The Chinese culture of filial piety has historically emphasised children's responsibility for their ageing parents. Little is understood regarding the inverse: parents’ responsibility and care for their adult children. This paper uses interviews with 50 families living in rural China's Anhui Province to understand intergenerational support in rural China. Findings indicate that parents in rural China take on large financial burdens in order to sustain patrilineal traditions by providing housing and child care for their adult sons. These expectations lead some rural elders to become migrant workers in order to support their adult sons while others provide live-in grandchild-care, moving into their children's urban homes or bringing grandchildren into their own homes. As the oldest rural generations begin to require ageing care of their own, migrant children are unable to provide the sustained care and support expected within the cultural tradition of xiao. This paper adds to the small body of literature that examines the downward transfer of support from parents to their adult children in rural China. The authors argue that there is an emerging cultural rupture in the practice of filial piety – while the older generation is fulfilling their obligations of upbringing and paying for adult children's housing and child care; these adult children are not necessarily available or committed to the return of care for their ageing parents. The authors reveal cultural and structural lags that leave millions of rural ageing adults vulnerable in the process of urbanisation in rural China.

Accurate navigation is required in many Unmanned Aerial Vehicle (UAV) applications. In recent years, GNSS Precise Point Positioning (PPP) has been recognised as an efficient approach for providing precise positioning services. In contrast to the widely used Real-Time Kinematic (RTK), PPP is independent of reference stations, which greatly broadens its scope of application. However, the accuracy and reliability of PPP can be significantly decreased by poor GNSS satellite geometry and outage. In response, a real-time four-constellation GNSS PPP is applied to improve the geometry in this work, and PPP is tightly coupled with an Inertial Measurement Unit (IMU) to smooth the position and velocity output, thus improving the robustness of the navigation solution. Experimental flight tests are carried out using a UAV in an open-sky area, and GNSS-challenged environments are simulated. The results show that the four-constellation GNSS PPP/IMU integration reduces the Root-Mean-Square (RMS) Three-Dimensional (3D) positioning and velocity error by 76.4% and 67.1%, respectively, in open sky with respect to the one-GNSS PPP. Under scenarios where GNSS measurements are insufficient, the coupled system can still provide continuous solutions. Moreover, the coupled PPP/IMU system can also maintain the convergence of PPP during GNSS-challenged periods and can greatly shorten the re-convergence period of PPP when the UAV returns to the open sky.

We present a scheme of electron beam radiography to dynamically diagnose the high energy density (HED) matter in three orthogonal directions simultaneously based on electron Linear Accelerator. The dynamic target information such as, its profile and density could be obtained through imaging the scattered electron beam passing through the target. Using an electron bunch train with flexible time structure, a very high temporal evolution could be achieved. In this proposed scheme, it is possible to obtain 1010 frames/second in one experimental event, and the temporal resolution can go up to 1 ps, spatial resolution to 1 µm. Successful demonstration of this concept will have a major impact for both future inertial confinement fusion science and HED physics research.

Deploying resistant cultivars is an economical and essential management method in controlling viral diseases, and there are several mutational resources for tobacco. In the present study, the inoculation of tobacco plants with tobacco viruses was performed in a greenhouse from 2011 to 2014 to identify mutants resistant to tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). The high-throughput screening included seeding uniformly, transplanting in seedbeds, inoculating by cloth brushes and reporting symptoms based on disease indices. A total of 4000 second generation segregating (M2) mutants of tobacco cultivar Zhongyan100 were screened. Seeds from highly resistant mutant M2 plants were selected and planted separately. The M3 were grown and mutational stability was measured. For TMV, ten highly resistant plants were selected in the M2 generation and the mutation rate was 0·012%. In the M3 generation, there were seven mutants with hereditary high resistance and, according to the results of real-time polymerase chain reaction, the N gene was detected in all seven M3. Two hereditary immune M4 mutants, one of which was a male sterile line, were identified and evaluated in the glasshouse and in the field. For CMV, seven highly resistant plants were selected from the M2 generation and the mutation rate was 0·009%. In the M3 generation, there was one mutant with hereditary high resistance. The results indicate that hereditary mutants may be identified in the M4 generation and back-crossed to wild-type Zhongyan100 to identify anti-viral genes.

Shockley-Queisser detailed balance theory predicts that under one sun a semiconductor with its bandgap in the range of 1.0 – 1.6 eV can potentially achieve an energy conversion efficiency > 30%. Therefore, the conversional wisdom would suggest looking for a semiconductor with a bandgap in this range for a single junction solar cell. Here we explore an alternative way of selecting the absorber material for PV, which allows using semiconductors with much larger bandgaps, in conjunction with new device architecture. Specifically, our device is based on an array of core-shell semiconductor nanowires, such as ZnO-ZnSe, where the two components exhibit type II band alignment. Our approach relies on the most basic property of a type II heterojunction, i.e., the staggered band alignment, that provides the function of charge separation, as in the case of dye-sensitized solar cell or (organic) bulk heterojunction solar cell. However, they differ in two important aspects: (1) the current structure is all inorganic, thus, expected to offer better chemical and photo- stability; and (2) In this approach, the interfacial transition provides an effective absorption or photo-response threshold that can be much lower than that of either component. In this work, using a ZnO-ZnSe core-shell nanowire array, we report the observation of the key signatures associated with the type II optical transition, and the demonstration of a solar cell based on the core-shell nanowire array.

An electron-beam accelerator based on spiral water pulse forming line which consists of a primary storage capacitor system, an air core spiral strip transformer, a spiral pulse forming line of water dielectric, and a field-emission diode, is described. The experimental results showed that the diode voltage is more than 500 kV, the electron beam current of diode is about 24 kA, and the pulse duration is about 200 ns. The main parameters of the accelerator were calculated theoretically. The distributions for electrical field in the pulse forming line were obtained by the simulations. In addition, the process of the accelerator charging a spiral pulse forming line was simulated through the Pspice software to get the waveforms of charging voltage of pulse forming line, the diode voltage and diode current of accelerator. The theoretical and simulated results agree with the experimental results. This accelerator is very compact and works stably and reliably.

A high voltage pulse Tesla transformer with a coupling coefficient of 0.75 was designed and experimentally investigated. The transformer was employed to charge a spiral water pulse forming line (PFL) in a high current electron beam accelerator, and was featured by its compactness, stability, and reliability. When the primary input voltage is 55 kV, the transformer can charge the PFL to 720 kV with an energy conversion efficiency of 36%. The formulas for calculating the primary and secondary inductances of the transformer were deduced, with which the main parameters of the transformer were calculated theoretically. The distributions for electrical and magnetic fields in the transformer were obtained by the simulations of calculation. In addition, the process of an accelerator of the transformer charging a spiral PFL was simulated through the Pspice software to get the waveform of charging voltage, the diode voltage, and diode current of accelerator. The theoretical and simulated results agree with the experimental results.

The microstructure of Ag-doped La2/3Sr1/3MnO3 (LSMO) thin films deposited on (001) LaAlO3 single-crystal substrates was systematically investigated in cross section and plan view by high-resolution electron microscopy and analytical electron microscopy. The results showed that the films deposited at 750 °C were perfectly epitaxial with or without Ag-doping. No Ag in the doped film was detected. On the other hand, the LSMO films deposited at 400 °C were less perfect. With increasing Ag-doping level, the shape of LSMO grains became irregular, and the grain size increased gradually. Large polycrystalline clusters consisting of LSMO, AgO, and Ag grains formed in the doped films, and the amount and size of them increased with increasing Ag-doping level. Ag existed at the LSMO grain boundaries in its elemental state. A growth process for the LSMO-Ag system is discussed based on the experimental results. The enhancement of the magnetic spin disorders at the grain boundaries and interfaces caused by doping Ag could result in an improvement of low-field magnetoresistance.

Zinc powder reacts with equivalent elemental selenium in solvent ethylenediamine at 120 °C for 6 h to form a complex, which is converted to ZnSe nanoparticles by pyrolysis or protonization. X-ray diffraction results suggest that the as-formed products have wurtzite structure. Transmission electron microscopy observation show that particles with spherical and laminar morphology were produced by pyrolysis and protonization, respectively. The formation of ZnSe nanoparticles is also investigated by infrared and thermal analysis.

Single-phase nanocrystalline Co9S8 was prepared by hydrothermal treatment of Co(Ac)2 and NH2CSNH2 in hydrazine solution at 170 °C. The products were characterized by x-ray powder diffraction (XRD) technique, transmission electron microscope (TEM), and wet chemical analysis. XRD indicated the product was the cubic Co9S8 phase. The relative crystallite size was 6.3 nm as determined by the Scherrer method. TEM images showed the particles were agglomerative. The electron diffraction pattern also revealed their nanocrystalline nature. In this hydrothermal formation process of Co9S8, hydrazine was a critical factor. The formation process is discussed.

The magnetic properties of single-crystalline Tb2Fe17−xSix (x = 0, 1, 2, 3, and 3.3) have been investigated. The Si substitution constricted the lattices by 1.5% and caused the Th2Ni17 transfer to Th2Zn17. The Curie temperature increased from 413 to 526 K, and the spontaneous magnetic moment decreased from 82.6 to 46.4 emu/g with the increase of Si. The stronger anisotropy and coercivity were generated by Si occupying the Fe sublattices. A domain wall pinning-dominated mechanism was responsible for increasing the coercivity force from 0.01 T (x = 1) to about 0.36 T (x = 3.3) at 1.5 K.

Ferroelectric and dielectric properties were measured for BaTiO3 thin films prepared by metalorganic chemical vapor deposition which were highly a-axis textured. No ferroelectric hysteresis was observed from the as-deposited BaTiO3 films on Pt coated MgO. Upon applying an electric field exceeding a threshold electric field, Et, ∼ 50 - 100 kV/cm, a ferroelectric hysteresis was observed. A spontaneous polarization Ps ≥ 15 μC/cm2 was measured for the textured films.

A new type of bistable center is observed in electron-irradiated Si and identified as an interstitial carbon-substitutional carbon pair by combining several spectroscopic techniques. In the positive and negative charge states, the stable configuration of the defect involves a carbon-silicon interstitialcy (each atom 3-fold coordinated) next to a 4-fold coordinated substitutional C atom. In the neutral state, the defect rearranges its bonds so that both C atoms are substitutional (4-fold coordinated) with a 2- fold coordinated Si atom nestled between. Configurational coordinate energy surfaces are determined for each of the three charge states.