A frequency servo SoC with output power stabilization loop technology for miniaturized atomic clocks

A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.

课程思政融入分析化学课堂的实践与思考

课程思政是高等学校实现思想政治教育工作贯穿育人全过程的重要途经。本文介绍了华东理工大学在分析化学教学中开展课程思政的整体思路和实践思考。根据分析化学学科特点,选择合适的分析化学知识点对接至思想政治课程的相关内容,通过构建思政案例库,挖掘学科前沿中的思政元素,开展灵活多样的全覆盖思政教学等具体措施与手段。将专业知识与思政教育有效融合,使思政教育内容自然渗透并融入课堂教学中,培养和深化学生在家国情怀和文化自信、科学精神、公民意识、健全人格等各方面的意识与能力。

探讨维生素B_(12)研究史中的思政元素

维生素B_(12)的研究史蕴含了丰富的思政元素。本文通过探究维生素B_(12)的发现、治疗恶性贫血机理、结构测定、人工合成、生物合成中的关键人物、事件,凝练出弘扬中医药学、用科学造福人类、团队合作、持之以恒、创新精神等五大思政元素,以期为相关专业课程中课程思政的开展带来有益的启迪。

Hierarchically porous S-scheme CdS/UiO-66 photocatalyst for efficient 4-nitroaniline reduction

Unveiling the pore-size performance of metal organic frameworks(MOFs)is imperative for controllable design of sophisticated catalysts.Herein,UiO-66 with distinct macropores and mesopores were intentionally created and served as substrates to create advanced CdS/UiO-66 catalysts.The pore size impacted the spatial distribution of CdS nanoparticles(NPs):CdS tended to deposit on the external surface of mesoporous UiO-66,but spontaneously penetrated into the large cavity of macroporous UiO-66 nanocage.Normalized to unit amount of CdS,the photocatalytic reaction constant of macroporous CdS/UiO-66 over 4-nitroaniline reduction was~3 folds of that of mesoporous counterpart,and outperformed many other reported state-of-art CdS-based catalysts.A confinement effect of CdS NPs within UiO-66 cage could respond for its high activity,which could shorten the electron-transport distance of NPs-MOFs-reactant,and protect the active CdS NPs from photocorrosion.The finding here provides a straightforward paradigm and mechanism to rationally fabricate advance NPs/MOFs for diverse applications.

A 2-step GPS carrier tracking loop for urban vehicle applications

Global positioning system (GPS) for vehicle applications in the urban area is challenged by low signal intensity. The carrier loop based on fast Fourier transform (FFT) can obtain a high signal to noise ratio (SNR) gain by increasing the observation time. However, this leads to a major problem that the acceleration cannot be ignored. The performance of the FFT-based loop will decline with the acceleration increasing. This paper discusses the effect of the dynamic on FFT first. Then a high performance carrier tracking loop for weak GPS L5 signals is proposed. It combines discrete chirp-Fourier transform (DCFT) and the phase fitting method to estimate Doppler frequency and Doppler rate simultaneously. First, a sequence of integration results is used to perform DCFT to estimate coarse Doppler frequency and Doppler rate. Second, the phase of the sequence is calculated and used to perform linear fitting. By the phase fitting method, the fine Doppler frequency and Doppler rate can be estimated. The computation cost is small because the integration results are used and the phase fitting method needs only coarse estimates of Doppler frequency and Doppler rate. Compared with FFT and DCFT, the precision of the phase fitting method is not limited by the resolution. Thus the proposed loop can get high precision and low carrier to noise ratio (C/N-0) tracking threshold. Simulation results show this loop has a great improvement than conventional loops for urban weak-signal applications.

Development Status and Prospect of Modern Fishery Parks

Along with the thorough development of the reform and open policy,the trend of broad agriculture and broad development is increasingly intensified. In order to promote the development of fishery industry in China and increase the income of fishermen,the paper analyzes the development status of modern fishery parks at home and abroad comprehensively and summarizes relevant research status and progress on the basis of copious research literature on the construction of fishery parks at home and abroad. Research shows that the parks have the problems of insufficient construction funds,similar construction patterns,inadequate technical support and improper operation and management mechanism. In allusion to relevant problems of modern fishery parks in China,the paper has put forward some countermeasures and made a future prospect.

Multi-omics integration reveals potential stage-specific druggable targets in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia(T-ALL),a heterogeneous hematological malignancy,is caused by the developmental arrest of normal T-cell progenitors.The development of targeted therapeutic regimens is impeded by poor knowledge of the stage-specific aberrances in this disease.In this study,we performed multi-omics integration analysis,which included mRNA expression,chromatin accessibility,and gene-dependency database analyses,to identify potential stage-specific druggable targets and repositioned drugs for this disease.This multi-omics integration helped identify 29 potential pathological genes for T-ALL.These genes exhibited tissue-specific expression profiles and were enriched in the cell cycle,hematopoietic stem cell differentiation,and the AMPK signaling pathway.Of these,four known druggable targets(CDK6,TUBA1A,TUBB,and TYMS)showed dysregulated and stage-specific expression in malignant T cells and may serve as stage-specific targets in T-ALL.The TUBA1A expression level was higher in the early T cell precursor(ETP)-ALL cells,while TUBB and TYMS were mainly highly expressed in malignant T cells arrested at the CD4 and CD8 double-positive or single-positive stage.CDK6 exhibited a U-shaped expression pattern in malignant T cells along the naıve to maturation stages.Furthermore,mebendazole and gemcitabine,which target TUBA1A and TYMS,respectively,exerted stage-specific inhibitory effects on T-ALL cell lines,indicating their potential stage-specific antileukemic role in T-ALL.Collectively,our findings might aid in identifying potential stage-specific druggable targets and are promising for achieving more precise therapeutic strategies for T-ALL.

Comparison of Ex‑PRESS implantation versus trabeculectomy combined with phacoemulsification in primary open‑angle glaucoma:a retrospective in vivo confocal microscopy study

Background:To compare the efficacy of Ex-PRESS implantation versus trabeculectomy combined with phacoemulsification.Methods:A retrospective 12-month study on patients with coincident primary open-angle glaucoma(POAG)and cataract.The patients underwent combined phacoemulsification and Ex-PRESS implant(Phaco-ExPRESS,n=35)or phacotrabeculectomy(Phaco-Trab,n=35).The morphological structures of the filtering bleb were examined by slitlamp,anterior segment optical coherence tomography(AS-OCT)and in vivo confocal microscopy(IVCM).Complete success was defined as postoperative intraocular pressure(IOP)<18 mmHg without the use of anti-glaucoma medication.Qualified success was defined as postoperative IOP<18 mmHg with or without anti-glaucoma medications.The data were collected preoperatively and postoperatively at 2 weeks,1 month,3 months,6 months,and 12 months.Results:No significant difference in the variables such as age,IOP and perimetry was found between the groups of Phaco-ExPRESS and Phaco-Trab.At the one-year postoperative visit for filtering blebs,Phaco-ExPRESS increased the mean area of epithelial microcysts significantly from 0.10±0.05 to 0.20±0.09μm^(2)perμm^(2),while Phaco-Trab decreased the mean area significantly from 0.08±0.04 to 0.04±0.06μm^(2)perμm^(2).Notably,the hyperreflective dots detected by IVCM decreased by 84.9%in Phaco-ExPRESS but increased by 36.3%in Phaco-Trab.The hyperreflective dots were further identified as neutrophil-and monocyte-like cells.The number of these cells were negatively correlated with the microcysts area(r=−0.7,P<0.01)but positively associated with the grade of connective tissue(r=0.5,P<0.01).By creating different microstructural changes in the filtering blebs,Phaco-ExPRESS produced a higher complete success rate(84.9%vs.41.2%,P<0.01)and significant decrease in the number of anti-glaucoma medications(P<0.01)when compared with those in Phaco-Trab.However,the qualified success showed no significant difference between the two groups(100.0%vs.91.2%,P=0.24).Conclusions:At the one-year follow-up,Phaco-ExPRESS generated better filtering bleb with larger area of microcysts,looser connective tissues,and less inflammation than that of Phaco-Trab,providing adequate IOP control and less IOP-lowering medications.These findings indicate that Phaco-ExPRESS could be more preferred than Phaco-Trab for the treatment of patients with coincident POAG and cataract.

A three-dimensional biomimetic microfluidic chip to study the behavior of hepatic stellate cell under the tumor microenvironment

In this paper, we designed a three-dimensional cell co-cultured microfluidic chip, which generated interstitial flow and oxygen gradient to simulate the complex tumor microenvironment. It consisted of five parallel cell culture channels and one hypoxic channel. These channels were constructed for the culture of mouse liver tumor cells(Hepa1-6), mouse liver stellate cells(JS-1), the simulation of extracellular matrix, complex biochemical factors(hypoxia and interstitial flow), and the supply of cellular nutrients. The 3D-interstitial flow-hypoxia model was used to study the behavior of JS-1 cells under the effect of tumor microenvironment(TME). The results showed that by co-cultured with Hepa1-6 cells, hypoxia of Hepa1-6 cells, and adding TGF-β1 by interstitial flow, the migration of JS-1 cells could be promoted. Similarly,activated JS-1 cells could led to the epithelial-mesenchymal transformation in co-cultured Hepa1-6 cells,which secreted more TGF-β 1.

Adaptive step-size forward advection method for aerosol process simulation

Outdoor aerosol processes are often associated with disasters and diseases,which threaten human life and health.Outdoor aerosols are afluid system affected by meteorological conditions and three-dimensional complex terrain.Their variable wind speed and direction and complex terrain boundary conditions make simulating advection processes difficult.Based on incompressibleflow conditions,we designed an adaptive time step algorithm for forward advection for the rapid simulation of aerosol processes.The method is based on thefirst-order forward semi-Lagrangian advection method with unconditional mass conservation.Thefirst-order truncated error coefficient function theory generates an adaptive time step to control the accuracy of forward advection.Smoke aerosol simulation experiments in two small outdoor scenes were designed,and the effects of the traditional backward advection and forwardfixed step methods were compared with the algorithm in this study.The proposed simulation method showed improved accuracy compared with the other two methods in experimental scenarios;moreover,compared with those of the traditional backward method,the computation time was significantly reduced and the conservation of mass was significantly improved.Thus,the proposed method is a fast simulation method for outdoor aerosol numerical prediction.KEY POLICY HIGHLIGHTS.The first-order forward semi-Lagrangian method,which requires no iteration and less computation and offers unconditional conservation,was used..The law of truncation error coefficient of thefirst-order forward method was studied and an adaptive step algorithm was designed..Full-size real aerosol experiments in small-scale complex outdoor scenes were conducted for verification and comparison of simulation effects.

Bicriteria Algorithms for Approximately Submodular Cover Under Streaming Model

In this paper,we mainly investigate the optimization model that minimizes the cost function such that the cover function exceeds a required threshold in the set cover problem,where the cost function is additive linear,and the cover function is non-monotone approximately submodular.We study the problem under streaming model and propose three bicriteria approximation algorithms.Firstly,we provide an intuitive streaming algorithm under the assumption of known optimal objective value.The intuitive streaming algorithm returns a solution such that its cover function value is no less thanα(1−ϵ)times threshold,and the cost function is no more than(2+ϵ)^(2)/(ϵ^(2)ω^(2))⋅κ,whereκis a value that we suppose for the optimal solution andαis the approximation ratio of an algorithm for unconstrained maximization problem that we can call directly.Next we present a bicriteria streaming algorithm scanning the ground set multi-pass to weak the assumption that we guess the optimal objective value in advance,and maintain the same bicriteria approximation ratio.Finally we modify the multi-pass streaming algorithm to a single-pass one without compromising the performance ratio.Additionally,we also propose some numerical experiments to test our algorithm’s performance comparing with some existing methods.

Automatic determination of optimal spectral peaks for classification of Chinese tea varieties using laser-induced breakdown spectroscopy

The accurate identification of tea varieties is of great significance to ensure the interests of tea producers and consumers.As a non-destructive or micro damage detection method,laser-induced breakdown spectroscopy(LIBS)has been widely used in the quality detection or classification of agricultural products and food.The objective of this research was to automatically select optimal spectral peaks from the full LIBS spectra,and develop effective classification model for identifying tea varieties.The LIBS spectra covering the region 200-500 nm were measured for 600 Chinese tea leaves including six varieties(i.e.Longjing green tea,Jinhao black tea,Tie Guanyin,Huang Jinya,White peony tea,and Anhua dark tea).A total of 50 optimal spectral peaks were automatically selected from full LIBS spectra(6102)by using the uninformative variable elimination(UVE)and partial least squares projection analysis,and the selected spectral peaks mainly represent the elemental difference in C,Fe,Mg,Mn,Al and Ca.Partial Least Squares Discriminant Analysis(PLS-DA)was used for developing classification model using selected optimal spectral peaks,and yielded the 99.77%classification accuracy for 300 test samples was reached.The results indicate that the proposed method can be used to identify leaf varieties in various tea products.

SPHINGOLIPIDOMIC AND CYCLOPEPTIDOMIC STUDIES ON CORDYCEPS

Cordyceps is a precious Chinese medicine with various pharmacological activities.In 1995,a potent immunosuppressive active sphingolipid named myriocin was isolated from the culture broth of Isaria sinclairii.FTY720,a sphingolipid analogue modified from myriocin,has been developed into an important oral drug for the treatment of multiple sclerosis and organ transplantation.