基于Direct3D技术的自然现象模拟

虚拟现实中自然现象的模拟一直都是研究的热点,其中雨雪天气的模拟可以增加虚拟现实的逼真程度.本文在分析粒子系统实现原理的基础上,基于Direct3D技术,实现了雨雪天气的模拟.本文采用的实现方法比较简单,实现效果具有较强的真实感.     

浅析胡萝卜直播覆盖采种法

叙述了胡萝卜直播覆盖采种法比常规采种法具有种子产量高、品质好、成熟一致和节省人力的突出优点．介绍了胡萝卜直播覆盖采种法的科学施肥、小株采种、合理密植、地膜覆盖、主茎留种、加强管理等主要配套技术要点。     

黑曲霉菌丝球对直接耐晒翠蓝FBL的脱色特性

探讨黑曲霉(Aspergillus niger)菌丝球的生长特性,以及染料种类对其脱色特性的影响.以直接耐晒翠蓝FBL为处理对象,考察染料初始质量浓度、曲霉孢子投加量、pH值、无机盐质量分数、温度、C源和N源对黑曲霉的脱色性能的影响.结果表明,黑曲霉对多种染料有很好的去除效果.对直接耐晒翠蓝FBL的最佳脱色条件是:染料初始质量浓度低于100 mg·L-1、黑曲霉孢子投加量为2.5×104个·mL-1、染料培养基pH值为6、Nacl质量分数低于5%,培养温度在30～40℃之间,并需适量补充C源、N源.     

延安大学学生膳食调查及分析

通过对延安大学春季一个月的膳食调查，与中国营养学会推荐的每日膳食中营养供给量比较，结果表明：我校学生膳食以粮谷类为主，占每日摄入量的58.4%；蔬菜摄入量偏低，仅为190g，占日总摄入量的18.7%；肉类、蛋类和豆类占日总摄入量的19.6%。每日摄入的蛋白质的数量不够，且主要是植物蛋白，膳食中钙、维生素B2不足，因调查时间在春季，故维生素C严重不足；热能摄入中脂肪提供的热能不足。     

Acquisition of nutrients from organic resources by mycorrhizal autotrophic plants

Summary Evidence exists to suggest that mycorrhizal fungi are capable of producing enzymes allowing them to access carbon, nitrogen and phosphorus from complex organic resources in soil. This facility is mainly demonstrated in ectomycorrhizal and ericaceous endomycorrhizal fungi associated with highly organic soils and climatically stressed environments. These data support a direct nutrient cycling hypothesis proposed for tropical ectomycorrhizal forests. In terms of forest succession, the evidence agrees with a major contribution of the mycorrhizal symbiosis in late stages of the succession, where elemental cycling becomes increasingly more conservative and process rates limited by biotic factors. Here, tree growth benefits from direct nutrient cycling mediated by their mycorrhizal symbionts.     

28GHz射频解调器设计与实现

针对Ka频段的宽带信号解调给出了基于射频直接解调的高速解调器设计方案。通过六端口直接变频,以及FPGA的并行载波恢复、时钟同步、信道均衡实现Ka频段高速信号解调。测试结果表明,该方案在28 GHz实现了2 400 Mb/s高速信号解调,解调损失小于2 dB。     

Localization and the interface between quantum mechanics, quantum field theory and quantum gravity II: The search of the interface between QFT and QG

The main topics of this second part of a two-part essay are some consequences of the phenomenon of vacuum polarization as the most important physical manifestation of modular localization. Besides philosophically unexpected consequences, it has led to a new constructive “outside-inwards approach” in which the pointlike fields and the compactly localized operator algebras which they generate only appear from intersecting much simpler algebras localized in noncompact wedge regions whose generators have extremely mild almost free field behavior.Another consequence of vacuum polarization presented in this essay is the localization entropy near a causal horizon which follows a logarithmically modified area law in which a dimensionless area (the area divided by the square of dR where dR is the thickness of a light-sheet) appears. There are arguments that this logarithmically modified area law corresponds to the volume law of the standard heat bath thermal behavior. We also explain the symmetry enhancing effect of holographic projections onto the causal horizon of a region and show that the resulting infinite dimensional symmetry groups contain the Bondi–Metzner–Sachs group. This essay is the second part of a partitioned longer paper.     

可持续发展战略中的太阳能--太阳能评价

对作为能源资源的太阳能进行了全面的评价,论述了什么是太阳能和太阳能在自然中的作用,并分析了其数量和质量。     

数传电台直扩中频单元设计与性能分析

针对现有航空电台在飞行参数传输过程中保密性和抗干扰能力较弱的现状,提出了基于Stel-2000A的数传电台扩频解扩中频单元研制方案,对发射端和接收端的具体实现进行了阐述,并对中频单元的扩频处理增益和误码率性能进行了测试与分析。性能测试证明,依此方案设计的数传电台中频单元满足要求的技术指标。     

国内网络直报食物中毒原因的流行病学分析

为规范指导食物中毒预防和控制工作,保障人民群众饮食安全,通过对2014年与2015年全国网络直报食物中毒季节、月份、原因、场所和学校等进行流行病学描述比较。表明:食物中毒第三季度最多,集中在6月、8月、9月;微生物性食物中毒起数和中毒人数最多,有毒动植物及毒蘑菇引起的死亡人数最多,家庭是食物中毒最多场所,学校食堂是学校食物中毒主要所在。应加大对不同情况食物中毒原因管理,避免食物中毒发生。