Scaling of the magnetic entropy and magnetization in YbRh_2(Si_{0.95}Ge_{0.05})_2

The magnetic entropy of YbRh_2(Si_{0.95}Ge_{0.05})_2 is derived from low-temperature ($T\geq 18$ mK) specific heat measurements. Upon field-tuning the system to its antiferromagnetic quantum critical point unique temperature over magnetic field scaling is observed indicating the disintegration of heavy quasiparticles. The field dependence of the entropy equals the temperature dependence of the dc-magnetization as expected from the Maxwell relation. This proves that the quantum-critical fluctuations affect the thermal and magnetic properties in a consistent way.Comment: 6 pages, 2 figures, manuscript submitted to SCES2004 conferenc

All CVD Boron Nitride Encapsulated Graphene FETs with CMOS Compatible Metal Edge Contacts

We report on the fabrication and characterization of field effect transistors (FETs) based on chemical vapor deposited (CVD) graphene encapsulated between few layer CVD boron nitride (BN) sheets with complementary metal oxide semiconductor (CMOS) compatible nickel edge contacts. Non-contact Tera-hertz time domain spectroscopy (THz-TDS) of large-area BN/graphene/BN (BN/G/BN) stacks reveals average sheet conductivity >1 mS/sq and average mobility of 2500 cm$^{2}$/Vs. Improved output conductance is observed in direct current (DC) measurements under ambient conditions, indicating potential for radio-frequency (RF) applications. Moreover, we report a maximum voltage gain of 6 dB from a low frequency signal amplifier circuit. RF characterization of the GFETs yields an f$_{T}$ x L$_{g}$ product of 2.64 GHz$\mu$m and an f$_{Max}$ x L$_{g}$ product of 5.88 GHz$\mu$m. This study presents for the first time THz-TDS usage in combination with other characterization methods for device performance assessment on BN/G/BN stacks. The results serve as a step towards scalable, all CVD 2D material-based FETs for CMOS compatible future nanoelectronic circuit architectures.Comment: 6 page

Observation of the spin-orbit gap in bilayer graphene by one-dimensional ballistic transport

We report on measurements of quantized conductance in gate-defined quantum point contacts in bilayer graphene that allow the observation of subband splittings due to spin-orbit coupling. The size of this splitting can be tuned from 40 to 80 $\mu$eV by the displacement field. We assign this gate-tunable subband-splitting to a gap induced by spin-orbit coupling of Kane-Mele type, enhanced by proximity effects due to the substrate. We show that this spin-orbit coupling gives rise to a complex pattern in low perpendicular magnetic fields, increasing the Zeeman splitting in one valley and suppressing it in the other one. In addition, we observe the existence of a spin-polarized channel of 6 e$^2$/h at high in-plane magnetic field and of signatures of interaction effects at the crossings of spin-split subbands of opposite spins at finite magnetic field.Comment: 5 pages, 4 figures, Supplement 6 figure

On Gammelgaard's formula for a star product with separation of variables

We show that Gammelgaard's formula expressing a star product with separation of variables on a pseudo-Kaehler manifold in terms of directed graphs without cycles is equivalent to an inversion formula for an operator on a formal Fock space. We prove this inversion formula directly and thus offer an alternative approach to Gammelgaard's formula which gives more insight into the question why the directed graphs in his formula have no cycles.Comment: 29 pages, changes made in the last two section

Cobertura do solo e área foliar de uma cultivar de soja de hábito determinado cultivada no sistema de plantio cruzado.

O sistema denominado Plantio Cruzado surgiu no Brasil com o objetivo de aumentar a densidade de plantas de soja sem concentrar demasiadamente as plantas na linha, o que acarretaria em competição intraespecífica muito intensa. Com essa técnica, alguns produtores de diversas regiões do Brasil têm conseguido superar a marca de 6 t ha-1 de grãos de soja. A partir desse contexto, objetivou-se com o presente trabalho avaliar a cobertura do solo e a área foliar da cultivar de soja de hábito determinado, BRS 294 RR, cultivada nos sistemas de plantio cruzado e não cruzado. O experimento foi conduzido na Fazenda Experimental da Embrapa Soja, Londrina, PR, durante o período de outubro de 2011 a março de 2012. Utilizou-se o delineamento de blocos ao acaso em esquema fatorial 2 x 2 x 2, com três repetições. Os tratamentos foram formados pela combinação de dois espaçamentos entre fileiras (0,4 e 0,6 m), duas densidades de semeadura (375.000 e 562.500 sementes por hectare) e dois sistemas de plantio (plantio cruzado e não cruzado). Em geral, o plantio cruzado, o aumento da densidade de plantas e a redução do espaçamento entre fileiras proporcionaram incrementos na cobertura do solo pelas plantas de soja da cultivar BRS 294 RR. O plantio cruzado não afetou a área foliar por planta, mas aumentou a porcentagem de solo descoberto com palha ou plantas de soja no início do ciclo de desenvolvimento da cultura

Cobertura do solo e área foliar de uma cultivar de soja de hábito indeterminado cultivada no sistema de plantio cruzado.

A modificação do arranjo espacial das plantas de soja pode ser a forma mais rápida de aumento da média de rendimento de grãos de soja, sem alterações na sustentabilidade dos sistemas de produção. A partir desse cenário, objetivou-se com o presente trabalho avaliar a cobertura do solo e a área foliar de uma cultivar de soja de hábito indeterminado, BRS 359 RR, cultivada no sistema de plantio cruzado e não cruzado. O experimento foi realizado a campo localizado na Fazenda Experimental da Embrapa Soja em Londrina-PR, durante o período de outubro de 2011 a março de 2012. Utilizou-se o delineamento de blocos ao acaso em esquema fatorial 2 x 2 x 2, com três repetições. Os tratamentos foram formados pela combinação de dois espaçamentos (0,4 e 0,6 m), duas densidades de semeadura (375.000 e 562.500 sementes por hectare) e dois sistemas de plantio (plantio cruzado e não cruzado). No plantio cruzado, o aumento da densidade de plantas e a redução do espaçamento entre fileiras proporcionaram incrementos na cobertura do solo pelas plantas de soja da cultivar BRS 359 RR. O plantio cruzado aumentou a porcentagem de solo descoberto por palha e plantas de soja no início do ciclo de desenvolvimento da cultura

Calibração de psicrômetros para avaliações de potencial hídrico foliar.

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When Interval Analysis Helps Inter-Block Backtracking

International audienceInter-block backtracking (IBB) computes all the solutions of sparse systems of non-linear equations over the reals. This algorithm, introduced in 1998 by Bliek et al., handles a system of equations previously decomposed into a set of (small) k × k sub-systems, called blocks. Partial solutions are computed in the different blocks and combined together to obtain the set of global solutions. When solutions inside blocks are computed with interval-based techniques, IBB can be viewed as a new interval-based algorithm for solving decomposed equation systems. Previous implementations used Ilog Solver and its IlcInterval library. The fact that this interval-based solver was more or less a black box implied several strong limitations. The new results described in this paper come from the integration of IBB with the interval-based library developed by the second author. This new library allows IBB to become reliable (no solution is lost) while still gaining several orders of magnitude w.r.t. solving the whole system. We compare several variants of IBB on a sample of benchmarks, which allows us to better understand the behavior of IBB. The main conclusion is that the use of an interval Newton operator inside blocks has the most positive impact on the robustness and performance of IBB. This modifies the influence of other features, such as intelligent backtracking and filtering strategies

Gemcitabine, Ifosfamide and Navelbine (GIN): activity and safety of a non-platinum-based triplet in advanced non-small-cell lung cancer (NSCLC)

To evaluate activity and toxicity of a non platinum-based triplet including Gemcitabine, Ifosfamide and Navelbine (GIN) in advanced NSCLC. Stage IIIB/IV NSCLC patients with WHO PS < 2 and bidimensionally measurable disease entered the study. Gemcitabine 1000 mg/sqm day 1 and 1000–800 mg/sqm day 4, Ifosfamide 3 g/sqm day 1 (with Mesna), Navelbine 25 mg/sqm day 1 and 25–20 mg/sqm day 4 were administered intravenously every 3 weeks. Objective responses (ORs) were evaluated every 2 courses: a maximum of 6 courses were administered in responding patients. According to Simon's optimal two-stage design more than 18 ORs out of 54 patients were required to establish the activity of this regimen. Fifty patients entered the study. Main characteristics of the 48 evaluated patients were: median age 63 years, ECOG performance status 0 = 65%, stage IV disease 79% and non-squamous histology 71%. The total number of courses administered was 200, median per patient 4 (range 1–6). Toxicities were evaluated according to WHO criteria: neutropenia grade 3–4 occurred in 47% of the courses; thrombocytopenia grade 3–4 in 6.6%; anaemia grade 3 in 3.5%. Twelve episodes of febrile neutropenia were reported and three patients required hospital admission. No toxic death was reported. Non-haematological toxicity, including skin rash, alopecia and fatigue, were generally. Twenty-five ORs (1 complete response and 24 partial responses) were obtained for a response rate of 52% (95% CI: 37.4–66.5%). One-year survival was 46.5%. This non-platinum-based outpatient triplet showed promising activity against NSCLC with myelosuppression, in particular neutropenia, being dose-limiting. The GIN regimen may represent a valuable alternative to standard platinum-based doublets and triplets in the treatment of advanced NSCLC and further studies with this platinum-free combination are warranted. © 2001 Cancer Research Campaign  http://www.bjcancer.co