高催化反应选择性.传统的半导体光催化剂在光吸收能力和活化有机反应底物等方面均存在一些劣势.近年来,基于贵金属纳米颗粒局域表面等离激元共振效应的新型光催化剂被认为是一种理想的可见光光催化材料,并已受到了广泛关注.通常单一组分的贵金属等离激元纳米颗粒在光催化有机反应中依然表现出一定的局限性.近年来,科研人员发展了一些双金属组分等离激元光催化剂体系,将等离激元组分(如Au)作为光能收集器,与具有催化活性的金属组分(如Pd)耦合形成合金或异质结构,可以实现较好的光催化性能.然而,对双金属组分等离激元光催化的催化微观机制理解仍然存在很大挑战,尤其是光照激发之后如何在等离激元组分和催化活性组分之间实现能量转移,催化剂表面物理化学性质的改变如何促进化学反应的发生等问题值得进一步深入研究.本文以负载型金钯(AuPd)合金纳米颗粒光催化剂为研究对象,利用光照条件下原位X射线光电子能谱研究催化剂表面电荷态,发现在可见光照射下,AuPd合金纳米颗粒上原位形成了缺电子态的Pd位点(Pd^(δ+)),这在双金属组分AuPd合金纳米颗粒光催化中起着决定性作用.AuPd合金纳米颗粒光催化剂对可见光驱动的Heck交叉偶联反应表现出较好的转化率和选择性.光照条件下催化剂表面原位形成的Pd^(δ+)为Heck反应提供了理想的反应平台,在温和条件(40℃)下的催化效率与传统热催化条件(>100℃)下的催化反应相当.催化反应动力学研究结果表明,光催化过程可显著降低反应活化能.反应物分子吸附行为研究结果表明,碘苯分子是在AuPd合金纳米颗粒的Pd位点活化的.此外,机理实验和理论计算结果表明,光催化Heck反应是通过AuPd合金上基于自由基的单电子转移过程进行的,原位形成的Pd^(δ+)提供了有效的催化位点有利于反应物分子的活化.综上,本文揭示了双金属组分等离激元光催化材料用于有机催化反应的新机制.

Dynamic modeling and RBF neural network compensation control for space flexible manipulator with an underactuated hand

In space operation,flexible manipulators and gripper mechanisms have been widely used because of light weight and flexibility.However,the vibration caused by slender structures in manipulators and the parameter perturbation caused by the uncertainty derived from grasping mass variation cannot be ignored.The existence of vibration and parameter perturbation makes the rotation control of flexible manipulators difficult,which seriously affects the operation accuracy of manipulators.What’s more,the complex dynamic coupling brings great challenges to the dynamics modeling and vibration analysis.To solve this problem,this paper takes the space flexible manipulator with an underactuated hand(SFMUH)as the research object.The dynamics model considering flexibility,multiple nonlinear elements and disturbance torque is established by the assumed modal method(AMM)and Hamilton’s principle.A dynamic modeling simplification method is proposed by analyzing the nonlinear terms.What’s more,a sliding mode control(SMC)method combined with the radial basis function(RBF)neural network compensation is proposed.Besides,the control law is designed using a saturation function in the control method to weaken the chatter phenomenon.With the help of neural networks to identify the uncertainty composition in the SFMUH,the tracking accuracy is improved.The results of ground control experiments verify the advantages of the control method for vibration suppression of the SFMUH.

Traveling Wave Characteristics Based Pilot Protection Scheme for Hybrid Cascaded HVDC Transmission Line

The hybrid cascaded high-voltage direct current(HVDC)transmission system has various operation modes,and some operation modes have sharply increasing requirements for protection rapidity,while the traditional pilot differential protection(PDP)has poor rapidity,and even refuses to operate when faults occur on the DC line.Therefore,a novel pilot protection scheme based on traveling wave characteristics is proposed.First,the adaptability of the traditional PDP applied in engineering is analyzed for different operation modes.Then,the expressions of the forward traveling wave(FTW)and backward traveling wave(BTW)on the rectifier side and the inverter side are derived for different fault locations.From the theoretical derivation,the difference between the BTW and FTW on the rectifier side is less than zero,and the same is true on the inverter side.However,in the event of an external fault of DC line,the difference between the BTW and FTW at nearfault terminal protection installation point is greater than zero.Therefore,by summing over the product of the difference between BTW and FTW of the rectifier side and that of the inverter side,the fault identification criterion is constructed.The simulation results show that the proposed pilot protection scheme can quickly and reliably identify the short-circuit faults of DC line in different operation modes.

Rotation Angle Control Strategy for Telescopic Flexible Manipulator Based on a Combination of Fuzzy Adjustment and RBF Neural Network

The length of fexible manipulators with a telescopic arm alters during movement.The dynamic parameters of telescopic fexible manipulators exhibit signifcant time-varying characteristics owing to variations in length.With an increase in the manipulators’length,the nonlinear terms caused by fexibility in the manipulators’dynamic equations cannot be ignored.The time-varying characteristics and nonlinear terms of telescopic fexible manipulators cause fuctuations in rotation angles,which afect the operation accuracy of end-efectors.In this study,a control strategy based on a combination of fuzzy adjustment and an RBF neural network is utilized to improve the control accuracy of fexible telescopic manipulators.First,the dynamic equation of the manipulators is established using the assumed mode method and Lagrange’s principle,and the infuence of nonlinear terms is analyzed.Subsequently,a combined control strategy is proposed to suppress the fuctuation of the rotation angle in telescopic fexible manipulators.The variation ranges of the feedforward PD controller parameters are determined by the pole placement strategy and length of the manipulators.Fuzzy rules are utilized to adjust the controller parameters in real-time.The RBF neural network is utilized to identify and compensate the uncertain part of the dynamic model of the fexible manipulators.The uncertain part comprises time-varying parameters and nonlinear terms.Finally,numerical simulations and prototype experiments prove the efectiveness of the combined control strategy.The results prove that the proposed control strategy has a smaller standard deviation of errors.Therefore,the combined control strategy is more suitable for telescopic fexible manipulators,which can efectively improve the control accuracy of rotation angles.

Sources of particulate organic matter in the Chukchi and Siberian shelves: clues from carbon and nitrogen isotopes

The stable isotopic composition(δ13C andδ15N)and carbon/nitrogen ratio(C/N)of particulate organic matter(POM)in the Chukchi and East Siberian shelves from July to September,2016 were measured to evaluate the spatial variability and origin of POM.Theδ13CPOC values were in the range of−29.5‰to−17.5‰with an average of−25.9‰±2.0‰,and theδ15NPN values ranged from 3.9‰to 13.1‰with an average of 8.0‰±1.6‰.The C/N ratios in the East Siberian shelf were generally higher than those in the Chukchi shelf,while theδ13C andδ15N values were just the opposite.Abnormally low C/N ratios(<4),lowδ13CPOC(almost−28‰)and highδ15NPN(>10‰)values were observed in the Wrangel Island polynya,which was attributed to the early bloom of small phytoplankton.The contributions of terrestrial POM,bloom-produced POM and non-bloom marine POM were estimated using a three end-member mixing model.The spatial distribution of terrestrial POM showed a high fraction in the East Siberian shelf and decreased eastward,indicating the influence of Russian rivers.The distribution of non-bloom marine POM showed a high fraction in the Chukchi shelf with the highest fraction occurring in the Bering Strait and decreased westward,suggesting the stimulation of biological production by the Pacific inflow in the Chukchi shelf.The fractions of bloom-produced POM were highest in the winter polynya and gradually decreased toward the periphery.A negative relationship between the bloom-produced POM and the sea ice meltwater inventory was observed,indicating that the net sea ice loss promotes early bloom in the polynya.Given the high fraction of bloom-produced POM,the early bloom of phytoplankton in the polynyas may play an important role on marine production and POM export in the Arctic shelves.

Transsphenoidal microsurgical treatment of infradiaphragmatic craniopharyngioma

Objective Typically,the transcranial approach has been used for the treatment of craniopharyngiomas with suprasellar extension,whereas the transsphenoidal approach has been used mostly for infradiaphragmatic craniopharyngioma.Total resection of craniopharyngioma can reduce the recurrence rate,especially in young children,but it may lead to severe complications.Therefore,any benefit of the degree of resection must be weighed against the risk of complications by the surgeons.The purpose of this study was to explore the therapeutic outcome after transsphenoidal microsurgical treatment of infradiaphragmatic craniopharyngioma and share our experiences.Methods Between January 2003 and June 2013,30 patients with infradiaphragmatic craniopharyngioma underwent transsphenoidal microsurgical resection in our hospital.The neurological,visual,and endocrine functions,and extent of resection were analyzed retrospectively.Recurrence or growth of residual tumor tissue during follow-up was assessed using magnetic resonance imaging(MRI).Results Total resection was achieved in 25 patients(83.3%),subtotal resection was achieved in 4 patients(13.3%),and partial resection was achieved in 1 patient(3.4%).There were no perioperative deaths.Cerebrospinal fluid(CSF) leakage occurred in 6 patients,and among them,2 required surgical repair of the sella.New-onset postoperative diabetes insipidus(DI) developed in 8 patients.Vision and visual fields were improved at different levels in 13 out of 16 patients who had sight impediments before treatment.Tumor recurrence and regrowth was observed in 2 patients;1 patient underwent transsphenoidal reoperation,the condition of the other patient who had undergone several craniotomies grew worse over the 6-month follow-up period.Conclusion Transsphenoidal surgery is an ideal choice in treating infradiaphragmatic craniopharyngioma.The transsphenoidal approach,which preserves pituitary function and avoids damage to the hypothalamic structures and optic nerve,is associated with fewer complications than the transcranial approach and a low mortality rate.

Carbon nanotubes decorated FeNi/nitrogen-doped carbon composites for lightweight and broadband electromagnetic wave absorption

Magnetic-dielectric component modulation and heterogeneous interface engineering were considered as an effective strategy for designing lightweight and broadband electromagnetic wave(EMW)absorbors.Herein,a series of carbon nanotubes(CNTs)decorated core-shell nitrogen-doped carbon(CNTs/FeNi/NC)composites were successfully fabricated via the carbonization of CNTs/NiFe_(2)O_(4)/PDA precursors obtained by hydrothermal and polymerization method.The EMW absorption(EMWA)properties of CNTs/FeNi/NC composites were explored by varying the CNTs content.When the CNTs content was 15%,the minimum reflection loss(RL_(min))value was-51.13 dB at 9.52 GHz and the corresponding effective absorption band-width(EAB)value was 2.96 GHz(8.96-11.12 GHz)at 2.5 mm.Particularly,the maximum EAB value can reach up to 4.64 GHz(12.80-17.44 GHz)at 1.7 mm.The excellent EMW attenuation capability resulted from the enhanced conductive loss,polarization loss,magnetic loss,and improved impedance matching.This work offers a novel reference for designing lightweight and broadband EMWA materials.

Research on Direct Torque Control of Permanent Magnet Synchronous Motor for New Energy Vehicles

This article introduces the control principle,technical status and two commonly used motor control schemes of permanent magnet synchronous motors for new energy vehicles.Direct torque control is selected as the research object,and its advantages and disadvantages with vector control are analyzed.A Simulink simulation model was established according to the control principle.

Development of a real-time magnetic island reconstruction system based on PCIe platform for HL-2A tokamak

A real-time magnetic island reconstruction(MIR)system based on PCI express platform for HL-2 A tokamak is introduced.The front-end analog circuit and high performance analog-to-digital converters complete high-precision synchronous sampling of 18 channel Mirnov signals,and the application of PCIe platform and direct memory access technology enables high speed data transmission between graphics processing unit and field programmable gate array(FPGA).FPGA,as a mainstream high speed parallelizable computing tool,was used to implement the MIR algorithm,while a parameter table is established in an external double data rate SDRAM to improve the computational efficiency.The software of the MIR system is developed with Compute Unified Device Architecture 8.0 in Centos 6 system,which mainly realizes driver development,data transmission,network communication,parameter calculation and system control.This system has been tested in HL-2 A plasma discharge experiment,and the reconstructed magnetic island structure can achieve a spatial resolution of 1.02 cm while the time resolution can reach 2 ms.

Boosting Hydrogen Evolution and Oxygen Reduction Performances of Pd/C upon Surface Phosphorization

Simultaneous heterostructure and composition engineering is an effective route to construct electrocatalyst of high performance. Conjugated microporous polymer(CMP) is a new emerging platform material with designable porosity and functionality. Here, a facile CMP-guest chemistry method was presented to prepare PdP2@Pd/C heterostructure with bifunctional electrocatalytic activity. The formation of heterostructure relies on a CMP precursor consisting of nitrogen groups that allow binding Pd species and introducing phosphorus inclusion. The Pd-bound CMP precursor formed in-situ could be directly converted into nitrogen-and phosphide-doped porous carbon(NPC) during pyrolysis, while P diffused to the Pd/C interface results in shallow phosphorization. The as-prepared NPC consisting of PdP2@Pd/C(Pd content 4 wt%) heterostructure demonstrated significantly enhanced electrocatalytic performances including a promising HER activity(58mV @ 10 mA/cm2), and an ORR activity approaching commercial 20 wt% Pd/C together with excellent long-term stability. Our work illustrates the intriguing power of CMP-guest potential in heterostructure engineering.

Luminescent terpyridine-based metallo-supramolecular systems:from design to applications

Luminescent metallo-supramolecules have received tremendous attention in recent years owing to their diverse yet well-defined structures,tunable luminescent properties,and broad applications.In this context,the development of terpyridine(tpy)-based luminescent metallo-supramolecular systems has seen rapid growth.This review aims to summarize the recent progress of luminescent metallo-supramolecular assemblies from tpy ligands with metal ions,with a focus on discrete metallo-supramolecular architectures and metallo-supramolecular polymers.The design strategies and common approaches for tuning the luminescence properties are detailed along with representative applications.Finally,the pitfalls and unmet challenges regarding the structural characterization and practical applications of tpy-based metallo-supramolecules are discussed followed by our perspectives on the future directions of this field.

Effects of Metal Cations and Counter Anions on the Structural Stability of Isoquinoline-Based Metallo-Supramolecular Cages

Metallo-supramolecular architectures that are constructed by coordination-driven self-assembly have received tremendous attention on account of their diverse yet molecular-level precise structures and broad applications.Of particular,metal cations and counter anions are fundamentally important in terms of self-assembly,characterization and property;however,their effects on the structural stabilities of metallo-supramolecular architectures have seldom been investigated.To address this issue,herein,a series of octahedral metallo-cages that are capable of tolerating with five metal cations(Pd^(2+),Cu^(2+),Ni^(2+),Co^(2+)and Zn^(2+)),and five counter anions(ClO_(4)^(–),OTf^(–),BF_(4)^(–),NTf_(2)^(–)and NO_(3)^(–))are constructed by the coordination-driven self-assembly of a well-designed tritopic isoquinoline-based ligand with corresponding metal salts.Structural stability studies show that metal cations and counter anions play a critical role in the stability of the resulting cages depending on their coordination abilities and stacking manners.This work provides deep insights in the ever-diversifying field of metallo-supramolecular chemistry,and will enable us to design more sophisticated assembled structure with desired function.

Small-molecule agents for cancer immunotherapy

Cancer immunotherapy,exemplified by the remarkable clinical benefits of the immune checkpoint blockade and chimeric antigen receptor T-cell therapy,is revolutionizing cancer therapy.They induce long-term tumor regression and overall survival benefit in many types of cancer.With the advances in our knowledge about the tumor immune microenvironment,remarkable progress has been made in the development of small-molecule drugs for immunotherapy.Small molecules targeting PRR-associated pathways,immune checkpoints,oncogenic signaling,metabolic pathways,cytokine/chemokine signaling,and immune-related kinases have been extensively investigated.Monotherapy of smallmolecule immunotherapeutic drugs and their combinations with other antitumor modalities are under active clinical investigations to overcome immune tolerance and circumvent immune checkpoint inhibitor resistance.Here,we review the latest development of small-molecule agents for cancer immunotherapy by targeting defined pathways and highlighting their progress in recent clinical investigations.