稳定直流

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直流[http://www.cn-vigor.com 稳压电源]又称直流稳压器。它的供电电源大都是交流电源，当交流供电电源的电压或负载电阻变化时，[http://www.cn-vigor.com 稳压]器的直接输出电压都能保持稳定。稳压器的参数有电压稳定度、纹波系数和响应速度等。前者表示输入电压的变化对输出电压的影响。纹波系数表示在额定工作情况下，输出电压中交流分量的大小；后者表示输入电压或负载急剧变化时，电压回到正常值所需时间。直流[http://www.cn-vigor.com 稳压电源]分连续导电式与开关式两类。前者由变压器把单相或三相交流电压变到适当值，然后经整流、滤波，获得不稳定的直流电源，再经稳压电路得到稳定电压(或电流)。这种电源线路简单、纹波小、相互干扰小，但体积大、耗材多，效率低(常低于40％～60％)。后者以改变调整元件(或开关)的通断时间比来调节输出电压，从而达到稳压。这类电源功耗小，效率可达85％左右。所以，80年代以来发展迅速。从工作方式上可分为：①可控整流型。用改变晶闸管的导通时间来调整输出电压。②斩波型。输入是不稳定的直流电压，以改变开关电路的通断比得到单向脉动直流，再经滤波后得到稳定直流电压。③变换器型。不稳定直流电压先经逆变器变换成高频交流电，再经变压、整流、滤波后，从所得新的直流输出电压取样，反馈控制逆变器工作频率，达到稳定输出直流电压的目的。

Emptying Commercial Space: An Opportunity for Your Nonprofit?

Recession or not, reports of empty storefronts are popping up nationwide – signs advertising "Free Rent" have actually been spotted in Las Vegas. That's bad news for the economy, but could actually be good news for some nonprofits.

Landlords hate to have an empty storefront. It's a potential target for thieves and vandals, and reduces traffic to other stores in the same strip or complex. But finding another tenant and negotiating a new lease can take weeks or months to complete.

Some nonprofits have been finding ways to fill the gap. For no or very low rent, they’ve used empty retail space for such temporary purposes as animal adoptions, a soup kitchen, a depot to collect and contribute clothes to the poor, and more. It’s a win-win situation: The nonprofits get higher visibility and a way to reach more people (both clients and potential donors); the landlord gets the benefits mentioned above, plus possible increased foot traffic to other stores; and both might get some good media coverage from the partnership.

If your nonprofit could benefit from such an arrangement, look around your area for empty storefronts and get in touch with the landlords.  They might have already heard of your idea — particularly if they read the “Commercial Lease Law Insider,” a respected publication that featured an article called “Protect Yourself When Temporarily Filling Retail Space with Nonprofits” in its September 2007 issue.

The “protection” part of the article simply referred to the fact that the landlord needs to sign some sort of agreement with any nonprofit to which it lends or rents space. Signing such an agreement is in your interest, too, to make sure everyone has the same understanding of price and other terms.

Instead of a standard lease, the landlord is most likely to want a license agreement, which is appropriate for situations where the arrangement is so temporary that the landlord shouldn’t have to evict you if you refuse to leave by the agreed-upon date. If, however, your organization turns into a long-term tenant, you'll want to sign a standard commercial lease. For help with this, see Negotiate the Best Lease for Your Business, by Janet Portman & Fred S. Steingold.

la certezza de’ noantri…

«Noi – a parlare è Ritanna Armeni – non sappiamo se Anna Maria è colpevole o innocente, ma ora dovrebbe prevalere un sentimento di pietà, di solidarietà. Non è un sentimento ignobile, anche se negli ultimi anni, mesi e giorni, tutti stanno cercando di convincerci di questo». Senza manco aver letto la sentenza, tutta ’sta bella intelligenza nostrana (sia detto con una punta d’ironia, si capisce) chiede la grazia per la signora Franzoni così, per un sesto senso o forse per simpatia (ma anche la maliziosa ipotesi del freddo calcolo utilitaristico ci sta tutta): tutti pronti a firmare in blocco senza pretendere di produrre né fatti nuovi né inedite controprove; senza nemmeno avanzare l’ipotesi di un’incompatibilità alla detenzione da parte della condannata. Nulla di nulla: si assolve, a prescindere, l’una per mandare a puttane il lavoro di ben 14 giudici rei – secondo il modo di ragionare di questi innocentisti ad oltranza – d’aver visto nei fatti la colpevolezza de "la madre di Cogne". Il pretesto, ad ogni modo, è buono – per quelli di Rifondazione, dico – soprattutto per mostrare a tutti che anche loro (loro che vantano l’amicizia dei vari Travaglio, dei Di Pietro e financo dei Pecoraro Scanio) hanno (avuto) il "dono della pietà" – e che pietà! – e che questo dono intendono usarlo fino in fondo: dopo tanto giustizialismo, appendono le manette ai chiodi e iniziano a chiedere grazie.
C‘è dell’altro? E certo che c’è dell’altro ché – e diciamolo francamente – la richiesta di una grazia a meno di 24 ore dalla sentenza di colpevolezza significa accreditare l’idea che la signora sia stata l’ennesima vittima del bislacco sistema giudiziario nostrano. Nonostante i tre gradi di giudizio, insomma, il delitto di Cogne rimane opinabile mentre il diritto si trasforma in arroganza: giudici senza cuore che non riescono a comprendere il dolore di una mamma. «In fin dei conti nel caso Cogne – continua l’Armeni – rimane un forte elemento di incertezza, nessuno ha dimostrato la colpevolezza della madre, e nel dubbio pro reo»… e che quelli dalla Corte di Cassazione, con la loro sentenza – l’aggiunta è mia; Ritanna non si spinge fino a questo punto –, se l’andassero a prendere in culo.
Per farla breve – e qui chiudo – siamo alle solite: la sola certezza, dalle nostre parti, è l’incertezza.

URGENT: Canadian DMCA about to come down again

URGENT: Canadian DMCA about to come down again -- blitz your MP, the PM, and Minister Prentice now to save us from US-style copyright rules!

Posted by Cory Doctorow, May 20, 2008 11:35 AM 

Word on the street is that Canadian Industry Minister Jim Prentice is about to try to shove the Canadian version of the US's failed Digital Millennium Copyright Act through Parliament very soon, and very fast. He made plans to do this before, and the overwhelming public outcry caused him to shelve them, but now he figures we're all distracted and we'll let him get away with it (especially since he's made a couple of cosmetic changes to the bill that he'll use to show how much he really, really cares about us poor Canadians, rather than the US government and entertainment companies who are giving him marching orders).

The Tories promised that they wouldn't do any more treaty-law without public consultation, but Prentice stalwartly refuses to have any public consultation on his plans, despite outcry from industry (he's the Minister of Industry, remember?), artists' groups, library groups, educator groups, and public interest groups. He just keeps on ploughing ahead with his half-baked plan to follow the US off the same stupid copyright cliff it leapt off of in 1998 when it passed the DMCA, a law which has done nothing to reduce infringement, but which has screwed up libraries, competition, and education, and has led to lawsuits against tens of thousands of ordinary citizens.