村庄整治中农户宅基地权属调整意愿及影响因素研究——基于广州、佛山、惠州共17村的调查

为促进村庄整治有序推进,实现土地资源的优化配置,本文从村庄整治中涉及宅基地权属调整的农户出发,利用广东省4个市(区)17个自然村共107户被调查农户的问卷调查数据,采用Logistic回归模型,分析农户宅基地权属调整意愿与农户个人特征、家庭人口及经济状况、土地整治及宅基地政策认知等的关系,找出村庄整治中影响农户宅基地权属调整意愿的主要因素。实证分析结果表明:(1)目前愿意参与宅基地权属调整的农户所占比例较低,仅为35.5%。(2)按作用程度排序,影响农户参与宅基地权属调整的因素依次为家庭劳动力人数、宅基地是否确权、承包地距离宅基地平均距离、参加农村新型合作医疗人数、性别、各处宅基地平均占地面积。其中,性别、家庭劳动力人数、承包地距离宅基地平均距离的影响方向为负,其余因素的影响方向为正。(3)影响农户宅基地权属调整意愿的深层次原因,是农户的宗族观念、乡土情结、风险意识、生产生活成本以及投机心理。(4)为了更好地开展村庄整治工作,政府应充分尊重农户意愿、全面推进宅基地确权、进一步加大农村基础设施的投入力度、进一步推广农村新型合作医疗制度、将宅基地申请和住房建筑标准规范化,严格落实一户一宅制度。

农地权属调整与乡村治理——基于清远叶屋村的个案分析

作为乡村社会中经济关系、社会规则、组织安排等一系列制度派生的基础,农地制度的调整与改善,无疑对乡村治理和乡村社会重构起着关键性的作用。本文以清远市叶屋村为研究对象,揭示农地权属调整与乡村治理的内在逻辑关系。研究表明:农地权属调整的实质是农地利用转型,农地产权形态由细碎分散转为集中配置,促进了农地面积、数量、种植类型等显性形态的调整和改善,并作用于农地经营模式、投入和产出等隐性形态,最终实现资源优化配置。农地经济价值得以释放并催生多重乡村经济新业态,农地持续高效产出,能够为农户提供满足生产生活以及未来长远发展所需的物质条件,从而吸引外流劳动力返乡,农户自愿留守农地且在精神层面认同农民身份,新型人地关系得以重构,乡村回归利益共同体。乡村经济繁荣和人口回流,为多元主体协同治理体系的构建提供了必要的基础,并源源不断地为各治理主体提供物质资源和权威资源等治理资源,治理主体治理能力的持续增强,为乡村经济持续发展和乡村社会秩序维护,奠定了扎实的组织基础。农地—农户—农村治理组织的圈层得以重塑,相互影响并高效循环运转,最终实现乡村社会的治理和复兴。

HiFAST:An HIdata calibration and imaging pipeline for FAST

The Five-hundred-meter Aperture Spherical radio Telescope(FAST)has the largest aperture and a 19-beam L-band receiver,making it powerful for investigating the neutral hydrogen atomic gas(HI)in the universe.We present HiFAST(https://hifast.readthedocs.io),a dedicated,modular,and self-contained calibration and imaging pipeline for processing the H?data of FAST.The pipeline consists of frequency-dependent noise diode calibration,baseline fitting,standing wave removal using an FFT-based method,flux density calibration,stray radiation correction,and gridding to produce data cubes.These modules can be combined as needed to process the data from most FAST observation modes:tracking,drift scanning,On-The-Fly mapping,and most of their variants.With HiFAST,the root-mean-square(RMS)noises of the calibrated spectra from all 19 beams were only slightly(~5%)higher than the theoretical expectation.The results for the extended source M33 and the point sources are consistent with the results from Arecibo.The moment maps(0,1 and 2)of M33 agree well with the results from the Arecibo Galaxy Environment Survey(AGES)with a fractional difference of less than 10%.For a common sample of 221 sources with signal-to-noise ratio S/N>10 from the Arecibo Legacy Fast ALFA(ALFALFA)survey,the mean value of fractional difference in the integrated flux density,Sint,between the two datasets is approximately 0.005%,with a dispersion of 15.4%.Further checks on the integrated flux density of 23 sources with seven observations indicate that the variance in the flux density of the source with luminous objects(Sint>2.5 Jy km s-1)is less than 5%.Our tests suggest that the FAST telescope,with the efficient,precise,and user-friendly pipeline HiFAST,will yield numerous significant scientific findings in the investigation of the H?in the universe.

FAST: Its Scientific Achievements and Prospects

FAST is the largest single-dish radio telescope in the world.The characteristics of FAST are presented and analyzed in the context of the parameter space to show how FAST science achievements are affected.We summarize the scientific achievements of FAST and discuss its future science based on the new parts of the parameter space that can be explored by FAST.

Ultra-broadband enhanced nonlinear saturable absorption for Mo0.53W0.47Te2 nanosheets

Alloying in two-dimension has been a hot spot in the development of new,versatile systems of optics and electronics.Alloys have been demonstrated to be a fascinating strategy to modulate the chemical and electronic properties of two-dimensional nanosheets.We firstly reported ultra-broadband enhanced nonlinear saturable absorption of Mo0.53W0.47Te2 alloy at 0.6,1.0,and 2.0μm.The nonlinear saturable absorption of Mo0.53W0.47Te2 saturable absorber(SA)was measured by the open aperture Z-scan technique.Compared to MoTe2 and WTe2 SAs,the Mo0.53W0.47Te2 SA showed five times deeper modulation depth,8.6%lower saturable intensity,and one order larger figure of merit.Thus,our research provides a method of alloys to find novel materials with more outstanding properties for optics and optoelectronic applications.

Liquid metal as a broadband saturable absorber for passively Q-switched lasers

We demonstrated the efficient plasmon-induced nonlinear absorption of liquid metal GaInSn nanospheres prepared by a facile liquid-phase method. With GaInSn as saturable absorbers, a passively Q-switching operation was obtained at both 1.3 and 2 μm. The pulse width of 32 ns was achieved at 1.3 μm with repetition rate of44 kHz, single pulse energy of 51.9 μJ, and output power of 425 mW. Meanwhile, 510 ns and 92 kHz pulses with energy of 36.1 μJ and output power of 2.48 W were obtained at 2 μm. This work provides the potential of liquid metal for improving metal functions and flexible optical devices.

Enhanced nonlinear optical response of layered WSe1.4Te0.6 alloy in 1 μm passively Q-switched laser

Due to the composition-dependent properties of two-dimensional(2D)transition metal dichalcogenides(TMDs),alloying of existing dissimilar TMDs architecture is a novel and controllable route to tailor crystal structures with superior optical and optoelectronic properties.Here,we reported the hexagonal-phase WSe1.4Te0.6 alloy can enable great promise for enhanced saturable absorption response exceeding the parent component WSe2 and WTe2,with larger modulation depth and lower saturable intensity.These advantages allowed the 1064 nm passively Q-switched lasers based on WSe1.4Te0.6 to be more efficient,with pulse duration narrowed to 45%,and slope efficiency increased by 232%.Our findings highlighted the appropriate alloying of TMDs as an effective strategy for development of saturable absorbers.

Thread Private Variable Access Optimization Technique for Sunway High-Performance Multi-core Processors

The primary way to achieve thread-level parallelism on the Sunwayhigh-performance multicore processor is to use the OpenMP programming technique.To address the problem of low parallelism efficiency caused by slow accessto thread private variables in the compilation of Sunway OpenMP programs, thispaper proposes a thread private variable access technique based on privilegedinstructions. The privileged instruction-based thread-private variable access techniquecentralizes the implementation of thread-private variables at the compilerlevel, eliminating the model switching overhead of invoking OS core processingand improving the speed of accessing thread-private variables. On the Sunway1621 server platform, NPB3.3-OMP and SPEC OMP2012 achieved 6.2% and6.8% running efficiency gains, respectively. The results show that the techniquesproposed in this paper can provide technical support for giving full play to theadvantages of Sunway’s high-performance multi-core processors.

Parallel Region Reconstruction Technique for Sunway High-Performance Multi-core Processors

The leading way to achieve thread-level parallelism on the Sunwayhigh-performance multicore processors is to use OpenMP programming techniques.In order to address the problem of low parallel efficiency caused by highthread group control overhead in the compilation of Sunway OpenMP programs,this paper proposes the parallel region reconstruction technique. The parallelregion reconstruction technique expands the parallel scope of parallel regionsin OpenMP programs by parallel region merging and parallel region extending.Moreover, it reduces the number of parallel regions in OpenMP programs,decreases the overhead of frequent creation and convergence of thread groups,and converts standard fork-join model OpenMP programs to higher performanceSPMD modelOpenMP programs. On the Sunway 1621 server computer, NPB3.3-OMP and SPEC OMP2012 achieved 8.9% and 7.9% running efficiency improvementrespectively through parallel region reconstruction technique. As a result,the parallel region reconstruction technique is feasible and effective. It providestechnical support to fully exploit the multi-core parallelism advantage of Sunway’shigh-performance processors.