Liquid crystals of anisotropic colloids are of great significance in the preparation of their ordered macroscopic materials, for example, in the cases of carbon nanotubes and graphene. Here, we report a facile and scalable spinning process to prepare neat "core-shell" structured graphene aerogel fibers and three-dimensional cylinders with aligned pores from the flowing liquid crystalline graphene oxide (GO) gels. The uniform alignment of graphene sheets, inheriting the lamellar orders from GO liquid crystals, offers the porous fibers high specific tensile strength (188 kN m kg(-1)) and the porous cylinders high compression modulus (3.3 MPa). The porous graphene fibers have high specific surface area up to 884 m(2) g(-1) due to their interconnected pores and exhibit fine electrical conductivity (2.6 × 10(3) to 4.9 × 10(3) S m(-1)) in the wide temperature range of 5-300 K. The decreasing conductivity with decreasing temperature illustrates a typical semiconducting behavior, and the 3D interconnected network of 2D graphene sheets determines a dual 2D and 3D hopping conduction mechanism. The strong mechanical strength, high porosity, and fine electrical conductivity enable this novel material of ordered graphene aerogels to be greatly useful in versatile catalysts, supercapacitors, flexible batteries and cells, lightweight conductive fibers, and functional textiles.

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Ultraviolet (UV) radiation has a variety of impacts including the health of humans, the production of crops, and the lifetime of buildings. Based on the photovoltaic effect, self-powered UV photodetectors can measure and monitor UV radiation without any power consumption. However, the current low photoelectric performance of these detectors has hindered their practical use. In our study, a super-high-performance self-powered UV photodetector based on a GaN/Sn:Ga 2 O 3 pn junction was generated by depositing a Sn-doped n-type Ga 2 O 3 thin film onto a p-type GaN thick film. The responsivity at 254 nm reached up to 3.05 A/W without a power supply and had a high UV/visible rejection ratio of R 254 nm /R 400 nm = 5.9 × 10 3 and an ideal detectivity at 1.69 × 10 13 cm•Hz 1/2 •W −1 , which is well beyond the level of previous self-powered UV photodetectors. Moreover, our device also has a low dark current (1.8 × 10 −11 A), a high I photo /I dark ratio (∼10 4 ), and a fast photoresponse time of 18 ms without bias. These outstanding performance results are attributed to the rapid separation of photogenerated electron−hole pairs driven by a high built-in electric field in the interface depletion region of the GaN/ Sn:Ga 2 O 3 pn junction. Our results provide an improved and easy route to constructing high-performance self-powered UV photodetectors that can potentially replace traditional high-energy-consuming UV detection systems. KEYWORDS: self-powered, ultraviolet photodetector, GaN/Sn:Ga 2 O 3 pn junction, superhigh photoresponsivity, 3.05 A/W, potential barrier U ltraviolet radiation has a significant impact on humankind. Some benefits are UV's ability to facilitate the synthesis of vitamin D, kill germs, and treat or prevent rickets when our skin is exposed to moderate UV light. 1 However, it can cause cataracts and skin cancer and accelerate the aging process due to an excessive amount of UV radiation. 1,2 Additionally, UV radiation strongly affects the production of crops and the lifetime of buildings. Fortunately, UV radiation can be measured and monitored using semiconductor UV photodetectors based on Einstein's photoelectric effect, which transforms UV radiation to measurable electronic signals. After decades of steady development, modern UV photodetectors, with high performances in photoresponsivity, signal-to-noise ratios, stability, and speed, have gained interest recently for their applications in environmental monitoring, advanced communications, air purification, leak detection, space research, etc. 3−13 Unfortunately, to acquire reasonable detectivity, an external electric field is applied to photodetectors to separate the photogenerated electron−hole pairs. 5−13 Therefore, external power sources are generally necessary. This makes photodetectors overall uneconomical and complex. On the contrary, self-powered photodetectors can help solve the energy issues and have attracted significant attention. 14−19 Compared to traditional photodetectors, self-powered structures, based on the photovoltaic effect su...

A solar-blind photodetector based on β-GaO/NSTO (NSTO = Nb:SrTiO) heterojunctions were fabricated for the first time, and its photoelectric properties were investigated. The device presents a typical positive rectification in the dark, while under 254 nm UV light illumination, it shows a negative rectification, which might be caused by the generation of photoinduced electron-hole pairs in the β-GaO film layer. With zero bias, that is, zero power consumption, the photodetector shows a fast photoresponse time (decay time τ = 0.07 s) and the ratio I/I ≈ 20 under 254 nm light illumination with a light intensity of 45 μW/cm. Such behaviors are attributed to the separation of photogenerated electron-hole pairs driven by the built-in electric field in the depletion region of β-GaO and the NSTO interface, and the subsequent transport toward corresponding electrodes. The photocurrent increases linearly with increasing the light intensity and applied bias, while the response time decreases with the increase of the light intensity. Under -10 V bias and 45 μW/cm of 254 nm light illumination, the photodetector exhibits a responsivity R of 43.31 A/W and an external quantum efficiency of 2.1 × 10 %. The photo-to-electric conversion mechanism in the β-GaO/NSTO heterojunction photodetector is explained in detail by energy band diagrams. The results strongly suggest that a photodetector based on β-GaO thin-film heterojunction structure can be practically used to detect weak solar-blind signals because of its high photoconductive gain.

A self-powered ultraviolet photodetector with an extremely high responsivity (54.43 mA W−1) was fabricated by constructing p–n junction of GaN/Ga2O3 films.

Weyl semimetals exhibit unusual surface states and anomalous transport phenomena. It is hard to manipulate the band structure topology of specific Weyl materials. Topological transport phenomena usually appear at very low temperatures, which sets challenges for applications. In this work, we demonstrate the band topology modification via a weak magnetic field in a ferromagnetic Weyl semimetal candidate, Co2MnAl, at room temperature. We observe a tunable, giant anomalous Hall effect (AHE) induced by the transition involving Weyl points and nodal rings. The AHE conductivity is as large as that of a 3D quantum AHE, with the Hall angle (ΘH) reaching a record value ($$\tan {\Theta }^{H}=0.21$$ tan Θ H = 0.21 ) at the room temperature among magnetic conductors. Furthermore, we propose a material recipe to generate large AHE by gaping nodal rings without requiring Weyl points. Our work reveals an intrinsically magnetic platform to explore the interplay between magnetic dynamics and topological physics for developing spintronic devices.

Graphene fibers (GFs) with superb electrical conductivity are produced via a chemical doping strategy. The electrical conductivities reach up to 0.77 × 10 -2.24 × 10 S m , which are the highest values among all the reported GFs. The combination of lightness, superb conductivity, and easy scalability makes GFs a promising new carbonaceous fiber species with high performance and advanced functionality.

There is limited data on hematopoietic cell transplantation (HCT) in primary plasma cell leukemia (pPCL), an aggressive plasma cell disorder. We report outcomes of 147 patients with pPCL receiving autologous (n=97) or allogeneic (n=50) HCT within 18 months after diagnosis between 1995 and 2006. Median age was 56 years and 48 years for autologous HCT and allogeneic HCT respectively. Progression-free survival (PFS) at 3 years was 34% (95% CI, 23%-46%) in the autologous group and 20% (95% CI, 10%-34%) in the allogeneic group. Cumulative incidence of relapse at 3 years was 61% (95% CI, 48%-72%) in the autologous group and 38% (95% CI, 25%-53%) in the allogeneic group. Overall survival (OS) at 3 years was 64% (95% CI, 52%-75%) in the autologous group and 39% (95% CI, 26%-54%) in the allogeneic group. Non-relapse mortality (NRM) at 3 years was 5% (95% CI, 1-11%) in the autologous group and 41% (95% CI, 28%-56%) in the allogeneic group. The encouraging OS after autologous HCT, establishes the safety and feasibility of this consolidative treatment option after initial induction therapy for pPCL. Allogeneic HCT, although associated with a significantly lower relapse rate, carries a much higher risk of NRM and no overall survival benefit.