浅析B2C服装电子商务企业如何吸引风险投资

初创期B2C服装电子商务企业高风险、高投入、高预期收益的特性使我国B2C服装电子商务企业在发展过程中时刻伴随着风险投资的身影,但如何吸引风险投资是B2C服装电子商务企业面临的一个难题。文章在分析风险投资选择项目的标准的基础上,从创业管理团队、商业模式两个方面论述了初创期B2C服装电子商务企业如何吸引风险投资。     

单片机AT89C52扩展USB接口实现

本文在介绍USB接口基础上,提出一种AT89C52扩展USB接口的实现方法。并指出由于USB接口使用方便、支持热插热拔,AT89C52扩展了USB功能有利于进一步拓展其应用,因而具有广阔的应用前景。     

利用DEA对科研机构规模效益的分析

利润最大化是生产经营性企业的追求目标。对于社会公共服务部门、科研单位等非赢利性机构而言,虽然利润最大化不是其追求目标,但由于规模效益问题涉及资源配置,资源使用效率等问题,所以至关重要。数据包络分析方法(DEA)是基于经济学概念上发展起来的非参数定量分析方法,可以提供决策单元规模效益变化的信息,因此可以用来对非赢利性公共部门或科研机构的分析。我们改进了标准DEA模型以克服其某些局限性,在实际应用中又与评估者的评估策略和价值导向相结合。作为应用实例,我们对某科研机构的34个研究组的规模效益进行了分析和探讨。     

A case of vitamin B12 deficiency neurological syndrome in a young adult due to late-onset cobalamin C (CblC) deficiency: a diagnostic challenge

Vitamin B12 deficiency can present with neurologic and psychiatric symptoms without macrocytic anaemia. We describe a case of late-onset cobalamin C deficiency which typically presents with normal serum vitamin B12 concentrations, posing an additional diagnostic challenge. A 23-year-old woman with decreased muscle strength and hallucinations was diagnosed with ‘catatonic depression’ and admitted to a residential mental health facility. She was referred to our hospital for further investigation 3 months later. Heteroanamnesis revealed that the symptoms had been evolving progressively over several months. Magnetic resonance imaging (MRI) of the brain showed diffuse symmetrical white matter lesions in both hemispheres. Routine laboratory tests including vitamin B12 and folic acid were normal except for a slight normocytic, normochromic anaemia. Over the next 6 weeks her symptoms deteriorated, and she became unresponsive to stimuli. A new MRI scan showed progression of the white matter lesions. The neurologist requested plasma homocysteine (Hcys) which was more than 8 times the upper limit of normal. Further testing revealed increased methylmalonic acid and the patient was diagnosed with adult-onset cobalamin C deficiency. This case illustrates that Hcys and/or methylmalonic acid should be determined in patients presenting with neuropsychiatric symptoms suggestive of vitamin B12 deficiency with a normal serum vitamin B12 to rule out a late-onset cobalamin C deficiency.     

关于企业铁路C62A型号货车增载的可行性探讨

随着国民经济的发展,铁路车辆的需求矛盾日益突出,从增加运输能力的角度考虑,对现有的车辆进行增载是一个投资少、见效快的途径,根据企业铁路目前使用的C62A型车辆的主要技术参数及状况,从垂直动载荷及技术指标分析,在标记载重60t的基础上增重5t是可行的,并能产生较大的经济效益,可以在企业铁路上进行推广。     

New physics searches at the BESIII experiment

The standard model (SM) of particle physics, comprised of the unified electroweak and quantum chromodynamic theories, accurately explains almost all experimental results related to the micro-world, and has made a number of predictions for previously unseen particles, most notably the Higgs scalar boson, that were subsequently discovered. As a result, the SM is currently universally accepted as the theory of the fundamental particles and their interactions. However, in spite of its numerous successes, the SM has a number of apparent shortcomings, including: many free parameters that must be supplied by experimental measurements; no mechanism to produce the dominance of matter over antimatter in the universe; and no explanations for gravity, the dark matter in the universe, neutrino masses, the number of particle generations, etc. Because of these shortcomings, there is considerable incentive to search for evidence for new, non-SM physics phenomena that might provide important clues about what a new, beyond the SM theory (BSM) might look like. Although the center-of-mass energies that BESIII can access are far below the energy frontier, searches for new, BSM physics are an important component of its research program. This report reviews some of the highlights from BESIII’s searches for signs of new, BSM physics by: measuring rates for processes that the SM predicts to be forbidden or very rare; searching for non-SM particles such as dark photons; performing precision tests of SM predictions; and looking for violations of the discrete symmetries C and CP in processes for which the SM expectations are immeasurably small.     

基于C8051F121和XSZ的无线电罗盘角度测量的设计

为解决飞机无线电罗盘输出角度信号的测量问题,设计了基于C8051F121和旋转变压器——直流电压转换器（XSZ）的测角仪。介绍了旋转变压器、旋转变压器——直流电压转换器的结构和原理,软件中航向角度的算法。     

基于政策文本视角的广东“十二五”科技政策研究

基于"政策年度""政策类型""颁布主体"和"文种类型"四位一体科技政策分析框架,对广东"十二五"期间颁布的80项科技政策样本进行统计分析,系统阐述广东"十二五"期间科技创新政策的类型分布、主要特点和存在问题,并提出若干对策建议。     

C/S结构与B/S结构的信息系统比较分析

传统的C/S体系结构虽然采用的是开放模式。但这只是系统开发一级的开放性，在特定的应用中无论时Client端还是Server端都还需要特定的软件，没有提供用户真正期望的开放环境。B/S结构则不同，它的前端是以TCP/IP协议为基础的，企业内的WWW服务器可以接受安装有Web浏览器，各种处理任务都可以调用系统资源来完成。这样大大简化了客户端。减轻了系统维护与升级的成本和工作量，降低了用户的总体拥有成本（TCO）。     

木防己多糖的组成及其清除活性氧自由基的作用

目的:提取并纯化木防己多糖(AFMP),确定其组成,研究其清除活性氧自由基的作用.方法:利用水提醇沉得到木防己粗多糖,再经DEAE纤维素和聚酰胺纯制.利用Fenton反应研究AFMP清除·OH的作用;利用邻苯三酚自氧化法研究AFMP清除·O2-的作用.结果:纸色谱显示AFMP由葡萄糖和半乳糖组成.AFMP清除·OH的能力较弱;清除·O2-时的效果稍强,IC50为1407.4μg/ml.结论:木防己多糖为首次提取制得,有一定的清除羟自由基和超氧阴离子自由基的作用.